Section 5: Bridge Caps
Risks of Chemical Damage
Bridge caps support the superstructure and are the elements
on which the beams are supported. Chemical damage occurs to caps
when the sealed expansion joints fail and the concentrated chemical
solution either falls from the deck through the joint to the cap
or it travels through the joint down the beam to the cap. Contamination
and damage to the cap can be accelerated when caps are finished
flush and the chemical solution is allowed to pond on the cap.
Maintain Joint Systems
Maintenance personnel should maintain joint systems, eliminating the possibility of chemical solution saturating this structural element. If joint systems have failed, or are designed as an open system, caps should be washed at the end of snow season.
Figure 5-7. Corrosion induced damage in high stress cantilever design.
Figure 5-8. Failure on cap due to corrosion damage. Bridge was closed until repair could be performed.