2015 CSCE Annual Conference Regina - Building on our Growth Opportunities Conference
Dr. Khaled Sennah, Ryerson University
Precast full-depth deck panels (FDDP) with transverse joints, placed over steel or concrete girders, are efficient in rapid bridge replacement. In this system, grouted pockets are provided to accommodate clusters of shear connectors welded to steel girders or embedded in concrete girders. In this research, ultra-high performance fibre-reinforced concrete (UHPFRC) and high-modulus glass fibre reinforced polymer bars are utilized in the closure strip between the adjacent precast for enhanced strength and durability. Two actual-size, GFRP-reinforced, precast FDDPs were erected to perform fatigue tests using the foot print of the truck wheel loading specified in the Canadian Highway Bridge Design Code (CHBDC). Each FDDP had 200 mm thickness, 2500 mm width and 3700 mm length in the direction of traffic and rest over braced twin-steel girder system. The transverse closure strip between connected precast FDDPs has a width of 200 mm with female-to-female vertical shear key designated as C-shape joint to increase moment capacity along the interface between the UHPFRC and the precast FDDP along the joint. GFRP bars in the precast FDDPs project into the closure strip with a development length of 175 mm. Two types of fatigue tests were performed, namely: (i) high-cyclic constant amplitude fatigue loading followed by loading the slab monotonically to-collapse; and (ii) low-cyclic accelerated variable amplitude cyclic loading. Overall, the test results demonstrated the excellent fatigue performance of the developed closure strip details. In addition, the ultimate load carrying capacity of the slab was far greater than the factored design wheel load specified in CHBDC.