ULTIMATE 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 glass fiber reinforced polymer (GFRP) bars to reinforce the precast bridge deck slab joints in prefabricated bridge bulb-tee (DBT) pre-tensioned girders. In this system, the concrete deck slab is cast with the prestressed girder at the precast plant, while precast slabs are jointed together using GFRP headed-end bars projecting into closure strips to provide continuity between the girders. The purpose of this study is to develop joint detail between the precast flanges of the DBT girders, incorporating GFRP bars with headed ends projecting into a closure strip filled with ultra-high performance concrete (UHPC). A precast GFRP-reinforced concrete deck slab was erected on two steel Ⅰ-girders with transverse K-bracings at their ends, to perform an ultimate test under increasing static wheel load. The slab has 200-mm thickness, 2500-mm width and 3500-mm length in the direction of traffic, and reinforced with the GFRP reinforcement ratio specified in the Canadian Highway Bridge Design Code (CHBDC). The experimental results indicate that ultimate load carrying capacity of the tested GFRP-reinforced slab is more than four times the factored wheel load specified by CHBDC.