Repetitive Load Test on Composite Precast Concrete Decked Bridges

摘要

Bridge deck replacement using precast concrete panels minimizes replacement time as well as traffic interference. An experimental study consisting of a repetitive load test on a 1/3 scale model of a 60-ft I-beam composite bridge with precast concrete panels connected with epoxy mortar and shear stud connectors is described here. Two million load cycles of an equivalent HS20-44 AASHTO design truck were applied to the model while deflections, flexural strains and slip displacements were continuously instrumented to determine changes in the flexural properties of the bridge or deteriorations at the interface connections. The results were analyzed and revealed no significant changes in the flexural properties after the two million cycles were applied. There was also no evidence of any expoxy mortar bond failure at the interface even though the amount of bond area was minimized. The epoxy mortar bond, although it is not considered for design, prolongs the fatigue life of the mechanical shear stud connectors. It is concluded that this type of construction yields a fatigue-resistant interface connection.