FATIGUE BEHAVIOR OF A DEVELOPED UHPC-FILLED PRECAST DECK JOINT IN BULB-TEE BRIDGE GIRDER SYSTEM REINFORCED WITH SAND-COATED GFRP BARS

摘要

This paper investigates experimentally the use of corrosion-resistant glass fiber reinforced polymer (GFRP) bars to reinforce the precast deck slab joints in prefabricated bridge bulb-tee (DBT) girders system. In this system the concrete deck slab is cast with a prestressed girder and casting a closure strip between precast flanges to provide continuity between the girders. The aim of this study is to develop joint detail between the precast flanges of the DBT girders, incorporating sand-coated GFRP bars with headed ends embedded in a closure strip filled with ultra-high-performance concrete (UHPC). Two actual-size, GFRP-reinforced, precast concrete deck slabs were erected to perform fatigue tests and determine their behavior under CHBDC truck wheel loading. Each slab has 200 mm thickness, 2500 mm width and 3500 mm length in the direction of traffic. Fatigue behavior and fatigue life of the GFRP reinforced precast (DBT) bridge girders system were investigated using different schemes of cyclic loadings (accelerated variable amplitude cyclic loading as well as constant amplitude cyclic loading followed by loading the slab monotonically to failure). Overall, the test results demonstrated the excellent performance of the developed closure strip details.