泡沫混凝土和混凝土耐火极限的比较研究

泡沫混凝土用在建筑节能保温工程中,其耐火性能对提高建筑物的抗火灾能力非常重要。在模拟火灾条件下,通过测定不同密度、不同煅烧时间、不同含水量的泡沫混凝土和混凝土的抗压强度值,比较泡沫混凝土和混凝土的耐火极限的变化规律。结果表明,在火灾条件下,泡沫混凝土和混凝土的抗压强度损失率均随密度的增大而降低;密度为300kg/m3和800kg/m3的泡沫混凝土,在800℃下煅烧20min后,其抗压强度损失率分别为66.3%和25.5%;在同样的煅烧条件下,密度为2200kg/m3和2400kg/m3混凝土的抗压强度损失率分别为18.6%和15.8%;泡沫混凝土和混凝土的含水量越高,耐火极限就越长。泡沫混凝土为具有不燃特性A级保温材料,被用于建筑外墙保温隔热材料时,其抗压强度会因火场可燃材料的高温煅烧而有所降低,但其耐火极限能完全满足《建筑防火设计规范》。

Comparison of the fire resistance limits of foamed concrete and concrete

Foamed concrete is used in architectural energy conservation and thermal insulation engineering, and its fire perform ante is very important for the fire resistant ability of building. In simulated fire conditions, the comlcressive strength values of foamed concrete and concrete were measured and compared in different densities, calcining time, and water contents, in order to investigate the fire resistance limit of foamed concrete. The results show that the compressive strength and the loss rate both decrease with foam density. When the foamed concrete was calcined at 800~C for 20rain, the compression strength loss rates were respectively 66.3% and 25.5% for foam densities of 300kg/m^3 and 800kg/m^3, and the values were 18.6% and 15.8%for densities of 2200kg/ma and 2400 kg/m^3 , respectively. Higher water content leads to longer fire resistance limit for both foamed concrete and concrete. When the foamed concrete is used for building external wall material and is subject to fires, its compressive strength will decrease due to high-temperature calcination. However, the fire resistance limit of this material can meet the standard ＂Code of Design on Building Fire protection and prevention＂.