中文摘要：

采用有限元法对组合楼板简支板和连续板在火灾下的热、结构响应进行模拟研究，得到简支板温度场分布及挠度随时间的变化曲线，并与试验结果进行比较，分析3跨连续板中跨受火后的变形特征及内力重新分布规律，研究负筋长度和直径对连续板抗火性能的影响．结果表明：连续板为超静定结构，受拉钢筋处于低温区，能充分利用其强度，抗火性能优于简支板；支座反力随火灾温度的变化，反映了结构内力的重新分布规律；负筋长度影响楼板的变形形态和变形过程，但对最终挠度影响不大，为提高抗火性能建议负筋长度取为板跨的1／2～2／3；增大负筋直径可明显减小挠度，对抗火有利．

英文摘要：

The finite element method is applied to simulate thermal and structural coupling responses of the simple supported and continuous composite deck slab in fire. The transient temperature distribution and the curves of deflection versus time of simple supported slab are obtained. The results acquired from nu merical simulation are compared with ones of experiment. The regulations of deformation and internal forces redistribution are discussed when the middle span of a three span continuous slab is on fire. The effects of length and diameter of negative bending moment reinforcement on fire behavior of continuous slab are studied. The results show that the continuous slab is an indeterminate structure and its fire resist ance performance is better than that of simple supported slab because the reinforcements in tension are in the low temperature region and their strength can be fully utilized. The reaction forces vary with elevated temperature, which indicates the redistribution of the internal forces. The length of negative bending moment reinforcement affects the shape and process of deformation of the slab, it does not do the final deflection. For improving the fire resistance performance of the continuous slab, it is suggested that the length of negative bending moment reinforcement is 1/2 to 2/3 of span. When the diameter of negative bending moment reinforcement is increased, the deflection is obviously decreased, which is favorable for fire resistance.