【摘要】 为了描述混凝土高温爆裂对构件热传导过程的影响,结合钢筋混凝土梁火灾试验,考虑爆裂时间和区域的不确定性,建立了火灾下钢筋混凝土梁数值分析模型,分析爆裂深度、爆裂面积比、爆裂位置等爆裂参数对梁跨中截面温度场的影响规律。研究结果表明:当钢筋混凝土梁发生受火爆裂,梁截面的温度显著升高,并随爆裂深度的增大而进一步增强;爆裂面积比对截面温度场影响不显著,当爆裂深度、爆裂位置一定,爆裂面积比增加达到13%左右时,截面温度场基本上不再变化;爆裂深度、爆裂面积比一定,梁跨中爆裂对截面温度场影响最大,但是底部纵筋处温度较顶部纵筋处温度升高较快。更多还原

【Abstract】 In order to describe the effect of concrete high-temperature spalling on the heat transfer process of components more scientifically,combined with the fire tests of reinforced concrete beam,a numerical analysis model of reinforced concrete beam under fire was established considering the uncertainty of spalling time and location. The influence of spalling parameters such as spalling depth,spalling area ratio and spalling location on the cross-section temperature field of the beam span was analyzed. The results showed that when the reinforced concrete beam occurred the spalling under fire,the temperature of the beam cross-section increased significantly and further enhanced with the increase of spalling depth. The spalling area ratio had no significant effect on the cross-section temperature field,and when the spalling depth and spalling location were certain and the spalling area ratio increased to about 13%,the cross-section temperature field no longer changed basically. When the spalling depth and spalling area ratio were certain,the spalling at the middle of beam span had the greatest influence on the cross-section temperature field,while the temperature at the bottom longitudinal bar increased more quickly than that at the top longitudinal bar.更多还原