Handbook for Bridge Inspections - TSP2

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