EXPERIMENTAL STUDY ON MECHANICAL PERFORMANCE OF STEEL-CONCRETE GIRDERS UNDER FIRE LOADING

The mechanical performance of steel-concrete girder structure under fire loading was investigated in the present study. Three typical scale models: a simply supported T-shape girder, a simply supported box girder and a continuous box girder, were manufactured. Fire loading was then applied on three sides of the girders in a fire experimental oven. The behavior of the these girders under normal condition and fire loading was observed. The thermal distribution and structural deformation of the three girders were also measured. Results show that thermal energy mainly concentrates in the steel girder in the composite structure, and the temperature rises fast in a non-homogeneous pattern. Concrete slabs absorb the heat energy to a certain extent, and their influence on temperature rising and thermal distribution of steel girders cannot be neglected. From deformation measurement, it is seen that continuous steel-concrete girders have a better anti-fire performance than simply-supported girders. Outcomes from the current study are expected to provide experimental guidance and theoretical reference for ati-fire design and analysis of steel-concrete girders.