再生混凝土筒体壁厚对抗火性能的影响

INFLUENCE OF WALL THICKNESS ON FIRE RESISTANT PERFORMANCE OF RECYCLED CONCRETE TUBULAR STRUCTURES

为研究再生混凝土筒体的抗火性能,进行了1个普通混凝土筒体和2个再生混凝土筒体的抗火性能试验,比较分析了其耐火极限及温度场分布的差异。基于试验,对筒体温度场进行了数值模拟,研究了不同筒体壁厚对其温度场分布的影响,提出了再生混凝土筒体在高温作用下的承载力计算公式。通过算例,研究了8个不同壁厚、不同混凝土材料筒体的承载力和耐火极限。研究表明:壁厚相同时,再生混凝土筒体比普通混凝土筒体的耐火极限相对短些,耐火性能相对差些;随着筒体壁厚的增加,再生混凝土筒体在高温作用下的承载力增大,耐火极限增长,抗火性能增强,与普通混凝土筒体有相似的规律。

In order to study the fire resistant performance of recycled concrete tubular structures, the test on the fire resistant performance of one normal concrete specimen and two recycled concrete specimens has been carried out. The differences of the fire endurance and temperature field distribution have been analyzed. Based on the experiment, the numerical simulation on temperature fields was processed; the influence of wall thickness on fire resistant performance was studied; the calculated formula of load beating capacity of the specimens under high temperature was proposed as well. The load bearing capacity and fire endurance of 8 tubular structures with different wall thicknesses and different concrete were analyzed by numerical examples. Results show that comparing to normal concrete tubular structures with the same wall thickness, the fire endurance is a little shorter and the fire resistant performance is a little worse for the recycled concrete specimens. The load bearing capacity, the fire endurance and the fire resistant performance of recycled concrete tubular structures increase with the wall thickness increasing, which is the same as the normal concrete tubular structures.