受火混凝土温度场的试验与数值模拟研究

Numerical Simulation and Experimental Study on the Temperature Distribution of Concrete under the Fire

对火灾下预埋温度传感器的混凝土试件进行高温试验,研究了单面受火和三面受火两种工况下温度在混凝土内部的传播以及分布规律。在试验的基础上采用大型通用软件ANSYS对混凝土试件内部的温度场进行了数值模拟,数值模拟结果与试验结果吻合较好。结果表明:混凝土单面受火或三面受火时,同时间下不同截面高度处的温度值不同,说明温度沿截面高度的传递存在时差;在两种受火工况下,当混凝土内部温度达到100℃时会出现温度平台,试件表面会伴随出现潮湿现象;两种受火工况下混凝土内部的温度随时间的增长规律类似,但是距受火面相同高度处的温度值不同。

A high temperature test is carried out on concrete specimens embedded in a temperature sensor under fire.The propagation and distribution of temperature in concrete when the specimens are exposed to fire on one face or three faces is studied.On the basis of experiments,ANSYS is used to simulate the temperature field of concrete specimens,and the numerical simulation results are consistent with the experimental results.The results of this study show that under the two fire conditions,a temperature platform will appear on the temperature rise curve when the internal temperature of the concrete reaches about 100℃or so,at the same time water vapor produced on the surface of the specimen.The growth of temperature with time inside the concrete is similar,but the temperature is different.Moreover,the difference of temperature at different heights is different.At the same time,the temperature values of concrete specimens at different heights is different,this shows that there is a time difference in the temperature transfer along the height of the cross sections.