Reduction of Joint Seepage and Cross-Grouting in Bridge Segments

摘要

Epoxy is normally used to seal segment joints in precast/prestressed concrete bridges. Historically, it has not always been possible to create a good seal at the joint faces. Two new epoxy applications were tested in this study; a top strip recess at the joint, and a recessed annulus groove around the duct that provides a distinct guide for the proper amount of epoxy application. Eight segmented beams were fabricated with various combinations of epoxy-face applications, top strip and annulus. The beams were post-tensioned with a minimum required prestress force. Tanks placed above the joints were used to measure the seepage of water and joint permeability comparisons. Pressurized water was used to detect cross-grouting between ducts. The top strip provided slightly more seepage resistance than that provided by the current one-face epoxy application technique. This feature also improved alignment problems, segment defects, and epoxy application procedures. The practice of one-face application performed well in both tests, but problems occurred in providing the proper epoxy thickness and clearances. Both features performed well and assisted the epoxy application process in producing a reliable joint equivalent to solid concrete.