1.Jiangsu Key Laboratory of Environmental Impact and Structural Safety in Engineering, China University of Mining & Technology,
Xuzhou 221008, China; 2. State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of
Mining & Technology, Xuzhou 221008, China; 3. Zhejiang University, Hangzhou 310058, China; 4. Institute of Building Fire Research,
China Academy of Building Research, Beijing 100013, China
Abstract：To investigate the mechanical behaviors of different spans subjected to fire in order, fire tests were conducted on three concrete continuous slabs. The influence laws of some parameters, such as the fire subsequences, time interval, reinforcement ratios and reinforcement layout, on the temperature, deflection, corners’ reaction forces and failure mode of the continuous slabs, were analyzed. In addition, the limit load-bearing capacity of each span in the continuous slabs were calculated and compared based on six theoretical methods. Experimental results show that the furnace temperature of each span and the temperature of slabs were mainly dependent on the self-furnace temperature. Meanwhile, the fire scenarios and the boundary conditions have important effects on the mid-span deflection trend, crack patterns and failure mechanism of the continuous slabs. The deflection trends in edge spans and middle spans were different. Compared to that of the edge spans, the cracks in the middle span were relatively more, and the integrity failure easily occurred in the middle span. Theoretical results show that compared to the effects of the boundary condition and the tensile membrane action, the fire sequences and reinforcement ratio have more critical effects on the limit capacities of different spans in the continuous slabs. In all, for any fire scenario, increasing reinforcement ratio and using the continuous reinforcement are beneficial to enhance the fire resistant performance of the concrete continuous slabs.
