Concrete Today May 2010 - the Irish Concrete Federation

Magazine of the Irish Concrete Federation 

May 2010 

Concrete Built is Better Built

Greece 

According to Ireland’s first history book, ‘Foras Feasa ar 

Éirinn’. (Seachrún Céitinn 1643), ‘the Irish originate from 

the Island of Crete’. Whether factual or just folklore, it is 

certainly true that both countries have made a significant 

contribution to Western civilisation. 

This edition of Concrete Today has a distinct ‘Greek’ 

flavour with three articles connected to Greece in different 

ways. Firstly, we are indebted to our Greek colleague Georgia 

Kremmyda, who has kindly penned a technical article based on 

The Conceptual Design of Precast Concrete Structures in Seismic Areas, 

in accordance to the provisions of European Code EC8 and to the damages observed at the 

most severe earthquakes. The article will be of particular interest in the aftermath of the recent 

devastating earthquakes which caused severe damage and loss of life in the L’Aquila region of 

Central Italy, Haiti where up to 230,000 people are thought to have lost their lives and most 

recently Chile, where one of the biggest earthquakes ever recorded recently occurred. 

Secondly, we are featuring an article on the opening of the new Acropolis Museum in 

Athens. This beautiful building, built predominantly in concrete and glass, is featured on 

the cover of our magazine. The building houses many of the ancient treasures of the nearby 

Parthenon, views of which are afforded to visitors from the museum building. Unfortunately, 

and much to the dissatisfaction of the Greek authorities, the building houses only a few of the 

Parthenon Marbles, most of which are housed in the London Museum. 

Our third article with a Greek flavour concerns the manufacture of special Precast 

concrete cladding panels for the 2012 London Olympics. Ireland’s leading Precast cladding 

manufacturer, Techrete Ltd., recently won a contract to supply reconstructed stone cladding 

panels, to be erected on 26 blocks of apartments within the Olympic village. The apartments 

will house the Olympic athletes and a number of the Precast panels will feature friezes, 

depicting ancient Greek battles, centaurs etc. These frieze depictions were scanned by Techrete 

from the original Parthenon friezes and reproduced at three times the original scale. 

Brian Ó’Murchú 

John Murphy - Obituary 

The staff and 

members of the 

Irish Concrete 

F e d e r a t i o n 

were greatly 

saddened to 

learn that our 

dear friend and 

colleague John 

A. Murphy, passed away on November 21st 

2009, following a short illness. 

Born and reared in Kildare town, John 

attended the De la Salle Primary and St. 

Josephs Academy Seondary School. Having 

qualified as an engineer in UCD he went on 

to work in many different areas, Roadstone, 

Kildare Co. Council, Q.K. Cold storage and 

finally setting up his own business Bracla 

in Newbridge Industrial Estate. In latter 

years John was appointed CEO of the Irish 

Asphalt Pavement Producers Association 

(IAPA), whose office is located within the 

Irish Concrete Federation office suite. 

John was a friend to all his colleagues, 

someone who listened attentively and 

offered advice if it was sought. He was 

a dedicated family man, who used his 

knowledge and drive to give his sons Brian 

and Alan and his daughter Caroline the 

From the Editor 

best possible start in life. He was ever 

positive and cheerful and loved nothing 

better than to engage in banter with his 

friends and colleagues. He was always the 

soul of the party. 

John had many passions in life, not least 

his undying support for the Kildare GAA 

team, whom he followed to every venue 

the length and breadth of the country. 

John also loved to play golf , though the 

banter and laughter that went with it was 

more important to him than the golf itself. 

A gregarious character and man of action, 

John joined the Newbridge Credit Union 

in 1995 and later served as a Director and 

member of the Credit Committee. He was 

noted by his fellow committee members as 

a person who paid great attention to detail 

in making decisions and who always strived 

to be fair and compassionate in his dealings 

with others. 

John was great company, a marvellous 

storyteller and brilliant raconteur. His 

wife Ann, his children and grandchildren 

were the mainstay of his life. The staff and 

members of the Irish Concrete Federation 

offer our sincere condolences to his wife 

and family at this challenging time. 

ICF Staff 

ics awards 

Irish Concrete 

Society Awards 

2009 

The winning entries at the Irish Concrete 

Society’s Awards Evening, which 

took place recently, came from all over 

Ireland and ranged from private houses 

to community buildings to cable stayed 

bridges. 

This was the 28th Awards Evening and 

the event is always one of the highlights 

of the construction industry’s calendar. 

The Awards recognise excellence in both 

design and construction in concrete. The 

jury reviewed a total of twenty projects 

entered in three categories– Elemental, 

Infrastructure and Building, where they 

were impressed by the quality and high 

standard of detail exhibited by all entries. 

They also considered suitable examples of 

the use of concrete in a sustainable context. 

The biennial Sculpture Award received 13 

high quality entries from all parts of the 

country, each demonstrating the creative 

potential of concrete as a material. The 

annual Sean de Courcy Student Prize was 

also awarded on the night. 

Winner – Sustainability Award 

Father Collins Park, Donaghmede 

The large park of 52 acres serves the 

established area of Donaghmede and new 

housing developments stretching out to 

Belcamp, Belmayne and beyond. 

Father Collins Park, Donaghmede 

concrete today 

2

concrete today - ics awards 

The park consists of shot-blast concrete 

paths and walkways, and a concrete 

skateboard park which is well-planned and 

detailed, and obviously well used. The jury 

noted that the ‘quality of the curved and 

angular shapes within the skate-park, and 

the innovation in their construction, are a 

credit to the Team and a challenge to the 

skateboarders’. The concrete bridges which 

traverse the various watercourses are simple, 

well planned and well executed. 

These concrete elements which contain 

GGBS are combined with 5 eye-catching 

wind turbines that provide for the park’s 

lighting, water-pumps and aeration 

systems. There are a series of extensive 

watercourses including a surprising waterfeature. 

These clean hard materials are 

complimented by the use of some well 

planned soft landscaping. The free form 

wetland reed beds which purify the water 

mesh well with the park’s linear features, 

and also create a sustainable solution to the 

lake and water features. 

Winner – Elemental Category 

Jigsaw, Dublin was winner in this category 

where 6 entries were considered. 

This project consists of a garden level 

single storey extension to the rear of a 2 

storey over garden level Victorian house in 

the inner Dublin suburbs. The extension 

is overlooked from the upper floors of the 

existing house. 

The use of concrete allowed the architect 

create a floating tubular space with the 

same material used in walls, floor and roof 

creating an interesting tension when viewed 

from the garden where this heavy element 

floats effortlessly over the garden terrace. 

The real success of the project was 

achieved by the excellent quality of the 

insitu board marked concrete where 

concrete is exposed internally and 

externally. The execution was of such a 

high quality that the finished concrete was 

very even in colour and texture with little 

evidence of construction joints. 

Jigsaw, Dublin 

Winner – Infrastructural Category 

River Suir Bridge was the selected winner 

in a category of 7 entries. 

The bridge is a cable stayed bridge of 

total length 465 metres crossing the River 

Suir upstream of Waterford City. The 

imposing visual aspect is driven by the 112 

metre high concrete pylon in the shape of 

an inverted Y out of which 19 sets of four 

cables hang, giving an almost symmetrical 

form extending out from the concrete 

pylon. 

The pylon was constructed using an 

automatic climbing formwork system while 

the bridge deck is a horizontal steel frame 

supporting precast concrete panels. 

The jury noted that ‘the design of the 

bridge has produced concrete and steel 

elements at a scale suitable to the overall 

structure and its setting. The relationship 

River Suir Bridge, Waterford 

of the concrete and steel is very well 

handled and the use of each recognises the 

inherent character of each’. 

Overall Winner (Building Category) 

Visual Centre for Contemporary Art and 

George Bernard Shaw Theatre, Carlow. 

The Overall winner was in the Building 

Category where 7 entries were considered. 

This building is sited in the heart of 

Carlow town adjacent to Carlow Cathedral 

and other historic buildings where the jury 

felt that ‘the concept of a glass box or jewel 

in a garden was most appropriate’. 

The success of the building is the 

apparently effortless use of large elements, 

mainly concrete, in sympathetic scale with 

the gallery spaces. The concrete elements 

have a textural scale of their own, such as 

the heavily ribbed slab soffits, the OSB 

board texture to the walls, which reads 

like wallpaper, smooth bands within 

the walls and the polished floors. The 

concrete walls are well co-ordinated and 

detailed especially at their base where no 

kickers were used and also at horizontal 

construction joints. 

The use of concrete in many forms and 

finish demonstrates the flexibility of the 

material and the appropriateness of its use 

in such a civic building. 

This building has met and overcome 

many challenges, particularly in the use of 

concrete and is a worthy Winner of both 

the Building Category and the Overall Irish 

Concrete Society Award for 2010. 


3

concrete today - ics awards 

Project Team Details 

Overall (Building Category) – Visual Centre for Contemporary Art and 

George Bernard Shaw Theatre, Carlow 

Client: 

Carlow Local Authorities 

Engineer: 

ARUP Consulting Engineers 

Architect: 

Terry Pawson Architects 

Contractor: 

BAM Building 

Major Supplier: 

Durkan & Ryan 

Infrastructural Category – River Suir Bridge 

Client: 

Waterford City Council / NRA 

Engineer: 

ARUP Consulting Engineers 

Contractor: 

BAM / Dragados JV 


Roadstone / Banagher Concrete 

Elemental Award – Jigsaw, Dublin 

Client: 

Private 

Engineer: 

Kavanagh Mansfield & Partners 

Architect: 

McCullough Mulvin Architects 

Contractor: 

Patrick Brock & Sons 


Roadstone 

Sustainability Award – Father Collins Park 

Client: 

Dublin City Council 

Engineer: 

O’Connor Sutton Cronin 

Architect: 

Ar Arq Ireland 

Contractor: 

Liffey Developments 


Goode Concrete / Bromac Construction / Erlin 

CHANGES 

occasion was very powerful and memorable. 

We commend the artist for his crafting - the 

expert modelling that brings so much life to 

the work and, by choosing to use standard 

grey concrete, resisting the temptation to 

prettify the work.” 

“On a technical level this work brings the 

use of concrete into new territory. On an 

artistic level it is work of true originality and 

integrity.” 

Visual Centre for 

Contemporary Art and 

George Bernard Shaw 

Theatre, Carlow 

Sean De Courcy Student Award 

This is an award given to the best final-year 

project on a concrete-related topic from 

the engineering faculties of the third level 

institutions. 

The award is named after the late Sean 

de Courcy, an inspirational professor for 

many years at UCD, a former chairman of 

the Irish Concrete Society and author and 

historian of note. 

The winner of the Irish Concrete 

Society Sean De Courcy Student award 

for 2009 is Stephen Cunningham of 

TCD for ‘Influence of Aggregate Size on 

Shear Capacity of non-Shear Reinforced 

Concrete Beams and Implications for 

Crack Slide Theory’. 

The project topic is very relevant in 

terms of analysis of older structures and 

sustainability – preserving structures that 

might otherwise have to be demolished. 

The jury also found that the objectives of 

the project were achieved. 

The research was thorough, the 

experimental work was comprehensive and 

correctly analysed and the entire project was 

well presented in a clear logical manner. 

Sculpture Award 

‘CHANGES’ by Kenneth Lambert is this 

years ICS sculpture award. It is a wallmounted 

artwork, a kind of painting, cast 

in concrete and resin. It measures about 2.5 

metres by 1.2 metres and about 150mm 

thick. It is made up of three interlocking 

curved panels. The side panels are cast in 

concrete and depict, in low relief, the artist 

and his brothers in a car returning from 

his mother’s funeral. The central panel, in 

contrast, is cast in clear resin. 

The jury noted: 

“There is so much about this work that we 

found immediately engaging and compelling. 

It challenged our pre-conceptions about the 

use of concrete. Familiar as we are to the 

use of concrete in buildings or larger scale 

public sculpture – it was extraordinary to 

see it used in this picture that expresses such 

an emotional atmosphere. The evocation, 

depicted in concrete, of the solemnity of the 

Winner’s presentation names as follows; Front row left to right; Tim Madden (Carlow 

Local Authorities), Carissa Farrell (Visual Centre for Contemporary Art & George 

Bernard Shaw Theatre), Aidan O’Connell (BAM Building), Seamus Maguire (Durkan & 

Ryan), Ian Roberts (ARUP) 

Back Row left to right; Eddie O’ Brien (BAM Building), Garry Dodds (ARUP), Joe Watters 

(Carlow Local Authorities), Hugh Gray (ARUP), Mark Richardson (Chairman, Irish 

Concrete Society), Michael Gillen (BAM Building), Eddie Ryan (Durkan & Ryan), Joe 

Flavin (VIisual Centre for Contemporary Art and George Bernard Shaw Theatre) 


4

concrete today - designing for earthquake - precast concrete 

Designing for Earthquake – Precast Concrete 

The Importance of the conceptual design of precast concrete structures in 

seismic areas and lessons from past earthquakes – The SAFECAST Programme 

By Georgia Kremmydia, National Technical University of Athens, Athens, Greece 

Dipl. Civil Engineer, PhD Candidate 

Introduction 

In recent years, there has been a sharp 

increase in the use of prefabricated, offsite 

construction techniques, including 

Precast concrete. Prefabricated elements, 

such as architectural cladding panels, 

Precast hollowcore and wideslab floors and 

stair flights are also being introduced to 

buildings which are primarily constructed 

insitu. A shortage of site operatives, the 

need to eliminate uncertainty in the 

programme caused by inclement weather 

conditions and the general requirement for 

fast, reliable and economic construction 

techniques are among the main drivers. 

Joints and Connections 

As is well known, the main difference 

between traditional, monolithic castinsitu 

R.C. structures and corresponding 

prefabricated structures, is that the 

latter are composed of several bearing 

members cast in a factory rather than on 

site; therefore the structure is composed 

of a set of ‘elements’ which are joined by 

‘connections’. Thus the main structural 

issue in Precast construction relates to the 

connections between Precast members 

and to the extent to which connections 

affect the response of the total structure 

under seismic actions. In this regard, the 

need for Precast structures to satisfy the 

fundamental structural requirements of 

‘non collapse’ and ‘damage limitation’ , 

L’Aquila earthquake central Italy 2009 

caption 


under design-earthquake conditions needs 

to be carefully studied. 

Experience based on the history of seismic 

engineering and recent experience of the 

seismic behaviour of R.C. structures, showed 

that in spite of the enormous development 

of computer simulation software, the 

satisfaction of the fundamental requirements 

under the design-earthquake cannot solely 

be achieved by means of calculations and 

that several basic design concepts proved to 

be more important. 

Structural simplicity and uniformity 

Among the most important of these design 

concepts is the concept of ‘structural 

simplicity’ as characterised by ‘uniformity’, 

‘symmetry’ and ‘regularity’ in the 

configuration of the structural systems in 

plan and/or, elevation. This concept should 

be addressed in the first step of the design 

process, namely ‘conceptual design’. That 

is to say, every analysis has to be carried out 

on a preconceived structural scheme. 

In fact, by simplifying the structural 

system, clear and direct paths (including 

alternative paths) for the transmission of 

the seismic loads should also be ensured. 

In this way, the modelling, analysis, 

dimensioning and detailing of the structure 

is subject to less uncertainty and thus the 

prediction of seismic behaviour is much 

more reliable. 

The ‘in plan regularity’ is primarily a 

function of the geometrical configuration 

of the building: the configuration should 

be compact and clear. In plan set-backs 

(re-entrant corners or edge recesses) or L, 

n, E or - L shapes etc. should be avoided, 

or otherwise limited and specially treated. 

• The ratio of Lmax: Lmin. should not be 

less than 4 

• The distribution of the lateral stiffness 


5



and the mass should be closely 

symmetrical in plan with respect to two 

orthogonal axes 

• In this respect, if necessary, uniformity 

may be realised by subdividing the entire 

building by means of seismic joints into 

dynamic independent units, provided 

that these joints are designed against 

pounding of the individual units 

• Uniformity in the development of 

the structure along the height of the 

building is also important and can be 

achieved when: 

• Almost all lateral resisting systems 

such as cores, structural walls or 

columns in frame systems, run without 

interruption from their foundations to 

the top of the building 

• Both the lateral stiffness and the mass of 

the individual storeys remain constant 

or reduce gradually and 

• A natural flow of forces is ensured by 

avoiding staggered beams or (worse) 

staggered columns 

• Other basic principles to be satisfied 

by a sound conceptual design are 

the bi-directional resistance, torsion 

resistance and stiffness 

Horizontal actions 

The structure must be made to resist 

horizontal actions in any direction. This 

can be achieved by arranging all structural 

elements (columns and/or walls) in an 

orthogonal in-plan structural pattern 

e.g. by distributing those close to the 

periphery of the building, ensuring similar 

resistance and stiffness characteristics in 

both main directions and limiting possible 

torsional motions which tend to stress the 

different structural elements in a nonuniform 

way. In all cases, special attention 

must be paid to the position of the 

elevators and staircases into the structural 

system. 

Soil, structure interaction 

In seismic areas, the interaction of the soil 

with the superstructure must be carefully 

studied. In general, the configuration of the 

foundation relative to the superstructure 

should be such as to ensure that the whole 

building is subjected to a uniform seismic 

excitation. 


Secondary structural elements and 

cladding panels 

Moreover, when designing precast 

structures where secondary elements such 

as infills/partition walls/claddings etc. 

are envisaged, special attention must be 

given to arranging them symmetrically in 

plan, to avoid all possible irregularities in 

a strong seismic event. Generally, all of the 

aforementioned secondary elements must 

be connected with the structural elements 

in a way that they will not disturb the 

predicted seismic response of the structure 

and that they will not partially or totally 

collapse. Based on experience from past 

earthquakes (e.g. earthquake at L’aquilla, 

Italy 2009) it has become obvious once 

again that inadequate connection details 

between cladding panels and the structural 

panels can lead to out-of-plane collapse 

of these cladding panels during a seismic 

event, with considerable risk to human life. 

The Development of Codes 

Experience from the past has shown 

repeatedly that construction techniques 

of every type preceded any theoretical 

and experimental scientific progress and 

relevant codes, since complete code-bodies 

governing the design and construction 

of structures and especially of Precast 

structures under seismic conditions, did 

not exist in their current organised form. In 

cases where basic code-bodies had formed, 

they did not reflect the more recent aspects 

of Earthquake Resistant Design Philosophy 

such as ductility demand, capacity design 

rules and other such factors. Also, in some 


6


cases of mass construction of Precast 

structures, speed of construction and low 

cost featured more as design considerations, 

rather than ‘conceptual design aspects’ 

which would contribute to increased safety 

against earthquakes, even taking into 

account the more limited level of scientific 

knowledge at that time. 

In this respect, the case of the Armenia 

earthquake of 1989 is worth mentioning 

in which, among other damage, two 

cities in particular, Leminakan and 

Spitak which were built extensively using 

prefabrication techniques were completely 

destroyed. According to the findings of the 

International Scientific Community, the 

extent of the disaster was not due to the use 

of prefabrication itself but, much more due 

to completely inefficient design concepts, 

e.g. lack of proper lateral resisting systems, 

very bad detailing of Precast members 

and their connections and finally very bad 

quality of the concrete and improper use 

of steel. 

Such cases and other cases of collapse of 

Precast structures after strong earthquakes 

in the past (Kocaeli earthquake 1999, 

Northridge earthquake 1994, Vrancea 

earthquake 1977 etc), gave the rather 

unjustified impression to the international 

community that Precast concrete 

constructions performed poorly under seismic 

actions due to the fact that prefabrication was 

used. 

Findings of International Scientific 

Community 

Nevertheless, according to the findings of 

the International Scientific Community, 

it is a fact that there are many examples of 

excellent behaviour of Precast structures, if 

properly designed and constructed in a way 

which takes into account the fundamental 

requirements of non-collapse and damage 

limitation, within acceptable cost limits. In 

this respect it is worth mentioning that the 

only buildings which survived the strong 

earthquake motions in one of the above 

mentioned two cities of Armenia were some 

multi-storey large-panel buildings which 

were designed and constructed, taking into 

account basic conceptual design aspects. 


Considerable research has been reported 

worldwide in the last decades due to the 

work of individual companies and by 

relevant institutions, which has contributed 

to the reliability of Precast structures 

built in seismic regions. Among them the 

PRESS (Precast Seismic Structural System) 

research programme carried out by the 

USA and Japan may be considered the 

most notable experimental investigation 

of the response of Precast structures to 

earthquake. Through this research project, 

new concepts and technologies have 

been invented and experimentally and 

theoretically supported, using innovative 

connections and prestressing. 

The SAFECAST Programme 

In March 2009, a new European 

Research Programme was initiated, 

entitled SAFECAST – Performance of 

innovative mechanical connections in 

Precast building structures under seismic 

conditions’ , financed under the 7th 


Framework Programme ‘Research for 

Small and Medium Enterprises (SME) 

Associations action’. The project derives 

from two previous research projects, the 

ECOLEDER and the PRECAST EC8 

project and completes them thoroughly. 

Both of these projects dealt with the 

seismic behaviour and ductility capacity 

of Precast concrete structures compared 

to corresponding cast insitu structures. 

However, it was clear from the findings 

that the actual design of the connections 

was not fully covered and therefore 

difficult to be modelled properly for 

the numerical studies used in the design 

of Precast building structures. Thus, 

SAFECAST has been established to 

investigate, both experimentally and 

numerically, the seismic behaviour of 

several types of connections between 

Precast members. The success of this 

project is critical to the design of Precast 

concrete structures, as reliable as cast 

insitu concrete structures. 


7

concrete today - precast schools solution 

Fast-track Precast Schools Solution 

High quality school building in just 20 weeks 

Project: Flemington National School, 

Balbriggan, Co. Dublin 

A high quality precast concrete school can be delivered in 20 weeks. With the combined 

experience of builders Sammon Contractors and the Concast Precast Group, a quality 

school solution has been provided at Flemington in Balbriggan, which will be ready 

well in advance of the September opening date. The more robust Precast building will 

greatly outperform alternative light-weight solutions, in terms of fire performance, sound 

performance and the overall durability of the structure. In particular the danger of the 

ignition of the structure by vandals during the construction phase is overcome by the use of 

completely non-combustible Precast concrete elements. 

Front Elevation Flemington School Balbriggan 

The Department of Education has 

recently approved a further seven new 

primary schools which are due to open 

next September. The substantial building 

programme proposed by the Department 

is being rolled out on foot of demographic 

studies which suggest that the school going 

population will rise sharply in the coming 

years. One such project is the new 18 

classroom Flemington National School, 

which is located in Balbriggan County 

Dublin, in a rapidly developing area. 

Sammon Contracting, headquartered 

in Kilcock, Co. Kildare and with offices 

in London, Dubai, Abu Dhabi and 

Tripoli, are a global provider of social 

infrastructure, with a particular strength 

in design & build of schools and colleges. 

Sammon is accredited with ISO 9001, 

ISO 14001 and OHSAS 18001 and 

are founding member of Buildsafe 

UAE, now the cornerstone Health and 

Safety organisation in the Middle East. 

Sammon Contracting have put together 

a Precast concrete solution which can 

deliver a complete Precast concrete 18 

classroom school in a 20 week period. 

Precast concrete schools provide superior 

Precast Panels by the Concast Precast Group 


8

concrete today - precast schools solution 

performance in terms of the durability of 

the structure and the low-maintenance 

requirements over the life-span of the 

building. The solid, high density wall units, 

which have only a small number of joints, 

have greater air-tightness and therefore 

greater thermal and sound reduction 

properties. 

Sammon Contracting have an impressive 

track record in the current schools 

programme and have recently completed 

projects in Tullamore, Mornington, 

Kinnegad, Drogheda, Middleton and 

Gorey. Concast were selected to design, 

manufacture and install the Precast 

concrete frame at Flemington, Balbriggan. 

The Concast Precast Group, were 

appointed in December 2009, to provide 

a complete Precast concrete frame. 

Concast are focused on competitiveness 

through quality, supported by their quality 

management systems ISO 9001:2008. 

The design team consisted of DBFL 

Consulting Engineers and McCarthy 

O’Hora Associates. The designers opted 

for the Precast option for a variety of 

reasons, not least the quality of finish, 

speed on site and the reduction in the 

number of follow on trades and wet 

processes. The selection of an off-site, 

factory production process was fortuitous 

as it transpired that temperatures in early 

January 2010 fell to as low as -10°C. A 

construction process involving insitu 

concrete would almost certainly have led to 

a delay in the construction programme. In 

the event, all Precast units were produced 

in a quality controlled environment and 

were delivered to site as per the building 

programme. 

The new Flemington school consists of 

18 large open plan classrooms, with activity 

areas, multi media rooms, and teachers 

lounge. The design includes particular 

focus on energy issues with the objective 

of achieving energy performance levels 

approaching ‘passive building’ standards. 

The use of Precast concrete panels to form 

attic spaces, with steel rafters connected 

directly to the top of the sloping panels, 

enhances security and provides greatly 

improved internal fire compartmentation. 

The incorporation of cast-in items, such 

as recesses and Halfen channels, facilitates 

follow on trades and reduces the need 

for ladders and drilling on site, which 

is desirable from a Health and Safety 

perspective. 

The Precast wall panels were installed 

over a five week period, at a rate of 18 

panels per day (i.e. averaging over 500sq/m 

of wall panels per day). Concast’s justin-time 

delivery capabilities and the 

array of efficiencies inherent in Precast, 

create a speed advantage throughout the 

construction process, saving costs and 

meeting deadlines. 

T h e c o m p o n e n t s w h i c h w e r e 

manufactured at Concast’s plant in 

Newcastle West Dublin, include: 

• both non load-bearing and load-bearing 

precast concrete panels 

• hollowcore and wideslab floor/ceiling 

planks 

• precast columns and beams 

A total precast concrete system saves 

money in many ways, both in the short and 

long-term. When using precast structures, 

several trades and materials are eliminated 

from the construction process. The savings 

include costs often hidden within overall 

construction budgets and create advantages 

that continue to save throughout the 

building’s lifetime. These life-cycle savings 

help control operational budgets, resulting 

in lower construction costs today and a 

reduced public tax burden in the longer 

term. 

The approach and quality of work 

now being applied to projects such as 

Flemington in Balbriggan, will ensure 

that schoolchildren and teachers alike will 

be provided with the best educational 

environment in which to learn and work. 

Project Team 

ECAP, prefinished external insulation fixed to precast 

cladding panel as supplied by Protherm 

Client: 

Department of Education & Skills 

Project Managers: 

KSN Project Management 

Developer/Contractor: 

Sammon Contracting 

Architect: 

McCarthy O’Hora Associates 

Consulting Engineers: 

DBFL 

M&E Consultants: 

Semple McKillop 

Precast Structural Frame: 

Concast Precast Group 

Health & Safety: 

Safety Solutions 


9

concrete today - techrete - olympic village, london 2012 

Techrete - Olympic Village, London 2012 

Techrete Reproduces the Parthenon Marbles 


10

concrete today - techrete - olympic village, london 2012 

Precast Cladding Panels by Techrete Ltd. 

Ireland’s leading Precast concrete panel 

manufacturer, Techrete Ltd., is currently 

involved in the construction of apartment 

buildings in London’s Olympic village. The 

village will house the Olympic athletes for 

the 2012 Olympics and will comprise a 

series of mansion blocks, each containing 

6 to 7 buildings, arranged in courtyard 

formation and varying in height from eight 

to twelve stories. Techrete were chosen as 

the Precast panel manufacturers, for four 

mansion blocks primarily on the basis that 

the company could demonstrate the ability 

to deal with the challenges posed by the 

project, in particular its complexity and tight 

programme and logistics. 

The project posed a further unusual 

challenge, in that the Architects specification 

required that two of the buildings should be 

clad in reconstructed stone panels, faced in 

frieze type images, replicated from 5 of the 

famous Parthenon Marbles (see text in side 

panel) the majority of which are currently 

housed in the British Museum. The 

architects selected these images specifically 

to reflect the Greek origins and invoke the 

ancient spirit of the Games. 

Replicating the images from the 

Parthenon Marbles posed a significant 

challenge which was eventually resolved by 

the use of scanning technology. The use of 

this technology negated the need for casts 

Precast Cladding Panels 

by Techrete Ltd. 

to be taken, which could potentially have 

caused damage to the marbles and therefore 

was not a viable option. The Scanning 

equipment produced 3-D image files which 

were then transferred to a CNC (5 axis) 

routing machine to create a positive MDF 

(wooden) carved copy of the originals, from 

which rubber moulds were produced to 

cast the reconstructed stone panels. This 

was a complicated process which required 

approvals at all stages and a high degree of 

technical expertise. 

Precast Cladding Panels 

by Techrete Ltd. 

The architect’s specification required 

that the frieze images be replicated at three 

times the scale of the original marbles. The 

use of digital technology facilitated this 

aspect of the specification. Another aspect 

of the reproduction is that all elements of 

the frieze images which could act as rain 

shelves were filled-in (in the construction of 

the mould). This however does not detract 

from the appearance, since the panels 

are generally viewed from the underside 

(looking upwards) and therefore the three 

dimensional appearance is retained. 

The use of frieze panels in modern 

buildings is rare and this is due in part to 

the influence of the modern movement in 

WHAT ARE THE 

PARTHENON MARBLES? 

When the Parthenon was built between 

447BC and 432BC, three sets of 

sculptures, the metopes, the frieze and 

the pediments, were created to adorn it. 

Of these, the metopes and the frieze were 

part of the structure of the Parthenon 

itself. They were not carved first 

and then put in place, high up on the 

Parthenon, but were carved on the sides 

of the Parthenon itself after it had been 

constructed. 

The metopes were individual sculptures 

in high relief. There were 92 metopes, 32 

on each side and 14 at each end and each 

metope was separated from its neighbours 

by a simple architectural decoration called 

a triglyph. The metopes were placed 

around the building, above the outside 

row of columns and showed various 

mythical battles. The North side showed 

scenes from the Trojan war; the South 

side showed a battle between the Greeks 

and the Centaurs - part man, part horse; 

the East side showed the Olympian gods 

fighting giants and the West side showed 

a battle between Greeks and Amazons. 

The frieze, 160 metres long, was placed 

above the inner row of columns, so it was 

not so prominently displayed. It is one 

long, continuous sculpture in low relief, 

showing the procession to the temple at 

the Panathenaic festival. 

Not all of the Parthenon Marbles, 

however, survive down to the present 

day. There were originally 115 panels 

in the frieze. Of these, ninety-four still 

exist, either intact or broken. Thirty six 

are in Athens, fifty-six are in the British 

Museum and one is in the Louvre. Of 

the original ninety two metopes, thirtynine 

are in Athens and fifteen are in 

London. Seventeen pedimental statues, 

including a caryatid and a column from 

the Erechtheion are also in the British 

Museum. So the Parthenon Marbles are 

almost equally divided, half in London 

and half in Athens. 

architecture, which rejected all forms of 

ornamentation. A more relaxed attitude has 

developed in recent times, and although 

designers continue to successfully produce 

pure forms, there is also recognition that 

there is room in some instances for a more 

‘human’ architecture. 

The advanced panel manufacturing 

methods used by Techrete in the Olympic 

village has broader applications, and could 

be used to depict scenes from Celtic lore 

(for example) for use in Precast school 

buildings or indeed industrial buildings. 


11

concrete today - acropolis museum 

The New Acropolis Museum 

Introduction 

The New Acropolis Museum is the 

result of an architectural competition 

which was announced in 2001. The 

competition winners, Bernard Tschumi 

Architects, and a range of consultants 

(see credits) were appointed in September 

2001 and the design completed in August 

2002. Construction began in 2003 and 

the building phase was completed in 

September 2007. Following the transfer of 

artefacts, the museum was opened to the 

public in June 2009. The project was by 

co-financed by the Hellenic Republic and 

the European Regional Development Fund 

(ERDF) 

Although there are some local reservations 

as to the scale of the building, which is 

located adjacent to a residential area, there 

is general agreement that it is a structure 

worthy of the many priceless artefacts, of 

world significance which are on display. The 

museum is home to copies of the renowned 

Parthenon Marbles – marble friezes 

Caryatids erechtheoin 

Precast concrete cladding panels 

removed from the face of the Parthenon. 

Controversially, many of the original friezes 

(also known as the Elgin Marbles) are 

housed in the London History Museum. 

From an Irish Perspective, it is difficult to 

look at the exposed ancient ruins, cleverly 

housed under the new structure, supported 

photographs by Nikos Daniilidis 

on pilotis and partially exposed to the open 

air, without reflecting on ‘what might 

have been’, on Dublin’s Wood Quay. The 

building is largely constructed in reinforced 

concrete and glass, with precast concrete 

and some steel elements featuring in various 

parts of the structure. 

Architects Description - Text 

Bernard Tschumi Architects 

Gallery area 

Site 

Located in the historic area of Makryianni, 

the Museum stands some 300 meters 

(980feet) Southeast of the Parthenon. 

The top floor (Parthenon Gallery) 

offers a 360-degree panoramic view of 

the Acropolis and modern Athens. The 

Museum is entered from the Dionysios 

Areopagitou pedestrian street, which 

links it to the Acropolis and other key 

archeological sites in Athens. 

Programme 

With exhibition space of more than 

14,000 square meters (150,000 square 


12


feet) and a full range of modern visitor 

amenities, the New Acropolis Museum 

will tell the complete story of life on the 

Athenian Acropolis and its surroundings. 

It will do so by uniting collections that are 

currently dispersed in multiple institutions, 

including the outdated Acropolis Museum 

(built in the19th century with gallery space 

of 1,450 square meters, or 15,500 square 

feet). The rich collections will provide 

visitors with a comprehensive picture of 

the human presence on the Acropolis, 

from pre-historic times through late 

Antiquity. Integral to this program is the 

display of an archaeological excavation on 

the site of the Museum itself: ruins from 

the 4th through 7th centuries A.D., left 

intact and protected beneath the building 

and made visible through the first floor. 

Other program facilities include a 200-seat 

auditorium. 

Archaeological excavation 

Parthenon friezes gallery area 

of museum. Light for the exhibition of 

sculpture differs from the light involved 

in displaying paintings or drawings. The 

new exhibition spaces could be described 

as a museum of ambient natural light, 

concerned with the presentation of 

sculptural objects within it, whose display 

changes throughout the course of the day. 

Second, the visitor’s route through the 

museum forms a clear three-dimensional 

loop, affording an architectural promenade 

with a rich spatial experience that extends 

from the archaeological excavations to the 

Parthenon Marbles and back through the 

Roman period. Movement in and through 

time is an important aspect of architecture, 

and of this museum in particular. With 

over 10,000 visitors daily, the sequence of 

movement through the museum artefacts is 

designed to be of the utmost clarity. 

Third and finally, the building is 

divided into a base, middle, and top, 

Architectural Description 

Three concepts turn the constraints 

and circumstances of the site into an 

architectural opportunity, offering a simple 

and precise museum with the mathematical 

and conceptual clarity of ancient Greece. 

First, the conditions animating the New 

Acropolis Museum revolve around natural 

light – more than in any other type 

Archaeological excavation 


13


Eastern façade 

which are designed around the specific 

needs of each part of the building. The 

base of the museum floats over the 

existing archaeological excavations on 

pilotis to protect and consecrate the site 

with a network of columns placed in 

careful negotiation with experts so as not 

to disturb sensitive archaeological work. 

The orientation gently rotates as it rises 

Gallery area 

so that the main galleries in the middle 

form a double-height trapezoidal plate 

that accommodates the galleries from the 

Archaic period to the Roman Empire, and 

is shaped to respond to the contemporary 

street grid. The top, which is made up of 

the rectangular Parthenon Gallery arranged 

around an indoor court, rotates gently 

again to orient the Marbles exactly as they 

were placed at the Parthenon centuries ago. 

The glass enclosure provides ideal light 

for sculpture in direct view to and from 

the Acropolis while protecting the gallery 

against excessive heat and light, thanks to 

the most contemporary glass technology. 

The three major materials of the Museum 

are glass for the facades and some of 

the floors, concrete for the core and the 

columns, and marble for some floors. The 

East and West facades and the Parthenon 

Gallery columns are made of steel. 

Project Team 

Client 

Organisation for the Construction of the 

New Acropolis Museum 

Dimitrios Pandermalis, President 

Architect 

Bernard Tschumi Architects, New York/ 

Paris 

Bernard Tschumi, Architect and Lead 

Designer 

Joel Rutten, Project Architect 

Associate Architect 

Michael Photiadis, ARSY, 

Associate Architect, Athens 

Consultants 

Structure: ADK and Arup, New York 

Mechanical and Electrical: MMB 

Study Group S.A. and Arup, New York 

Civil: Michanniki Geostatiki and Arup, 

New York 

Lighting: Arup, London 

General Contractor: Aktor S.A. 

Leonidas Pakas, Project Manager 

Costis Skroumbelos, Architectural 

Consultant 

Glass Consultant: Hugh Dutton 

Associates (HDA) 

Southern Façade 


14

concrete today - icfai 

Insulating Concrete Formwork Association of 

Ireland Recently Formed 

Insulating Concrete Formwork House 

new organisation, the ICFAI was 

A recently formed to promote the 

objectives and goals of the Insulating 

Concrete Formwork sector. Comprising 

six companies, the ICFAI proposes to 

represent the industry in all dealings with 

the regulatory authorities, specifiers and 

the general public. It is intended that the 

formation of the new organisation will help 

to consolidate the ICF market in Ireland 

which has managed to establish itself in the 

last five years. 

Although relatively new to the Irish 

market , ICF has become established as 

a mainstream method of construction in 

Germany, France, the USA and Canada, 

following its introduction in the 1960’s. 

The system is highly thermally efficient and 

is suitable for residential, commercial and 

public buildings. 

There are four generic ICF types 

including block, plank, large panel and 

composites. The most common materials 

used in the manufacture of ICF’s is 

expanded polystyrene (EPS) or extruded 

polystyrene (XPS). The thickness of 

concrete varies from system to system and 

in accordance with structural requirements, 

but is normally in the range of 100mm 

to 300mm. The most commonly used 

sizes are 140/150mm and 200mm. The 

thickness of the external polystyrene 

can also be varied for additional thermal 

performance. Thicknesses of 150mm and 

200mm and U-values of 0.11 to 0.35W/m²k 

are not uncommon. 

Basement formed in Insulating Concrete Formwork 


15

concrete today - icfai 

Insulating Concrete Formwork Wall 

Insulating Concrete Formwork Upper Floor 

Insulating Concrete Formwork, 

is a permanent shuttering for the 

construction of concrete walls and floors. 

The formwork remains in place after 

the concrete is poured, as a permanent 

part of the wall assembly. The insulating 

formwork acts as thermal and sound 

insulation and in some systems is dovetailed 

to receive dry-lining on the inside 

Insulating Concrete Formwork House 

and plaster on the outside. The external 

render is comprised of a waterproof, 

mineral based render which is applied to 

a loose weave fabric mesh for adequate 

adhesion. ICF’s have a number of benefits 

including the virtual elimination of cold 

bridges, low air filtration, high thermal 

performance and dimensional accuracy. 

Panelled roof systems, with co-extruded 

steel stiffening members within the 

panel are also available. These panels 

are battened and counter-battened 

top and bottom for slating on top and 

to carry plasterboard on the underside 

and look identical to the traditional cut 

roof or trussed roof when completed. By 

eliminating timber trusses, and replacing 

them with reinforced polystyrene panels, 

cold bridging in the roof is virtually 

eliminated. 

ICF walls can be reinforced or 

un-reinforced depending on the loading 

requirements. Concrete beams, spanning 

window and door heads, can be easily 

constructed by inserting re-bar into the 

formwork prior to pouring the concrete. 

When the concrete is poured, the ICF 

walls can be subject to high levels of 

hydrostatic pressure, particularly if the 

mix is too wet. A 25N mix with a 10mm 

rounded stone is normally specified. To 

prevent misalignment of the walls the 

formwork is braced prior to the concrete 

pour. Proper bracing of the ICF is crucial 

to ensuring that the ICF walls are plumb. 

For further information contact the 

Irish Concrete Federation or alternatively 

contact the ICFAI companies direcly: 

The members of the newly formed ICFA 

are: 

Amvic Ireland, Naas, Co. Kildare 

Tel: 045 889276 

Clantec, Future Build Systems Ltd., 

Portarlington, Co. Offaly 

Tel: 057 8645000 

Kore, Kilnaleck, Co. Cavan 

Tel: 049 4374000 

Minimum Carbon Konstruction, 

Scotstown, Co. Monaghan 

Tel: 047 79792 

Thermohouse, Coolcaslagh, Killarney, 

Co.Kerry 

Tel: 064 6631307 

Warmbuild (Authorised Nudura 

Distributor) 

Tel: 057 8627318 


16

concrete today -zero carbon emissions 

Concrete Moves towards Zero Carbon Emissions 

By Liam Smyth FIEI, Sustainability and Marketing Manager, ICF 

In a previous article for Concrete Today, the initial design and early stages of 

construction of Ireland’s first Zero Carbon Emissions Concrete House were discussed. 

Now, as the project nears completion, key aspects of achieving the design targets as well as 

lessons learned are reviewed. 

Design Overview 

Originally designed to Passive House 

standards (and an A3 BER Rating in 

this case), the Irish Concrete Federation 

became involved in the project prior to 

construction, having agreed with the 

owner/builder the much higher targets of 

Zero Carbon Operational Emissions (from 

primary energy needs) and an A1 BER 

Rating (0-25 kWh/m² per annum for 

primary energy). 

Target U values of 0.1 W/m²K were 

adopted for the ground floor, external 

walls and roof, while an overall U value 

of 0.8 W/m²K was specified for windows. 

Outstanding thermal bridging performance 

was required, ever harder to achieve in a 

super insulated house, by the specification 

of a Y value of 0.04 W/m²K. 

General Construction Details 

Achieving these targets required very 

close attention to detail by both designer 

and builder as energy performance and 

constructability do not always go hand in 

hand. 

The foundation detail chosen was a raft 

foundation which is completely underlaid 

with EPS, with 200kPa non-compressive 

EPS under the beam sections and 100kPa 

specified under the floor areas. This 

minimises heat loss through the floor 

Window fixed with external brackets 

Zero Carbon Concrete House 

and substantially eliminates the thermal 

bridging heat loss problems associated 

with traditional strip and raft foundations 

directly in contact with the ground. 

Wall construction is a standard 

heavyweight block laid on the flat (215mm 

thick), plastered internally with EPS on 

the external face with a suitable render. 

While these details are similar to type 2 

wall construction as per the Acceptable 

Construction Details, published by 

DEHLG in late 2008, thermal bridging 

performance is achieved by windows 

and doors being cantilevered into the 

external insulation on simple stainless steel 

L brackets, in addition to the enhanced 

foundation details. 

At roof level, a warm roof detail whereby 

EPS is placed above, between and below 

the rafters was chosen. At eaves and 

gables, the insulation meets the external 

wall insulation to complete the insulation 

envelope. 

So, while overall a fairly simple build 

in principle, the devil is in the detail. 

Substantially, a direct build by the owner/ 

builder, technical expertise was provided 

by Aerobord Ltd., the chosen insulation 

supplier, and CPI Ltd., whose Baumit 

system was the chosen external render. 

Getting Foundations Right 

Working from a levelled base of Cl804 

aggregate, blinded with sand and covered 

with a radon barrier which also acts as a 

damp proof membrane, overlaid with the 

appropriate EPS grade for the location. The 

outside of the raft was timber formwork 

with all internal support for beam sections 

formed with EPS panels in place to provide 

the floor insulation. While this led to 

increased use of insulation, it saved on 

time and added certainty to the process, 

ensuring exact coverage and minimal 

thermal bridging. As built, the floor U 

value achieved was 0.09 W/m²K, even 

better than the design target. 

Of substantial overall importance 

is to bring all service pipes, e.g. sewers, 

water, electricity, air ducts, through the 

foundation to avoid breaking the insulation 

envelope above ground. All such piping 

was wrapped in insulation throughout 

the foundation to minimise thermal 

bridging. This complicated the foundations 

somewhat and is a plumber’s nightmare 

(given a lack of internal walls for guidance) 

but serves the project targets well. The raft, 

when poured, can then be power floated to 

leave the finished floor, thereby saving time 

later in the project. 

CEMEX (Ireland) Ltd.supplied the 

readymix concrete for the pour, using a low 

carbon 30N mix. The same company later 

supplied the blocks and first floor structural 

screed. 

Walls and Intermediate Concrete 

Floor 

In building a 215mm block wall, it is 

important to ensure that it is well jointed 

with mortar, to minimise air permeability, 

and kept smooth externally, to ensure the 

external insulation can be fitted correctly. 


17

concrete today -zero carbon emissions 

The external edge of the wall was 

180mm from the edge of the raft allowing 

for120mm of insulation to extend down the 

side of the raft in due course, in the same 

plane as the 300mm of external insulation 

would form later in the build. This raft 

edge insulation would then overlap with the 

200kPa insulation underneath the outside 

raft beam – again, this is done later in the 

construction process. 

The first lift was executed very quickly, 

with full depth lintels supplied by Killeshal 

Precast Ltd. to save time otherwise wasted 

making up heights with brickwork. 

The concrete intermediate floor selected 

was 100mm wideslab precast flooring 

from B.D. Flood Ltd., which was designed 

for use with a 100mm structural screed, 

although 125mm was used for reasons of 

levels with receiving steel. Importantly, 

the wideslab was placed on walls which 

had a wet mortar bed to help spread 

load correctly and also to ensure air 

impermeability between the slab underside 

and the external wall. 

Later in the build, the external wall must 

be sealed internally between where the 

slab rests and the level of the suspended 

ceiling, again to ensure air impermeability. 

Cementicious slurry would be used for this 

purpose. 

With the intermediate floor in place, the 

structural screed was poured and floated 

and within a few days was ready to support 

blockwork for the second lift. The roof 

structure was traditional cut timber rafter, 

highly insulated and finished in concrete 

slate tiles supplied by Condron Concrete 

Ltd. Most of the EPS for the roof was 

installed at this stage, using a simple jig 

template and hot wire to cut panels exactly 

to size. 

External Finishing 

Windows and doors, with an overall U 

value of 0.7 W/m²K, arrived from Haussler 

in Germany and were fitted to cantilever 

into the external insulation space. The 

insulation is then fitted tightly around the 

windows, with sealing tape connecting 

window frames to the block wall to avoid 

the most common form of air leakage. 

Zero Carbon Concrete House 

When the insulation is completed, the 

external render is applied. As this is a new 

build, as distinct from retrofit, two layers of 

base course were used to ensure longevity of 

the render. 

It should also be noted that super 

insulated houses requires depths of 

insulation beyond the normal range 

provided for in current IAB certification. 

Though the use of insulation in thicknesses 

greater than 200mm is not unusual 

in Europe, only recently has such IAB 

certification been applied for. In practice, 

the only difference found on this build was 

the use of some additional insulation ties 

around windows and doors which were 

easily fitted. 

Problems Encountered 

Low energy construction needs all 

aspects of the build to be thought out at 

design stage, as remedies for problems 

encountered during construction can be 

difficult to incorporate. Perhaps the biggest 

problem was that there are a number of 

cantilevered balconies which provided a 

substantial thermal bridging problem as 

they were part of the intermediate floor 

slab. The solution was to wrap the balcony 

in insulation with only stainless steel 

supports for safety rails allowed through the 

insulation. 

Simplicity of form, certainly in roof 

design, is to be encouraged, as it will 

minimise the number of points where 

placing substantial depths of insulation 

cannot be achieved. At these points, a 

proprietary textile, its’ 100m thickness 

equivalent to 50mm of the standard EPS, 

was used to save space and achieve the 

required U value. 

For aesthetic reasons, it was desirable to 

place the rainwater downpipes within the 

external cladding. As this compromised the 

depth of insulation, the proprietary textile 

insulant was again used to make up the 

difference to equivalent depths of standard 

EPS. 

Air Permeability 

As the house nears completion, a 

provisional “blower door” test will be 

carried out as will thermographic imagery 

to find any remaining construction 

weaknesses. It is hoped that the air tightness 

will be

concrete today - bridge beam construction 

New developments and advances in bridge 

beam construction 

By Peter Deegan, Banagher Concrete Ltd. 

Precast Concrete Bridge Beams, Banagher Concrete 

Many advances have been made in 

both the design and construction of 

precast prestressed bridge systems in recent 

years. Probabilistic design techniques 

and more efficient bridge beams (girders) 

help deliver faster and more cost effective 

solutions in leaner times. 

The range of bridge beams used in 

Ireland from the 1950’s was the same as 

that used in the U.K. These beams were 

developed by the Department of Transport 

and the Cement and Concrete Association. 

They are still in use today with the family 

being made up of the inverted T Beam, 

M Beam, Box Beam, TY Beam, Y Beam, 

Super Y and U Beam. 

Through R & D and continuous 

investment, Banagher Concrete Limited 

continually looked at improving the 

efficiencies of these systems and ways to 

potentially bring cost savings to the overall 



19

concrete today - bridge beam construction 


build. From 2000 to 2008 Banagher 

developed 3 new beam types to add to 

the range. The approval and acceptance 

of these beams involved third party 

checking and detailed reports. These 

reports were then submitted to the NRA 

(National Roads Authority) for analysis 

and approval. Having gained approval 

the Super U Beam was launched in 2000. 

This beam which in effect is a deeper U 

beam was developed to accommodate 

large spans. These spans were beyond 

the capacity of the existing U beam and 

provided more options to designers at 

longer spans. 

In 2005 the ‘W’ beam was developed 

as an alternative to the existing U, super 

U beam and Y beam ranges. The W 

beam system provides increased stability 

during transportation and erection, greater 

design economies and can accommodate 

longer bridge spans. The range typically 

spans from 17m to 45m. Investment in 

8 axle twin steering modular bogie systems 

ensures easy transportation to site with staff 

highly trained in their operation. 

In 2007 the MY beam was developed 

to provide a more efficient prestressed 

beam for the smaller span ranges. This 

compliments the existing inverted T and 

TY beam but, the 970mm soffit provides 

a complete closed bridge soffit. This beam 

is ideally suited over line rail and work may 

continue without the risk of falling debris. 

With these new products Banagher 

Concrete can now supply customers 

with more efficient, cost effective design 

solutions, the highest quality product and 

on time delivery. 



20

concrete today - fibre reinforced polymer 

FRP reinforced laterally restrained slabs for 

sustainable structures 

G Tharmarajah, S.E Taylor, D.J Robinson and D.J Cleland 

School of Planning, Architecture and Civil Engineering, Queen’s University Belfast 

Fibre reinforced polymer (FRP) 

reinforcement is a corrosion free 

alternative to steel in reinforced concrete 

structures to meet the structural and 

safety requirements. FRP is a light weight 

material with higher strength capacities, 

but the brittle behaviour and low modulus 

of elasticity were the perceived drawbacks 

of this composite material. Compressive 

membrane action (CMA) or arching 

action has a beneficial influence on the 

flexural strength of laterally restrained 

slabs. It has been recognised for some time 

that restrained slabs behave differently 

to simply supported slabs and thus FRP 

reinforcement may perform well in 

structure which develop CMA. 

Introduction 

Concrete can be a very durable 

material. However, the corrosion of 

steel reinforcement can cause severe 

deterioration to reinforced concrete 

structures which can result in spalling 

and cracking of concrete (see Figure 1). 

Extreme environmental conditions cause 

chloride intrusion and carbonation in 

concrete structures which subsequently 

lead to expansive corrosion of steel. 

Expansive corrosion in steel reinforcement 

significantly reduces the design life and 

durability of concrete structures. In some 

cases repair and maintenance costs, as a 

direct result of deterioration caused by steel 

corrosion exceed the original cost of the 

structure(1). 

Fibre reinforced polymer (FRP) 

reinforcement, stainless steel and epoxy 

coated steel reinforcement are alternative 

reinforcement materials to replace 

high yield steel in reinforced concrete 

structures(2). Among the alternatives, 

glass fibre reinforced polymer (GFRP) 

reinforcement has good strength, is cost 

effective, durable and widely available. 

Laterally restrained slabs are inherent 

in much of bridge deck construction. To 

date, the benefits of arching action have 

not been fully realised to produce highly 

durable FRP reinforced concretes slabs in 

Ireland and the rest of Europe. Therefore, 

this research investigates how the benefits 

of arching action can be incorporated 

to effectively use GFRP reinforcement 

Figure 1: Chloride induced corrosion damage 

(Courtesy: http://cce.oregonstate.edu) 

to replace conventional steel without 

compromising the strength, serviceability 

and safety of reinforced concrete slabs. 

Previous research has outlined preliminary 

findings(3, 4, 5) and this paper gives an 

overview of recent research at Queen’s 

University Belfast. 

Research Programme 

The research programme is aimed at 

investigating the effect of GFRP in laterally 

restrained concrete slab strips typical of 

bridge deck slabs in Y beam bridges in 

Ireland and the UK. Several parameters 

were investigated including bar size, 

different reinforcement percentage, 

spacing, position and size. The slabs 

were loaded with a knife edge line load 

representing local wheel loading on a 

bridge deck slab at the mid-span of the slab 

using an accurately calibrated hydraulic 

actuator (see Figure 2 & 3). A steel rig was 

used to represent the vertical restraint of 

Restraint, 

K 

b=475mm 

h=150mm 

d=effective 

Figure 2 – Model Test Slab Set-up 

Load, PkN 

the supporting Y beams and the horizontal 

restraint of the surrounding slab. 

Given concerns by some researchers and 

practitioners over the service behaviour 

of GFRP reinforced concrete slabs, the 

deflection and crack width and pattern 

were fully investigated within the service 

load range. Deflection was observed 

directly below the loading line using two 

50mm displacement transducers. A steel 

rig was used to represent the supporting Y 

beams and surrounding area of unloaded 

slab. The displacement of the rig was 

monitored using two 25mm transducers 

placed at both ends of the rig to check 

for any lateral expansion. The strain 

development on GFRP bars was monitored 

using embedded Fibre Optic Sensors (FOS) 

and Electronic Resistant Strain (ERS) 

gauges. Crack width development was 

recorded using vibrating wire gauges placed 

perpendicular to the primary cracks formed 

during the test. 

1425mm clear span 

h 


21


Figure 3 – Test rig and test arrangement 

Test Test slabs Concrete 

Strength 

(N/mm2) 

S1 

S2 

S3 

S4 

LRS-0.6%- 

12mm-125 

C 

LRS-0.6%- 

12mm-125 

T&B 

LRS-0.15%- 

8mm-300 

C 

LRS-0.15%- 

8mm-300 

T&B 

Failure 

load 

(kN) 

Deflection 

at failure 

(mm) 

Maximum 

strain on bar 

at failure(µE) 

Failure mode 

64.7 235 16 10534 Concrete 

crushing 


crushing 


crushing/ FRP 

rupture 


crushing/ FRP 

rupture 

It was found that the slabs reinforced 

with two reinforcement layers were stiffer 

than the slabs reinforced with single 

mid-depth reinforcement. However the 

significant effect of CMA can be seen 

through comparing S2 with S4. Slab S2 

(0.60% GFRP) was reinforced with 4 

times as much reinforcement as S4 (0.15% 

GFRP), but the maximum load capacity 

difference between those two slabs was only 

17% of slab S4. Even more striking is the 

fact that S1 (0.60%) failed at 90% of the 

failure load of S3 (0.15%); both with middepth 

reinforcement. 

A comparison of two slabs, one with steel 

reinforcement and the other with GFRP, 

is presented in Table 2. This shows that 

Table 1: Test results 

Test Results and Discussion 

The four slabs were used to analyse the 

influence of reinforcement percentage and 

position on the performance of the laterally 

restrained slabs. The first two slabs were 

reinforced with 0.6% GFRP reinforcement 

and the other two with 0.15%. Among 

those two, one was reinforced with single 

mid-depth reinforcement and the other 

was reinforced with two layer conventional 

reinforcing method. The test results are 

provided in Table 1. Load versus deflection 

behaviour of the four slabs is shown in 

Figure 4. 

Figure 4 – Load Vs Deflection of slabs 


22


Figure 5: Condition of GFRP inside a tested slab (No indication of rupture on bars) 

Figure 6: Ruptured GFRP during material test 

the failure load is very similar for both 

slabs. This shows that CMA is the main 

contributor to the ultimate capacity of the 

slabs and since the capacity is far in excess 

of the design load the lack of ductility is 

not a significant issue. Serviceability on 

the other hand, is ensured by the GFRP; 

in the case of crack width when placed 

near the surface only. Also there was no 

evidence of complete GFRP rupture when 

the embedded bars were examined after 

tests (Figure 5 and Figure 6). 

III. Compared with laterally restrained 

slabs reinforced with an equivalent 

amount of steel reinforcement those 

reinforced with GFRP showed excellent 

performance at ultimate load. 

Therefore GFRP reinforcement can be a 

substitute for steel in restrained slabs such 

as bridge deck slabs. 

Acknowledgement 

• Irish Concrete Society for awarding 

a Travel Bursary to attend the Fibre 

Reinforced Polymer Reinforcement for 

Concrete Structures 2009 Conference. 

• Schock Bauteile GmbH, Germany 

for generously providing GFRP 

(ComBAR) material for the research 

and staff at QUB for their supports 

with experiments. 

• Sengenia (http://www.sengenia.com/) 

for providing Fibre Optic Sensors for 

the research. 

Reference 

1. Read, J.A, ‘FBECR, The need for 

correct specification and quality 

control’, Concrete, Vol.23, 8, 23-27, 

1989. 

2. Clarke, J.L., The need for durable 

reinforcement, Alternative Materials 

for Reinforcement and Prestressing of 

Concrete, Chapman & Hall, (1993). 

3. Taylor, S.E. and Barry Mullin, ‘Arching 

action in FRP reinforced concrete 

slabs’, Construction and Building 

Materials, 20, 71-80, (2006). 

4. Tharmarajah, G., Robinson, D.J, 

Taylor, S.E & Cleland, D.J, FRP 

reinforcement for laterally restrained 

slabs, Proceedings of Bridge and 

Infrastructure Research in Ireland 

2008, December 2008. 

5. Tharmarajah, G., Cleland, D.J., Taylor, 

S.E & Des Robinson, Compressive 

Membrane Action in FRP reinforced 

slabs, Proceedings of Fibre Reinforced 

Polymer Reinforcement for Concrete 

Structures 2009, July 2009. 

6. Taylor, S.E., Rankin, G.I.B., Cleland, 

D.J, ‘Arching action in highstrength 

concrete slabs’, Proceedings 

of the Institution of Civil Engineers 

Structures and Buildings, Institution 

of Civil Engineers,Vol.146,4, 353-362, 

2001. 

Table 2: Comparison of test results with some previous research results 

Conclusion 

The following conclusions were drawn 

from this experimental study. 

I. Restrained slabs can have substantial 

ultimate capacity even with minimum 

amounts of reinforcement. 

II. GFRP reinforcement in laterally 

restrained slabs showed excellent service 

behaviour in terms of deflections and in 

terms of crack widths. 

Slab Reinforcement Reinforcement 

yield stress (N/ 

mm 2 ) 

S5 

(Taylor 

et al., 

2006) 

S6 

(Taylor 

et al., 

2006) 

GFRP 0.5% at 

Mid depth 

Steel 0.5% at 

Mid depth 

fcu 

(N/ 

mm 2 ) 

Failure 

load 

kN 

504 67.9 200 12.0 

530 85.0 210 15.0 

Deflection 

at 115 kN 

load (mm) 


23

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8 Newlands Business Park, Naas Road, Clondalkin, Dublin 22 

Tel: 01 464 0082 Fax: 01 464 0087 E-Mail: info@irishconcrete.ie Web: www.irishconcrete.ie

Concrete Today May 2010 - the Irish Concrete Federation

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