A TEST AND ANALYSIS OF ULTIMATE LIMIT STATE OF CONTINUOUS COMPOSITE GIRDER BRIDGES BY APPLYING THE THERMAL PRESTRESSING METHOD

Abstract

At an intermediate support of continuous composite girder bridge, the compressive stress is generally introduced into the concrete-slab to improve the serviceability limit state of girder. The main method for introducing the compressive stress is jack-up-and-down or PC-bar methods. These methods can improve the serviceability limit state, whereas they cannot improve the ultimate limit state of bridges. The authors have been studied thermal prestressing method by using the stiffning members in order to improve the serviceability limit state of girder. In this paper, the experiment of loading test for two-span continuous composite girder model by applying this thermal prestressing method is presented herein and then the effect of improvement conserning the ultimate limit state, i.e. ultimate strength of girder by this method is discussed concretely through the comparisons with analytical results.