带粉刷层混凝土试块高温后抗压性能试验及数值模拟

以过火温度和粉刷层厚度等参数为主要研究对象,通过27个带混合砂浆粉刷层的混凝土立方体试块高温作用后的抗压性能试验,并与其热-结构耦合数值计算分析的结果进行对比.研究结果表明:高温作用后混凝土的损伤程度与过火温度、粉刷条件、恒温持时和静置时间等有关;过火温度越高,损伤越严重,抗压强度越低;粉刷层对遭受火灾作用的混凝土结构有较好的保护作用,能有效减少外部能量输入结构;四面受火混凝土试块的温度分布呈环形分布由表面向内部温度逐渐降低,且试块截面4个角部温度最高.

Experimental Study and Numerical Simulation on the Compressive Behavior of Concrete Cubes with Mortar Cover after Exposure to Fire

Twenty-seven concrete cubes with mortar cover after exposure to fire were tested under axial loading to investigate the axial compressive behavior of specimens.The main parameters are temperature in the furnace and thickness of the mortar cover.Thermal-structure coupling analysis of these concrete cubes using ANSYS was carried out,the calculation results was compared with test results.It is indicated that the damage of the concrete cube due to fire is influenced by the fire temperature,mortar cover,duration of fire and time for cooling down;the increase of the fire temperature dete-riorates the damage,and lowers the compressive strength;the mortar cover can effectively protect the concrete members from the damage of fire.The temperature distribution of concrete cubes exposed to four-side fire is of circle shape,and the temperature of concrete cubes decreases from the outside to the inside of the concrete cubes.The temperature at the corner of the cubes is the highest.