【摘要】 为了研究钢筋混凝土简支梁在高温过程中破坏形态的变化规律，通过建立钢筋混凝土简支梁的温度场模型，计算高温过程中钢筋混凝土简支梁的极限承载力。并对考虑不同影响因素的3组简支梁试件进行理论分析，研究高温过程中不同参数对简支梁破坏模式临界点β的影响。结果表明：受拉侧纵筋配筋面积越大，β点对应受火时间t越滞后；混凝土保护层厚度的增加使得β点对应受火时间t提前，但影响较小；混凝土强度越高，β点对应受火时间t越提前。并确定各参数与临界点受火时间之间的计算方法。更多还原

【Abstract】 In order to study the change rule of failure mode of reinforced concrete simple supported beam in the process of high temperature,this paper calculates the ultimate bearing capacity of reinforced concrete simple supported beam in the process of high temperature by establishing the temperature field model of reinforced concrete simple supported beam. Three groups of sim-ply-supported beam specimens with different influence factors are analyzed theoretically to study the effect of different parameters on the critical point β of the failure mode of simply-supported beam in the process of high temperature. The results show that the larger the area of longitudinal reinforcement on the tension side,the time t corresponding to the point β under fire lags behind.The increase of concrete cover makes the fire time t corresponding to the point β advance,but the impact is small. The higher the concrete strength,the earlier the fire time t corresponding to the point β is. And the calculation method of the relationship between the parameters and the fire time at critical point is determined.更多还原