Handbook for Bridge Inspections - TSP2

Norwegian Public Roads 

Administration 

• • 

Handbook for Bridge 

Inspections 

D es embf>,2005

Norwegian Public Roads 

Administration 

Handbook for 

Bridge Inspections 

Desember 2005

Copyright 

Copyright © 2000-01-1 2 by Norwegian Public Roads Administration. 

A ll ri ghts reserved under the International Copyright Conventions. This book is part of the 

Norwegian Bridge Management System, developed and owned by the Publ ic Roads 

Admini strati on in Norway. and may not be reproduced in w hole or in part in any foml or by 

any means, electronic or mechani cal, including photocopyi ng, recording or by any 

infommtion storage and retrieval system now known or hcreancr invented, without tbe prior 

written permission of the Copyright holder. 

Exception: 

Any Customer of the Norwegian Bridge Management System is an authorised Copydght 

holder for thi s handbook with in their jurisdiction. This authorisation may be extcndcd by the 

Customer to any person or company within the borders of the nali ve country for a particular 

assignment. The Customer is also authorised to ut il ise thi s Handbook when they are involved 

in international assignments.

INTRODUCTION 

Bridge inspections are essential with regards to safeguard the bridges and keep properly management 

of the bridge assets. Assessment of risk and prediction of future conditions are all elements 

which a Bridge Management System has to deal with. The examination of the present c ondition and 

o f expected deterioration leads to the detenninati on o f strategies for the interventions. T he process 

is completed by the execution and control of the repairs. It is therefore obvious that consistent 

inspections of bridges are important , not only for the bridge safety as such, but also in order to keep 

the infrastructure sufficiently operating for the society. 

Hence that the Norwegian BMS is developed to facilitate all aspects of bridge maintenance and 

management, it contains additionally to the handbooks al so an advanced computerised system 

avai lable for handling both the required inventory, inspection and maintenance data. A complete, 

user-fri endl y, accurate, and compatible database constitutes the foundat ion of our bridg e management 

system. 

This Inspection Handbook has been prepared to coverthe requirements of the staffinv()lved in 

Bridge Inspections, and it provides thorough and detailed guidance on Damage Evalua ti on. 

Emphasis has been made 10 explaining a wide range of different types of damage on different Iy pes 

of structures by means of photos in connection with explanatory damage Evaluati on guiding. The 

photos have been used ex tensively to facilitate a better understanding as "seeing is beli eving". 

In the BMS, all data is intended to be stored in computers. To avoid mistakes and to make the 

System consistent with regard to th e computeri sation, a numerical code for di ffe rent typ es of damage 

and cause of damage have been introduced. These are presented in chapter 5 and irl the 

Appendi ces of the Handbook 

References are made to different handbooks from the Norwegian Public Roads Admiinistration. 

These have 10 be altered with simular handbooks issued at the National Road Authori1y.

Foreword 

Inspections of hridges are among the main objectives which every 

Road Manager has to take serious in order to ful fi l its obligations 

to achi eve a safe and secure management, operation aJ1d maintenance 

orlhe country's bridges. Superior obligations atld requireme 

nts for the inspection of bridges arc stated in the "Guideli nes 

for the Management of Bridges". 

This Handbook deals with all types of routine and per iodie inspections 

to be carried out on all bridges. Bridge inspcctio:n is defined 

as: "Visual checks of bridges combined with measurem ents and 

materials investi gations in order 10 determine the condition and 

safety level ofhridges. The Inspections shall identi fy 1he needs for 

remedial actions, any req uired maintenance or repair activities in 

general and the strengthening or rebuilding of any bri c:ige within 

the jurisdiction o f the Road Manager". 

The purpose of the Handbook is to offer guidance on bridge 

inspections in order to provide a sustainable and unified system for 

bridge inspectors th roughout the entire country. 

It is envisaged that every modem Bridge Managemen t System 

should have a databased computer system, handling both inventory, 

inspection and maintenance data. The foundation for detennining 

the repairs and maintenance activities on bridges w il l be the 

results oflhe bridge inspection data recorded in Brutu s 

International which also constitute the basis for the budget 

requirements when composing the budget. The BMS system provides 

recommendations for structura l maintenance an.d strategy. 

Bridge Inspectors are exposed to many ri sks during in spections, 

e.g. being struck by vehicles, fa lling from the super or. substructure 

etc .. Safety equipment, safety precautions and safety requirements 

are therefore important aspects to be included both in this 

Handbook and during the inspection procedures. 

The Inspection Handbook is developed by NPRA 's Bridge 

Departme nt. 

This edition have been sl ightl y corrected compare to t he 

previous edition of February 200 I. 

The Directorate of Publ ic Roads, 

Desember 2005

TA BLE OF CONTENTS 

Introductiont 

Acknowledgements 

Foreword 

3 

4 

5 

I Inspection of Bridges 

1.1 General 

1.2 Inspection Types 

2 Terminology 

2.1 Location System 

2. 1.1 General 

2. 1.2 The Consept of Division by Axis 

2.1.3 The Division by Axes for Big Bridges 

2. 1.4 Location System when Beams 

2. 1.5 Reflected Plan of the Superstructure 

2. 1.6 Reflected Plan of Columns and Foundat ions 

3 Planning of Inspection 

3. 1 General 

3.2 Inspecti on Plan 

3.3 Inspection Programme 

3.4 Inspection Fonns 

3.5 Inspection Resources and Safety Precautions 

3.5. 1 General Req ui rements of the Inspectors 

3.5.2 Inspection Tools 

3.5.3 Safety Precautions 

4 Inspection Tools and Access Equipment 

4.1 Inspecti on tools 

4. 1.1 Personal/protective equipment 

4. 1.2 Ordinary Inspection Tools 

4.1.3 Inspection Tools for general inspection 

4. 1.4 Inspection Tools for Major Inspection 

4. 1.5 Inspection Tools for Special Inspection 

4. 1.6 Inspection Tools fo r Major Underwater-Inspec;tion 

4. 1.7 Inspection Tools for Major Cable-Inspection 

4.2 Access Equipment 

4.2. 1 General Inspection 

4.2.2 Other Inspections 

4.2.3 Ladder 

4.2.4 Ordinal)' type of Lifts 

4.2.5 Types of Bridge Lifts 

4.2.6 Other types of Access Eq ui pment 

5 Damage Evaluation Fundamentals 

5.1 General 

5.2 Types of Damage 

5.3 Degree of Damage - Consequence of Damage 

5.3. 1 Degree of Damage 

12 

15 

21 

25 

41 

Handbook for Bridge Inspections 

7

5.4 Damage Eva luation 

5.4.1 Primary & Secondary Damage 

5.4.2 The Extent to which Damage has Developed 

5.4.3 Compound (Combined?) Damage 

5.5 Prioriti sing Maintenance 

5.6 Ca use(s) of Damage 

6 Carrying out In spections 59 

6. 1 Acceptance Inspection 

6. 1. 1 Scope 50 

6. 1.2 Visual Checking 

6.2 Warranty Inspection 

6.2.1 Scope 

6.2.2 Visual Checking 

6.3 Gcncral lnspecli on 

6.3.1 Scope 

6.3.2 Basic General lnspeclion 

6.4 Major inspection 

6.4.1 Scope 

6.4.2 Visual Inspection 

6.5 Major Inspection of Cables 

6.5.1 Objective and Scope 

6.5.2 V isual Inspections 

6.6 Major Inspection · Underwater 

6.6.1 Scope 

6.6.2 Visual Inspections 

6.7 Special Inspection 

6.7. 1 Scope of inspection 


6.8 Ma intenance Measures - Extent of Damage 

7 Surveys, Materials Tests and Instrumentation 83 

7. 1 General 

7.2 Surveys (Type of measurements) 

7.2.1 Levell ing 

7.2.2 Horizontal Distances/Disp lacement 

7.2.3 Measuring the Thickness of Wearing Surfaces 

7.2.4 Measuring of Ruts 

7.2.5 Measuring Evenness orthe Deck Surface 

7.2.6 Measuring Sag 

7.2.7 Recording Bridge Details 

7.2.8 Measuring ofVcrt ical Clearance 

7.3 Adequate Materials In vestigation - Concrete 

7.3.1 Locating the rcin forcemcn t - Measuring its Cover 

7.3.2 Measuring the Depth of Carbonation 

7.3.3 Measuring Chloride Content 

7.3.4 Corrosion Testing (EC P) 

7.3 .5 Detennining the Level of Strength 

7.3.6 Structural Analysis 

7.3.7 Inspecti on of Prestressed Tendons 

7.3.8 Cutting open the Concrete to Assess the Corrosion level 

7.3.9 Location of Materials Testing for Concrete Coastal Bridges 

8 Handbook for Bridge Inspections

7.4 Adequate Materials Testing - Steel 

7.4. 1 Checking the Torque of Screws 

7.4.2 Checking Rivets and Scrcws 

7.4.3 Checking Welds 

7.4.4 X-ray Check 

7.4.5 Ultrasound Check 

7.4.6 Magnetic Powder Check 

7.4.7 Fibre Optics 

7.4.8 Ultrasound Measurement of Material Thickness 

7.5 Adequate Materia ls In vestigal'ions - Timber 

7.5. 1 Invcstigation o f the humid ity levcl of Timber 

7.5.2 Checking fo r Fungus and ROI- Timber 

7.6 Adequate Material s Investi gation - Stone 

7.6. 1 Compressive Strength for Stone 

7.7 Adequate chccking ofthc Surface Trcatment 

7.7. 1 Thickness of Surface Coating - Concrete 

7.7.2 Adhesive bonding between Surface Coating a:nd Concrete 

7.7.3 Depth of Penetration of Water Repellent Improegnation 

7.7.4 Thickness of Surface Coaling of Steel 

7.7.5 Adhesive Bonding bctwecn Surface Coaling

9.3.8 

9.3.9 

9.3. 10 

9.3. 11 

9.4 Stone and Masonry Elements 227 

9.4. 1 

9.4.2 

9.4.3 

9.4.4 

9.4.5 

9.4.6 

9.4.7 

9.5 Timber Elements 24 1 

9.5.1 

9.5.2 

9.5.3 

9.5.4 

9.6 Wearing Courses & Waterproofin g Layers 259 

9.6.1 

9.6.2 

9.6.3 

9.6.4 

9.6.5 

9.6.6 

9.6.7 

9.6.8 

9.6.9 

9.6. 10 

9.7 Bearings & Bcaring Scats/Shelves 289 

9.7. 1 

9.7.2 

9.7.3 

9.7.4 

9.7.5 

9.7.6 

9.7.7 

9.8 Joints & Thresholds 297 

9.8.1 

9.8.2 

9.8.3 

9.8.4 

9.8.5 

9.8.6 

9.9 Parapets 305 

9.9.1 

9.9.2 

9.9.3 

9. 10 Water Drainage System 32 1 

9. 10.1 

9. 10.2 


9. 10.3 

9.10.4 

9.11 Other Equipment & Attached Utilities 

9. 11.2 

9. 11.3 

9.12 Codes 

327 

333 


11

1. Inspection of 

Bridges 

Guidel ines 

1.1 General 

Reference is made to "Guidelines for the Management of Bridges" 

as superior guidance on management of bridges. To fu lfi I their 

obligations with regards to bridge management, the compUlerised 

Brutus International Bridge Management Syst.em (BMS) is 

intended to be the assisting tool for conducting the duties stated in 

the Guidelines. 

The planning of inspections, entering the results from pc rfonned 

inspections into the computerised part as well as composing and 

recommending all relevant remedial actions to be taken on 

bridges, sha ll be done by using the Brutus International. 

1.2 Inspection Types 

The inspection types re flect the thoroughness and frequency of 

inspections. 

The first In spectio ns 

The bridge inspection cycle starts when construction is completed 

at which point the fo llowing inspection types shall be pe:rformed: 

* Acceptance Inspection 

'" Warranty Inspection 

Ro ut ine Inspectio ns 

After the bridges have been handed over, routine inspect ions shall 

be carried out for the remaining bridge's service life time. This 

involves the following in spection types: 

'" General Inspection 

'" Major In spection 

'" Major Inspection of Cabl es 

'" Major Underwater lnspection 

Additio na l Inspections 

General inspection intend to be carried out also during the warran· 

ty (guarantee) period. 

To complement the above mentioned inspections, or in tbe event 

of extraordinary occurrences there may be a need to perfonn: 

'" Special Inspection 

Purpose of Inspectio ns 

In the following, descriptions of purposes of the inspecti ons are 

outl ined. For more det"ailed descriptions, reference is ma de to 

Chapter 6 of this Handbook or to the "Guidel ines for the 

Management of Bri dges".

Acceptance Inspection 

Warranty Inspection 

General Inspection 

Major Inspection 

Major Inspection Cables 


Underwater 

Special Inspection 

The Acceptance Inspection is the first type of inspection to be carried 

out after the completion of a new bridge. The purpos e is to 

accept or not the acceptance criteria fo r the take-over res.ponsibility 

of the bridge owner, where the acceptance criteria is to uncover 

any deficiencies, damage or defects to the structure which have 

arisen during the construction phase, as well as identifyillg inappropriate 

design sol utions and any sources of deterioratio n that 

may be of significance in conjunction with future maintenance. 

Acceptance Inspecti on shall also be performed after maj~ r rehabilitat 

ion or maintenance works have been carried out on a "bridge. 

The purpose of the Warranty Inspecti on is to chec k that a ny work 

done during the construct ion phase, or repairs following 

theAcceptance Inspection are acceptable, and that new damage, 

faults or de ficiencies have not occurred to the bridge. 

Any new sources of deterioration of relevance for later maintenance 

should also be identifi ed. 

The purpose of the General Inspection is to check if any serious 

damage affecting the load canying capacity, traffic safety, fu ture 

maintenance or environment/aesthetic have appeared to lhe structu 

re 

The purpose of Major Inspection is 10 ensure that the ent ire bridge 

is funct ional, detenn ining any needs for maintena nce actions 

including making cost estimates for these. The inspectioll includes 

also taking measurements and materials investi gations iEnecessary. 

The purpose of Major Inspection of Cables is to evaluate any damage 

to cables, hangers inclusive clamps and anchorage plOi nts to 

verify their funct ionali ty. Remedial actions incl usive cos.t estimates 

shall also be dctennined. 

The purpose of Major Underwater In spection is to check. the condition 

of any bridge elements unden.vater to ensure their fu nctionality. 

The river bed in the vicinity of the bridge shoul d also be 

checked. Remedial actions inclusive cost estimates shall be determined. 

The purpose of Special Inspection is to investigate close .. any damage 

and the cause of damage observed during previous inspections, 

but also to fonn the basis for any description of costly and/or 

complicated action wh ich might be recommended. 

Special inspections are not being carried out at regular intervals, 

but can be triggered off from the fo llowing: 

'" Requ irements from previous major inspections 

'" Accidents such as impact damage from vehicles 

'" Overloading 

'" Flood or flooding 

'" When experience from similar types of bridges and en-.i ronment 

so indicates

2 TERMINOLOGY 

Location System 

2.1 The location System 

2.1 .1 General 

It is important that everybody uses the same way to describe where 

a damage is located on a bridge and where measurem ents and 

material in vestigations are carried out. Therefore, on all bridges, a 

localisation system shall be established to make this possible. 

The following sections illustrate how such a system can be 

planned by using axi s, the numbering of beams and the projection 

of columns, superstructure etc .. 

In case such a system has been prcviously establi shed for the 

bridge, thi s shall be continued or integrated in the new system. 

Divisio n by Axes 

2.1.2 The Concept of Division by Axes 

All bridges sha ll be di vided into an axis number by each abutment 

and each column. The div ision by axcs shall be recorded in BRU 

TUS and thereby appear on the inspection fonns. 

The main rule is that the di vision being used on the construction 

draw ings or as built drawings shall be used. 

Numbering the 

Axes 

Ifno system with regard to axes has been used on the drawings, 

axis I (or axis 0) shall be placed at the abutment with the lowest 

kilometre in relation to the kilometre direction on the road. On the 

draw ings of the bridge, axis I shall be to the left. As a. reference, 

designations like column axis 2, superstructure ax.is 2-3 etc. shall 

be used. 

At the abutments the geographical di rection or the closest village 

sha ll be used to detennine the direction of a xes geographical. The 

division by axes can with advantage be marked with s pray on larger 

bridges. However, this must be done with care to a"Void a spoil- 

Figllre 2.1-1: Exumple o/Numbering rhe Axes 

Handbook f or Bridge Inspections 15

2.1.3 The Division by Axes for Big Bridges 

For arch bridges, truss bridges, suspension bridges an

Hangers 

/ ® ® 

23456189 

Suspension Bridges 

Figllre 2. 1-4: .'Vllmbering 'he AxeslHangers on Suspension Br idges 

Bundle of Cables 

Left hand-side 

6 5 432 

~ : 

Layers 

:mm 

Right tland-side 

123456 

Figllre 2. 1-5: .'VlIIl1bering 'he Cable Bundles 011 S1Ispellsioll liridges 

@ ® 

® 

Cable Stayed Bridges 

2345678 

Connection ints 

Figure 2./-6: Dirisioll of Axis 0 11 Cable Stayed Bridges 

Cross Sections 

2.1.4 Location System when Beams 

All cross sections shall be sketched looking in the direction of the 

chainage (nonna1l y identical to the direction of inc reasing axisnumbering). 

Designation of where the cross sectioll is taken can 

for example be axis 3 + 5 m, see Figure 2. 1-7. 

Left hand-side or right hand-side can be used to assign precise 

localisation of details of a cross section. Alternative ly, 

upstream/downstream or geographical directions c an be used. 

Cross secti ons of beams shall be assigned using letters, alternati 

vely numbers, marked from left to right. 

Handbook for Bridge Inspections 17

Numbering of Beams 

1 r 

~·~~'.~I VII! ~~> .. - ... 

Cross-section 01 Axis 3+5 

Figllre 2./-7: Cross Seclioll 0/(/ Be(/III Bridge 

Reflected Plan of 

Superstructure 

2.1.5 Reflected Plan of the Superstructure 

In some cases it can be rel evant to make a reflected pl.an of the soffit 

of the superstructure in order to locate the defects and testing 

spots Exampl e of a refl ected plan of a beam bridge is shown in 

Figure 2. 1-8 and Figure 2. 1-9. 

- 1 

- 

2 

'V 

/'. 

Figllre 2./-8: Exampleo/Foldillg 0111 o/u Beam Bridge 

18 

Handbook for Bridge Inspections

Figure 2. 1-9: Example of a Reflecled Plan of a Box Girder BiI·illge 

2.1 .6 Reflected Plan of Columns and 

Foundations 

For rectangu lar columns, surface I shall be facing the lowest axis 

number. The remaining surfaces shall be numbered against the 

clockwise direction. The re flected plan shall make it possible to 

look at each surface in such a way that sides with jo intly comers 

are naturally tied together. The column is folded alii al the corner 

between surface 1 and 4 in a clockwise direction. S ee Figure 2. 1- 

10. 

-k. +100 

....c 

. 

,~ D.15M 

- .. 

..- 

,~ 

• 

Reflect ed Pla n of a 

Rectangular Co lumn 

K=altitude 

Flate=surface 

k. +2, 

....c 

9 

• 

2 

Surface 3 

3 4 

Surface 4 

Surface 1 

Surface 2 

Fig. 2. /-10 Numbering of surfaces ami the folding 01/1 of a re c/allglliar colllllln 


Circular columns are di vided according to the watch as shown in 

figure 2. 1- 11. The folding takes place by opening the column at 

12 o'clock and then fold to both sides. The folded col umn starts 

with the 12 o'clock spot at the left hand-side of the plan and fin ishes 

with 00 o'clock to the right. 

Reflected Plan of a 

Circular Column 

~ + 10,0 

,---~--~----~--, 

k. +2,C 

,--- 

~-- c-----~------~----~o_----~ 

12 09 06 03 00 

• 

06 

Figure 2.1-11: £.ml/lple 0/ Rejleclel/ Plan O/ll Circular ColwlII~ 

20 

Handbook f or Bridge Inspections

3 Planning of 

Inspection 

Planning Procedures for 

the Inspections 

3.1 General 

Planning of inspections includes all relevant tasks from detennination 

of which bridges shall be inspected to the performance of the 

inspection. It is assumed that most of tile duties shall be carri ed out 

by assistance from the computerised part of the BMS. 

The planning phase includes the foll owing: 

• Make inspection plans 

'" Make inspection programme 

* Pri nt out inspecti on fonns 

'" 

'" 

'" 

Determine necessary inspection too ls 

Determine necessary access equipment 

Pl an and prepare necessary man force, waming signs, safety 

requirements etc. 

Examples of inspection tools and access equipment are more thoroughl 

y ex plained in chaptcr4. The other items li sted above are 

further elaborated in this chapler. 

Reference should also be made to chapter 6 "Carrying Out 

Inspections" and chapter 7 "Surveys, Materials Tests and 

Instru mentation". 

For major underwater inspections, it is recommended to carry out 

the inspections during the most appropriate season, that means 

when the water level is low, the water speed is slow and the sight 

in the water is good. 

Inspection plan 

3.2 Inspection Plan 

All bridges shall have an inspection pl an in the computerised part 

of the BMS, where the fo llowing shall be included: 

* Decide whi ch inspections shall be carried out 

>I< Detennine and sc hedule the di fferent inspections (programme); 

that means detcrmination of date, year and frequencics 

>I< Elements to be inspected fo r the different inspection types 

>I< Measurements, material investigations and read ing off instru 

mentation planned for on eaeh ind ividual inspection, inclusive 

extent of the work and exact time schedule 

>I< Determination of special damage/elements that need special 

attention 

>I< Determine required access equipment for the different inspec 

tions

When New Bridges 

Ex isting Bridges 

Inspection Programme 

Sub Programmes 

When new bridges, Ihe inspection plan is equal to the Acceptance 

Inspection. Practical experience shows however, that in most 

cases, the inspection plan is being carried out after th~ handingower 

process, and then based on the report from the acceptance 

inspection .. However, the Acceptance Inspection shall nevertheless 

be planned fo r in the inspection plan and the results recorded. 

For existing bridges, the Major Inspection shall be the: basis for 

establishing the inspection plan if the latter do not ex ist. In the 

case where the inspection plan is unsatisfactory fi lled in, the data 

from the Major Inspection can be used as supplement or as amendment. 

3.3 Inspection Programme 

An inspection programme is a listing of all bridges decided for 

inspection in a specific yea r. The Inspection Programme contains 

also measurements, material investigations, levell ing ~tc. that shall 

be carried out during the schedul ed inspections for each bridge. 

The in spection programme shall provide an overview to the 

Bridge Engineer and his superiors on whi ch bridges ar e to be 

inspected in a current year. 

The Inspection Programme can be split into sub-inspe::clion programmes 

grouped by different inspection types, road number, 

bridge types, districts etc._The status of bridge inspec1ion for each 

bridge is visualised in the programme by means of di fferent background 

- colours in the column for the current inspecti...on year like: 

White: You are free to fi ll in the inspection type and. year you 

wanl. 

Orange: The bridge is currently under inspection, me aning that 

the inspection form has been printed out for the bridge. 

Green: The inspection has been completed as planned and data 

entered. 

Red: The inspection date has expired and you are behind 

schedule. (No data entered) 

Inspection Forms 

3.4 Inspection Forms 

Based on the decisions made in the inspection programme for the 

bridges in question, the programme prints out individual inspection 

fonns for each bridge fo r the selected inspection type. 

When printing out inspection forms for each bridge, there is a possibility 

of selection of transferring previous inspection data to be 

included in the present inspection form or not.

3.5 Inspection Resources and 

Safety Precautions 

3.5.1 General Requirements of the Inspectors 

In order to have reliable inspection data, it is very important thai 

the data entered into the system is as correct as possibl e. 

Inspection data is fundamentally based on judgements made by 

the inspectors, and their quality depends very much on the skill s 

and bridge experience they have gained. Therefore, it is important 

that the inspeclors have specific quali fications such as accuracy 

and reliabili ty, and arc properly trained in BMS.ln additi on, an 

inspector has to be a careful worker, and he/she must be in good 

health and responsibl e (docs nol take unnecessary risks). 

Before the inspection starts, it is very important that the inspector 

clarifies tbe obligati ons and responsibi lities of the staff in volved in 

the in spection process. Each person in volved in the inspecti on 

must know what hi s or hers duties are. It is the inspector's responsibility 

to provide all personnel involved in the inspection with relevant 

inspection tools and safety equipme nt. 

Tra ining 

However, it is the Bridge Engineer's responsibility to train and 

equip the inspection personnel properl y within all aspects of 

inspection procedures and safety routines and to provide adequate 

tools and equi pment to the inspectors. Generally speaking, the 

Bridge Engineer should be responsible for all aspects within the 

fi elds of securing Health, Environment and Safety at the inspection 

site. 

3.5.2 Inspection Tools 

In order to perform Ihe different types of inspections, different 

lools and equipment have to be used. These include non-sophisticated 

tools which wi ll be termed ordinal)' and spec ialised tools for 

specific unique jobs which will be used depending on the type of 

inspection and site conditions. There are nonnally no inspecti on 

lools and equipmenl for an infonnal inspection but for the other 

types of inspections, the lools and equipment li sled in chapter 3 

should be made availabl e: 

3.5.3 Safety Precautions 

The safety of bridge inspectors and road users during the inspection 

fall s within the responsibility of the Bridge Engineer. It is 

important that he/she ensures that they frequent ly get appropriate 

training in safety procedures and especially w hen new inspectors 

have been employed. 

Possibilities of injury arise mainl y from: 

* Traffic on the deck or approaches. 

* A fall from the superstructure to the river or road below.

• Attack from insects, repti les, animals or vegetation around the 

bridge. 

To try to alleviate these dangers, there should be at least two people 

when performing an inspection. One might be the driver, who 

can also assist when tak ing measurements. 

Always use the safety eq ui pment fo r yourself and on the road, 

even on roads with very light traffic. When inspecting bridges 

crossing rivers with high speed currents it is important to use a 

li fe-jacket and safety-rope. 

It is always important to remember tha t accidents occur without 

warmng.

4. Inspection Tools & 

Access Equipment 

When inspecting bridges the inspector always has to bring with 

him different kinds of equipment. The necessary equipment 

depends on the type of bridge to be inspected and the type of 

in spection to be carried out. 

Below there are lists which show examples of such equipment, but 

the inspector always has to decide what equipment is necessary in 

each speci fic case. 

4.1 Inspection Tools 

4.1.1 Personal/protective equipment 

It is recommended that the inspector is supplied with the fo llowing 

personal equipment: 

'" 

'" 

'" 

'" 

'" 

'" 

Boi ler suit 

Insulal'ion sui t 

Rain suit 

Working gloves 

Rubber boots/waders 

Li fe-jacket 

Figure 4. / - / Personal Equipmenl 

In addition the inspector needs to be supplied with the following 

personal protecti ve equipment: 

Personal Safety Equipment 

'" Helmet 

'" Luminolls wai stcoat 

'" Protective shoes 

'" Goggles 

'" Ear protection 

Handbook for Bridge Inspect ions 25

When there is danger of fa lling from he ights, the inspector 

ha s to use equipment to prevent th is. Figure 4.1 -2 shows an example 

of such equipment that can be led past a pole without being 

detached. 

Figure 4.1-2 Equipmel1l to prevent/all 

When a number of bridges are to be inspected, the inspector must 

always be supp lied wit h all the listed personal and protective 

eq uipment. 

In other cases the type of equipment must be adjusted to the actual 

bridge and the aim o f the inspection. 

Ordinary Tools 

4.1.2 Ordinary Inspection Tools 

The ordinary inspection lools are listed below: 

* inspection form, included results of the previous inspection 

* As built drawing 

* Other relevant drawi! 

* Maps, road numbers 

* Weather resistant per 

and pencils 

* Clipboard 

* Handbook for bridge 

inspection 

* Mobi le te lephone. 

Figure 4.1-3 OrdillUlY Inspectioll Tools recommended/or Gei/era/illspection 

26 


4.1.3 Inspection Tools for General Inspection 

The ordinary inspection equipment is listed below: 

Equipment Genera l 

Inspection 

Inspection fo rm, included resu lts of the previous in speetion 

As built drawing 

Other relevant drawings 

Maps, road numbers 

Weather resistant pens and penc il s 

Clipboard 

Handbook for bridge inspection 

M obi le telephone. 

Figure 4.1-4 DIY/iI/my inspection Tools 

4.1.4 Inspection Tools for Major InspeI< Traffic warning signs 

• Dictaphone 

'" Video recorder 

'" Plumbli nc 

• Thennometer 

'" Magnifying glass 

... Gauge for measuring crack widths 

'" Sliding calliper. 


Fil,,'1lre 4.1-5 £qllipmelll Major Inspec/ion 

When carrying olltmajor inspection it is also normal to carry out 

different measurements and in vest igations of materials. 

In vestigations of concrete are most common. 

Measureme nts 

Investigation of Concrete 

Equipment and tools needed for these measurements and investigations 

of concrete are: 

• Small level 

• Levell ing equipmen t 

• Straight edge 

• Measuring device 

• Rebound hammer 

• Covermcter 

• Phenolphthalein fluid 

• Wire brush 

• Electric chisel 

• Hammer drill, AC- or battery 

• Small plastic bags for concrete dust 

• Water proof markers 

• Aggregate for AC current 

• Dry cement mortar and/or joint seal 

• Tools for mixing ofmortar 

Water. 

28 


4.1 .5 Inspection Tools for Special Inspection 

In addition to the equipment described for major inspection, the 

special inspection may require eq uipment to carry out material 

examinations to veri fy cause and degree of damage. Tllis equipment 

is: 

Equipment - Special 

Inspectio n 

• Un iversal instrument fo r electrochemical potential and resistan 

ce mappmg 

• Device for con tro l of surface treatment (Measuring thickness, 

bond, etc.) 

• Concrete core drill 

• Magnetic powder eq uipment 

• Ultrasonic equipment 

• X- ray equipment. 

The use of special inspection equipment often requires 

special skil ls or certifica tes, thus qualified inspectors must be hired 

from specialist or certifying agencies. Ref. also chapter 7 - 

"Surveys, Materials Tests and Instrumentation". 

4.1.6 Inspection Too ls for Major Underwater 

Inspection 

The diver has to use diving equipment in accordance with national 

regulations. 

To carry out the major inspection 

under water may require: 

Equipment - Unde rwat er 

Inspectio n 

• Camera for under water use 

• Video recorder for 

under water 

use 

• Ranging rods 

• 50111 tape 

measure, nylon 

• Folding ruler 

• Levell ing 

equipment 

Figure 4. 1-6 Eqllipmelllfor Major Illspectioll Vllder IfI(lter 


In some cases there can be obslacles that prevent inspection of 

foundations under water such as fo rmwork, the foundation being 

overgrown, etc. In these cases it can be necessary to use heavy 

equipment/tools such as: 

Equipment for removal 

of Formwork 

• Lorry equipped with a crane or winch 

• Hydraulic tools 

• Hydraulic aggregate 

• Water jetting equipment 

• Barking spade 

• Iron bar 

• Crow bar 

• Axe. 

4.1.7 Inspection Tools for Major Cable· 

Inspection 

When carrying out a major inspection of cables it wi ll in most 

cases be sufficient to use the same eq uipmen t as fo r major inspection. 

4.2 Access Eq u ip m ent 

The choice of access equipment when carrying out a bridge 

inspection will depend upon the type of inspection and bridge, the 

pattern and density of traffic and the total economy of the inspection. 

Access Equipment - 

General Inspection 

4.2.1 Generallnspection 

When carrying out general inspection it is not necessary to use 

hcavy access equipment like bridge li fts etc, but it may sti ll be 

necessary to use light equipment listed below in order to perfonn a 

visual check of important construction elements. 

• Keys to doors and gatcs 

• Under water viewer 

• Necessary access equipment to reach specified bridge elements 

or parts of elements. 

Accesss Equipment 

Other Inspections 

4.2.2 Other Inspections 

For all other types of bridge inspection it is required that the 

inspector is within reach of tile structure. In many cases it will be 

necessary to use access equipment such as: 

• Ladders 

• Ordinary lifts 

• Bridge lifts 

• Boats/pontoons/rafts 

• Suspended worki ng platform s 

• Professional mountaineering equipment 

30 


The site conditions may decide which access equipment to be 

used. In most cases the best choice wi ll be a bridge lift. When in 

use on narrow bridges or during dense traffic, bridge lifts may 

restrict the traffic flow. In such cases the inspection shou ld, ifpossib 

le, be carried out from a boat, pontoon, raft or an ordinary lift 

from underneath the bridge. Suspended working platforms may in 

certain cases be a choice. 

It is possible 10 combine different types of access equipment. An 

ordinary lift can for example be used from a pontoon. 

Power lines close to the bridge or the existence of a railroad under 

the bridge will often influence upon the choice of access equipment. 

During the win ter the inspection can, in some parts of the country, 

be carried out from the ice. It is important to first control that the 

ice is safe. 

In the following chapters different types of access eq uipment are 

described. 

Ladder 

fllSpectiolljrOIll (l 

4.2.3 Ladder 

For minor bridges or bridges with restricted height, the use of a 

ladder may be sufficient to get access. Ladders longer than 4 m 

must be secured by appropriate means. Inspectors working alone 

are not allowed to work from a ladder. 

lifts 

4.2.4 Ordinary type of Lifts 

Ordinary lifts that operate from ground level with the platfonn 

moving upwards may be used for inspection of overhead trusses 

and overhead crossing bridges. Ordinary li fts may also be useful 

for inspection of bridges with access fo r the equipment from roads 

or other hard surfaces under the bridge. The different types are: 

* Telescopic lift with scissors action 

* A hydrau lic arm with a basket mounted on trailer to be pulled by 

car 

* A hydraulic ann with a basket mounted on lorry 

Scissor lifts 

Bascet lifts 

Telescopic lifts with sc issors action have rather large work platforms 

that move vert ically. The vertical reach is limited to between 

5 and 10 metres. 

A hydraulic arm with a basket mounted on trai ler to be pul led by 

car has a vertical reach from 10 to 20 m and a horizontal reac h 

from 5 to 10m depending on the size and make. They are more fl e 

xible in use than te lescopic lifts and have a lifting capacity for two 

persons or one person with some equipment. 

Handbook for Bri dge Inspections 31

Figure 4.2-1 Ordillwy Baskel Lift all pOIltOOI1S 

A hydrau lic arm with a Basket mounted on a lorry has a vertical 

reach from 10 to 45 m and a horizontal reach from 5 to 20 m. 

Figure 4.1-3. Smo'f{ Basket 

Lift 1I101lllted 011 (J Lorry 

4.2.5 Types of Bridge Lifts 

A bridge li ft is a lift specially designed to inspect the lower parts of 

a bridge structure from a basket or platform lowered down underneath 

the bridge deck whi le the operating vehicle still is travell ing 

on the roadway. In addition supplementary working envi ronment 

and safety requirements may appl y. 

Minimum Technical 

Requirements of a Bascet 

Lift 

1) The downward reach should exceed 6 m and the ho riz~nta l 

reach underneath the bridge deck should be at least 6- 7 m. 

2) The device shou ld be equipped with one basket with a safe wor 

32 


king load capacity of at least 300 kg at maximum reach. This 

will accommodate 2 persons and sufficient equipment. The bas 

ket has to be fitted with automatically vertical adj ustment. 

3) Manoeuvring must be possible both from the basket and the dri 

vers seat in the vehicle. The basket must be fitted with an emer 

gency stop device to freeze any movement immed iately. 

4) There must be a fixed means of communication between the 

basket and the driver's seat. 

5) The vehiele should be able to move during the inspection. 

6) The maximum allowable pressure from wheels and support legs 

is 0.4 N/mm2. Maximum axle load of8 tons. 

7) The bridge lift must be able to work from bridges with up to 

10 % longitudinal slope 

8) The basket must be fitted with electrical power connection and 

li ght. 

There are two types of bridge lifts available Ihal fulfillhese 

requirements: 

* Bridge lift with basket 

* Bridge lift with work platfo rm. 

Bridge Bascet lift 

Bridge lift with ba sket is the most common type, see Figure 4.2-4 

to 3.2.6. The hori zontall y distance is normally 8-1 0 m, but is 

depending of how far down the basket can go and how far from the 

edge of the bridge the lorry has to drive. 

The largest lifts of this type has a downwards range of up to 20-25 

m. NormaJl y the reach is 10 m. Most of this type of bridge li fts 

may reach upwards as well, see Figure 4.2-7. A typical work diagram 

for a bridge lift is shown in Figure 4.2-8 

Figure 4.2-4 Small Bridge Lift with a Basket 

Handbook f or Bridge Inspections 

33

Example of Bridge Lifts 

Figure 4.1-5 MediuIII size Bridge Lifill'ilh a Baskel (BI'OIl IO sky/iji) 

(Mllllllle/a bridge Lifi) 

Figure 4.2-6 Large Bridge Lifill'ilh a Baskel 

Figure 4.1-7 Large Bridge Lifiusedfrom 

Ground 

34 

Handbook for Bridge In spections

Work Diagram for Bridge 

Lift 

,.... 

' .. 

limitations to Bridge lifts 

It is important to be aware of what limitations there are on the operation 

of a certain bridge lift in order to make the proper choice. 

The limitations are mainly related to the following conditions: 

* Bridge type 

* Width of the roadway 

* Railings and light posts 

* TaU piers 

* Load carrying capacity ( of different parts of the bridge) 

Inspecting different 

Bridge Types 

The largest cantilevered box-girder bridges may have a construction 

height of up to 15 m at the piers. In order to inspect the lower 

flange of the box-girder in this area a bridge lift with sufficient 

reach is required. See figure 4.2-10. 

The same requirements as above are va lid for the inspection of 

arch bridges. See figure 4.2-11 . 

Figure 4.2-10 Illspeclioll of call1ilevered Box-Girder Bridge (K-lijt 

r 

Figl/l"c 4. 2-11 hrspeclioll of a COllcrele Arclr Bridge (Bl"OlIlo sJ.)'lijtJ 

36 


When inspecting suspension bridges, trusses and arch bridges the 

manoeuvrabili ty of the bridge lift is of outmost importance. The 

basket must be able to move easily in and out between the vertical 

and diagonal elements. See figure 4.2- 12. When inspecting minor 

through truss bridges the bracing of the top boom may restrict the 

movement of the bridge li ft considerably. 

Bridge Width 

Railings/Light Posts 

Figure 4.1-11 Illspeclioll of a Tmss Bridge (K-lifi) 

The space needed for the different types of bridge lifts when the 

supporting legs are in place varies and has to be considered, especially 

on narrow bridges, in order to cause as few problems for the 

traffic flow as possible. 

When footwalks are separated from the roadway by rai ling, this 

may influence the required range oflhe bridge li ft in ease it has to 

be used from the roadway only. Moving past light posts may hamper 

the speed of the in spection considerably. There are bridge lifts 

in the marked suitable for pass ing light posts and other obstructions 

without delay, see Figure 4.2-13. 

Figure 4.1-13 Passing a Flagpole (Nummela Brulifi) 


Passing Tall Piers 

The access to tall piers may in some cases present a challenge 

because reach of the largest lifts is limited. A few of the bridge lifts 

may be fitted with a light suspended working platform, or similar 

device underneath the main working platforn1 or basket. See figure 

4.2-14. 

Figure 4.2-14 Inspection o/Tall Piers 

load Carrying Capacity 

Pa int Wagon 

The load canying capacity of the bridge may in certain cases prohib 

it or restrict the use of bridge lifts. It should be noted that that 

the pavement may not allow the same loads as the rest of bridge. 

Bridge lifts or their supporting legs should not be placed on pavements 

unless it has been checked thai the pavement is able to cany 

the loads in question. 

4.2.6 Other types of Access Equipment 

Some bridges are fitted with integrated access and maintenance 

carriages that can travel underneath the bridge. See figu re 4.2- 15. 

Figure 4.2-15: Inspectioll/rom Maintenance Carriage 

38 


Suspended Working 

Platform 

Also suspended working platforms can be used for inspection, see 

fi gure 4.2- 16. In spection from thi s kind of more stationary equipment 

may be an alternative in cases when disturbances to the traffi 

c must be avoided. The inspection can not be performed as fast as 

with a proper bridge lift, especially if a number of verti cal members 

or light posts influence shifting of the equipment. 

Figure 4.2-/6: Inspec/ion from a Sllspende(/ Working Platform 

Mountaineering Equipment 

Inspection using professional mountaineering equipment may in 

some cases represent the only economic alternative to get close 

enough to the bridge elements. This alterna tive is not recommended 

for normal inspection tasks. Such mountaineering equipment 

is considered as personal safety equipment and the use and maintenance 

is the responsibility of the person to whom it has been issued. 

Figure 4.2-17: Inspectioll 

/Ising Professio!!al 

Moul/tail/eering £qllipll1elll 


39


5 Damage 

Evaluation 

Fundamentals 

5.1 General 

When evaluating a damage on a bridge the fo ll owing must be decided: 

Basis for Evaluation 

of Damage 

Types of Oa mage 

• Dclcnninc the Type of Damage 

• Detennine the Consequence of Damage to the bridge 

• Dctcnnine the Cause of Damage 

In most cases the evaluation ofa damage consists of a visual 

check, sometimes followed by measurements and ma.terial investigations. 

However, in some special cases, it may be necessary to 

carry out calculations of structural capacity, economical considerations 

and/or in vestigation by implementing long lenn instrumentati 

on survey on the bridge in order to establish rel iab Ie information 

to evaluate the damage correct. 

Deg reel Consequence 

of Damage 

Cause of Damage 

In order to established a unified description of damag e, the listed 

types of damage in chapter 5.2 have to be used. 

Any damage to be recorded shall be assessed by consjdering the 

degree of damage and the consequence of damage. 

As part of a complete damage evaluation, al so the cause to the 

damage has to be determined. The most common causes of damage 

are li sted in chapter 5.6. 

5.2 Types of Damage 

The most common "Types of Damage" are listed below with a 

brief explanatory text connected to each of them. A more extensive 

and detailed description of each type of damage inelu sive examples 

are given in chapter 9 The Damage Evaluation Catalogue. 

Each type of damage is given a three-digit code where the first 

digit indicates the material or element the damage referred to, and 

the second and third indicate the type of damage. This in order to 

ease the registration of damage in the data base, and make it possible 

to scan the data/and make statistics. It should be noticed that 

one defect may consists of several Types o f Damage.

Da mage typical to Ground 

Damage to Ril.'er COllrse 

101 Subsidence of • Vertical movement of the ground or 

ground/embankment 

embankment 

102 Obstruction of waterway • When the waterway is partially or totally 

blocked 

103 Scouring/erosion of river • Removal of soil in river bed area caused by 

course 

the stream flow 

104 Inadequate clearing • All kinds of unwanted vegetation, stones, 

up/removal 

sand etc. in the river course or items stored 

under the bridge 

Depositing of mud Is and in river bed 

105 Silting up • 

106 Insufficient discharge capacity • When the volume of water per unit oftime 

flowing under lhe bridge is less than 

necessary 

107 Change of ri vcr course • When the river flows outside its natural 

course 

109 Other type of damage to river 

course 

• Any other damage not li sted here 

Damage to protection 

facilities: 

III Wash out of protection facil ity 

• When the stones for the rip rap are washed 

away 

11 2 Scouring of protection • Removal of soil under protection facility 

facilities 

caused by the water flow 

11 3 Movement of protection • The protection facility has moved 

facility 

horizontally or vertically 

114 Defective part of protection • Part of the protection facility is not working 

facility 

in accordance with expectations 

119 Other damage to protection • Any other damage not listed here 

facility 

2 Damage to Concrete 

Elements 

20 1 Settlemcnt o f concrete element • Vertical movement of element 

202 Movement of concrete • Rotation/dislocation of element(s) from its 

element 

original position 

203 Defonnation of concrete • Loss of original shape or geometry. Includes 

element 

buckling, bending etc. 

204 Cracks in concrete element • Includes all types of cracks 

205 Rupture of concrete element • Broken concrete element, member or post 

etc. 

206 Damage to the concrete • Damage to any surface treatment on 

surface treatment 

concrete

207 Leakage/dampness of concrete 

element 

• When liquid penetrates through the element 

208 Discoloration of concrete 

element 

• Discoloured surface of a concrete element 

209 Insufficient/damaged cover of 

concrete element 

• Less cover than designed for 

210 Weathering of concrete elem. • Normal wear and tear 

211 Honeycombing of concrete • Caused by for example, insufficient 

element 

vibration of concrete 

212 Delamination of concrete • Separation into concrete layers 

element 

213 Spalling of concrete clement • Bits of the surface concrete falling down 

214 Corrosion of reinforcement • Reinforcement damaged by corrosion 

215 Wash out of concrete element • Removal of particles from the concrete hy 

water 

216 Inadequate cleaning of • Debris, dirt, vegetation etc. not removed 

concrete element 

from the element 

217 Inadequate clearing 

up/removal 

• Formwork. bars, strip steel etc. not removed 

218 Poor concrete quality 

• Quality of concrete lower than can be 

accepted 

219 Scoring/undermining of • Holes in the ri ver bed or bank under 

concrete clement 

concrete element caused by the flow of river 

220 Missing part(s) of concrete • Originally designed part of an element is 

element 

mlssmg 

290 Other damage to concrete • Any other damage not listed above 

element 

3 Damage ty pical to 

SteellAluminium and Iron 

Elements 

301 Settlement of steellalum.liron • Vertical movement of the element 

element 

302 Movement of steellalum.liron • Rotation/dislocation of element(s) from its 

element 


303 Defommtion of • Loss of originally shape or geometry, i.e. 

steel/alum.liron element 

buckling, bending, kinks etc. 

304 Cracks in steeJlalum.liron 

clement 

• Includes all types of cracks 

305 Fracture of steellalum.liron 

element 

• When a part ofthe steel element is broken 

306 Damage to steel surface 

treatment 

• Damage to coatings. galvanizing etc. 

307 Leaks/dampness impact of • When a steel element is leaking

steellalum .liron clement 

308 Discolouration of • Discoloured surface of clement 

steeValum.liron clement 

309 Loose connections of • Looseness of bolts, ri vets or any other part 

steel/alum.liron element 

of steel element 

310 Corrosion of steeUiron 

element 

• Disintegration of the surface through rust 

311 Friction/abrasion of 

stcellalum .liron clement 

• Abrasion behveen parts caused by friction 

312 Broken cable strands • When strands of a cable are broken 

313 Inadequate cleaning • All kinds of debris, sand etc. on the element 

314 Missing partes) on • Part of ori ginally designed member is 

steel/alum .liron clement 

missing 

315 Inadequate clearing 

• Formwork or any other unwanted item on 

up/removal 

the structure 

316 Material fault of steel element • Insuffi cient quality of steel 

390 Other damage to steel element • Any other damage not listed above 

4 Da mage typica l to 

StonelMasonry Elements 

401 Settlement of stone/masonry • Vertical movement of the clement 

element 

402 Movement of stone/masonry • When the element has moved from its 

element 


403 Deformation of stone/masonry • Loss of original shape or geometry, i.e. 

element 

buckling, bending, etc. 

404 Cracks in stone/masonry 

element 

• Includes aJ l types of cracks 

405 Leakage/dampness of 

stone/masonry clement 

• Leaks through portion of an clement 

406 Discoloration of • Discoloured surface of a stonclmasonry 

stone/masonry clem. 

element 

407 Displaced stones in stonework • Slippage of a stona1 portion of the element 

408 Collapsed stonework 

• When a part of or the entire element has 

collapsed 

409 Inadequate cleaning of • All kinds of debris, sand etc. on the element 

stone/masonry element 

410 Inadequate clearing • Fonnwork or any other unwanted item on 

up/removal 

the structure 

411 Wearing of pointing 

• Deterioration of mortar in the joints 

490 Other damage to • Any other damage not listed above 

stone/masonry clem. 

5 Damage typical to T imber 

Elements

501 Settlement of timber element • Vertical movement of the element 

502 Movement of timber clement • When the element has moved from its 


503 Defonnation of timber • Loss of original shape or geometry, i.c. 

element 

buckling, bending, etc. 

504 Cracks in timber element • Includes all types of cracks 

505 Fracture of timber element 

• A broken member of the timber element 

506 Damage to timber surface • Damage to painting, impregnation etc 

treatment 

507 Leakage/dampness of timber • Unwanted leakage through or from an 

element 

element 

508 Discoloration of timber 

element 

• Discoloured surface of a timber element 

509 Chipping & splintering of 

timber 

• Splintering of timber surface 

510 Timber decay • Deterioration of the timber leading to 

softness 

511 Inadequate cleaning of timber 

clement 

• All kinds of debris, sand etc. on the element 

512 Missing partes) on timber 

element 

• Lack of any originally designed partes) 

513 Loose connections of timber • Looseness of bolts, rivets or any other 

element 

member 

514 Delamination of timber 

element 

• Separation into layers 

590 Other damage to timber 

element 

• Any other damage not listed above 

6 Damage typical to Deck 

Pavement 

601 Cracks in the surfacing • All types of cracks 

602 Leaks through the surfacing • Leaks through portion of the surfacing 

603 Ruts in the wearing course • Channelled depressions of the surfacing 

following the wheel tracks 

604 Unevenness of the surfacing • Corrugation etc. of the wearing course 

605 Cracking/potholes of the • Crazing or irregular shaped, disintegrated 

surfacing 

areas of the surfacing 

606 Blistering (toadstools) of the 

• Happens nomlally to the watcr proofing 

surfacing 

layer 

607 Flaking of surfacing • Looseness of portiones) of the surfacing 

608 Inadequate cleaning of the 

• Debris, sand, gravel etc. on the wearing 

pavement 

course 

609 Sweating of the surfacing • When bitumen penetrates to the surface and 

make the wearing course slippy 

690 Other damage to the surfacing 

• Any other damage not li sted above

7 Damage to Bearings/Joints 

Damage to Bearings 

701 Bearings out o[position • Abnormal position of bearings 

702 Deformation of bearings • Abnormal deformation of bearings 

703 Cracks & Fissures in bearings • Includes all types of cracks 

704 Fracture of bearing member • A part of the bearing is broken 

705 Damage to surface treatment • Damage to coatings, galvanizing etc. 

ofbcarings 

706 Corrosion of bearings 

• Disintegration of steel surface through rust 

707 Inadequate cleaning of • Debri s, sand, gravel etc. on the bearing shelf 

bearinglbearing shelf 

708 Missing partes) of bearing • Part of original design missing 

709 Other damage to beari ngs • Any other damage not listed here 

Damage to Joints 

711 Abnormal movement of joint • The expansion and contraction behaviour of 

the joint is not in accordance with the design 

712 Cracks & Fissures in joint • Includes all types of cracks 

713 Fracture of joint part • Broken part(s) of the joint 

714 Leakage of joint 

• The joint is not water tight 

715 Corrosion of joint • Disintegration of steel surface through rust 

716 Unevenness of joint • Height difference between the joint and the 

approaching deck 

717 Crackinglholes in joint • Cracking only nonnally appears in asphalt 

joints 

718 Inadequate cleaning of the • Debris, sand, gravel etc. collected in the 

joint 

joint 

719 Missing part(s) oflhe joint • Part of original design mi ssing 

720 Loose part(s) oflhe joint 

• Looseness of bo lts, cover plate or any other 

part oflhejoint 

790 Other damage to the joint • Any other damage not listed here 

8 Damage to 

Drainage/Approaches and 

Accessories 

Damage to tile Drain System 

801 Defective drain pipes 

• Pipes not functioning as planned 

802 Leakage o f drain pipes 

• Leakage oflhe drain pipe or through the 

joint between the pipe and the deck 

803 Corrosion of drain pipes 

• Disintegration o f pipes through corrosion 

804 Inadequate cleaning of the 

• Debris, sand, gravel cte. in the drain system, 

drain system 

but not blocked 

805 Blockage of drain system 

• Does not allow water to pass 

806 Missing part of drain system 

• Originally part missing

809 Olher damage to the drain 

system 

• Any other damage not listed here 

Damage to the Bridge 

A pproaches 

811 Settlement/subsidence of the 

bridge approach 

• Depressions in the road surface approaches 

812 Potholes in bridge approaches 

• Irregular shaped, disintegrated areas orthe 

approach road surface 

813 Erosion of bridge approaches • Materials removed from the slopes of the 

embankment, normally caused by flowing 

water 

8 14 Extensive vegetation • Vegetation reducing the traffic safety 

8 15 Defective drain ditches • Drain ditches arc not functioning as 

intended 

816 Loss of road camber • Improper cross fa ll of the road surface 

819 Other damage to bridge 

approaches 


Damage to Accessories 

821 Defective or missing sign(s) 

• Sign damaged or mi ss ing 

822 Damaged insulation on • Water pipes, electric cables etc. 

accessories 

829 Other damage to accessories 


990 Olher da mage to tbe bridge • Any other damage to the structure not listed 

in this section

5.3 Degree of Damage 

Consequence of 

Damage 

Degree of Damage 

The Degree of Damage is used to indicate the seriousness or severity 

of the damage which depends on the development speed and 

the rate of severity at the inspection time for each indiv idual damage 

or group of damage. Four characters indicate di fferent levels of 

seriousness of a damage as outlined below: 

Degree of Damage 

Condition 

that releases Maintenance 

Action 

I : 

2: 

3: 

4: 

9: 

Minor damage or defects that might not require any 

remedial action within the next 10 years. 

A verage or slight damage or defects that require 

remedial action within 4 - 10 years. 

Serious damage or defects that requ ire remedial 

ac tion within I - 3 years. 

Critical damage or defects that require remedial action 

within 0 - 1/2 year. 

Not inspected 

The objective of these characters is to let the inspector indi cate, 

the seriousness of the damage observed, based on hi s professional 

judgement, and when they have to be repaired. 

If the damage may affect the carrying capac ity, thoroughly static 

calculations may be necessary in order to determine the severity 

before the degree of damage settles. 

When the damage affect the maintenance costs severely, and the 

extent is exten sive, a cost benefit analysis should preferably be 

carri ed OUI on the bridge before the degree of damage detennines. 

When inspecting a bridge, the inspector has to detennine if the 

present condition of the bridge has reached a level where maintenance 

action is rel evant or not. The way of doing this for the 

inspector, is as follows: 

Degree of damage 1 is a state of condition which can be accepted 

without any recommended action. 

Degree of damage 2-4 is a state of condition which demand action. 

The inspector has to detennine if degree o f damage 2, 3 or 4 

shall be selected, combin ed with recommended year of action to 

avoid that the carrying capacity, traffic safety etc. sha ll be affected 

seriously. 

Conseqence of Damage 

The consequences of damage indicate what it will affect if the 

damage is not repaired in time. Three effects have been considered 

and are abbreviated by letters as fo llows: 

C :Damage or defect that affects carrying capacity 

T:Damage or defect that affects traffic safety 

M: Damage or defect that affects maintenance cost 

E: Damage or defect that affects the environment/aesthetics

These effects are presented in order of importance. Damage that 

affects carrying capacity, will therefore be given higher priority 

than that affecti ng environment or maintenance costs. 

When relevant, the cost of repairs shall also include traffic costs as 

wei l. 

One damage may have several consequences. 

Assessment of Damage by 

Combining Degree and 

Consequence of Damage 

Damage that affects the 

Carrying Capacity 

The condition of a bridge element is assessed by cOllS idering the 

seriousness and effect of any damage to it. The assessment therefo 

re, is a combination of the degree and consequence of the damage. 

This combination results in the final assessment ofthc damage as 

outlined below: 

I C = Minor damage/defect that in the long run may present 

danger to the carrying capacity of the structure. The 

damage might not require repair within the coming 10 

years. 

2C = Average damage/defect which can reduce the carrying 

capacity of the structure ifno repair is carried out within 

the next 3-10 years. The damage must be repaired within 

3- 10 years. 

3C = Serious damage/defect which can rcduce the carrying 

capacity of the structure ifno repair is carried out within 

the next 1-3 years. The damage must bc repaired within 

\-3 years. 

4C = Critical damage which has reduced or is about to reduce 

the carrying capacity of the structure. The damage must 

be repaired immediately or within half a year if safety 

precautions shall be avoided. Report on the findings 

shall be submitted to the Bridge Engineer immedia 

tely. 

Damage influencing the 

Traffic Safety 

Damage inftuencing the 

Maintenance Cost 

lT ~ 

2T ~ 

3T ~ 

4T ~ 

lM ~ 

Minor damage/defect that might in the long run present 

danger to the traffic safety. The damage m ight not requi 

re to be repaired within the coming 10 years. 

Average damage/defect which can reduce the traffic 

safety if no repair is carried out within the nex t 3-1 0 

years. The damage must be repaired withill 3- 10 years. 

Serious damage/defect whi ch can reduce t he traffic safe 

ty lfno repair is carried out within the nex t 1-3 years. 

The damage must be repai red within 1-3 years. 

Critical damage which has reduced or is about to reduce 

traffic safety. The damage must be repaired immediately 

or wi thin half a year if safety precautions s hall be avo 

ided. 

Report on the findings shall be submitted to the 

Bridge Engineer immediately. 

Minor damage/defect that in the long run, is considered 

to influence the maintenance costs. The damage mi gh t 

not require to be repaired with in the coming 10 years.

2M = Average damage/defect that can develop in such a way 

that repairs will be more comprehensive, compl icated 

and costly ifnothing is done within the next 3- l 0 years. 

The da mage must be repaired within 3-10 years. 

3M = Serious damage/defect that can develop in SUcJlI a way 

that repairs will be more comprehensive, complicated 

and costly ifnothing is done within the next 1-3 years. 

The damage must be repaired within 1-3 years. 

4M = Critical damage that can develop in such a way that 

repa irs wil l be more comprehensive, complicated and 

costly ifrepair to the damage is not carried out im medi a 

tely or within half a year. 

Da mage influencing 

Environment! Aesthetics 

1 E = Minor damage/defect that might in the long rUTh effect the 

environment/aesthetics. The damage might not require to 

be repaired within the coming 10 years. 

2E = Average damage/defect that can develop in such a way 

that envi ronment/aesthetics can be effected adversely 

within the next 3- 10 years. The damage must be repai red 

within 3- 10 years. 

3E = Serious damage/defect that can develop in suclll a way 

that environment/aesthetics can be effected adverse ly 

within the next 1-3 years. The damage must be :repaired 

within 1-3 years. 

4E = Critical damage that already has nega ti ve impact on 

environment/aesthetics or wi ll have withi n 0- 1 (2 year if 

the damage is not being repaired immediately or withi n 

haifa year. 

Examples of damage/defects that affect the Environment/-Aesthetics 

can be like noisy joints, painted surfaces with graffiti etc .. 

When evaluating a damage determining the consequen ce 10 affect 

the Environment/Aesthetics, the Type of Damage is rar ely rated to 

be4. 

5.4 Damage Evaluation 

5.4.1 Primary & Secondary Damage 

Sometimes a damage(primary damage) can init iate oth er types of 

damage (secondary damage). 

Below are listed examples of typical primary damage followed by 

some examples of initiated types of secondary damage. 

* Settlement of abutment or piers will normal ly lead to deforma 

tion of superstructure fo r contin uous bridges. 

* C racks in concrete will normally lead to lea kage, stains, disco 

loration etc. 

Splits in timber may lead to timber decay 

* Insufficient covering wi ll normall y lead to corrosion on rein 

fo rcemenl or spalling.

The Development o f 

Damage 

It is important to fully realise the relationship between primary and 

secondary damage when both evaluating the damage and decidi ng 

the type ofrepair(s).ln most cases primary damage has to be 

detennined before any remedial action can be taken. Repai rs deduced 

from secondary damage are rarely successful. 

5.4.2 The Extent to which Damage has 

Developed 

It is usually easy to come to a concl usion about serious damage 

which has already reduced carrying capac ity or traffic safety when 

remedial measures require to be speedil y set in motion. 

Measu rements/Materials 

Testing 

The Co urse of Development 

of Specific Damage 

On the other hand it is more difficult to evaluate damage which is 

sti ll developing. In such instances it is important to produce a 

detailed overview of the following circumstances: 

I. How long has it taken for the damage noted to develop? 

2. How quick is the probability that it will continue developing in 

the future? 

Observations recorded during previous inspections wi ll be valuable 

in connection with assessing how quickly an incidence of 

damage has been developing. 

In order to assist in assessing the development of damage measurements 

and materials testing can additionally undertaken. As an 

example, levelling can be employed in recording the development 

of settlement, whilst measuring the depth of carbonisation and 

chl oride content over a period can be used in evaluating the ri sk of 

the re inforcement corroding in the fut ure. 

In addition to practical experience theoretical models exist for 

assessing the speed at which carbonisation and chlorides are spreading 

when it comes to Slating how quick ly specific damage will 

continue to develop. 

When evaluating the speed of damage destruction one should particu 

larly note that different kinds of damage take different courses: 

• No development 

• Decl ining course of development 

• Steady pace of development 

• Accelerating pace of development 

No Development 

Figure 5.4-1 ill ustrates these points. The following sub-secti ons 

provide more detailed descriptions of the different courses of 

development. 

An exampl e could be spalling due to traffic impact. This can arise 

quite suddenl y, yet does not develop any further. The damage is 

either so immaterial that no action need be taken or so serious that 

immediate measures are required. One should, however, real ise 

that minor damage to concrete and steel due to traffic impact that 

is not repaired in the long run can later lead to secondary damage 

such as corrosion.

Declining Course of 

Development 

Steady Pace of Development 

Accelerating Pace of 

Development 

This can be exempli fied by settlement whi ch usually develops 

quickly at the start and then later begins to decline. Nevertheless 

one should be aware that settl ement can demonstrate both a steady 

and an accelerating course of development. 

Rutting can act as an example here. Its development wi ll usuall y 

be linear, but an increase in wear and tear must be reckoned with 

when the ruts become deeper because traffic impact wi ll be more 

concentrated. 

Examples of this kind of damage are insufficient surface 

cover/damaged cover, secondary damage such as reinforcement 

corros ion or spal1ing. Since the cover has become carboni sed or 

infected with chlorides, the corrosion process wi ll start in the reinforcement 

clements with least cover with the consequent development 

ofspal1ing in the area of these steel elements. As the extent 

of the carbon isation or the effects of the chlorides penetrate deeper 

into the concrete, so the speed of corrosion development in the 

already corroded reinforcement elements wi ll increase, and the 

corrosion wi ll spread to new reinforcement. As a consequence 

both corrosion in the reinforcement and flak ing will demonstrate 

an increasing trend. 

Inspection 

I 

InspeCtion 

I 

Time I 

to Concrete J 

== I 

I 

I 

SetUemenl 

I 

I 

o 

CotliSion 

I 

I I J Critical ConOition 

----,- --~------ 

I 

I 

L -1_ - - - - - - , ____ _ 

Figure 5.4-1: The Development o/Damage 

5.4.3 Compound Damage 

Damage to bridges is often composed of severa l types of damage. 

Corrosion of reinforcement elements often occurs together with 

spalling and insufficient/damaged cover.

Whatever types of damage are observed should be used to describe 

them, but their assessment shou ld be carried out as a totality. For an 

example please refer to Figure 5.4-2. 

- - 

• 

. --. 

~- 

, ~ - ~ 

- 

\ . 

\ 

• 

I "; / / 

--'- 

Figllre 5.4-2: InsufJiciell//damaged Cover. Corrosion /0 Ille Rein/oreemenl (111(/ 

Spalling. 

The damage illustrated in Figure 5.4-2 consists of insufficient/damaged 

cover, corrosion to the reinforcement and spalling. Such compound 

damage can be assigned different degrees of damage f or carrying capacity, 

maintenance costs, the environment and the bridge's overall appearance. 

The table be low provides an example of how to describe and 

present specific damage. 

Evaluation of Compound 

Damage 

Descri tion of the Dama e C T M E 

Insufficient/damaged cover, oorrosion of the reinforcement 

and spaJlillg on lhe underneath side of the deck. I 2 3 

The basis for the above damage evaluation is as follows: 

The corrosion has occurred in structural reinforcemen t but its speed of 

development is so low that the carrying capacity wi ll remai n unaffected 

for the next ten years. A degree of damage of I has been allocated with 

respect to cart)'ing capacity (C). The amount of concrete falling off 

does not represent any danger to traffic safety (T) since no traffic passes 

under the bridge. This column has consequently been left blank. 

Even though the speed at which the corrosion is spreading is low, there 

exists the probability of the corrosion spreading to several other rein-

fo rcement el ements with a resultant increase in the extent of spa l ~ 

ling. In tum this will lead to increased repair costs. A d egree of 

damage of2 has been given for maintenance costs (M). 

The bridge is si tuated in an urban environment; consequently s p al~ 

ling and corroded reinforcement present a very unsatisfactory 

impression for bridge users. A score of 3 has thus beeIll allocated to 

environment and overall appearance (E). 

5.5 Prioritising 

Maintenance 

When evaluating damage as already described in Chapters 5.3 and 

5.4 it will be possib le in the future to draw up a consciously 

thought out prioritisat ion of what damage should be repaired only 

once the consequences of possibly de laying maintenance for bud~ 

getary reasons have become known. 

However, maintenance should be carried out as and wilen described 

in an inspection jfthe damage affects carrying capac ity or traf~ 

fie safety. Should such maintenance be delayed for budgetary 

reasons, the consequences may well be a reduction in traffic flow 

or the implementation of safety measures. 

Additionally when prioritising maintenance one ought to take into 

consideration the fact that items of less serious damage can be 

delayed if its locat ion allows it to be postponed and easily included 

with repairs of serious damage using the same rig or scaffolding. 

Table 5.5~ I shows an exampl e of prior it ising and grouping m a int e~ 

nance tasks as indicated in the previous paragraph. 

Priority Element - Damilge Degree of Damage & Time (Of Maintenance 

Consequences 

I Parapet 4T At unce or within 6 montlt~ 

- end piece 4T at Lhc:: !~test 

Joints 

- loose screws 

2 Wearing course 3M,2T Ought 10 be carried out 

-ru" 

within 3 years, hut can be 

I OOSIDOnoo a Iitl le 

3 ae,~ Ought to be tarried out 

- paint damage 2C, 3M within 3 years, but tan be 

postponed for 4 to 10 years. 

Cross girders 

All of these elements require 

- rdnforccmtnt torrosion maintenaoce simultaneously 

2e, 3M as they also need staffolding 

Bearings 

on the undersid e of the 

- cleaning 3M bridge. 

- ad iustments 2M 

Table 5.5-1: Priori/ising alld GroupingojMaimell(lnce Tasks

5.6 Cause(s) of Damage 

The most common causes of damage have been gathered and systematised 

using the two digit codes detailed in the foll owing section. 

There can be several causes of damage. 

Figllre 5.6-1: Hairlinefraell/res & 

cmch causetl by Defecl No. 15 

Alkalille Reactil'e Materials 

Visual checks, suppl emented by measurements and materials testing, 

fo rm the basis of determining the cause of damage. However, 

a thorough knowledge of tile planning, construction and management 

of bridges is also important. The success ofa repair depends 

often on correctl y determin ing the primary cause of the damage 

when describ ing repairs. 

There is no requirement to provide the calise of damage after an 

infonnal inspection, but the cause of damage must be given after 

all other types of inspection whenever possible. 

"-igure 5.6-1: Corroded reinforcemenl 

due 10 Defect No. 31 

Incorrectl), Placetl reillf orcemenl & 

No. 34 bwif.jicient Finishing 

" , 

Figllre 5.6-3: Hairlille Fractures & 

Cm cks dlle to Defect No. 61 Traffic 

Loads 

Figllre 5.6-4: Gap c(llI.\·el! by traffic 

impaci (No. 71)


I 

Faulty Design 

11 lncorrect choice of materials 

12 Erroneous calculations 

13 Poor design solutions 

14 Deviation from standards 

15 Inadequate regulations 

19 Other fau hy design 

2 Material DamagelDefect 

21 Poor material composition 

22 Inadequate strength 

23 Delamination 

24 Chloride introduced during mixing 

process 

25 Alkaline reactive aggregates 

29 Other material defects 

3 Faulty Construction 

31 Settlement of scaffolding 

32 Incorrectly placed reinforcement 

33 Faulty concreting 

34 Insufficient finishing 

35 Inadequate curing procedures 

36 Premature loading 

37 Installation fault 

39 Other faulty construction 

4 Insufficient Maintenance 

41 Excessive vegetation 

42 Insufficient removal of ice 

43 Untimely application of protective 

measure 

44 Inadequate maintenance 

• Wrong materials selected. 

• improper or wrong calculations. 

• Poor design with regards to maintenance 

• i.e. those in force when the bridge was 

constructed. 

• e.g. coastal bridges which have been 

constructed according to the regulations laid 

down for inland bridges 

• Wrong or improper compositions of materials 

or incorrect concrete mix 

• Can be like: Poor quality of materials in 

taking compression, less tension capacity than 

expected, less shear capacity etc .. 

• Separation of material into layers. 

• Chlorides from aggregates or additives during 

the mixing of concrete. 

• Aggregate containing alkal ine minerals 

• Vertical movement of scaffolding. 

• Reinforcement not located within the 

limitations of tolerance. 

• Wrong vibration, to dense reinforcement, etc. 

• The surface is not in accordance with 

requirements. 

• Lack of or poor curing lead ing to cracks, 

improper quality etc .. 

• Loading before concrete has achieved 

required strength. 

• Improper installation of a component 

• Vegetation growth in river course that can 

obstruct the waterway 

• Lack of or improper removal of ice 

• Incorrcct protection of material 

• Maintenance work not carried out in

49 Other insufficient maintenance 

5 Environment 

51 Chloride loading 

52 Sulphate attack 

53 Carbonation impact 

54 

55 

56 

57 

58 

59 

Leaching 

Frost attack 

Abrasion 

Biological attack 

Chemical attack 

Other environmental attacks 

accordance with regulations/procedures 

• From de-icing salt, sea or other salty source. 

• Deterioration due to sulfatic acids or materials 

• Reaction between the carbon dioxide in the air 

and the lime in the building material. 

Reduction of the concrete's ability to protect 

the reinforcement against corrosion. 

• When calcium is washed out of the concrete 

and deposits as lime on the surface. 

• Freeze/thaw cycles that may cause sl'all ing. 

Happens normally with porous conc rete. 

• Wearing or grinding away of surface material 

by water or traffic 

• C.g. fungi, maggots 

• e.g. acids etc. 

6 

61 

62 

63 

64 

65 

66 

67 

68 

69 

7 

71 

72 

73 

74 

75 

76 

79 

Live Loads 

Traffic loads 

Soil pressure 

Impact from currents 

Wind impact 

Ice impact 

Temperature 

Shrinkage/Creeping 

Impact from overloads on wearing 

surface 

Other loadings 

Accidents 

Vehicular impact damage 

Impact caused by vessels 

Flooding 

Landslide! Avalanche/Rockslides 

Explosion 

Fire attack 

Other accidents 

• Damage caused by loads from traffic 

• Damage caused by soil pressure 

• Damage caused by pressure from flowing 

water 

• Damage caused by wind pressure. 

• Damage caused by ice pressure. 

• Damage caused by temperature changes 

• Time dependent effects which can result in 

cracking (shrinkage) and deformation (creep) 

• Damage of wearing surface caused by 

overloads. 

• Damage daused by vehicles. 

• Damage caused by vessels when navigable 

water under the bridge. 

• Damage caused by flood. 

• Damage caused by 

landslide/avalanche/rockslides 

• Damage caused by explosion 

• Damage caused by fire.

8 

8 1 

82 

83 

84 

89 

Damage Incurred In Service 

Normal wear and tear 

Consequential/secondary damage 

Impact damage from snow removal 

equipment 

Vandalism 

Other cause to incurred in service 

damage 

e.g. in the wearing course, surface treatmen t etc. 

e.g. de formation of the superstructure due to 

settlement, discoloration from leaks and moisture 

etc .. 

• Damage caused by snow ploughs, graders or 

other snow removal tools. 

• Damage caused by vandalism 

9 Other/U nknown Cause of Damage

6 Carrying out 


Ba sis of BRUTUS 

Internationa l 

Any re levant reports and possibly also drawings should be examined 

before carrying out an inspection with the exception of in formal 

inspections. 

The access and safety equipment required for carrying out a specific 

inspection should be detailed in the BMS. 

For those bridges recorded in the BMS according 10 given axes 

inspection forms should incorporate their elements and the corresponding 

axes, -numbers. 

The inspection should begin with the lowest axis and progress in 

ascending order of axis number. In the absence of classificalion by 

axis number in the BMS the inspector should assess whether this 

should be introduced. 

Systematic Checks 

11 is imporlant to inspect bridges in sllch a way that all clemen Is 

are checked in a systematic fashion. The following example shows 

the possible order in which the elements of a standard, large bridge 

could be checked: 

I. Ground 

2. Substructural elements accessible from land 

3. Sub and superstructural elements requiring a bridge lift for 

inspection purposes. 

4. Elements belonging to the superstructure which can be in spec 

ted from the bridge or the ground 

5. Deck, wearing course and accessories 

However, the use o f a bridge lift must be assessed in the light of 

the above sequence. 

Measurementsf M ateria Is 

Testing 

Pupose of an Inspection 

These can be undertaken at the same time as visual checking or be 

clearly detailed so that someone else can carry them Ollt. Ifmeasurements 

and materials testing have already been planned in advance 

of an inspection, these should be specially assessed and adapted 

to the findings of the visual check. 

The purpose of the different inspections is described in Chapter B 

in the "Guidelines fo r the Management of Bridges, whi lst the fo l 

lowing chapters provide a more detailed description of how the 

inspections themselves wi ll be carried Ollt. 


6.1 Acceptance Inspection 

6.1.1 Scope 

An Acceptance Inspection incorporates a visual check of the entire 

bridge including any underwater foundati ons - please refer to 

Chapler 6.6. Cables and their hangers should also be checked for 

suspension and cable-stayed bridges - see Chapter 6.5. Acceptance 

Inspections should be supplemented by measurements and materials 

testing - referto Table 7. 1-\ and Chapters 7.2 - 7.7. 

One must be fully aware of the: "Should the owner not advise any 

faults di scovered during the forma l acceptance procedures, or 

which ought to have been discovered as a result of a customary 

careful inspection, he cannot then later plead ignorance of them," 

Damage, faults and defects should be recorded along with their 

location. Refer to Chapter 7.1 concerning how to draw up the relevant 

reports. 

6.1 .2 Visual Checking 

This should be carried out at close quarters as described i n Chapter 

6.4.2 and should incorporate as a minimum the points lis ted below 

for indi vidual elements. Please refer to Chapter 9 'Detailed Li st of 

Categories of Damage' for the assessment of damage. 

The Ground 

Concrete El ements 

* Subsidence of embankment close to abutments, piers and 

columns 

* Erosion of in fill close to abutments or supports caused by rain 

water aC l'ion. 

* Materials used for ballast are of the prescribed type 

• The banks and/or the protection facilities against erosi on com 

ply with the description 

* Green/planted areas are as ori ginally proposed 

* Surrounding areas have been returned to their original condition 

• Clearing up operations have been carried out satisfactorily 

• Settlement of abutments, piers etc. 

• Deformation - the shape of the element is correct, e.g. straight 

ness/evenness, clearance, defl ection etc. 

• Unacceptable hair-cracks/cracks 

* Satisfactory quality - thickness, binding agents, evenlless, con 

struction - as well as the colour of the surface treatment 

• Unacceptable discolorati on due to leaks, dampness impact, cal 

cium deposits. 

• Insufficient/damaged surface treatment 

• Honeycombing or delaminati on 

• Spalling due to mechanical impact 

• Construction of the concrete's surface is as described 

• Formwork removed both from above and below water level 

• Nail s and fo rm work stays removed 

60 


o 

Fig ure 6.1- 1: Honeycombing 

* Holes le ft by stays filled in as described 

teel Elements 

Timber Elements 

Wearing Course 

* Settlement or movement in, for example, the superstructure 

* Deformation - the shape of the element is correct, c:.g. straight 

ness/evenness, clearance, deflection etc . 

• Cracks 

* Quality and colour orthe surface treatme nt acceptable 

* Surface treatment of mounting joints 

* Screws and connections correctly installed 

* Transition between the concrete and other material s are as pre 

scribed 

* As fo r steel elements 

* Protection of end pieces 

* Dampness traps which can lead to rot 

* Correctly prepared so that the timber dries Oul after dampness 

impact 

* Wearing course and, ifnecessary, the membrane are of the pre 

sc ribed type 

* Correct thickness - assess need for taking measurements 

* Finishing edges with joints and raised pavements correctly con 

structed 

* Depressions - assess need to take measurements 

* The drop to the drainage pipe/drain 

* Has any damage occurred sllch as fractures and cracks 

* Fonnwork, concrete leftovers etc removed 

* Cast of pillows underneath bearings correctly carried out wit 

hout damage 

* Bearing properly located, e.g. facing the correct dir..::ction of 

movement 


Bearings & Bea ring Shelves 

'" Bearing's positionldefonnation correct in relationship to actual 

temperature 

'" Protective bellows properly installed 

'" Surface treatment as prescribed 

Figllre 6.1-2: Too {o w Joilll-Sleeper 

Joints & Joint Construction 

Pa rapets 

Drainage System 

'" Formwork removed from joint openings 

'" Size of joint openi ngs correct in proportion to the prevailing 

!temperature 

'" Are the prescribed joint constructions watert ight? 

'" Joint sleeper of correct qualit ies and heights 

'" Verticall y and horizontall y correctl y shaped 

'" Methods of attachment in accordance with regulations 

'" Colour and smoothness of surface treatment satisfactory 

'" Transition to road guard ra ils carried out in accordanc e with 

regulations 

'" Corrcct level for the upper cdge 

'" Sealant around drainpipes and drains sati sfactory 

'" Pipe extension below the deck sufficient 10 avoid dam pness 

impact to elements located underneath 

'" Drain outlets/pipes adeq uately attached and joints tightened 

'" Heating cables fu nction as prescribed 

6.2 Warranty Inspection 

6.2.1 Scope 

A Warranty Inspection wi ll incorporate a visual check of the whole 

bridge structure as fo r an Acceptance Inspection ~ see C:hapter 

6.1. 1. Usua ll y only those measurements and materials testing prescribed 

for an Acceptance Inspection should be carried o ut. If 

damage has occurred during the warranty period Ihe scope of any 

measurements and materials testing must be re-assessed ~ refer to 

Table 7. 1- 1 and Chapters 7.2 ~ 7.7. For maki ng reports r efer to 

Chapter 8.1. 

62 



The visual inspection should be carried out in the same way as for 

a Major Inspection - see Chapter 6.4.2. Any inspecti ons of the 

cables or underwater foundations should conform to Chapters 

6.5.2 and 6.6.2. 

6.3 Generallnspection 

6.3.1 Scope 

A General Inspections encompasses a simple visual check of all 

elements above water level. As much of the foundati ons below 

water level should be checked as is possible w ithout employing a 

diver. In addition, any specia l checks a lready detailed on (he 

inspection fonn should be carried out. Generally speaking, measurements 

o r materia ls testing are not required for General 

Inspections. However, the presence of serious rutting may render 

measurements necessary to check whether there is a risk of the 

dampness insulation being perforated. 

The least that must be recorded during a General Inspection is 

damage req uiring repair before the next inspection, i.e. in practice 

damage assessed w ith Degrees of Damage 3 and 4. Refer to 

Chapter 8.2 for the submission of reports. 

6.3.2 Basic General I nspection 

This is a Basic Visual Inspection without the use of access equipment, 

i.e. most of the clements of a large bridge w ill have to be 

inspected at a distance. Neverthe less, binoculars should be used 

should certain details require to be looked at more closely. 

Underwater binoculars may be of assistance when inspecting 

items below the surface oftne water. 

Ground 

During a Visual Inspection each element should be checked 

for the presence of serious damage - refer to the list below. For 

damage assessment please see C hapter 9 Damage Evaluation 

Catalogue. 

* Settlement o f the ground undemeath the carriageway up against 

the abutment piers 

* Erosion of the embankment around the abutment pi ers due to 

surface water 

* More serious underwater damage caused by erosion which can 

be detected without using a di ver 

* Damage to embankment retaining walls 

* Unintentional removal or fi lling up ofloose material in the regi 

on of the foundations 

* Damming up of driftwood whi ch reduces the water flow 

* Unwanted vegetation and trees 

* Accumulation of combustible material s under the bridge 

* Damage to piles above the waterline 


• Damage to permanent pi lewalls above the water level 

Figure 6.3-1: AcculI1ulation of 

Twigs and piecesofrree 

Figure 6.3-2: End Section of 

a Cross-Beam showing broken 

off concrete 

Concrete Elements 

Steel Elements 

• Serious sett lement, movement and deformation 

• Spalli ng, broken off parts or other damage caused by traffic 

im pact 

• Discoloration of concrete surfaces due to water or graffi ti 

• Unwanted vegetation 

• Fonnwork or stays which have not been removed 

• General cleaning 

• Serious sett lement, movement and deformation 

• Defonnation, cracks or breaks caused by tra ffic impact 

'" Discoloration due to leaks/dampness impact or graffiti 

'" General cleaning 

D 

Figure 6.3-3: Broken Sleel Girder 

64 

Handbook for Bridge Inspect ions

Stone Elements 

• Serious settlement/movement of the abutment piers or columns 

• Defonnation of stone arches etc. 

• Stone slip, stones falling out or missing stones 

• Cracked stonework 

• Discoloration due to leaks/dampness impact or graffiti 

• Unwanted vegetation growth on the element 


Figure 6.3-4: Stonesjallen 0111 ojlhe SIOJlework 


• Serious settlement/displacement of timber columns etc. 

• Defonnation of timber superstructure 

• Missing parts, braces etc. 

• Damage caused by rot 

• Chipping or broken off pieces due to traffic accidents 

• Discoloration caused by leaks/dampness impact, rust or graffi ti 


D 

Figure 6.3-5: ROlto limber Kerb 



• Ruts 

• Cracks or fissures especially around joints 

• Crazing or holes 

• Flaking off thin wearing courses, e.g. epoxy 

• Chippi ng and rot damage (on timber decks) 

• Protruding plank ends and nails (timber decks) 

FiW-lre 6.3-6: Wear callsetf by Rills 

Bearing & Bearing Shelves 

Joints & Joint Construction 

• Cracks or fissures in sections of a bearing 

• Cleaning the bearing and its recess 

• Joint anchorage points - possible missing parts 

• Mechani cal damage, cracks, breaks in the constructioD due to 

sn ow~ c\ eari n g equipment or general wear ca used by tr affic 

• Condition of the joint edges & their operation; possibly missi ng 

edges 

• Cleaning of the joint construction and the gap 

Fil:,'1/re 6.3-7: Fixing poinls of a Joilll 

66 


Parapets 

* Deformation due to traffic colli sions 

* Cracks or breaks 

* Loose or missing screws, bolts and other parts 

* Support struts/posts satisfactorily anchored 

* End secti ons and transition/connection to guard rai Ds compl y 

with regulations 

* General cleaning 

* Operating satisfactorily 

* Pipes and sand traps are free of blockages and cleaned 

Water & Dra inage System 

Pipes & Ca bles 

Other Equipment 

* Leaks and moisture impact (water and sewage pipes.) 

* A special list will be produced for each bridge 

6.4 Major Inspection 

6.4.1 Scope 

The major inspection consists of a visual inspection o:fthe entire 

bridge structure above water except for major inspection of cables 

described in chapler 6.2. Whenever considered necessary measurements 

and material investigations should suppl ement the visual 

inspection and serve as a basis for evaluation of the fu. ture development 

of any observed defects. Reference is made I~ Tab le 7.1-1 

and Chapter 7.2 - 7.7. 

When great need for repair is di scovered during the m.ajor inspection 

or when the infonnation gathered is insufficient te decide 

what type, degree, consequence, extent or cause of daJl1age that 

has been observed, a special inspection mllst be triggered. 

Reference to chapter 6.7. Also refer to Figure 6.7- 1. 

In the report it should be stated what kind and amount of measurements 

and material in vestigations that are needed and for which 

elements they have 10 be perfonned. 

Handbook f or Bridge Inspections 

67

For reporting refer to chapter 8.2. 

6.4.2 Visual Inspection 

The Visual Inspection has to be performed as a close visual inspection, 

which means that the inspector must be within reach of element 

concerned. This requirement can be suspended provided that 

a possible defect can be detected with certainty from a longer di s 

tance. This may be the case for inspection of larger uniform steel 

or concrete areas. In such cases representative areas should be 

selected for close visual inspection and the remaining areas left for 

observation from a larger di stance. Hi ghly stressed areas such as 

bearings and joints should be subjected to close vis ual inspection. 

Serious damage and characteristic defects should be illustmtcd by 

means of photographs and lor sketches. 

It is necessary to use the appropriate means of access to reach within 

the speci fi ed distance of inspection. Reference chapter 4.2 

"Access Equipment". 

When perfonning the visual inspection all elements shall be surveyed 

for the existence oflhe following ty pes of damage or 

defects. Reference chapter 9 "Catalogue for Evaluation of 

Defects". 

The Ground 

• Subsidence of the subso il of the roadway close to the abutments 

or in the vic inity of the abutments or supports. 

• Erosion of infill close to abutments or supports due to ra inwater 

action 

• Scouring of river bed 

Figure 6.4-/ Erosioll oj£mbal1kmelll 

68 

Hand book for Bridge Inspections

• Damage to slope protection 

• Damage to piles above water 

• Damage to pennanent sheet piling above water 

• Un planned removal or deposition offill material in the vicinity 

of foundations 

• Accumulation of waste etc. restricting the water flow 

• Excessive vegetation, trees etc. 

• Accumulation of combustible materials underneath bridges. 


Steel Ele me nts 

• Settlement or movement of abutments, supports, superstructures 

etc. 

• Deformation of superstructure or other element due to differenti 

al settlement, excessive load or defomlation of scaffolding 

during construction. 

• Cracks and possible leakage through these. (It should be eonsi 

dered to register crack-widths and crack patterns). Special con 

sideration should be given to check anchorage zones of prest res 

si ng cables for cracks. 

* Defect to surface treatment 

• Discoloration of concrete surfaces due to leakage or graffiti. 

• Reduced or damaged concrete cover with possible future corro 

sion damage in mind (carbonisation, ch lorides, binding wire, 

di stance holders etc.) 

• Disintegration due to frost or weathering 

• Pouring defects or areas with obviously bad workmanship, areas 

with possible penetration of mo isture, pores in the surface etc. 

• Lack of adhesion and/or spalling of structural concrete, integral 

ly cast concrete, repaired areas, casting joints, prestressing anc 

horages, etc. 

• Spall ing, failure or other damage due to coll ision 

* Visible reinforcement bars or spall ing due to corrosion or woo 

den pieces cast into the concrete etc. 

• Obvious reinforcement corrosion or signs of ongoing corrosion 

processes shown by cracking along the outermost reinforcement 

bars or rust staining. 

* Satisfactory concreting around prestressing cable anchorages 

• Excessive vegetation, trees etc. 

• Scaffolding or ties left in place, etc 

• The general state of cleaning o f the considered element. 

• Deformation of superstructure or other elements due to differen 

tia l settlement of foundations, excessive load or col lision. 

• Relative movements of superstructure or other elements 

• Cracks or fa il ure in base material, welds, bolts or rivets 

• Defects in corrosion protection system (paint, galvanising, coa 

ting) and possible corrosion. The connection area between cone 

rete and steel is especially vulnerable. The same appli es to the 

upper flanges supporting wooden roadways. 

• Discoloration due to leakage or graffiti 


= 

Figure 6.4-2 Reinforcement 

CorrosiOI/ 011(/ Spallil1g 

o 

Figllre 6.4-3 DeJeels oil/he Coating Sysrem wilh CorrosiOIl 

'" Loose bolts or rivets 

'" Missing bolts or ri vets 

'" Wear and tear between elements due to movements in_ the bridge 

'" Detai ls and profiles with accumulation of dirt and mo:isture 

'" General cleaning orthe element. 


'" Settl ements or movements of abutments and supports , 

'" Defonnation of stone arches, etc. 

• Split masonry stones 

'" Leakage and moisture through abutments, arches etc. 

• Discoloration due to leakage or graffiti 

'" D isplaced masonry stones 

'" Lac king masonry stones 

'" Scouring or disintegrati on of mortar in joints 

'" Excessive vegetation, trees etc. 

• General cleaning. 

Figure 6.4-4 Cracks ill Stolles 


• Settl ements or movements of wooden supports, etc. 

• Defonnation in wooden sllperstmctures, etc. 

70 


• Cracks in timber members 

• Splintering or fai lure due to collision 

• Defects in surface treatment 

• Discoloration due to leakage, moisture, corrosion o:r graffi ti 

• Timber decay due to rot or insects 

• Lacking parts, shoring, etc. 

• Defects in corrosion protection system (paint, galvanising, coa 

ting) for steel bolts and struts, with subsequent corrosion 



• Cracking, especially close to expansion joints 

• Leakage or moisture caused by insufficient tightness of the wea 

ring surface. (This may result in moist areas and li my deposits 

underneath the roadway slab). 

• Assessment of wear due to studded tyres, etc. Meas urements 

shou ld be considered performed 

• Unevenness 

• Crackled areas, holes, or bl istering. 

• Flaking oflhin wearing surfaces 

• Lack of adhesion to base course for separately cast wearing sur 

faces 

• Lack of sealing along edge beams and joints 

• Lack of slope towards drain pipes and outlets 

D 

• • 

"!'". ,:- 

• • 

Figure 6.4-5 Wear (fue 10 siudded lyres 

, • • 

• Correct thickness of wearing course, to be assessed by measure 

ments when required 

• Splinteri ng or rot damage (For wooden wearing surfaces). 

• Protruding na ils and board ends. (For timber weariDg surfaces). 


Bearings & Bearing Shelves 

• The position of the bearing clements with regard to the actual 

temperature, to be measured ifnecessary 

• Deformation damage to elastomeri c bearing pads 

• Cracking or fa ilure to any part og the bearing 

• Defects in corrosion protection system (paint, galvanisi ng, coa 

ling) and possible corrosion of the bearing. 


I< 

>I< 

>I< 

>I< 

>I< 

>I< 

Lack of contact in any part of the bearing 

Damage to protection cover 

Damage to anchor bolts. 

Defects in grouts, e.g. cracks, spalling etc. 

Damage to concrete bearing seats. Vulnerabl e in case of open 

joints in connection with use of dc-icing salt. 

Clean ing of bearing and bearing shelv 

Joints/Joint Construction 

>I< 

>I< 

>I< 

>I< 

>I< 

>I< 

>I< 

>I< 

Joint opening related to temperature, to be measured if necessary 

Mechani cal damage, cracks, or failure caused by traffi c or snow 

plough 

Unexpected leakage in waterti ght joints 

Damaged or lacking joint threshold 

Damaged or lacking anchorage of the joint 

Lacking parts in the expansion joint 

Blows or noise from the expansion joint when vehicles are pas 

sing by 

Clean ing status of the expansion joint. 

D 

Pa rapet 

>I< 

>I< 

>I< 

Defonnations due to coll ision 

Cracks or failure 

Defects in corrosion protection system (paint, gal vanis ing, coa 

ting) and poss ible corrosion. Posts are vulnerable where cast 

into concrete 

D 

Figure 6.4-6 RIlPllll'e ofS1eering 

Pill oflhe Bellring 

Figure 6.4- 7 Missillg ParI 

D 

Fil:,'1/ re 6.4-8 DlIlI!aged Cooling lind Corrosion 

72 


• Discoloration 

• Loose or lack ing bolts or parts 

• Unsati sfactory connection of posts 

• Proper repairs or reinforcements performed 

• Height in accordance with current regulations 

• Ends and transitions to road railing in accordance with current 

regulations 


Drain Pipes and Outlets 

Pipes and Cables 

Other Equipment 

• Pipes and sand traps are open 

• Top at corrcct level 

• Scaling around pipes 

• Offspring underneath structures suffi cient to reduce risk of wet 

ting elements underneath 

• Defects to pipes such as cracks, corrosion, etc. 

• Suspension of drain pipes 

• Sealing of joints. 

• Damage to fittings 

• Damage to insulation 

• Leakage of water or sewage pipes 

• Unused pipes and cables that may be removed. 

• Special checklists to be issued for a particular bridge. 

o 

Figul'e 6.4-9 Corrosion of 

Draill System 


73

6.5 Major Inspection of Cables 

6.5.1 Objective and Scope 

Inspections incorporate a visual inspection of the load-bearing 

cables, suspension rods and retaining elements so as to ensure 

these are fulfi lli ng their funct ion. Where necessary measurements 

and examination of materials should be undertaken to supplement 

the visual check and act as a basis for evaluating possible fu ture 

damage and wear. See Table 7. 1-1 and Chapter 7.2 

It is recommended that a special inspection is carried out whenever 

the main cable inspection reveals the need for repairs or this 

latter inspection has not been suffic ien tly thorough in order to 

determine the kind of damage, its consequences, extent or cause. 

Refer to Chapter 6. 7 ~ Special Inspections. It should be stated 

which measurements! materials inspections are to be carried out, 

their scope and location. See Chapter 8.2 for submitting the relevant 

reports. 


Visual inspections should be of the close type as detailed in 

Chapter 6.4.2 for main inspections. 

This involves carrying out a closc visual inspection of all cables 

from anchorage to anchorage and around the entire cross-section, 

and of both the upper and lower suspension 

rods and the suspension rod clamps. In special circumstances this 

special requirement can be departed from if one can with certainty 

detect anticipated damage from a longer distance. Thi s can be the 

case with clearly visible lengths of cable or suspension rods. In 

such cases representative sections should be selected fo r closer 

visual inspection whi lst the remaining areas can be inspected from 

greater distances. C haracteristical ly serious damage should be ill u 

strated in photographs or sketches. 

Access equipment should be used as required so that one can reach 

the prescribed measuring distance. Refer to C hapter 4 .2 - Access 

Equipment. 

A bridge should be inspected in such a way that a ll its elements are 

systematically checked. Cables, anchorages, towers and suspension 

rods should be marked with a number which conforms with the 

system for parts location as detai led in Chapter 2.4.3. 

Individual elements are to be checked for damage, defects and 

fau lts during a visual inspection as listed below. Please refer to 

Chapter 9 - Damage Evaluation Catalogue 

74 


load Bearing Cables 

• Broken strands. A cable is most subject to broken strands around 

the clamps, saddles and anchorage caps. Broken strands can be 

identified by longitudinal cracks in the painted surface along the 

edges of the broken strands. New brea ks should be marked on 

the sketch by specifying the cable number and the approximate 

distance from the tower, suspension rods or similar parts. 

• Corrosion. Cables should be checked fo r external corrosion and 

signs of internal corrosion. This is especially the case with 

unprotected cabl es. One indication of internal corrosion can be 

an increase in cable diameter. 

• Wear and tear/chaffing. Cables are often subj ected to wear and 

tear or chaffing around the suspension rod clamps if the suspen 

sian rods are hanging out of line. 

• Check whether any of the spinning material has begun to leak 

out of the inner cable. 

• The condition of the surface treatment should be evaluated. 

• Check whether there has been any slipping between cables and 

their saddles. 

• Packing around the saddl es. Ensure that the cables are compl e 

tely surrounded by packing material if this has been used and 

that the fasteners are in good condition. The packing material 

should be soft and elastic and bear no signs of cracks or other 

damage. 

Figllre 6. 5- /: Broken Strands of a Cable 

Saddles/ Bearings of 

Main Cables 

Anchorage Caps 

• Loose/missing bolts, nuts or clamp plates 

• Movement 

• Cracks 

• Corrosion damage 

• Condit ion of the surface treatment 

• Birds' nests or other forms of surface soiling 

• Check that the anchorage caps arc correctly seated on their stays 

and that the tangents of the cabl es fonn the correct angles. 

• Check whether the cement grouting in the joints betwcen cables 

and cable heads is still intact. The grouting should be removed 

from a couple of the cable heads of each anchorage. If corrosion 


is discovered in the grouting cement then all joints shou ld be 

checked. New cement grouting of the same type should be 

app lied to the joints once these have been thoroughly cleaned. 

• Check for sagging in the cast anchorage cones. This can be iden 

tified by the presence o f leaked casting material along the cable 

at the entrance to the cable head. 

Anchorage o f Ca bles 

• Some cable anchorages have been constructed in such a way 

that the cable head and parts of the cable have been cast in con 

crete. This concrete should be removed in order to release the 

cable up to the anchor head for inspection. 

Figure6.5-2: Cable Heads imbedded ill COllcrete 

• Cables/stays slink into weak soi l: an assessment should be made 

as to whether a partial excavation should be undertaken to deter 

mine their condition. However, excavation work must not in any 

way weaken the rivet holders for the gravitat ional anchorage 

points. 

Suspension Rod Clamps 

• Movement. The suspension rods should be checked for out-of-l 

line movement; check also whether the suspension rod plates 

have moved in such a way that the suspension rods are touching 

or rubbing against the cables. 

• Movement. Sagging can arise around the cable suspension rods 

between the cables and the cable cap. The cast metal can be 

extruded as thin flakes in the joint between the cap and the 

cable. 

• Deformed bolts, clamps etc. 

• Cracked or broken bolts, clamps etc. 

76 


* Damage to the surface treatment 

Figure 6.5-3 

Wear& Tear 

When an underwater main inspection has revealed the need for 

major repairs or has not been adequate enough to ascertain the 

nature of any damage, its consequences, scope or cause, then more 

comprehensive measurements and materials testing may require to 

be carried oul. 

The inspection should be undertaken by di vers who must possess 

the necessary quali fications and approval in accordance with 

public regulations. 

Refer to Chapter 8.2 for making reports of Underwater Major 

Inspections. 


These should be made at close quarters, i.e. the diver should be 

able to touch the different bri dge elements. 

Before a visual inspection can be conducted all fo rm work and 

overgrowth remaining should first be removed from a large 

enough area so as to provide a sufficien tl y clear overview of the 

condition of the fou ndat ions. The anti-rust protection does not 

have to be taken away in order to remove absolutely all the formwork. 

Ice Sheath ing does not require to be removed either. 

Overgrowth can be removed either with a barking spade orland a 

high pressure hose. 

In accordancc with Chapter 2.1.6 any damage should be recorded 

on fold-out drawings of the foundations. 

The foundations should be inspected from the riverbed upwards to 

the water surface and include tida l areas. Any damage should be 

photographed and described accurately. 

Each element is to be inspected for damage, defects and faults as 

detailed below. Refer 10 Chapter 9, Damage Eva luation Catalogue. 

Underwater (; round 


'" Erosion and lor undermining of foundations 

'" Damming up caused by loose material, wood, branches whi ch 

can reduce the through flow of water. 

'" Damage to free-standing piles 

'" Damage to protection agai nst erosion 

'" Settlement/movement of abutment pi ers, piers etc. 

'" Hair cracks and cracks. 

'" Reinforcement with little or damaged cover. 

'" Weathering due, for example, to frost, strain caused by weather 

cond it ions etc. especially in areas subject to tides. 

'" Depressions/holes in castings or badly cast joints. 

'" Corrosion of the re inforcement or spalling. 

'" Areas subject to wash out. 

78 



Steel Elements 


* Settlement or movement 

* Cracks 

* Earth slips, landslides or mi ssing stones 

* Pointing which has been washed away or has becom e weathe 

red. 



* Corrosion 

* Missing support braces/parts 

* Damage to cathodic protection 



* Damage due to rotting 

* Missing pans/supporting sections 

* Corrosion of retaining bolts and steel stays 

* Worm infestati on 

* Scouring or wear and tear due to ice 

Figure 6.6-1 Erosion Gild Scouring 

Figure 6.6-2 Fa(led Areas 

6.7 Special Inspection 

When a special inspection has been initiated as a result ofa main 

inspection, the course of the inspection work could be as described 

below in Figure 6.7-1. 

6.7.1 Scope of Inspection 

A Special Inspection should be carried out either ofth.e entire bridge 

or only of critically exposed or damaged elements. A Special 

Inspection will encompass 

visual checks and/or surveys/materials testi ng. 

The type and scope of surveys and materials testing w ill be that 

stated in earl ier 

inspections, but should additionally be evaluated by t he Inspector. 

If the Special Inspection has not been in itiated by a previous 

inspection, the I 


a'or ns ection 

Normal lnspecticn & 

Maintenan

6.8 Maintenance Measures - 

Extent of Damage 

The aim of carrying out maintenance to bridges is to ensure that 

the same standards and levels of safety are kept during their entire 

planned life. 

Agreed Time for 

Maintenance 

Description of Measures 

Alternative Stratigies 

Pro cedural Codes 

Repairs to Concrete 

Maintenance shal l be carried out when the fo llowing three considerations 

coincide: 

-a) Costs are at thei r lowest point. 

-b) The bridge's carry ing capacity ca n be main tained. 

-c) Users are afforded adequate safety and access. 

Addi tionally, one must ensure that a bridge does not negatively 

affect the environment and surroundings in whic h it is situated. 

Whenever a Major Inspection uncovers damage which requires 

ma intenance (Degree of damage 2), a descript ion of the required 

measures and associated cost overview must be drawn up. 

Following either a Major or Special Inspection an evaluat ion of the 

possible alternative ma intenance strategies can be undertaken in 

accordance with the Norwegian Public Roads Administration 

Handbook No. 147: "The Management, Running & Maintenance 

of Bridges". 

The description of the measures to be taken should be based on 

procedures which comply with the Norwegian Public Roads 

Admi ni stra tion Handbook No. 026; " Procedural Codes - 2, 1997". 

The materi al s quanti ties incl uded under the different procedures 

should be decided on as much as possible at the bridge location. 

The extent of, fo r example, mechanical repairs to a concrete bridge 

are decided most eas il y by selec ti ng one or more smaller but representative 

areas or test sections. Here one can recordfevaluate the 

extent of the different kinds of damage. 

If the decision is taken to employ special repair methods such as 

the following: 

- Re-a lkalising 

- Chloride extraction 

- Cathodic protective measures 

then a simultaneous inspection should be carried Oul for the presence 

of surface impuriti es on, for exampl e, metal rein forcement 

spacers, nails and binding wires, al l of which could affect the technical 

and financial measures adopted. In addition, surface impurities 

can have an effect on the surface treatment of the concrete. 

Re pairs t o Steel 

As with concrete bridges it can also be of interest to undertake surveys 

of smaller representative sections of steel bridges showing 


evidence of deep-seated corrosion. In this way one can determine 

the size of the surface area requiring sandblast ing and the application 

of new paint surfaces. 

Surface Treatment 

The most conveni ent way of calculating the area that and treatment, 

is from the original drawings. If these do not exist,measurements 

must be performed. In some cases there might be a necessity 

of taking samples in order to determine the type of coatings. The 

selec tion of repainting system is dependent on the existing coating 

system. In most cases it is reasonabl e to paint some test-areas 

before th e final painting system is being determined. 

Railings and Parapets 

Joints 

So far as damage to rai lings or parapets is concerned, measurements 

should be taken of the total length in meters of those sections 

to be repaired and those to be repl aced. The total number of 

posts to be rep laced should also be calculated. 

If the renewal of joint sections is considered a possibility, the joint 

apertures should be measured and th e temperature recorded. It will 

also be necessary to clarify whether the apertures are sufficiently 

wide or whether they shou ld be widened/narrowed. In add ition the 

length of the joint construction should be measured. A check 

should al so be carri ed out to determine whether there are ex isti ng 

railing posts which could be in the way of new joint constructions. 

Consideration should also be given to the need to jack up/adjust 

bearings due to differences in their settings. 

82 


7 Surveys, Materials 

Tests & Instrumentation 

7.1 General 

It may be necessary to supplement visual checks by surveys, mat e~ 

rials testing and instrumentation in order to find a better basis for 

determining the extent orany damage, its cause, degree and consequences 

or for uncovering hidden damage. 

Scope 

The scope of these measurements and investigations must be evaluated 

in every case and will depend on: 

* The type of inspection 

• The type ofhridge 

• The type o f materials lIsed 

• Wear caused by the climate 

• Visual observations 

In order to carry out such measurements and in vestigations in a 

focused manner one should have a clear picture of their need and 

uti litarian value. For the sake of appearance, thi s is advisabl e with 

regard to the costs and the possib ly destructive measures employed. 

An overview of which surveys and material s testing can be undertaken 

in connection with the different types of inspections can be 

found in Table 7. 1-1. Provided the prescribed measurements and 

materials testing have been documented at the building stage, 

these do not require to be repeated for a completion survey. 

Special Routines 

Special routines may have been pu t into effect for certain bridges 

in connection with surveys, materials testing and/or surveillance 

by instruments. This will become evident from the inspecti on plan 

in BRUTUS International. 

Several of the surveys and materials in vestigations require special 

routines and additional quality assurance. Often special competence 

and equipment are also needed. Such is always the case for the 

installation of surveillance instruments. Refer also to Chapler 8 

- Reporting of Inspection Results.

TYPE OF INS PECTIONS 

0 

g 

Possible Measurements & Materials Investigations 0 

0 '5 

"5 0 0 , 

0 0 

'5 .2 " 0. 

0- ~ 

= .2 

~ 0 ti 

0 

= .2 

0 0. ti 

- 'u - 

" i\. ti 

" " " 

'" 

~ :0 " " 0- 

0 0. o.v ~ 

0 c - = 

" • ~ - 0 

0 

• 

U = • 0 

15. r! - " -: ~ - 

• " 0 • 

" " 0 

o " ·0 

0 

I ~ 

., 0 

0 

If . .~" 

;;:

All the measurements and materials investigations li sted in Table 

7. 1·1 are also described in the "Working procedure Code" 

(handbook from NPRA) 

Supplementary infonnation can also be found in Chapter 7.2 - 7.8 

of this manual. Amongst other things the fo ll owing information 

has been detailed: 

Purpose of such measurements/investigations 

Advantages and disadvantages of the different methods 

Requ ired eq uipment 

Reference to other manuals which can provide more deta iled 

infonnation 

7.2 Measurements 

7.2.1 Levelling 

Purpose 

Procedures 

To measure settlement, movement and defannation and follow up 

possibl e developments. 

The need for levelli ng differs fo r new and older bridges, which is 

reflected in the need for levelli ng during completion surveys and 

other types of inspections. 

When measurements are taken on a bridge's superstructure, the 

effects of the vibration caused by heavy traffic must be taken into 

consideration. If serious vibrations are experienced, measurements 

should be taken during periods oflow traffic or while the bridge is 

closed for this purpose. 

Scope 


For each bridge, levelling should be conducted on all axes and 

centrall y in each section. 

Levelling bolts require to be installed on bridges with foundations 

in weak ground. Regular measurements need not n0011ally be 

taken for bridges whose foundations have been sunk into rock; 

neither are levell ing bolts requi red. 

A decision must be reached as to whether follow·up is to be 

undertaken during the operational phase. 


Any fo llow·up inspection in the operational phase stipulated 

during a completion survey must be carried Olii. 

Levelling must be undertaken in the event of settlement, move· 

menl or defonnation. Levell ing can be carried out direct ly on the 

relevant clements. However, if developments are to be fo llowed 

up over a period, then levelling bolts should be installed.

Equipment 

* Theodolite 

* Tripod 

* Levell ing pole 

* Measuring tape 

* Levelling bolts and hammer action drill, if necessary. 

Purpose 

7.2.2 Horizontal Distances/Displacement 

To measure movement, for examp le of abutment piers, piers, 

superstructure etc. 

Procedures 

Reference is made to Procedure Movement. Movement can often 

be noted in bearings and joint apertures and can be measured w ith 

a folding rule or poss ibly by using a sma ll spirit level. Movement 

in piers can be measured with a plumb linc. The measurement o f 

movement should be taken in connection with recording the temperature. 

Ifmovement has to be followed up over a period bolts 

should be installed between which the measurements are to be 

taken. In order to determine which parts are subject to movement, 

a levell ing instrument can be empl oyed . 

.. . 

• • 

Figure 7.2 ~ I MeaSliremelll of Displacemelll 


sco pe 

For all bridges with moving bearings an inspection must be made 

of the bearing's placement, orientation and any displacement. The 

first two points should specifically be checked against the original 

drawings. The joint apertures and their associated temperatures 

should also be recorded. 


The need for taking measurements should be assessed in connection 

with the visual inspec tion. 

Equipment 

Purpose 

* Fol di ng rul e 

* Spirit level 

* Plumb and line 

* Thennomeler 

* Levell ing Telescope 

7.2.3 Measuring the Thickness of Wearing 

Course 

To measure the thickness of the asphalt wearing surface on the 

bridge deck to check whether it meets requirements or not.

Procedures 

Scope 

Equipment 

The thi ck ness of the wearing surface may vary in a crosswise 

direction for bridges on a bend. 


A minimum of three sets of measurements must be taken along the 

centre line as we ll as along each side of the bridge at 100 metre 

gaps. At least four sets of measurements should be carried out per 

bridge. 

Measuring the thi ckness of concrete wearing surfaces should be 

conducted as for locating reinforcement elements (See Chapter 

7.3.1: Locating Reinforcement Elements - Measuring Cover). 


The need fo r taking measurements should be assessed in connection 

with the visual inspection. The scope of the measurements 

should be the same as for a completion survey. 

* Fo lding rul e 

* Drill 

* Ma terial to refi ll holes 

Figure 7.2-2: Measurillg Track Wear 

Purpose 

7.2.4 Measuring of Ruts 

To measure the depth of wear in the tracks created by studded 

lyres in the wearing surface. 

Reference is made to rel evant procedures. 

Scope 


The measurement of track wear is not relevant. 

Equipment 

Other inspections 

When track wear indicates a need for taking measurements, measurements 

should be made in a minimum of two sections of tile 

bridge - one wi th minimal, the other with maximum wear - lIsing a 

straightedge. For long bridges over 200 metres, measurements are 

to be taken in one section for every 100 metres. The depth of the 

wear should be recorded crosswise every 250 metres.

A special note should be made whenever track wear is so great that 

the dampness insulation material or the bridge dec k have become 

visibl e. 

Equipment 

• An aluminium straight edge rul e 

• A measuring wedge 

Purpose 

Procedures 

Scope 

Equipment 

7.2.5 Measuring Evenness of the Deck Surface 

To measure the evenness of the wearing surface of new bridges or 

whcnever a new wearing surface has been laid on older bridges. 

Reference is made to Procedure 87. 1815. Damage No 604 on page 266 


Measurements fo r evenness can be taken using a straightedge or a 

measurement vehi cle. The height of the joint construction should 

be checked in relationship to the wearing surface and then recorded. 


Evenness measurements are not nonnally carried out. 

• Straight edge, either 1 or 3 metres long with lugs 

• Measuring wedge 

Purpose 

7.2.6 Measuring Sag 

To measure the relative sag in suspension bridge cables in order to 

check the loads in the suspension rods. 

Relative Sag 

Plumb line 

Hanger

Procedures 

Scope 

Sag is measured using cord or possibly piano wire as indicated in 

Figure 7.2-3. A bob should be hung on the end of the cord; alternati 

vely a spring balance may be used. The vertical distance bctween 

the central suspension rod and the taut cord (the amount of sag) is 

then measured. The procedure is repeated for all suspension rods 0 

n both sides o f the bridge. The amount of sag is nonnally the same 

over the whole bridge, but can vary somewhat near the towers 

because ofthe di stance between the fi nal suspension rod and the 

tower, and the tension of the braces. It is important that the bridge 

is not subject to traffic loads or lift during measuring. 


Sag should normally be measured in conjunction with the bridge's 

construction . However, iflhis cannol be shown 10 be documented, 

then these measurements should be taken during the Acceptance 

Inspection. 

Main Cable Inspection - Special Inspection 

The need to take these measurements should be evaluated during 

the visual inspection. 

Equipment 

Purpose 

Procedures 

Scope 

• Cord, possibly piano wire 

• Plumb line, possibly a spring balance 

• Folding rule 

7.2.7 Recording Bridge Details 

To record: 

• mi ss ing data co ncerning elements, element types, size etc. 

• marking a bridge 

• erecting traffic signs 

• bridge drawings (completed drawings) 

• archi ve/computer system data 

Procedures and eq uipment requirements wi ll vary according to the 

task in hand. 


Should data for new bridges not have been recorded at the building 

stage, then this should be done at the latest during the Completion 

Survey. 

Major Inspection - Special Inspection 

The data in BRUTUS should be checked for accuracy. Additional 

inspections should be carried out after reconstruction or reinforcement 

works. 

Equipment 

• Trip counter 

• Bridge traffic sign and tools for erecting it 

• Fo ld ing rule 

• Measuring tape 

• Camera 

• Surveying equipment

7.2.8 Measuring of Vertical Clearance 

Purpose 

Procedures 

Scope 

To measure the headroom for bridges crossing roads and the clearance 

for sh ips under bridges over the sea or other water. 

A headroom check may become necessary after rcasphalting or 

ot her changes to the roadway or, for example, after a heavy load 

has used the road. Depending on the bridge's design and the purpose 

of the measurements it may be relevant to take maximum and 

minimum headroom measurements. 


Should the headroom of a new bridge not have been carried out at 

the building stage, then this should be done al the latest during the 

Completion SUlVey. 

Major Inspection - Special Inspection 

Headroom should be measured after rcasphalting or other works 

which can affect a bridge' s headroom. 

Equipment 

* Measuring tape 

* Telescopic measuring rod 

* Surveying equipment 

7.3 Adequate Materials 

Investigation - Concrete 

The following sections provide a description of the materials in vestigations 

which can be undertaken during the inspection ofbridges 

and their concrete elements. 

When evaluating the condition of a concrete construction it is 

important 10 remember that the different materials investigations 

should be viewed in relationship to one another. 

The local ising of materials investigations fo r coastal bridges is 

specificall y dealt with in Chapler 7.3.9. 

Refilling Test Holes..cuts 

Several of the materials investigations carried out on concrete 

require the drilling of holes or chiselling out cuts in the concrete. 

Procedural Code - 2 lays down a requirement in sllch instances 

that the holes/cllts be refilled. However, no guidelines have been 

given as to how th is should be completed. The foll owing procedures 

have therefore been recommended: 

Holes of a Diameter < 25 mm 

The hol es should be fi ll ed with grey paintable single-component 

polyurethane grouting or equivalent cement mortar, 

The holes should be completely fi lled using a tube connected to a

grouting gun pushed all the way to the bottom of the hol e. As the 

hol e fill s up the tube is gradually removed. 

Holes resulting from Core Drilling or larger Chiselled Cuts 

Dust and loose particles should be cleaned out with water after 

which any water remaining should be dried up . The mortar to be 

used for the repair(s) should be mixed to the required consistency 

and put in the ho le(s) to 2·3cm below the surface level. Once the 

mortar has set the remainder of the hole should be fill ed with mar· 

tar flush with the surface. Immediately thereafter a layer of thick 

elastic cement-based coating should be applied to the surface. 

Mortar used to repair holes resulting from core dri ll ing or larger 

chiselled cuts should satisfy the same requirements for mortar 

used during mechanical repairs. 

Purpose 

Procedures 

7.3. 1 Locating the Reinforcement - Measuring 

its Cover 

To locate the reinforcement and measure its cover. 

Reference is made to the Nonvegian Public Roads Administrati on 

Handbook No. 015: "Tests carried out in the Field", Method 

No. 15.542. 

The description given in the procedural code of how cover is measured 

should be used to obtain accurate measurements. However, 

these can be simpl ified as follows if the measurements are more in 

the nature of a spot test: 

In the area where the cover is to be measured locate the load bearing 

reinforcement and the direction in which it is lyi ng. If possible 

the nearest mounting rod should also be located 

The cover is to be measured for a minimum of three rods in the 

outennost layer of the load bearing reinforcement. 

Measurements are to be taken at a point halfway between intersecting 

rods (see Figure 7.3- 1). 

x 

® 

x 

x 

o x 

, 

Me8wrernent poinllOl I~d l;JeR ri~ reinloroem ent 

Outermost layer 

of load bearing 

reinfor(lement 

>,·-1 . Intersecting Rods: ,....,. , 

• I 

Itw! nf!'xt outermo!ll 

layer of load bc.aIing ~. 

Mounting fl od 

, 

.., 

. . . 

" . ,~~ . 

, ' 

,... ...... 

...... 

., 

' ~,'\ ~ ....... , 

. , 

. . , 

" •• II' .\, • 

",. 

MeR!2IurerTlPrnt point tm mountin9 Rnds Figure 7. 3-1 Defil1ition a/takil1g a Cover MC(Jsuremelll by Spot Testing 

The cover for possibl e new mounting rods has to be measured at 

least one point.

A report should be made of the cover measurements incorporating 

the three values obtained for the load bearing reinforcements 

together with the average of these. An additional report should be 

given for the mounting rod cover. 

scope 

General 

Taking measurements of the cover can be relevant in the fol lowing 

situations: 

It is likely that the cover is less than Ihal described, e.g. on the 

underside of the bridge deck, and areas with reinforcement guides 

or h a lf~ lap joints. 

Neither reinforcement spacers nor mounting rods have been used. 

Clearly corroding reinforcement with little cover ava ilable. 

Large amount of stress due to chloride. 

Places where other materials investigations are being carried out. 

Figure 7.3-2: Measurillg the COI'cr 


The cover of all concrete elements should be checked if this has 

not already been done during the construction phase. For small 

bridges such as culverts and single-span simply supported bridges 

at least ten measurements should be taken of the cover spread over 

both Ihe super and substructures. For larger bridges the scope of 

testing should be evaluated, but should lie between 5 and 10 measurements 

per 100 square metres of concrete. 


If it is suspected that there is little cover, spot checks should be 

conducted of the cover. Should these suspicions be confinned, 

then the scope of the inspections can be extended. 

Special Inspections 

Measurement of the cover is 10 be carried oul in accordance with 

specifi c requirements. The scope and location should be adapted 

to the situation. 

Equipment 

Advantages and 

Disadvantages 

* Covermeter 

* Drawings of the reinforcement, if necessary 

* Folding rule 

* Sl ide calliper 

* Chalk 

* Hammer aclion drill for use in measurementlesting 

* Materials and equipment for refilling holes 

This is a simple, n o n~d estructive, speedy method which allows 

one 10 chec k large areas in a short lime. The di sadvantage is that 

some cover meters indicate an incorrect cover thickness for closely 

spaced reinforcement. Cover meters should therefore be ca libra~ 

ted according to the density of the reinforcement.

7.3.2 Measuring the Depth of Carbonation 

Purpose 

To measure the depth of carbonisation in concrete in order to 

assess the risk of corrosion of tile reinforcement or to discover the 

cause of the damage. 

Carbonisation wi ll 1ead to corrosion of the reinforcement once the 

carbonisation has reached the actual re inforcement elements. 

Carbonisation in concrete progresses most quickl y in a dry climate 

(inland areas) and/or in areas subject to road traffic or ind ustri al 

pollution. 

Figure 7.3-3: Carbonised COllcrete 

Carboni sation is nol usually a problem in good qua lity concrete 

and when the cover is described as being 30 mm or morc and has 

been so applied. 

Procedures 

Reference is made to the NOf\vegian Public Roads Administration 

Handbook No. 0 15: "On Site Testing", Method No. 15.554. 

scope 

General 

Measuring the depth o f carboni sat ion can be necessary in the fo l 

lowing cases: 

* Bridges built during or immedi ately after the Second World War 

* Older girder bridges ut ili sing unstressed reinforcement and clo 

sely spaced reinforcement guides on the underside of the beams; 

these may also have been cast in concrete without stone ele 

ments. 

* Sections with little cover (I 0-30 mm) 

* Sections showing clearly corroded reinforcement 

* Sections containing porous or bad quality cement 

* When cutting out pieces of concrete or making chl oride profil es 


Measuring the depth of carbonisation is not necessary in this case.

Major Inspections 

Whenever carbonisati on is suspected as a problem, spot tests 

should be undertaken over a sufficientl y large area so as to be abl e 

to conclude whether carbonisation is/is not a problem for the bridge 

in question. Should these suspicions be confirmed then the 

scope of the testing can be en larged. In add ition measurements 

should be taken of the cover (compare Chapter 7.3.1 for the recor· 

ding of the extent of the earbonisation). As an alternative a special 

inspection can be requisitioned. 


The depth of the carbon isation is to be measured in accordance 

with special instructions. The extent and location should be adap· 

ted to during execution of the inspection. 


Disadvantages 

Eq uipment 

The method is quite simple but req uires cutting or dri ll ing of the 

structure. 

• A I % solution of phenolphthalein, or possibly I gm. phenol ph 

tha lein in all. mixture of water (50%) and ethanol (50%). 

• Spray bottle 

• Fold ing n ile 

• Slidingcall iper 

• Hammer 

• Chi se l 

• Pure water 

• Material and equipment for refi lling holes 

• Core drilling equipment, ifnecessary 

7.3.3 Measuring Chloride Content 

Pu rpose 

To measure the chloride content of hardened concrete at various 

depths so as to evaluate the risk of corrosion of the reinforcement 

or 10 uncover the cause of damage. 

The penetration of chloride wil l cause corrosion of the re inforcement 

in the event of the chloride concentration becoming too hi gh. 

The limit for critical chloride content, namely a level wh ich can 

lead to corrosion of the reinforcement, was earl ier assumed to be 

around 0.06% of the weight of the concrete (0.4% of the weight of 

the cement). However, ex perience gained fro m the bridges mana· 

ged by the Public Roads Admini stration indicates that the chloride 

content can be much higher without the occurrence of damaging 

corrosion of the reinforcement. 

The following circumstances are of significance for the speed of 

corrosion and must be considered in conj unction with the recorded 

chl oride content:

* The density of the concrete in relationship to the transfer of oxy 

gen (quality of the concrete, thickness of the cover). 

* The electrochemical properties of the concrete (variation in its 

qual ity, high mo isture content, possible presence of macro 

cells). 

Chl oride can penetrate concrete via three different sources: 

* Embedded chloride 

* Defrosting sa lt 

* Mari ne climate 

Embedded Chloride 

This can be found in older bridges due to the lise of sea water 

during construction, or aggregate or setting agent containing chloride. 

The use of sea water and aggregate dredged from the sea 

were previously acceptable and can still be found in several older 

coastal bridges. 

Calcium chloride (CaCI) is used as a setting agent especially by 

the concrete casting industry to allow casts to be speedily released 

for reuse. Elements so cast can be found, for example, on the 

underside of bridge decks supported on steel plates where the brid· 

ge deck is partially prefabricated. 

Embedded chloride produces a flat chloride profile deep within 

concrete. The chloride profile can be overlaid by chloride which 

has penetrated from outside the concrete. A further effect of carbo· 

ni sation wi ll be a reduction in the concrete's ability to bind the 

chlorides. Consequently the chloride profi le achieves a low value 

in carbonised concrete or in crushed stone with a hi gher concentra· 

tion at the leading edge of the carbonisation process before the 

concentration flattens out to the embedded level. (Refer to Figure 

7.3-4)

Carbonation Depth 

OL-________ L-~~------------~ 

o 

Depth 

'Figure 7.3-4:Chloride Pl'Oji/c.embeddefJ chlol'ide ill C(ll'bollisetl COl/crete 

Defrosting salt 

Chloride resulting from defrosting salt or sand mixed w ith salt is 

able to penetrate the bridge deck fro m the topside if tl1-e bridge has 

not been equipped with a damp course. The fo llowing ca n be considered 

as vulnerable areas: 

* Edge girders and the underside of bridge decks along a bridge's 

edges 

* Joint constructions 

* Pillars supporting approach sections to a bridge 

* Abutment piers and cul vert walls situated 0 - 2 m. from a bridge 

* Localised areas under water outl ets and otherwise in depressi 

ons where waler is stagnant . 

Marine Climates 

Vu lnerable sections of coastal concrete bridges are described in 

Chapter 7.3.9. 

Procedures 

Reference is made to the Norwegian Public Roads Administration 

Handbook No. 0 14: " Laboratory Testing" and No. 015: "On Site 

Testing". 

The diffe rences in depth of the measurements and the intervals 

between test sites in a profile must be estimated in light of the 

positioning of the reinforcement and the objective oft he test. In 

some cases the intelVals detai led in Procedura l Codc-2 can appear 

to be a little rough. The alternative depth intervals for 30 mm. and 

50 mm. respectively for a pl anned cover could for example be: 

30 mm planned cover: 

50 mm planned cover: 

2-10 mm ., 10-20 mm. , 20-30 mm., 30-45 mm., 45-70 mm. 

2-15 mm., IS-3D mm., 30-50 mm., 50-75 mm. , 75- 100 mm.

Any dust should be extracted using an 18 mm. dri ll from four test 

hol es per test. The holes should form the corners of a 5X5 em . 

Square. 

Methods 

Figure 7.3-5. Drilling 0111 Cemelll 

Dlis/ 

Equipment 

Figure 7.3-6: RCT Allalysis Case 

Scope 

The choice of method of analysing concrete dust - on site or in a 

laboratory - depends fi rst and foremost on how much accuracy is 

required and on the costs. 

On Site Methods 

The most common methods are RCT (Rapid Chloride Test) and 

Quantab. Reference is made to the National Public Roads 

Administration Handbook No. 015: "On Site Testing", Methods 

15.552 and 15.553. These methods are less precise than those used 

in a laboratory, but in most cases they will be sufficiently accurate 

provided they are checked aga inst reference dust or laboratol)' 

methods. 

* Equipment fo r test extrac tions (hammer effect drill) 

* Plastic bags fo r collecting the dust in 

* Felt-tip pens for marking the tests 

* Material and eq uipment for refi lling the holes 

* Equipment for analysis purposes (on site kit) 

* Scales with an accuracy of III 0 grams 

* Dust for reference purposes 

Laboratory Methods 

The most common laboratory methods are potentiometric titration 

and Vo lhardt's Method. Laboratory methods must be used whenever 

the results of the analyses have to be very precise. 

The analysis methods are described in the National Pub lic Roads 

Administration Handbook No. 014: "Laboratory Testing", whil st 

Volhardt's Method is described in NS 3671. 


So far as large new coastal bridges are concerned routines require 

to be established in connection with taking chloride measurements 

from selected construction elements. Any incursions of chl oride 

should be followed up with repeated measurements during future 

main inspections. 

Otherwise, measurements of the chl oride content are not taken 

during completion inspections. 

Major Inspections 

If embedded chloride is suspected, for example, because of the 

visible results of corrosion, peeling and corroded reinforcement on 

the surface concrete, measurements should be taken of the chloride 

content.

For roads subject to salti ng spot checks of the chloride content 

should be taken in exposed areas such as pi llars supporting the 

approach sections to a bridge and the edge girders of bridges along 

the route. This is most va lid for bridges constructed according to 

older regulations, namely before 1996/97. 

Repeated chloride content measurements ought to be taken during 

each main inspection at approximately the same locations as a fol 

low-up over time. Measures can accordingly be taken timeously 

should the need arise. 

For new large coastal bridges inspection routines should be fo llowed 

or establi shed if necessary. 

Spot tests should be carried out on older bridges which have not 

previously been chec ked for chloride incursion. The need for a 

special inspection incorporating more extensive materials tests 

should be assessed. 

Measurements of the covering and the depth of any carbonisation 

should be undertaken at the sa me time as any dri lling for dust in 

connection with chloride tests. Alternatively a special inspection 

can be carri ed out including comprehensive materials testing and, 

if necessary, EC P measurements. 


Chloride measurements are carri ed out according to special prescriptions. 

Their extent and location should be taken into during 

execution of the test. 

Ad vantages and 

Disadvantages 

On site testing is cheap and easy to carry Oul but are less accurate 

than laboratory methods. Analyses conducted in a laboratory are 

time-consuming and costly but result in a high level of accurac 

7.3.4 Corrosion Testing (ECP) 

To measure the reinforcement's electrochemical potential (ECP) 

and associated resistance in order to assess the probability of the 

reinforcement co rroding. 

Procedures 

Reference is made to the National Publ ic Roads Administration 

Handbook No. 0 15: "On Site Testing", Method NO. 15.552 and the 

National Pub lic Roads Administration, Bridge Division's Report 

No. 94- 16 Bridges: 

"Recommendations for the Equipment for Measuring 

Electrochemical Potential (ECP)". 

General 

Scope 

ECP measurements should be taken if latent rein forcement corrosion 

is suspected.

Completion Surveys & Major Inspections 

ECP measurements are not normally taken in these instances. The 

need for such tests during a main inspection will be init iallyassessed 

on the basis of visual observati ons and the resul ts of the tests 

both of the depth of carbonisation and the chloride c ontent. 


EC P measurements should be conducted as per special instructions 

and should be verified by cutti ng into the concrete. Refer to 

Chapter 7.3.8. The chloride content, depth of carbonising and 

cover should all be measured at the place where the concrete is cut 

inlo. 


Disadvantages 

• 

FigWl? 7.3-7: Takil/g ECP 

AI eusu rem e illS 

Equipment 

Figure 7.3-8: Drillil/g Ollt (I 

Concrete Core 

Methods 

This method is easy to use, non-destructive and rel"tively quick 

with the resu lt that large secti ons can be checked. It can provide a 

satisfactory picture of the cond ition of the reinforce ment at any 

given moment. The risk of corrosion can be detectetd during an 

earl ier phase before visible damage becomes obvious. People possessing 

professional competence should be used both for site work 

and the interpretation of the results. The method does not record 

the speed of the corrosion process. 

ECP Equipment: 

• Metering electrodes 

• Voltmeter 

• Cables 

• Data recorder 

Other: 

• Spray bottle for moistening concrete 

• Device for measuring the cover 

• Clips for mak ing contact wilh the reinforcement 

• Chalk 

• Wire brush 

7.3.5 Determining the level of Strength 

To detennine the compressive strength of hardened concrete 

should, for example, below standard concrete be suspected. 

Compressive strength can be determined by, amongst other things: 

• Pressure testing of concrete cores dri lled out 

• Jackhammer 

Pressure testing of concrete cores drilled 0 ut 

Procedures 


Di sadvantages 

Reference is made to the Norwegian Public Roads Admini stration 

Handbook No. 015: "On Site Testing" for the drilliog Oul of concrete 

cores, and to the Nat ional Public Roads Administration 

Handbook No. 014: " Laboratory Test ing" fo r pressure testing the 

concrete cores. 

This methods produces precise pressure test val ues for the cores in 

question, but does req uire expensive equipment and is to be consi-

dered time consuming. This is a destructive method; one has to 

take care du ring the dri ll ing process so as to avoid damaging the 

reinforcement. Core dril ling in pre-stressed concrete bridge elements 

should be carried out only in special situations. 

Equipment 

* Core drilling equipment 

* Materials and equipment fo r refilling the hol es 

* Pressure testing device 

Rebound Hammer 

Procedures 


Handbook No. 0 15: "On Site Testing", Method No. 15.544. 

Figure 7,3-9: Measurillg the 

Compressive Strength o/ Col/crete 

!lsillg a Rebowui flammer 

Equipment 

This is an extremely speedy, simple and cheap method. However, 

the test results are very inaccurate because of a great deal ofuncertainty 

about them. Nevertheless the results can be used to obtain a 

picture of how the compressive strength can vary in different ele-. 

ments. Values can be obtained only for a concrete surface. 

* Schmidt hammer or pendulum hammer 

General 

Scope 

The strength level of concrete is rarely lower than that used as a 

basis at the design stage. Generally speaking the need for compressive 

strength testi ng does not arise during routine inspections. 

Acceptance Inspections and Major Inspections 

Determining compressive strength is not usual ly carried out. 


Determining compressive strength may be necessary should the 

load bearing capacity be too low, and verification of the actual 

strength can benefit the calculati ons. 

Purpose 

Procedures 

7.3.6 Structural Analysis 

To determine the structure of the concrete by analysi ng the results 

of Plane Ractify ing and/or of Thin Section Method to discover 

amongst other things the reason for any damage, e.g. alka li reactive 

aggregate. 

Concrete structures will be analysed using surface gri nding or fine 

grinding depending on the purpose of the analysis. Both types of 

anal ysis are carried out in a laboratory on drilled out cores. 

Plane Ractifying 

A concrete core is sawn along its central axis, burnished and surface 

treated. Surface grinding providcs the following information: 

* The \VIc ratio

• Homogeneity of the binding agent 

* Distribu tion of the aggregate (quality) 

• Air content Idi stance between air bobbles? (durabil ity aga inst 

frost) 

• Cracking 

Thin Section Analysis 

A piece of fin e ground concrete nonnally measures 40 x 45 mm. 

and is ground down to a th ickness of20-25 my. Apart from that 

obtained from surface grinding, fin e grinding provides the fo llowing 

addit ional information: 

• Carbonisation 

• Leve l of hydration (q ualitative) 

* Type of aggregate 

• Chemical reactions such as reaction to alkali 

Scope 


Structural analyses sha ll not be carried. 

Speciallnpections 

Structural analyses are carried out only when required, e.g. suspected 

reaction to alkali. 


Disadvantages 

Plane Ract ifying and th in section analysis are both good methods 

for detennining concrete qua lity but are destructive, costly and 

time consuming. They should only be considered if the possible 

damage and its causes cannot be detennined using any other method 

or when it is important to know the composition of the concrete. 

Since only a small part of a structure is examined, it is vital that 

representative dri ll ed cores are removed for analysis and that 

wide-ranging conclusions arc not drawn from the analysis resu lts. 

Figure 7.3-10: Analysis IIsing Thin Sec/ioll Me/hod 

Equipment 

• Core drilling equipment 

• Laboratory analysis equipment

Purpose 

Procedures 

7.3.7 Inspection of Prestressed Tendons 

To conduct an inspection of the condition of pre-tensioned and 

post-tensioned cabl es anchored in concrete. Checking pre-tensioned 

cables may be worthwhile if defective injection is suspected, 

as this can have very serious consequences for the bridge's load 

bearing capacity. 

Checking post-tensioned cables is difficu lt and should only be carried 

out by a specialist company using special equipment, and then 

only after consulting the bridge's designers. 

Ultrasound, X-rays or a fibre optic endoscope can be used to locate 

damage. The use of a fibre optic endoscope requires holes to be 

drilled in the cable tubes. One should, therefore, have a clear 

understanding of where the cavities and the damage arc located, as 

drilling incorrectly and damaging a tension cabl e can have serious 

consequences. 

Scope 


Tension cables are not normally checked. 


A tension cable check wi ll be undertaken as required, fo r example 

when badly executed injection of the cable tubes is suspected. 

Fig1lrc 7.3-/1 

Fib.·c Optic Testiflg 

of a Tel/siollcd Cable 


Disadvantages 

Equipment 

Purpose 

A good overview can be obtained of the conditions inside a cable 

tube, but the method is destructive and it is all too easy to hit the 

cable tube or the cavit ies. In addition there is a risk of damaging 

the cable itself. 

To be decided for each specific occasion. 

7.3.8 Cutting open the Concrete to Assess the 

Corrosion level 

To carry out a visual check of the level of corrosion in the reinforcement 

and to record the type of reinforcement and its diameter. 

Additional ly, the cover should be measured.

Procedures 

In most cases it is sufficient for the width of the area to be cut to 

match the dimensions of the re inforcement and the cover sllch that 

the minimum width equals the cover plus the diameter of the reinforcement 

(0 + d). Refer to Figure 7.3- 12. Approximately 1/3 to Y2 

of the reinforcement element's circumference s hou~d be bared for 

atleasl 0.3 cm. 

.r 

minimum 

O+d 

.r 

.- 

:T- 

O 

:Ty 

d r 

Figllre 7.3-/2: Recommended Breadll! & Deplh oflhe CIIII/llc ision 

The degree of rusting in the reinforcement wi ll be assessed usi ng 

the fo llowing scale: 

Level A: No damage. Dull grey coating on the rein forcement ele 

ment. 

Level B: The first small traces ofrus! can be seen. Assess whether 

these date from the bridge's construction period. 

Level C: Even distribution of surface rust. 

Level D: Severely peeling surface rust as we ll as clear cross-secti 

onal reduction in size. 

Level E: Corrosive pi tting. 

The degrees of rust ing are illustrated in Figures 7.3-13 to 7.3-17. 

Figllre 7.3-/3: Example ofRusl Level A

Figl/Ye 7.3-14: Example 0/ Rilsi lel'ef B 

Figllre 7.3-15: £wmp/e 0/ RIiSf Lel'ef C 

Figllre 7.3-16: bump/eo/Rllsf Lel,e/ D

Figure 7.3-17 E.wmpleQJRlIsl Level £ 

Cutting open the concrete reveals the actual level of corrosion to 

the reinforcement and acts as a check for the resu lts of other materials 

testing. The method is destructive and ought only to be 

employed to a very limited ex tent. It shoul d be noted that the area 

to be cut open is not necessarily representative of an entire bridge. 

Acceptance Inspections & Major Inspections 

Cutting open concrete fo r corrosion assessment purposes is not 

usually undertaken. However, it can be worthwhi le in the assessment 

of any cross-secti onal reduction in the reinforcement when 

there is visible evidence of corrosion. 


tain ing latent corrosion. In these cases areas with cl ear evidence of 

corrosion should not be cut open. 

Should noth ing else specifica lly be mentioned, then cutting operations 

should be undertaken for consecutive areas measured for 

potentiality for the following locations: 

* The lowest measure of potentiality 

* The middle measure of potentiality 

* The highest measure of potentiality 

When cutting into concrete to veri fy ECP measurements the fo llowing 

materials tests should be undertaken in the order given: 

I. ECP measurements (recording the potential and resistance 

levels) 

2. Measuring concrete cover 

3. Measurin g the ch loride content from layers adj usted for the 

cover measured such that the chloride level is measured in each 

or the layers. 

4. Cutting operati ons and evaluating the level o f rust and the 

reduct ion in the cross-section. 

5. Measuring the depth of ca rbonisation

6. Measuring the actual cover to check the cover meter 

7. Re-filling 

Cutting into concrete can also be carried out in connection with the 

assessment of the scope of corrosion to the rei nforcement elements. 

Barriers should also be cut open to assess the reduction in 

cross-sectional reduction of the reinforcement. Areas showing 

visible signs of surface corrosion of the concrete should be approached 

in a similar fashion. This is especiall y desirable for 

barrierslthe results of corrosion which are found in areas prone to 

static strain. 

Equipment 

* Cutting equipment (chisel hammer) 

* Camera 

* Slidc callipcr 

* Magnifying glass 

* Wire brush 

* Materials and equipment for refilling holes 

7.3.9 Location of Materials Testing for 

Concrete Coastal Bridges 

Chloride Penetration 

It has become apparent that chloride penetration on exposed coastal 

bridges is characterised principal ly by three sets of circumstances: 

I. Height above Sea Level: Chloride penetration increases 

according to the he igh t of the superstructure above sea level 

refer to Figures 7.3- 18 and 7.3- 19. The same applies to co lumns 

(see Figure 7.3-20). However, in some instances the chloride 

contem has been shown to be lower further down the columns 

than nearer the top. 

2. The Windward/Leeward Effect: Chl oride penetration is mar 

kely greater on surfaces subject to wind and rainfa ll on the lee 

ward side. The effects can depend on their being/not being sub 

ject to rain and negative pressure on the leeward side resu lting 

in sea spray settling on the concrete surfaces - refer to Figures 

7.3-18and 7.3-19. 

Leeward facing surfaces are to be found on both the sub and superstructures. 

The following are some typ ical examples: 

* Vertical surfaces in the lee of wi nd and ra infall (columns, webs 

in box gi rders and beams. 

* Horizo ntal downward fac ing surfaces - the undemeath of top 

cross-beams, beams, top plates and wings, and base plates of 

box girder bridges.

" 

~ 

~ 

~ 

• 

E 

E 

u 

B 

~ 

~ 

u 

'" 

~ 

0 

• 

... 

0 

-. 

g~ 

";: ...J 

 

"Qj ..8 

~ . 

~ 

,. 

'" 

'. 

,. .' 

~ 

... .. .. ,.. " 

- 

~ 

~ 'OO 

;" . . 

.. - 

~\..-~,,'"' 

.' 

, 

, 

, 

, .. 

'" 

.. , . • 

CD , 

BeJow Bo~ Girder 

."~ Wall 

.......... 

Figure 7.3-18: Average Chloride Content in the Box Girders. Gimsoyslruwllen 

Bridgeal a Depth 0[0- /0 mm. 

""""\ 

=:c..::::::::c= 

-'---- --o:c;;::::::::= 

"~[ ~KS! ~ . 1'1.11' 

____ I.. South O))'lIO ~ ':; 

Dominant Wind 

DirectiOf1 during 

Precipitation 022'11. s'7 6 

--''---~-+ 

North 

.- 

ktr116 

1 

::--:-_.".~ South 0119'1' 

Dominant Wind 

Direction during 

Presipilalion 

North 

::--,.-,,,,,I~ South 

Dominant Wind 

Direction during 

Precipitation 

Ao(SE 

'] • 74m • 

" 

" 

'66% 

North 

Chloride conlent as % of cement weight for depths (}'1 0 mm 

Figure 7.3- 19: Varia/ioll a/Chloride Con/enl of Box Girders according to 

Height above Sell-fel'el.

t I e 

---::--._.- . -. 

._'_.. ! 

Figure 7.1-10: V(lrimioll ill Chloride COl1lel1l OfCO/III11I1S accQrding 10 Height 

above Sea-/e~·e1-Gil/lsoystraulllen Bridge 

3. Geometric Effects: Exposure is greater on large cross-sections 

and badly geometrically shaped cross-sections - see Figure 7.3- 

18. 

In addition, local circumstances can exist related to the terrain 

around the bridge or to the sea bed around the columns and which 

can also affect chloride impact (skerries and foundations produce a 

lot of spray). 

All of these factors produce simultaneous effects and a joint chloride 

impact pattern. 

The following contains a rough overview of those sub and superstructural 

surfaces most and least exposed to chlorides. 

Surfaces most exposed 

to Chloride Penetration 

Surfaces least exposed 

to Ch loride Penetration 

Substructure 

Large cross-sections of the leeward side of columns between 0 and 

20 metres above the surface oflhc water, e.g. the ma in columns of 

cantilever bridges; also the underneath of top cross-beams near the 

surface of the water. 

The windward sides of thin columns with a high elevation above 

sea-level.

Superstructure 

Surfaces most exposed 

t o Chloride Penetration 

Surfaces least exposed 

to Chloride Pene tratio n 

Chloride and Mo isture 

Combination of 

Materia ls Testing 

Leeward facing surfaces low down and near the water surface, 

especially large cross·sections, for example pil lars of Cantil ever 

Bridges;also the underneath of bottom plates, cross girders and 

beams. 

The windward sides of sl im superstructures with a hi gh elevation 

above sea· level. 

Concrete surfaces containing a high level of chloride will retain 

moisture longer during the drying out process and will consequently 

be of a darker shade than surfaces with a low salt content. 

It is therefore possible in a damp coastal cl imate to see with the 

naked eye which surfaces have most been affected by chloride. 

Surfaces greatly subject to wind and rain (on the windward side) 

will gradually acquire a sandy appearance because the top surface 

layer of the concrete will have been washed away. 

When deciding the places to undertake materials testing one 

should make use of this knowledge of chloride instigated stress. 

It is important to carry out several kinds of materials testing, e.g. 

surface cover measurements, chloride analyses, ECP measurements, 

cutting open the concrete, in such a way that these can be 

compared wi th one another before the condition of the concrete is 

decided on. Materials testing should also be viewed in relationship 

to any visual inspections undertaken. 

in order 10 be able to compare the result's of materials testing such 

as surface cover and ECP measurements, measuring the chloride 

content and the depth of carbonisation, and cutting open the concrete, 

they must all be carried out at the same places. Refer to 

Chapter 8.5 for a presentation of materials testing for concrete. 


Testing - Steel 

In the following section a description wi ll be given of the possible 

materials testing for use in inspections of bridge sib ridge elements 

made of steel. 

Purpose 

Procedures 

7.4.1 Checking the Torque of Screws 

To check the stud torque of screws in friction joints. 

Checking the torque of screws may be necessary in connection 

with acceptance inspections if this has not already been carried out 

during the construction phase. Reference is made to the National 

Public Roads Admini stration Manual No. ISO: 'Bridges - Safety 

and Technical Standards', Point NO.7.

This check may also prove necessary during Special Inspections 

should there be any suspicion of screws having lost theirorigina l 

tension. 

Equipment 

• Torque wrench 

Purpose 

Procedures 

Equipment 

7.4.2 Checking Rivets and Screws 

To check whether rivets and/or screws are loose or have possibly 

dropped out of place. 

Loose screws or ri vets can cause cracks to appear in the surface 

treatment at the cross-over point between screw/rivet head and the 

basic material. By lightl y tapping on one side oflherivet wi th a 

hammer whi le placing one's finger on the opposite side of the ri vet 

at the cross-over point one can feel whether the ri vet is loose. 

• Magnifying glass 

• Torch 

• Hammer 

Figure 7.4-/: Checking a RiI'el 

Equipment 

Purpose 

Procedures 

Equi pment/Competence 

7.4.3 Checking Welds 

To carry out visual check for fau lts in the welding or whether 

damage has been caused to the welding. 

If material defects are suspected, X-ray or ultrasound checks 

should be carried out in addition - see points 7.4.4 and 7.4.5. 

• Magni fy ingglass 

• Torch 

• Tool for measuring the width of cracks 

7.4.4 X-ray Check 

To carry out X-ray inspections of welds and other steel elements to 

check for material defects. 

The X-ray fi lm should be used to document the results. 

The inspection should be undertaken by a pe rson with the relevant 

training and the necessary speciali st equipment. 

Purpose 

Procedures 

7.4.5 Ultrasound Check 

To ascertain with the use of ultrasound equipment whether there 

are material defects in welds, or cracks in screws or ri vets. 

Reference is made to Procedure No. 87. 1835 

The measurements should be taken using a test sensor whi ch transmits 

and receives ultrasound waves which actually work on a frequency 

beyond the that of human hearing (approx. 16,000 Hz).

The sound waves can be transmitted into solid materials, but not 

air. The test sensor should be placed on the surface; the sound 

waves are then bounced off the reverse surface oflhe test area. 

The results are recorded via an oscilloscope, and their interpretation 

places great demands on the operator. This person should possess 

the necessary qualifications and ex perience for recording and 

interpreting the results. 

X-ray and ultrasound tests complement each other. Ultrasound testing 

is the preferred method for checking for faults in bonding 

materials and certain types of cracks. 

Eq u i p me ntl Com pete nce 

Purpose 

Procedures 

Purpose 

Procedures 

E qu i p mentl Com petence 

These checks should be carried out by companies with properly 

trained personnel and special equipment. 

7.4.6 Magnetic Powder Check 

To check for the presence of cracks in the steel which are not 

visibl e to the naked eye. 

The extent of the cracks should be documented by means of drawings 

or photographs. Both cracks all the way through the steel 

and on the surface are to be drawn as a record. This type of test 

does not provide any measurements of the depth of the cracks. 


trained personnel and special equipment. 

7.4.7 Fi bre Optics 

To check for the presence of damage, e.g. corrosion or cracks, in 

enclosed or not easily accessible steel elements with the use of a 

fibre-optic equipped endoscope. 


trained personnel and special equipment . 

Purpose 

Procedures 

Eq u i p m e ntl Com pete nce 

7.4.8 Ultrasound Measurement of Material 

Thickness 

To measure the thickness of steel parts when directl y taken measurements 

are not possible, for example when only one of the steel 

surfaces is accessible. This may be the case with corrugated steel 

pipes and piles. 

Reference is made to Procedure 87.1838 and Chapter 7 A.5. The 

possibl e results of corrosion on the reverse surface do not reflect 

ultrasound impulses. The effecti ve thickness wi ll therefore be 

measured. 


trained personnel and special equipment.


Investigation - Timber 

This chapter contains in formation about materials investigations 

which can be recommended for Ihe inspection of timb er bridges 

and bridge elements. 

Figure 7. 5-/: Measurillg Mois/ure 

Le l'e/s in Wood 

Purpose 

7.5.1 Investigation of the Humidity Level of 

Timber 

To measure the moisture content of timber elements. The moisture 

level recorded wi ll reveal, amongst other things, whether there is a 

danger of the existence of dry rot fun gus. This test will, however, 

be of usc only in special cases and only for load-bearing clements 

since an already high moisture level must be taken into account in 

limber bridges . 

• Electric moisture meter 

• Measurement electrodes 

Purpose 

7.5.2 Checking for Fungus and Rot - Timber 

To carry out analyses of timber in order 10 ascertain the type of 

fun gus wh ich has ca used the rot damage. These are worth consideri 

ng when the test area is large and any possible replacement of 

sections could have serious consequences. 

Procedures 

Equ ipment/Com petence 

Samples should be taken of any fungus visible and these are to be 

sent 10 a laboratory which conducts tests on fung i. 

A pi ece of wood core can also be extracted using a drill to obtain a 

picture of the timber's cross-section. The core removed should be 

of the smallest possible diameter so as to avoid weakelling the 

cross-section. The hole should be re-fi lled. 

Samples should be removed with a knife or other equipment for 

drill ing out core sections. The analyses should be conducted by a 

specially equipped laboratory with com petent personnel. 


Investigation - Stone 

In the fo llowing secti on a description is provided ofth e materials 

testing which can be used during inspections of stone bridges and 

bridge clements. 

Purpose 

7.6.1 Compressive Strength for Stone 

To ascertain the compressive strength of stone by press ure testing. 

This may be necessary when checking the load bearing capacity of 

slone bridges.

Procedures 

The compress ive strength of stone is ascertained by removing 

stone cores and subjecting these to pressure testi ng. Only stone 

which is representative and free from cracks and scratches should 

be used in core sampling. This method can also be em ployed to 

determine the modulus of elasticity of the stone. 

These tests should be carried out by suitably qualified people 

using specialist equipment and can be used during Special 

inspections. 

Equ ipme nt 

'" Core drilling equipment 

'" Pressure testing machine 

7.7 Adequate Checking of the 

Surface Treatment 

What fo llows is a description of the tests which can be carried out 

when inspecting the surface coating of concrete, steel or timber. 

These tests should primari ly used during Acceptance Inspections 

in the absence of any records indi cating they have al ready been 

conducted. Moreover, they should be executed during Special 

Inspections. 

A licensed Inspector should preferably be employed for special 

checks of the surface coating of steel, especially when extensive 

maintenance work is under consideration. 

Purpose 

Procedures 

Equipment 

7.7.1 Thickness of Surface Coating -Concrete 

To check that the thickness of the surface coating of the concrete is 

as prev iously described. 

The test can be conducted on already cut out sections whose thickness 

can be directly measured by use of, for example, an instrument 

ror measuring the width of cracks or a magni fying glass. 

Alternatively for concrete a sli ver of tile surface coating can be 

tested for thickness. 

'" Core drill ing equipment 

'" Measuring Gauge or a Magnify ing Glass 

Purpose 

7.7.2 Adhesive Bonding between Surface 

Coating and Concrete 

To measure the surface coating's bonding to the concrete using a 

stripping instrument. 


Manual No. 0 15: 'On Site Testing' ~ Method No. 15.541 .

Procedures 

Equipment 

Surface sections subjected to stripping shoul d be treated with a 

new coating. 

Equipment: 

'" Stripping equipment 

'" Sa mpl e bea kers 

'" Core drill 

'" Quick-sett ing gl ue 

'" Wire brush or ordinary brush 

Figure 7.7-1: Strippil1g Il1sll"IImellt 

Purpose 

Procedures 

Equipme nt 

7.7.3 Depth of Penetration of Water Repellent 

Impregnation 

To measure the depth of the penetration of water repeDent impregnation 

in concrete. 

The depth of penetration is measured by cutting out sa mple cores 

of a minimum diameter or60 mm, cutting them open, drying them 

at a temperature of 50 0 - 60 0 C and using water as an indicator. A 

test consists o f 3 cores, and the penetration depth is recorded for 

each of the 6 half cores using a magnifying glass for cracks. 

'" Core drill 

'" Measuring Gauge 

Purpose 

Procedures 

Equipme nt 

7.7.4 Thickness of Surface Coating of Steel 

To chec k that the thi ckness of the dri ed coating of paint or surface 

coating of steel is as previously described. 

Reference is made to the Norwegian Public Roads Admin istration 

Report No. 94-08 (Bridges): ' Maintenance of Anti-Co rrosion 

Coatings for Bridges' 

For Acceptance Inspections testing the thickness orthe surface 

coating should be carried out in accordance with the Norwegian 

Public Roads Administration Manual No. 150: ' Bridges - Safe ty 

and Techni cal Standards', Point NO.7 if this has not been done 

during the construction phase. Moreover, thi s test is suited to 

Special In spec tions. 

'" Electromagneti c thickness gauge 

'" Feeler gauge for ca libration purposes

Figllre 7.7-2: Thicklless ofSllrface Coalingo/Sleel 

7.7.5 Adhesive Bonding between Surface 

Coating and Steel 

Purpose 

Procedures 

Equipment 

To measure the surface coating's adhesive bonding to the steel 

using a stripping instrument. 

For Acceptance Inspections measuring the surface coating's adhesive 

bonding should be carried out in accordance with the 

Norwegian Public Roads Administration Manual No. 150: 

' Bridges - Safety and Technical Standards', Point No.7 if thi s has 

not been done during the construction phase. Moreover, this test is 

su ited to Special Inspections. 

The method is destructive and should not be used unnecessarily. 

Surface sections subjected to stripping should be treated with a 

new coating. 

'" Stripping instrument 

'" Round sheets of aluminium 

'" Magnet 

'" Quick-setting glue 

'" Sand paper 

'" Knife or simi lar 1001 

7.7.6 Other Checks - Surface Coating of Steel 

In addition to a visual check of the old surface coating for damage, 

the following checks may be worthwh il e in connection with 

Special Inspections before undertaking painting as part of the 

maintenance programme: 

Sectional Measurements 

lattice Section 

The thickness of the each layer of paint is measured as well as the 

number of coats and the th ickness of each coat (this presupposes 

the use of a different colour for each layer). 

This provides a measurement of the adhesive bonding to the bottom 

surface. This technique cannot be used on thermally applied 

coatings

Ability to Accept New 

Layers of Pa int 

Ana lysis o f o ld Pa int 

This should be checked with regard to old surface coatings and to 

the adhesive bond ing between old and new surface coatings. 

It can be advisable to anal yse samples of the old surface coatin g to 

ascertain its composition with some certainty. 

7.8 Readings from 

Instruments 

Instruments can be mounted on a bridge to follow the development 

ofa situation over a peri od of time. This will act as a suppl ement 

to visual checks, measurements and materials testi ng. In some 

instances instruments are installed to veri fy the stress levels 10 

which the bridge is subjected. The fo llowing are representati ve of 

the instruments which could be used: 

Instrume ntation 

* Reference electrodes 

* Equipment for measuri ng the speed of corrosion 

* Wind speed detector 

* Wave height detector 

* Resistant Wire Strain Gauge (on steel) 

* Vibrating Wire Strain Gauge (on concrete) 

The instruments can be read during main or special inspecti ons or 

separately if desired.

8 Reporting 

the Results of 


8.1 Acceptance Inspections - 

Warranty Inspections 

Acceptance Inspections and Warranty Inspections should preferably 

be printed on Bridge Management Systems inspection forms, 

since these have been designed to suit each individual bridge 

depending on the data in the BMS module for the structure. 

Irthe data for some bridges have not been recorded in the BMS, 

indi vidual reports require to be drawn lip, the contents of which 

can have the fo llowing stmcture: 

1. Summary containing an overview of any damage, faults or 

defects to be repaired. 

2. Description of the bridge and the system afloealing damage. 

3. Results of visual inspections. 

4. Results of the measurements and material testing. 

5. Assessment of the recorded damage, faults or defects. Indicate 

which of these require repair and whether some of them may be 

possible sources of future destructi ve developments. 

8.2 Routine Inspections 

The reports for all Routine Inspections should be printed on the BMS 

inspections fonns which have been designed to suit each individual 

bridge and type of in spection. 

The inspection fonns should be taken to inspections and then completed 

on site. The fo llowing routines can be of assistance. 

General Inspections require points I to 6 and 12 to be carried out. 

I. The Inspector should check whether there are missing or incom 

plete data with reference to bridge category, its position, type of 

stmcture or the equipment required to gain access. 

2. The name (initials) of the Inspector together with the date of the 

inspection should be completed on the form. 

3. The Inspector can record any general comments about the 

inspection. 

4. Experiences, events, specific damage or the such like can be 


ecorded under their own points should they be considered 

important for others in the future. 

5, Only those elements wh ich wi ll be checked during the actual 

inspection are to be mentioned on the inspection fonn. Elements 

located above the water level wi ll not be included in inspection 

fonns used for Ma in Inspections Under Water. Should the 

bridge incorporate elements other than those ind icated, these 

can subsequently be added to the fonn. Any fau lts or defects 

should be commented on so that they can be rect ifi ed by the 

next inspection. One should check that the elements have been 

recorded as us ing the correct material, have been allocated the 

correct type description and, ifneed be, axes. 

6. All elements included in an inspecti on shall be checked for pos 

sible damage which should then be described for each element 

with the use of damage designations. In each instance the degree 

and the consequences of the damage is to be assessed. I freIe 

vant, the damage can be illustrated by taking a photograph. 

7. Ifpossible, provide the cause(s) of the damage. 

8. Proposed maintenance measures and when these will be carried 

out must be described for all damage of level m 2. Procedure 

Nos. 87 and 88 in Norwegian Public Roads Admini stration 

Manual No. 026: ' Procedural Code - 2. 1997' \ .... ill be of assitance 

in describing these measures. 

9. Esti mates should be drawn up for each proposed pi ece of main 

tenance based on the extent of the damage and the unit cost. The 

extent of the damage, i.e. size and quantity, should be noted on 

the fonn during the in spection. 

10 The results of any measurements and materials testing should 

be presented as indicated in Chapter 8.4 'Measurements' and 

Chapter 8.5 'Materials Testing'. 

II. A Special In spection (see Chapter 6.7) is to be recommended if 

Routine Inspections uncover a great need for repairs or are not 

sufficient fo r determining the kind of damage, its consquences, 

extent or cause(s). A note should be made of the measure 

menls/materials testing to be undertaken, the degree to which 

this should be done and the localion(s). 

12. The results of the inspection should be recorded in BRUTUS 

International at the conclusion of the inspection. 

13. Ifrequired the inspection and maintenance plans may be adjusted. 

118 


After carrying out a major inspection of a larger bridge it could be 

advisable to produce an expanded report in which the inspection 

form represents just one part of the report. It should contain a more 

detailed description of any damage, the operational and maintenance 

measures and an estimate of the costs. The report can build 

on the relevant points suggested for drafting reports of Special 

Inspections - see Chapter 8.3 'Special Inspections '. 

8.3 Special Inspections 

As much as possible a Special Inspection should act as a good 

basis for choosing the correct maintenance strategy, describing the 

associated measures stating the scope, when they are to be carried 

out, and the costs. 

Thus it is important fo r the report to be given a struct ure and content 

which will form an unequivocal basis fo r prioritising and 

assessing the suggested measures. The fo llowing sec tion therefore 

provides suggestions as to the contents of a Special Report. In 

each individual case an assessment should be made of the points to 

be included and of how comprehensive each point is to be. When 

making use of external inspectors prior agreement SllOU ld be 

reached about the extent of the report itself. 

1. Summary 

2. Introduction 

* Summary of the scope of the investigation and t.he damage. 

* Specification of the cause(s) of the damage and the mechanisms 

leading up to it. 

* Required measures, descriptions thereof, time frame, and 

fi nancing. 

* Recommendations for fu rther work 

* Name of owner/principal 

* Bridge number and name 

* Name of the consultant 

* A description of the purpose of the inspection including refer 

ence to the particulars of any damage. 

* A description of the extent of the investigation together with 

which elements have been included. 

3. -Basic Dat a of the 

Bridge 

3.1 -Description of the 

Bridge/ Elements 

* Geographical posi tion of the bridge 

* Yea r of construction; possibly also the builder and the engineer 

ing consultant. 

* Bridge's design and principal geometric measurements. 

* Special elements 

* Materials em ployed 

* Design Loads and Service Loads 

The BRUTUS International's Bridge Card contains most of these 

data and can thus be used as an appendix to the report. 


3.2 - Accessible 

Documentation 

3.3 location System 

4. Descriptio n of 

Condition 

4.1 Introduction 

4.2 Visually Recorded Da ta 


4.4 Materials Testing 

Accessible documentation can be like: 

• Drawings 

• Descriptions 

• Calculations 

• Previous inspection reports 

- mention should be made of who undertook the inspection 

together with a highlighting of the main findings. 

• Documentation from the execution of the inspections like: 

- Special conditions surrounding the bridge's construction 

- Load conditions during the construction phase 

- Relevant infonnation given during construction meet 

ings, drawings etc. including speciali st infonnation rele 

van! in assessing the development of any damage. 

- Pi les records/minutes 

- Documentation concerning the surface treatment 

- Weather conditions during the construction period 

Steel: • Certi ficates for the materia ls used . 

• Documentation of the checks carried out 

on the welding. 

Concrete: • Composition 

• Conditions during casting process 

• Requirements fo r the hardening process 

w/c ratio 

• Type of cement and quantity used 

• Aggregates 

• Add itives 

• Type offormwork used 

• Description oflhe axis numbering system with reference to 

appended drawings. 

• Time oflhe inspection 

• Weather conditions 

• Access equipment 

• Brief description of the scope and execution of the inspection 

• Extent to which consultants were employed 

• Data recorded should be allocated to the relevant elements 

• Visuall y recorded data should be described with reference to 

annexed photographs and sketches 

• The level and consequence(s) of any damage should be assessed 

in accordance with the codes deta il ed in Chapter 5 - 

" Damage Evaluation Fundamentals" 

• One summary of the resu lts per type of measurement taken 

should be drawn up and included as an annexe. The summary 

should be edited after the location has been fix ed. 

• One summary of the results per type of materi als test undertaken 

should be drawn up and included as an annexe. The summary 

should be edi ted after the location has been fixed. 

120 


4.5 Statistical Background 

4.6 Submission of Reports 

to BRUTUS 

5. Damage Assessment and 

the Measures Re quired 

6. Description of the 

Measures to be taken a nd 

Main Costs 

7. Alternative Repair 

Strategies 

Appendices 

• The scope and results of any specially required calculations 

shou ld be described. 

• Any ass umptions used in the calculations should be given. 

• The results of any stati stical calcul at ions should be presented 

with the complete set of calculations included as an annexe. 

• This includes a full y completed BRUTUS inspection form. 

• The fOnTIS for any measurements or materials testing should 

also accompany the inspection fOnTI. 

• The scope and cause(s) of any damage together with the 

measures required to be taken should be assessed on the bas is of 

the data collected and the tests undertaken. 

• It is recommended that the li me required for any necessary 

repairs reflects the degree of damage. 

• The description should be di vided into secti ons corres ponding 

to the elements involved. 

• The grouping together of different types of damage requiring 

repair measures and their attendant degree and consequence(s) 

should be arranged according to the recommended time for car 

ry ing out the repairs. 

• [n accordance with Brutus International' s 

'Guidelines for the Management, Running and 

Maintenance of Bridges' alternative repair strategies must be 

presented on the basis of the description of the measu.res to be 

taken and their associated costs. 

• These strategies should incorporate costs 10 the road user and 

other possibl e costs 10 the community should these prove re le 

vant. 

• An assessment shou ld be drawn up of the existing remaining 

lifespan of the bridge, the lifespan after completing tbe repairs 

and the costs of demolishing/rebui lding the bridge. 

• (Net) present day va lues should be calculated fo r the di ffe rent 

strategies, discounted over 25 years using the prevailing rea l 

rates of interest. 

'" Grouping of the strategies 

A Small-sca le (and poss ibly detailed) drawings of the rele 

vant elements. 

B Measurements - refer to Chapter 8.4 for present.ation and 

results. 

C Material s Testing - refer to Chapter 8.5 for presentation 

and results. 

o Photographs accompanied by comments taken from visua l 

records. 

E Any necessary statistical analyses. 

F Any necessary drawings relating to the descripti_on(s) of 

the proposed repa irs. 



Forms have been developed in BRUTUS for recording the follow· 

ing measurements: 

* Levelling 

* Horizontal distances/di splacement 

A form for general use is avai lable for other measurements. 

The forms are based on Microsoft Excel spreadsheets linked to the 

BRUTUS International inspection module. The identity of a bridge 

is transferred directly from BRUTUS International when a new 

measuremenl fonn is drawn up. An already existing Excel form 

containing previous measurements should continue to be used 

for recording new measurements of the same type. 

Recording and Making 

Reports 

The foll owing data must be recorded and reported: 

* Date when measurements were taken 

* Which type of ins peel ions the measurements relate to 

* The intervals at which the measurements were taken, especially 

if this deviates from the inspection intervals 

* Those taking the measurements and, possibly, the person ulti 

mately responsible for them 

* Time/temperature/weather conditions. Additionally, for levelling 

the following factors should be included: 

measuring horizontal distances/displacement 

height of sag 

vertical distances 

headroom 

* Type of measuring equipment used 

* Other comments such as special weather conditions, deviations, 

and other infonnation which could be important for interpreting 

the results 

* Location on tbe bridge wbere the measurements were taken - see 

Chapter 2.4 " Location of Measurements". 

* Results of the measurements 

It may be worthwhile presenting the results of, fo r example, a 

Special Inspection in an extended report incorporating tables and 

visual di splays. After levelling has been carried out, profiles could 

be portrayed both lengthways and transversely; the results can be 

shown together with previolls measurements and even theoretical 

values. 

The results of measurements taken should be di scussed and 

assessed and will then fonn part of the process of establishing the 

degree of any damage, its consequences and cause(s). 

122 


8.5 Materials Testing 

As with measurements, BRUTUS International also contai ns 

specific Excel based fo rms fo r recording the results of the fo llowing 

materials testing: 

* Locating reinforcement elements/surface cover of concrete 

* Measuring the depth of carbonisation 

* Measuring chloride content 

A general fonn is ava il able for recording other types of materials 

test ing. 

The following data must be recorded and reported on: 

Recording and Making 

Reports 

* Date of the materials tests 

* Which type of inspection the materials testing is associated with 

* Those conduct ing the materials testing and, possibly, the person 

ultimately responsible for them 

* Temperature and weather conditions 

* Method(s) and eq uipment employed, possibly also making ref 

erence to Norwegian Pub lic Roads Administration Manuals 

Nos. 0 14:'Laboratory Testing ' and 0 15:'On Site Testing' 

* Remarks, for example concerning the surface treatment, devia 

tions and other in fonnation with special significance for assess 

ing the results 

* Location of the materials testing, e.g. which elemeot(s)/axis 

reference - see Chapter 2.4 ' Location System' 

* The results of materials testing 

Figure 8.5- 1 shows examples of the symbols which may be used to 

illustrate the different kinds o f tests in drawings and sketches. 

Symbols and Type of Testing 

® Test site (Bk, Kp, Kd, Oh) 

@ Photograph No.3 

r,;:;....., Area with a surface cover less than 10 mm 

'--'V 

Kd3 =5 In Test Area 3 the depth o f carboni sation is 5 mm 

Od2 The surface cover for Test Area 2 

Kp2 The chloride profile for Test Area 2 

Oh2 Material cut from Test Area 2 

Bk6 Core No.6 

Figure 8.5-1: Ewmples oflhe symbols which maybe IIsed 10 ilIlls/Y(I/e difJerel1l 

killds of tests 


The test sites of materials test ing co nducted during a Specia l 

Inspection should be collective ly illustrated in drawings or sketches 

as indicated in Figure 8.5-2. 

Numbering the Tests 

Presenting the Results 

The tests are to be numbe red fo r each element tested, e. g. for each 

column. So far as columns are co ncerned Test No I sho uld be th e 

one conducted lowest down the co lumn with the numbers all ocated 

in ascending order moving up each co lumn. 

If, fo r examp le, measuring the surface cover, the depth of carbonisatlon 

and the chloride content have all bee n conductedsimultaneously, 

then the results should be prese nted in a table in such a way 

that al l the results from each particular test site can be co mpared. 

The assumed cement content should be given in kg/m3 of concrete. 

The co nversion facto r for the chl oride content of co ncrete by 

weight to the chloride content of ce ment by weight shoul d also be 

indicated. In the foll owing calculation the specific weight of the 

concrete is taken as 23 00 kg/m3 

Altiluoa -k. + I 0,0 

J 

0 4 .1"'1 

I 

o 2·IOd/KI>'OhJ 

® 

~ 3 

2 

.l0.]:; r 

1.(0d/Kp) 

0 

3 

,.on 

4 

,, 117S l 

> . 

Su~No.4 

Surtace No.3 (West) 

• 

(South) 

~II _ '"_No.' 

.. (North) 

Test 

" 

Assumed Volume of Cement XlCI kWm' 

Conversion Facto< 7.67 

Figure 8.5-2: Presenlalion ofTesl Areas & Resulls 

124 


Drilling cores 

In this instance an exception can be made concerning the nurn· 

bering system already mentioned above. Cores removed by 

drilling could, for example, be consecutive ly numbered for a 

whole bridge. The number should be fottowed by a further form 

of identification to show where the test was taken: 

Bk I (A3+ I 0): Core No. 1 taken from the superstructure al ong 

axis No.3 + 10 m. 

- 45 % 

-E 40 % 

35 % 

'" 30% 

:;; 25 % 

'" c: 

" => 

'" 

-0 20% 

" 0> 

'" 

15 % 

c: 10 % 

u 

-" 5% 

"- 

0 % 

Bk2(P5): 

Core No. 2 taken from Column (Pillar) No 

'4 Covering of Assembly 

~ Rods as described 

,---- I 

,---- :.- 

Covering of Static Reinforcement 

I 

, 

- 

as described 

.11. 

Interval for Surface Cover in mm 

Figllr€ 8. 5-3: Dis/ribll/ioll of/he SlIrface Cover 

Presentation of Chloride 

Profiles 

"" 

.l:! )'00 

• 

, 

h " 

• 

E 1.00 

0 

~ 1-'0 

u 

~ 1.00 

." 

"00 , 

'" 

"" 

], 1-'0 

~ 

, W> 

• 

8 1-'0 

" v 1.00 

• "" 

It is important thaI the resul ts of materials testing are presented in 

such a way that they are eas ily understood. The fo llowing shows 

examp les of how the results of ordinal)' materials testing of concrete 

were presented. 

Figure 8.5-3 shows the distribution of the surface cover of the reinforcement 

in the superstructure, Area I ofGimseystraumen Bridge 

in Norway. The distribution results are based on 2029 indi\' idual 

measurements. 

Figure 8.5 A illustrates examples of the presentation of chl oride 

profiles for Ihe central section of Area 1,5 metres from Axis No .2 

in the superstructure ofGimsoystraumen Bridge in Norway. 

potential readings (mV CS E) 

25 125 225 32S 425 525 625 725 825 925 

0, 12 - 135 -131 -140 -74 -21 -8 -32 -120 -101 

100: -83 -84 -84 -85 -71 -30 7 -68 -31 -III 

200 : -9' -114 -83 -58 -51 -2] -IS -34 -10 I -79 

300 : -75 - 158 -99 -68 -101 -100 -35 -68 -105 -87 

400: -4' -110 -75 -60 -42 -100 -32 -38 -92 -102 

500 : -130 -215 -163 -117 -119 -56 -23 -64 -75 -42 

600, -9 1 -209 -57 -97 -112 -112 -65 -71 -96 -77 

700 : -90 -170 -74 - 11 4 -71 -67 -60 -40 -67 -147 

800 : -134 - 182 -156 -114 -80 -33 -45 -44 -72 -47 

900 : -40 - 122 -121 -82 -43 -40 -45 -89 -88 -55 

a) Minorcritical colorcombination 

potent ial readings (mV CSE) 

25 125 225 32S 425 525 625 725 825 925 

0, 12 - 135 -1]1 -140 -74 -21 -, -32 - 120 -101 

100: -83 -84 -84 -85 -71 -30 

, 

-68 -31 -III 

200 : -9' -114 -83 -58 -51 -23 

-34 -10 I -79 

300 : -75 -158 -99 -68 -101 -100 -35 -68 -105 -87 

400: -4' -110 -75 -60 -42 -100 -32 -38 -92 -102 

500 : -I ]0 -215 -16] -117 -119 -56 -23 -64 -75 -42 

600, -91 -209 -57 -97 -112 -112 -65 -71 -96 -77 

700 : -90 - 170 -74 -1 14 -71 -67 -60 -40 -67 - 147 

800 : -I ]4 - 182 -156 - 11 4 -80 -33 -45 -44 -72 -47 

9o,,, -40 - 122 -121 -82 -43 -40 -45 -89 -88 -55 

b) Most possible colorcombination 

potent ial readings (mV CS E) 

25 125 225 325 425 525 625 725 825 925 

0, 1 ' -135 -131 -140 -74 ' 1 -, J:I -120 -101 

100: -83 -84 -84 -85 -71 ~() 7 -68 -31 -III 

200 : -9' -114 -83 -510: -51 -2J -IS 

-101 -79 

]00 : -75 -158 -99 -6, -101 -100 J5 -68 -105 -87 

400: -44 -110 -75 -60 -42 -100 12 -lK -92 -102 

500 : -I ]0 -215 -16] -117 -119 

-2] -64 -75 -42 

600 : -91 -209 ·57 -97 -112 -112 " -65 -71 -96 77 

700 : -9' -170 -74 -114 -71 -67 -60 40 -67 -147 

800 : -134 -182 -156 -114 -80 -33 -45 -44 -72 -4' 

90

ECP-Measurements 

For the presentation of potential readings (ECP) the 

drawings/sketches should clearly indicate where the measurement 

was taken for each element and the location of the earthing point. 

EC P readings should be interpreted in accordance with Report 

No.94-l 6 issued by the Norwegian Publ ic Roads Administration, 

Bridge Di vision: ' Recommendations for the Use of 

Electrochemical Equipment for Measuring Potential'. The in terpretati 

on should include, amongst other things, the requirement 

for three different versions according to co lour setti ng; 

Less cri tical colour setting than (b) 

Colour choice considered to be the best 

More critical colour setting than (b) 

Exampl es of the above are shown in Figure 8.5-5. 

8.6 Presentation of Damage 

Drawings and Sketches 

For the reporting of visual inspections drawings/sketches can be 

made showing the location and scope of the different kinds of 

damage which are in ev idence. This can prove to be an extensive, 

time consuming task and should only be undertaken in very special 

circumstances. 

One exception will be the presence of serious, special sc ratches 

and fissures which have to be photographed and/or drawn in on 

sketches stating thei r total, the distance from each other and their 

length. Both the maximum and average opening of these scratches 

and fissures should be indicated. 

The symbols which can be empl oyed in draw in gs for each Iype of 

damage are presented in Figure 8.6- 1. 

w • 

Casting j Oint 

Delam ination, spalling 

Po ro usa r bad qu a Ii ty co n crete 

_. 

0,2 m m ,2,O mm 

Cracking 

V isi b Iy co rrod ing rein fa ree · 

ment 



9 DAMAGE EVALU 

ATION CATALOGUE 

The detailed list of the different categories of damage is intended 

to assist in the assessment of the significance of any damage to 

individual bridges in ajustifiable and proper manner. 

Sub-chapters 

The list has been divided into Ihe fotlowing II sub-chapters which 

deal with types of damage to different materials and to the usual 

elements and accessories fou nd on a bridge. 

9. 1 Elements in or on Ihe Ground 

9.2 Concrete Elements 

9.3 Steel Elements 

9.4 Masonry Elements 

9.5 Timber Elements 

9.6 Wearing surfaces/insu lat ion against dampness 

9.7 Bearings with bearing shelflbearing shelf 

9.8 Joints/joint threshold 

9.9 Raili ngs & parapets 

9.10 Dra inage system 

9. 11 Other items of equipment 

Each of the above elements are in turn subdivided into the different 

types of damage - refer to Chapter 5.2 "Types of Damage". 

The following standard layout should be used for each type of 

damage: 

Description 

Ca use of Damage 

Re leva nt 

Measu rements/Materials 

Testing 

Degree of Damage and the 

Consequenses 

Condition w hich trigger 

Maintenance Works 

Action to be ta ken 

Examples 

Explanation of the damage in question 

Possible causes of the damage ari sing 

Measurements /materials testing which ought to be undertaken in 

order to discover hidden damage, to ascertain its scope and to project 

future developments and/or propose possible causes of damage. 

Description of how to evaluate the seriousness and consequences 

of the particular type of damage. 

Requirements and recommendations concerning the condition 

which can trigger maintenance work . A degree of damage':::"2 is 

requ ired as a minimum. 

Suggested action needed to fo llow up a damage or repa ir it. 

Most of the types of damage will be described with illustrat ions.

9.1 Elements in or 

on the Ground 

These elements are detailed in Chapler 2.2 'Types of Elelnents', 

and the following types of damage can be found. 

Damage 

101 Subsidence of ground/embarkments 

102 Obstruct ion of waterway 

103 ScouringlErosion of river course 

104 Inadequate cleaning up/removal procedures 

109 Other Iypes of damage/defects 

Page 

13 1 

133 

135 

14 1 

143 

The above items will now be described more fully.

9.1 ELEMENTS IN THE GROUND 

101. Subsidence of Ground/Embarkments 

Description 

Vertical movements in the soil behind abutment, wing walls and infill etc. which do not affect the 

bridge itself. 

Degree of Damage 

Error during the planning phase. The load capaci ty oflhe soi l has been overestimated . 

• Incorrect material(s). Wrong compos ition of material has been used in the backfill. 

'" Work incorrect ly exec uted - not as origina lly described. 

* Loads. Traffic causes overloading. 

'*' Damage caused by accidents, e.g. flooding 

'" In-service damage, e.g. the results of erosion. 

'" Relevant Measurement 

* Levelling 

'" Evenness 

Degree of Damage/Consequences of the Damage 

The degree of damage should be selected based on its scope and probable rale of development. 

Basically subsidence can be of significance fo r traffic safety, maintenance costs and the environment. 

In fact subsidence behind abutment piers can result in differences in the height of the road 

surface where intill and pavement meet. This in turn has implications for traffic safety. Height diffe 

rences can also lead to impact in the joints and consequent noise pollution for those living in the 

vicin ity of the bridge. 

Conditions Triggering Maintenance Measures 

The inspector must assess each case indi vidua lly. If the lengthwise height difference for the carriageway 

on a main road exceeds 20 mm (or 30 mm for other national roads) when measured with a 

2m long straightedge, then the necessary maintenance measures should be set in motion. 

Maintenance Measures 

* Fill in with sui table material(s) 

* Small differences in he igh t can be evened out with asphalt 

• If the subsidence continues then consideration should be given to replacing the entire inti II 

behind the abutment.


Example9.1-1 

Subsidence or the infill behind the abutment pi er 

has caused a difference in height of27 mm in the 

road surface. The bridge is situated on a main road 

and subject to a lot ofhcavy traffi c. The gap has 

resulted in noise pollution for those li ving in the 

vicinity of the bridge. The damage has affected 

both traffic safety and the environment. 

Type of Damage: 

Degree of Damage & 

Consequences: 

Cause of Damage: 

101 Subsidence 

3T,3M 

61 Traffic Loads 

Procedures: 

Fill with asphalt within I year. 

Example 9.1-2 

Severe subsidence of the bark infi ll with a resultant 

large difference in height between the bridge and 

the inti I\, The damage is to be considered as dangerous 

for traffic, and the subsidence has also affected 

Ihe appearance of the wall underneath the bridge. 

The di splacement of the columns indicates that the 

pressure exerted by the earth has cause additional, 

great strai n on them. 



Consequences: 


of Materials 


3T,2M 

II Incorrect Choi ce 

Procedures: Replacement of the material with, for 

example, EPS. The condition of the columns must 

be carefully checked after removal of the old material. 

Example 9.1-3 

Subsidence o f the earth under a small part of a 

wing-wall. This can affect load bearing capacity 

should the subsidence develop. 



Consequences: 



2C 

9 Other/Unknown 

Procedures: 

5 years. 

Fill with appropri ate material within

102. Obstruction of Waterway 


Description 

The accumu lation of debris, branches, driftwood and the like have resu lted in constrictions in drainage 

cul verts. The speed of the water flow will consequently increase, and the slate of the current 

will also change; this can in turn lead to erosion and scouring. 


'" Insufficient regular management/maintenance; insufficient clearing out of the drainage culvert. 

'" Accidental damage, e.g. flooding. 

Degree of Damage/Consequences of the Damage 

Since erosion and scouring can very qui ckly result from constrictions in drainage culverts, the 

degree of damage should normally be given a high score. 

Constricti ons can affect the bridge's load bearing capacity, traffic safety and maintenance costs as 

fo llows: 

'" Increased risk of erosion and scouring leading to reduced load bearing capacity and consequently 

to increased maintenance costs. 

* A combination of damming up and breaking up of ice particularly can lead to the water flooding 

over the road, thus affecting traffic safety. 

Conditions Triggering Maintenance Measures 

Routines should be established for clearing river courses. In the event of constrictions arising the 

need for remedial measures should be assessed in each case. This wi ll depend on, amongst other 

th ings, the degree of the constriction and whether the drainage culvert has extra capacity or not. The 

necessary measures should be taken before directly related damage arises. 


• Clear out the drainage culvert 

* Restore the ori ginal water course 

* Special action required for damming up


Exa mple9.1-4 

The complete water course has been fi lled with 

debris from bushes and trees. The bridge is situated 

above a typical flood course. It has, however, satisfactory 

enough foundations such that there should 

be no danger of scouring. The constrictions can 

have consequences fo r the maintenance costs if the 

water runs out over the road into the material 

behind the abUlmenl pier which is then displaced. 

Type of damage: 

102 Obstruction of 

waterway 


Consequences: 


nmg. 

Procedures: 

Thorough cleaning out within 1 year. 

3M 

44 Insuffi cient clea- 

Example 9. 1-5 

Rubbish bui ld-up in the drainage culvert. There is a 

risk orlhe material around the pipe sufferi ng from 

scouring after a flood. The load bearing capacity of 

the bridge and the maintenance costs can conse~ 

quent ly be affected. 


waterway 


Consequences: 


nmg. 

102 Obstruction of 

2C.3M 

44 Insufficient clea~ 

Proced ures: 

Thorough cleaning out within I year.


103. Scouring/Erosion of River Course 

J~~~~ ~~:'" '" ABOVE WATER 

,- 1... ______ _ 

OR IGINAL LEVEL 

........ 1 

1... ________ -' 

CAUSED BY SURFACE 

WATER 

Description 

Damage in th is category includes erosion oflhe earth both above and below the water line. An 

exampl e of the latter could be erosion of the natural river bed or of protection against erosion. If the 

erosion is not stopped in time the fou ndations will become under-scoured. On the other hand damage 

above the water line can be exemplified by erosion of embankments and slopes in the immediate 

area of abutments and columns. 


Some of the possible causes are as fo llows: 

• Faulty design: During the plann ing period inadequate development or lack of attention paid to 

the draining ofT of surface wate r. inadequate design of a bridge can result in a narrowing of 

the waterway and a consequent increase in water speed. 

• Faulty construction: not carried out as prescribed 

• Unsatisfactory day-to-day run ning/maintenance; Damming up of the water course due to the 

accumulat ion of branches and other debris. 

• Accident impact; Erosion/scouring caused by severe water discharge from fl ooding. 

• In-service damage; For example the results of changes to the water course fo ll owing work carri 

ed out on the ground in the vicinity. 

Degree of Damage & its Consequences 

Erosion below water level should be all ocated a high degree of damage because it can develop very 

quickly. Even small movements of earth around foundati ons can affect the carrying capacity. 

Erosion can qui ckly turn into scouring. The degree of damage fo r situations above the water level 

should be assessed based on the local conditions and probable developments. 

Un derwater erosion can affect both carry ing capacity and maintenance cost. 

Carrying Capacity 

• Erosion around a bridge opening can reduce the carrying capacity of the foundations when the 

earth around them is removed. Foundations without pi les are especiall y vul nerable, and the risk 

of under-scouring is great - please refer to th e drawing above. Base slab foundations will always 

lose carrying capacity when subjected to underscouring with resultant subsidence.Subsidence in 

the foundations produces deformation of the superstructure and can lead to the partial or ful l col 

lapse of the bridge in question.


• 

Clfklinallevel 

V 

, \ • 

- 

V 

V 

V • 

/ 

B 

~ 

- ~ - 

""'"'" 

/' • V 

• V • 

7 

vi 

1,5 m 

Foundations on piles do not no rmally need ea rth masses under the foundations to achieve carrying 

capacity. Free-standing piles, on the other hand, will be vu lnerable to damage from ice, dtifnvood, 

rot and should therefore be protected. The figure above is based on the formulae for calculating carry 

ing capacity detailed in the Bridge Manual and demonstrates how carrying capacity is reduced 

from 100% (at the original levei 'A ') to 50% (at new level 'S') when erosion. Should the erosion be 

allowed to continue up to level 'C', th en carrying capacity will be reduced to 25% of the o:riginal 

figure. 

Maintenance Costs 

Even minor damage to protective measures against erosion show a tendency to accelerate and become 

expensive to repair. It is important that protection against erosion be in working order especially 

in a flood situation, otherwise scouring can arise with resultant severe co nsequences for the carrying 

capacity. Erosion above water level can offect the carrying capacity, traffic safety, majntenance 

and the environm ent. The removal of earth masses from around abutment piers can lead t() reduced 

carrying capacity. Erosion can produce holes in the pavement wi th resultant risk to road users. The 

scope of the damage can increase markedly if measures are not taken to halt the erosion. 

L- 

Conditions which Trigger Maintenance Measures 

Maintenance measures must be undertaken immediately when erosion and particularly under-scouri 

ng of foundations have occurred underwater. Cases of erosion above the water line should be individually 

assessed by the inspector. 


Undenrarer : 

• Flushing out the water course 

• Repair of damaged erosion protection 

• Construct erosion protection 

• Replenishing earth masses below and around foundations with suitable material 

• Recasti ng of concrete under the foundations if the carrying capacity enables so. Found alions 

supported on pi les should be given special attention. 

Above /Va/erLeI'e1 

• Replenishing with suitable new materia ls 

• Covering em bankments w ith paving stones 

• Improvements to the drainage system directed fonvards removal of surface water. 

• Sowing seeds/planting to encourage binding of the soil.


Original Level 

~-..I....- \--1" .f-:7--.~ 

/ :"" 

. r . 9~· ~ ~ 

\le'/el after Erosion 


The original undenvater ground level has been eroded 

down to the same level as the bottom of the 

base foundation slab due to insufficient protection 

against erosion. 

Type of Damage: 103 

Scouring/erosion of river course 


Consequences: 

3C 

Cause of Damage: 13 

Poor design solutions 

Procedures: Replenish with suitabl e materials and 

install protection against erosion within one year. 

• 

, 

Original level 

\ " • 

• 

" 

• 

• " 

" 

• 

Level after Erosion 

~ 


The original underwater ground level has altered 

due to erosion with severe consequences for the 

carrying capacity. The ba ll ast co nsists of too fine a 

grade of material. 




Consequences: 


Construction fa ult 

103 

4C 

38 

Procedures: Replen ish wit h suitab le materials and 

install protection against erosion in the course of 

s ix months. 

Example 9.1-8 

The base foundation slab has suffered under-scouring 

as the result of a serious flood. Carrying capaci 

ty has been greatly reduced. 




Consequences: 

4C 


Flooding 

Procedures: The bridge should be closed until 

repairs have been carried out" immediate infilling 

with concrete under the foundations, replenish ing 

w ith suitable materials a nd installing protection 

against erosion to the same level as the origi nal 

river bed.


Example 9.1-9 

Under-scouring of foundations on vertical piles 

because of insufficient protection agai nst erosion. 

Vertical, but not horizontal loads can be accommodated, 

whilst the piles can be subjected to unforeseen 

sources of impact. The consequences for the bridge's 

carrying capacity arc serious. 




Consequences: 

4C 


Erroneus calculat ions 

Procedures: Infi lling with concrete under the foundati 

ons, replenishing with su itable matcrials and 

installing protection against erosion. This shou ld be 

carried out within 6 months. 

Example 9.1-10 

Erosion of the embankment caused by the water 

from the pavement not being drained off as planned. 

If the situation is allowed to continue at the present 

rate of development, maintenance costs will be 

affected. Since a lot of public transport passes under 

the bridge, the damage is also of consequence fo r its 

appearance. 




Consequences: 


Construction fau lt 

103 

3M,3E 

38 

Procedures: Infill ing with suitable materials, 

improvements to the drainage system and installati 

on of protecti on against erosion. To be carried oul 

during the year in question. 


A combination of erosion of the in fi ll behind the 

wing-walls and inadequate anchoring of the elements 

has resulted in the displacement of the fac ing 

slabs at the top edge of the bridge. Consequently 

there is a risk of them falling onto the pathway 

below the bri dge. 




Consequences: 

4T 


Faulty Construction 

Procedures: The elements should be righted and 

made safe within 6 months.



As a result of erosion some of the concrete blocks 

on the front of an abutment pier have started to sl ip. 

Settlement and holes have appeared in the infill 

behind the abutment pier which in turn has an effect 

on traffic safety. 




Conseq uences: 

4T 


Faul ty Construction 

Procedures: Temporarily repair by immediately 

infilling with material and later permanently by 

installing a relief plate against the back wall. 


A small amount of erosion under an abutment pier 

due to lack of attention being paid during the planning 

phase to the draining away ofwaler. 


Scouring/erosion of rive r course 


Consequences: 

1M 


Poor design solutions 

Procedures: None 


Erosion has started under an abutmenl pier because 

insufficient attention has been paid during the construction 

phase to draining water from the roadway. 

Ma intenance costs may be affected if the erosion is 

allowed to develop. 




Consequences: 

2M 



Procedures: Replacement of ballast materials, 

improvements to the drainage system and protection 

against surface erosion. To be carried oul within 

5 years.


Example 9.1 -15: 

Erosion on the front of an abutment pi er has caused 

some of the concrete blocks to start sl ipp ing out of 

place. 

\ 


Scouring/erosion of ri ver course 


Conseq uences: 2.\1 



Procedu res: 

Improvements to the drainage system, infi ll ing 

underneath the flagstones and relaying the flagsta· 

nes. To be carried oul within 5 years.


104. Inadequate Clearing Up & Removal 

Procedures 

Description 

Included under this heading are the following: 

• Insufficient clearing up once construction work is complete 

• Failure to remove vegetation under and against a bridge 

• Failure to remove materials/equipment stored under a bridge 


• Construction fauit - insufficient clearing lip once constructi on work is complete 

'" Inadequate day-to-day management/maintenance 

Degree of Damage/Consequences 

The degree allocated to the damage will depend on its type, scope, and the speed at which other 

kinds of damage can develop. A hi gh degree of damage should be used for new bridges. 

Inadequate clearing up and removal procedures can cause further damage which could affect maintenance 

costs or the environment. Costs to remove or clear up items are often less than to repair 

secondary damage. 

Conditions which Trigger Maintenance 

Clearing up and removal procedures should be fo llowed immediately after the construction ora 

new bridge is complete. For already existing bridges procedures should be effected if inadequate 

clearing up or removal of items resulting in damage which could affect ma intenance costs or the 

environment. 

Procedures 

* Clearing up or removal of the items in question


Examplc9.1-1 6 

Dense vegetation on an abutment pier. 


Inadequate Clearing Up/Removal 


Consequences: 3,\1 


Inadequate Maintenance 

Procedures: 

The vegetation shou ld be removed within a yea r. 

Example 9.t-1 7 

Culvert used to store bails of straw. 


Inadequate Clearing Up !Removal 


Consequences: 

3M 



Procedures: 

Clear olil ihe culvert with in onc year.


109. Other Types of Damage to River 

Course 

Description 

Th is category includes damage/shortcom ings not already covered in Chapler 9.1 , fo r example the 

loads exerted on foundations will increase if infi ll is deposited around them. Excavation work near 

to foundations can reduce carrying capacity, whilst the fiver can suffer from erosion in a different 

way after excavation of the water course. The foundations can then be put at risk. 

This category also includes faults/shortcomings in the soil itself which can also lead 10 damage, for 

example the absence ofwaler training wal ls, or a waterway with insufficient capacity. Additional 

examples may have originated from the co nstruction period, such as embankments wh ich remain 

unsown or yet to be installed protection against erosion. 


'" Design fault 

'" Construction fault 

'" Inadequate daY-Io-day maintenance 


The degree must be assessed against the background of the prevailing local conditions and how 

much the damage could develop. 

The inspector must assess the consequences. 


Action should be taken whenever fau lts/shortcomings can lead to the development of damage 

which cou ld affect carrying capacity. 

Procedures 

These should be assessed in each individual case.

9.2 

ConcreteE lem ents 

The undernoted types of damage may arise in elements made of 

concrete: 

No. 

Page 

201 Settl ement of concrete element 146 

202 Movement of concrete element 148 

203 Deformat ion of concrete element 150 

204 Cracks in concrete element 153 

205 Rupture of concrete element 160 

206 Damage to concrete surface treatment 162 

207 Lea kage/dampness of concrete 164 

208 Discolorati on of concrete element 168 

209 Insufficicnt/damaged cover of concrete element 170 

2 10 Weathering of concrete element 173 

2 11 Honeycombing of concrete element 176 

21 2 Delamination of concrete element 179 

2 13 Spalli ng of concrete element 180 

2 14 Corrosion of reinforcement 184 

2 15 Wa sh out of concrete element 188 

21 6 Inadequate cl eani ng of concrete element 19 1 

2 17 Inadequate Clearing Up/Removal 193 

290 Other damage to concrete element 195 

Examp les or the above will now follow. 

Damage to concrete wearing surfaces is described in Chapter 

9.6.2, whilst damage to concrete parapets is dealt with in Chapter 

9.9. 1. 

Handbook for Brid ge Inspections 145

9.2 CONCRETE ELEMENTS 

201 Settlement of Concrete Element 

Description 

Vertical movements in concrete abutment , wing walls, pillars etc. Sett lement in these eleme nts can 

late r lead to defonnation of the superstructure - refer to Type of Damage No. 203. 


• Design fault - overestimati on of the ground's carrying capacity, underestimati on of the pressure 

exerted by the ground 

• Material fau lts - incorrect composition of infill material 

• Construction faults - fo undations not constructed as agreed 

'" Loads - caused by traffic or extra pressure on the ground in connection with construction work in 

the vicinity 

• In-service damage - secondary damage from erosion or underscouring of the ground. 

Current Measurements 

• Levell ing 


The degree of damage must be assessed based on the scope of the settl ement and its development as 

well as on any damage the settl ement may cause to the element which is subsiding. Both carrying 

capacity and/or maintena nce costs can be affected. 



Conditions which trigger Maintenance 

Action must be taken immediate ly whenever settlement has lead to too Iowa carrying capac ity. For 

settl ement which can result in 100 Iowa carrying capacity action must be taken before this happens. 

Action should also be taken in cases where settlement can be of importance for maintenance costs 

Procedures 

. Replacement of infil l wit h a lighter material in order to reduce vertical loads and the pressure 

exerted by the ground . 

. Constructi ng new foundations usi ng, for example, pi les. 

Example 9.2-1 

Severe settlement of an abutment which is built on 

infill. The infi ll material's sensitivity to subsidence has 

been underestimated. The abutment has nol been subjected 

to any damage whi ch requires repair in the short 

term. The superstructure is of the continuous type, and 

it has become necessary to temporarily build up the 

bearings in order to reduce deformation. 


Dcgrce of DamagcJ 

Consequence: 


Procedures: 

20 I Settlement (abutment) 

203 Deformation of concrete 

element (Superstructure) 

I C for the abutment 

4C for the superstructure 

before the temporary 

support 

13 Poor design so lutions 

No action is required for the abutment , but the settlement 

should be fo llowed up by us ing levell ing 

The deformation of the superstructure was so severe 

that the bridge had to be closed to heavy traffic until it 

had been jac ked up and the bearings had been bui lt up. 

Handbook fo r Bridge Inspections 147


202 Movement of Concrete Element 

Description 

The movement of bridge elements away from their original position, e.g. horizontal disp lacement 

or rotation of abutment , piers or parts of the superstructure. Evidence of movement can o ften be 

seen in bearings and joint gaps. 


... Design fau lts - overestimation of the ground's carrying capacity; earth pressure underestimated . 

... Materia l defects - incorrect materials for the infill. 

... Construction fau lts - foundations not constructed as designed . 

... Loads impact from traffic. 

• Inadequate day-ta-day operation/maintenance - absence of cleaning measures for joints . 

... Accident impact, e.g. flooding or traffic impacts. 

Current Measurements 

'" Measuring th e movements. 


The degree of damage should be fixed based on the size and probable development of the movement. 

Please note that movement is more cri tical for inclined than straight bridges because of the 

sideways di splacement of the superstructure. 

Extreme movements can affect the carrying capacity, but nonnally it is the maintenance costs 

which are influenced. Protruding edges along the kerb may affect traffic safety. 


These should be assessed for each particular case and wi ll often depend on the relationship between 

the move ments whi ch have come to light and the capacity of the bearings and possibl y of the joint 

constructions. Furthermore the situation may depend on whether protruding edges represent a 

danger to trafiic. 

Actions 

• Cleaning joints 

• Jacking up and adjusting bearings and possibly also building them up 

• Replacement of infillmaterial with lighter ones in order to reduce the pressure onthe ground. 



Example 9.2-2 

Unstable conditions have lead to movement in the 

abutment. The joint openings have become completely 

closed, and the spalling evident on the abutment 

and cross-girders indicates thai the superstructure 

is under continuous stress. 

Type of Damage: 202 Movement of concrete 

element 


Conseq uences: 2C 

Cause of Damage: 12 Erroreous calculation 

Procedures: 

Continuous taking of measurement s to fo llow developments. 

If these continue the infill behind the 

abutment will have to be rep laced within five years. 

Example 9.2-3 

The backfil l contains frost susceptible materials 

below ground level with the resu lt that the abutment 

has been subject to movement, whilst the 

superstructure has suffered sideways movement 

because the connection between the bridge and the 

abutment is skewed. There are protruding kerb 

edges on the superstructure on the roadway. The 

structures' abi lity to withstand the movements is 

temporarily suffi cient, and the bridge's carrying 

capacity has not yet been affected. 

Type of Damage: 202 Movement of concrete 

element 


Conseq uences: 2M for Abutment 

3T Superstructure 

Cause of Damage: I I Incorrect choi ce of materials 

Procedures: 

The intill behind the abutment should be replaced, 

and the superstructure jacked up within three years. 

Example 9.2-4 

The pier cap has been deflected 55 mm in a longitudinal 

direction during a period of 40 years apparen 

tly because of ice loads. 

Type of Damage: 202 Movement 


Consequences: I C (for Piers) 

Cause of Damage: 65 Ice impact 

Procedures: 

Continuous fo llowing up. 



203 Deformation of Concrete 

Element 

The type of damage "Deformationy" covers bridge elements which have developed bowing whencompared 

to their original shape. They can consequently have been subj ected to additional loads or 

now have reduced carrying capacity. The consequence can be pennanent deflection of, for example, 

the main carrying element or the bridge deck etc. 


• Design fault - under-designed elements or incorrect assumptions. 

• Construct ion fault - settlement of the scaffolding during construct ion; unintentionally applied 

loads. 

• Loads - overloading due to heavy vehicular loads; too thick an asphalt layer. 

• Accident impact - traffic colli sions. 

• In-service impacts - c.g. secondal)' damage due to subsidence for example. 

Possible Measurements 

• Levelling. 

Degree of Damage & Consequences 

Deformation of load bearing elements can be an indication of too Iowa carrying capacity or of 

overloading. 

The degree of damage assigned must be based on the severity of the defonnation and its probable 

further development. 

So far as continuous span bridges are concerned deformat ion of the superstructure due to subsidence 

in abutments/columns will affect carrying capacity . Calculations must be undertaken before 

deciding the degree of damage. In many instances differential subsidence has been taken into 

account during the design period and should therefore be included in the process of deciding the 

degree of damage. 

Deformation due to subsidence can also affect future maintenance costs since the long-term deformation 

of concrete caused by creep will make jacking procedures more difficult. 

Carrying capacity will not be affected by subsidence of scaffolding. 

Both traffic safety, maintenance costs and the environment can be affected byabnormallong-tenn 

deformation due to the bridge's fully laden weight. 




When deformation has lead to too Iowa carrying capacity measures must be taken immediately. 

Action should also be taken when deformat ion spoils the appearance of a bridge. 

Procedures: 

* Jacking up and adjustment of the bearings (continuous span bridges) 

* Removal of unwanted loads such as asphalt 

* Strengthening or reconstruction 

* Replacement of elements 

Example 9.2-5 

Deflection ofa cantili vered slab due to insufficie nt 

reinforcement/incorrectly installed reinforcement. 


Deformat ion of Concrete Elemen ts 


Consequences: 

3C 


Erroneous calculations 

Procedures: 

Strengthening within one year 

Example 9.2-6 

Bowing ora column caused by fonnwork left 

behind after completion,resulting in an increase of 

the ground pressure on the column. 


203 

Deformation of Concrete Element 

Degree of Damage & Consequences: 3C 


Construction fault 

62 

Soil Pressure 

Procedures: 

Strengthening of the columns and replacement of 

materi als with lighter ones (E PS) within one year. 



Example 9.2-7 

Deformation caused by settlement of the scaffolding 

during the construction phase; this was subsequent 

ly levelled off with asphalt. 


Defomlation of Concrete Element 


Consequences: 

I B 


31 Settl ement 

of scaffold ing 

Procedu res: 

None 

152 Handbook for Bridge Inspect ions


204 Cracks in Concrete Elements 

Description 

Thi s category covers all hamlful cracks a nd fi ssures in concrete. Thus cracks in concrete which 

have been subject to stress from flexura l or tensile forces are normal. However, these cracks must 

fall within certain limits. 

Bridges containing pl ai n steel reinforcement bars can be subject to large cracks more widely spaced 

apart than is the case for ribbed reinforcement bars. Pre-stressed constructions do not nonnally suffer 

from cracking. 


* Design fault - insufficient reinfo rcement! hi gh tension in the reinforcement during in-service 

condition. 

* Materials fault - an incorrect concrete mixture can produce shrinkage cracks. Aggregates which 

react to alkali can therefore react with alkali contained in cement and water and in the long tenn 

produce an expansion in the volume of the concrete. This can lead in turn to cracks. 

'" Construction fau lts - both an inadequate casting process and faulty finishing treatment may cause 

cracks during curing, cracks resulting from loss of plasticity, wastage due to dehydration or 

cracks caused by the heat of the curing process Itemperature gradients. 

'" Inadequate day-to-day maintenance - badly cleaned out joints may result in 

unforeseen loads. 

'" Environmental impact - hostile environment, e.g. cracks caused by chloride induced corrosion on 

reinforcement. 

'" Impacts from traffic, subsidence etc .. 

'" Accidental impacts - traffic collisions. 

'" In-service impacts - secondary damage. 

Possible Measurements 

'" Measuring the width and pattem of cracks 

'" Removal of concrete specimens, drilling out cores or thin sli cing. 


The degree of damage should be assessed in relation to the location of the cracks, extent, cause, 

probable development and the amount of stress the elements have been subjected to. In addition, 

climate impact may be of importance here. 



Serious cracks and fi ssures can indicate too Iowa carrying capacity. They can also lead to corrosion 

of the reinforcement which also affects carrying capacity. Cracks or fi ssures pennitting the passage 

of dampness will be substantially more dangerous than dry cracks when taking corrosion Qfthe 

rein fo rcement into account. 

In most cases cracks and fi ssures wi ll be of consequence for maintenance costs and also for the 

environment dependent on their location. 

The followi ng rul e of thumb can be used to determine the degree of damage for cracks or fissures 

which could affect future maintenance costs: 

Sli ghtly Aggressive Environment (SAE): Crack/fissure < 0,5 mm 1M 

Crack/fissure 0,5· ],0 mm 

2M 

Crack/fissure > 1,0 mm 

3M 

Aggressive Environment CAE): Crack/fissure < 0,2 mm 1M 

Crack/fissure 0,2-0,5 mm 

2M 

Crack/fissure > 0,5 mm 

3M 

Cracks or fi ssures penetrated by dampness must always be assessed as irthey were located in an 

aggressive environment. Cracks or fissures in concrete situated in an aggressive environment 

should be checked fo r corrosion of the rein forcement by cutting away specimens in a few places. 


Very often cracks or fissures have been caused by other fonns o r damage such as deformation, 

movement, lack of cleaning etc. Measures must be taken against primary damage before carrying 

out procedures fo r cracks and fissures. Similarly measures are required to be taken against cracks 

and fi sssures before other kinds of damage can develop, e.g. corrosion of the reinforcemellt, which 

can result in reduced carrying capacity and increased maintenance costs. 

Procedures 

Surface treatment, which provides permanent cover of the cracks/fi ssures. 

* Scaling of cracks/fissures 

* Injection of cracks/fi ssures 

* Strengthening 

~ FLEXURAL MOMENT 

JTOR510N 

"-~-I 

I 

/ // 

SHEARING 

! 

~L ______ -----1t 

CO"" "'""" COAD 

Fig1lre showillg diiferelll killlis of cracks!fi.HIIIY!S which call be caused by ex/ernalloalls 

154 Handbook f or Bridge Inspections


Plastic Settlement Crack 

~~~?f ./ 

T " A ( 

If 

Crazing 

(ratk Caused by Reaction to Alkali 

Crack Caused by Thermal COlltraction 

(Heat During the Curing Process) 

Crack caused by ther al contraction 

eat un"g! ecurin9Process",,) ... ",~~ 


Crazing 


Cracks Caused by Corrosion of the Reinforcement 

Figure showillg examples of differel1l types of c/'Gch 10 be/oulld ill COl/crete bridges. 



Example 9.2-8 

Cracks on the deck of a suspension bridge caused 

by blocked joints. A total collapse is not anticipated. 

Refer to Chapter 9.8 for joints. 

Type of damage: 204 

Cracks in Concrete Element 

Cause of Damage & Consequences: 3C 



Procedures: 

Chi selling out the concrete; casting ornew cross 

beams; installation of tight joints. To be carried oul 

within one year. 

Example 9.2-9 

Cracks under a bearing whi ch has been sited too 

near the edge. 



Cause of Damage & Consequences: 4C 


Poor Design Solutions 

Procedures: 

Reli eve pressure on the bearing immediately; 

strengthening the bearing shelfwithin a year. 

Example 9.2·10 

Cracks on a pier caused by a reaction to alkali. The 

cracks arc up to I mm wide and located in a aggres· 

sive environment. 



Cause of Damage & Consequences: 3M 


A Ikaline reactive Aggregates 

Procedures: 

Joints above the pi er should be sealed \ ... ·ithin 2 

years in order to reduce water leakages down on the 

pIer. 




Cracks on a retaining wall caused by a reaction to 

alakali (con finned by structural analysis). De-icing 

salt on the pavement is normally not used. The 

width of the cracks does not exceed 0.8 mm. The 

site is not very accessible, and the public rarely go 

there. 



Cause of Damage & Conseq uences: 


Alkaline reactive Aggregates 

204 

2M, IE 

25 

Procedures: 

Surface water should be drained orfand the bridge 

deck treated with waterproofing layer. This should 

be carri ed out within 5 years. 


Cracks in a concrete beam due to bowing. Statical 

calculations indicate that there is adequate reinforcement. 





Traffi c Loads 

Procedures: 

Treatment of the surface within 5 years with a coating 

of material designed for covering cracks. 


Crack in a wing wall due to subsidence. 





Consequenti al/Secondary Damage 

Procedures: 

Follow up by taking levell ing measurements. Once 

the subsidence has stopped the cracks can be injection 

filled. 




Cracks in the side wa ll of an abutment due to skewed 

settlement. There is only minor traffic on the 

road. The settlement process has ceased. 


CracksIFissures of Concrete Element 

Cause of Damage & Consequences: 2.\1 


Consequential/Secondary Damage 

Procedure: 

Replace with lighter intil (E PS) together with injecti 

on of the cracks within 5 years. 


Cracks on lOp ofa pier caused by subsidence of the 

abutment. The settlement process has ceased, and 

the carrying capacity remains intact. 





ConsequcntiallSecondmy Damage 

Procedures: 

Cracks to be sealed within one yea. 


Settlement crocks which occurred during the casting 

process. 


Crocks inConcrete Element 



Construction Fault 

Procedures: 

Seal the crocks within one year. 




Through cracks in a newly cast bridge deck caused 

by the curing temperature when casti ng on to cold 

concrete. 





Inadequate curing Procedures 

Procedures: 

Cracks to be injection filled within onc year. 


Dampness and lime precipita tion in a crack on the 

underneath orthe deck of a prefabricated footbridge. 

None of the cracks exceed 0.7 mm in width. 



207 

Leakage/Dampness of Concrete 



Shrinkage/creeping 

Procedures: 

Cracks to be sealed within 2 years. 


Lime precipitation in shrinkage cracks in a culvert 

due to earlier water penetration which has now 

dried out after the lime products closed the cracks; 

the leakage then stopped. There is a lot of pedestrian 

traffic through this culvert. 



Cause of Damage & Consequences: 


Shrinkage/creeping 

204 

(M,3E 

67 

Procedures: 

The surface of the concrete should be sandblasted 

within one year in order to improve its appearance. 



205 Ruptures of Concrete Element 

Description 

Extensive damage to the whole or part of a bridge element, c.g. cracks or areas of broken orf concretc. 


* Design fault - attention has not been paid to concentrated loads; there is little room for 

expanSion. 

* Construction fau lt - post-tensioning before the concrete had achieved its prescribed fi rmness can 

lead to rupture. 

* Insufficient day-to day maintenance. 

* Impacts from traffic, ground pressure and the li ke. 

* Accidents - e.g. traffic impacts. 

* In-service damage - e.g. secondary damage. 

Degree of Damage/ Conseq uences 

The degree of damage should be assessed based on its location, size and probable development. A 

high degree of damage shou ld be allocated to load bearing elements. 

For load bearing elements, ruptures will affect the carrying capacity. Regarding non-load bearing 

elements, a rupture may affect traffic safety, future maintenance costs and/or the environment. 


Immediate acti on must be taken if the bridge's canying capacity is to low or traffic safety has been 

reduced. 

If the damage has affected maintenance costs, acti on should be taken before other damage leading 

to increased maintenance costs develops. 

Procedures 

* Mechanical repairs 

* Replacement 

* Strengthening. 




Broken cross-beam Of sllspcnsion bridge resulting 

from blockedjoint . 


Ruptures of Concrete El ement 

Degree of Damage ICon sequences: 3C 



Procedures: 

Existing cross-beam to be CUi away and replaced 

within onc year. 

Exam ple 9.2-21 

Broken beam res ulting from a traffic accident. 

Reduced carrying capaci ty as well as the ri sk of 

pieces of concrete fall ing off. 


Ruptures of Concrete El ement 

Degree of Damage & Consequences: 4C, 4T 


Vehicular Impaci Damage 

Procedures: 

Bridge to be closed to traffi c until repairs effected. 


Broken ba llast wall due to movement in an abut 

ment caused by ground prcssurc. 


Rupture of Concrete Element 

Degree of Damage & Consequences: 2M 

Causc ofDamagc: 62 

Soi I Pressure 

82 


Pr ocedures: 

Replace with lighter in fi ll materials (EPS) and 

effect repairs to the ballast wall within 5 years. 

Handbook for Bri dge Inspect ions 161


206 Damage to Concrete Surface 

Treatment 

Descri ption 

Damage to the surface treatment of concrete bridge elements, i.c. water repellent impregnation, 

painting/coating, whitewashing/pore filling. Flaking, cracking, bli stering, and discoloration can be 

incl uded here; additionally, the surface treatment might not fu lftl lhe required in-service standards. 

Surface treatment applied to concrete must be able to protect the concrete from environmental 

impacts and improve its general appearance. 


• Design Fault - incorrect type of surface treatment chosen. 

• Material Fault - incorrect type of surface treatment applied. 

• Construction Fault - poor pre-treatment of the surface, or the material was appl ied during damp 

or cold weather. 

• Insufficient operation/maintenance of the surface treatment. 

• Environmental impacts - a hosti le environment can break down the surface treatment faster than 

expected 

• In-service damage - regul ar wear and tear. 

Possible Materials Testing 

• Thickness of the surface treatment 

• Adhesion between the surface layer and concrete. 

• Impregnation depth to concrete of repellent impregnation. 

• Measuring chloride content and depth of carbonisation. 


All types of surface treatment gradually become broken down by the environmental influence. The 

degree of damage a ll ocated shall reflect the time remaining before the surface treatment requires 

renewal, i.e. before it loses its protective properties. Damage to the surface treatment wi ll affect 

maintenance costs and result in increased chl oride penetration and speed of development of carbonisation. 

These last two items can, in addition, lead to corrosion of the reinforcement and to spalling. 



If the damage is extensive and/or the surface treatment has lost its protective qualities, a new layer 

of surface treatment must be appl ied. When the damage is minor, action need only be taken before 

any other types of damage develope and before the damage becomes so extensive that the enticre 

surface treatment has to be renewed. 


Procedures: 

. Regular cleaning and renewal orthe surface treatment 

. Removal orthe existing treatment and the application ora new coating. 


Localised spall ing of the surface treatment ofa 

concrete parapet. 


Damage to the Concrete Surface Treatment 

Degree of Damagei 

Consequences: 



3M, 2E 

38 

Procedures: 

Maintenance measures to be taken within three 

years for damaged surface treatment. 


Surface treatment damaged by wind and weather. 

This bridge has been greatl y subjected to chl oride 

attack, and the surface treatment has no longer any 

of its protective qualit ies. The appearance o f the 

bridge can hardly be described as attmctive. 


Damage to the Concrete Surface Treatment 

Degree of Damage/ 

Consequences: 



Normal Wear and Tear 

3M, 3E 

44 

81 

Procedures: 

The ent ire surface treatment should be removed and 

renewed within three years. 



207 LeakagesJ1)ampness of 

Concrete 

Description 

This covers water seeping through cracks, leakage between prefabricated concrete elements and/or 

dampness attack resulting fro m leaks or fa iled attention to detai ls. Leakages Idampncss attacks can 

produce corrosion orthe reinforcement and spall ing to the covering. Leakage leads to discoloration 

of the concrete (lime deposits on the surface). 


* Design Fault - unsuccessful design causing leakage/dampness .. 

* Material Fault - incorrect composition of the concrete can lead to porosity so that the concrete is 

not water resistant. 

* Construction Fault - concrete has nol been correctly vibrated which has resulted in porosity. 

* Depressions cause insufficient drainage of water and the risk ofleakage and dampness attacks. 

* Insufficient day· to-day operation/or maintenance. 

* In-service damage, e.g. secondary damage. 


The degree of damage should be selected depending on the age of the bridge, the extent of the lea· 

kage/dampness impact and the speed at which other damage can develop. 

Leakage/dampness impact can affect maintenance costs and/or traffic safety in so far as icicles and 

icy road surfaces can form in winter. 

Conditions which Trigger Maintenance Measures 

Measures should be taken to stop leakage/dampness impact before the risk arises of other damage 

develop ing such as corrosion oflhe re inforcement and spalling. If, fo r example, reduced traffic 

safety or icy sections can result from leakage/dampness impact, then immediate action must be 

taken. 

Procedures 

* Sealing, injection fill ing 

* Alteration to the water drainage system 

* Mechanical repairs to the concrete 

* Installation of new waterproofing layer on the bridge deck. 

164 Handbook for Bri dge Inspect ions



Leakage through joints between concrete elements 

because ofinadequalc seal ing ca using a dampness 

attack on the underside orthe bridge. 

The elements are prestressed and therefore particularly 

vulnerable to corrosion of the reinforcement. 

The bridge deck has been exposed to de-icing salt. 


LeakagelDampness of Concrete 


Consequences: 

3M 



Procedures: 

In sta llation ornew waterproofing layer on the bridge 

deck within one year 


Leakage through joints between the clements of a 

pedestrian culvert because of inadequate seal ing. 


Lcakage/Dampncss of Concrete 


Conseq uences: 



207 

3T, 2M 

38 

Procedures: 

The joints should be sealed within three years. 


Serious leakage in the region of a power cable duct. 

There is a pathway under the bridge. 



208 

Di scoloration of Concrete Element 

Degree of Damage ICon sequences: 2M, 2E 

Cause of Damage : 38 


Procedures: 

Leakage to be sealed within five years. 




Leakage through the bridge deck over a small , 

badl y cast area. The bridge is approx imately 30 

years old and has not been salted. 



211 

Honeycombing 

Degree ofDamagc/Consequcnces: 2M 



Procedures: 

Installation of new waterproofing layer and wearing 

course within five years 


Dampness and li me deposits on the underside of the 

bridge deck indicate the existence of 

leakages/dampness impact for some time. Both the 

wearing surface and the membrane are worn 

through. 



Degree ofDamagc/Conscqucnces: 2M 


Conseq uentiaVSccondary Damage 

Procedures: 

Installation of new waterproofing layer and wea~ 

ring course within five years. 


Leakage between cross ~ beams has been caused by 

porous concrete and leaky joints directly above the 

c ross~beams. The water has worn away the surface 

treatment of the steel. 


Leakage/dampness of Concrete Element 

Degree of Da mage & Consequences: 3M 


II 

Incorrect Choice of Materials 38 


Procedures: 

No action is required for the concrete cross~beams. 

The joints, however, must be cleaned out and sealed 

within three years. In addition, the steel elements 

should be painted. 




Leakage through the bridge deck made of very 

poor, porous concrete has resulted in severe corrosion 

orthe re in fo rcement, spalling and crumbling 

concrete. 



209 

Insufficien t/damaged covering 

210 

213 

Spalling of Concrete Element 

214 

Corrosion of the Reinforcement 

Degree of Damage/Consequences: 3C 



Procedures: 

Rebui lding ofhridge deck within I year. 


Leakage through the cast-joints of a retaining wall 

leads to weathering orthe concrete. The retaining 

wall is located adjacent and parallell to the road. 



208 

Di scoloration of Concrete Element 

210 

Weathering of Concrete 

Degree of Damage/Consequences: 1 C, 2M, 3E 



Procedures: 

Inj ection filling of the cast joints, and cleaning 

up/treatment of the surface material within three 

years.

Handbook for Bridge Inspections - TSP2

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