孔级配对高温下泡沫混凝土强度的影响

Effect of pore gradation on the strength of foamed concrete at high temperature

文章基于40、60、70 g/L 3种泡沫密度制备3种孔级配(孔径分布)的泡沫混凝土,通过测量其高温煅烧后的强度和强度残余率,研究孔级配对高温下泡沫混凝土强度的影响规律;采用显微镜图像处理技术,探究泡沫密度对泡沫混凝土孔级配的影响规律及其与泡沫混凝土强度之间的关系。结果表明:在105~800℃温度条件下,基于40 g/L泡沫密度所制备的泡沫混凝土残余抗压强度和残余抗折强度最大;平均孔径越大,泡沫混凝土的抗折强度越大;孔径小于200μm的孔径占比越小,孔径在400~600μm之间的孔径占比越大,泡沫混凝土的残余抗压强度越大;孔径在200~400μm之间的孔径占比越大,泡沫混凝土的残余抗折强度越大。

Based on three foam densities of 40, 60 and 70 g/L, three kinds of foamed concrete with different pore gradation(pore size distribution) were prepared. By measuring the strength and strength residual rate after calcination at high temperature, the influence of pore gradation on the strength of foamed concrete at high temperature was studied. In addition, microscopic image processing technology was used to explore the influence of foam density on the pore gradation of foamed concrete and the relationship between foam density and foamed concrete strength. The results show that at 105-800 ℃, the residual compressive strength and residual flexural strength of the foamed concrete prepared based on 40 g/L foam density are the highest. The larger the average pore size is, the greater the flexural strength of foamed concrete is. The smaller the proportion of pore size smaller than 200 μm, and the larger the proportion of pore size between 400-600 μm, the greater the residual compressive strength of the foamed concrete is. The larger the proportion of pore size between 200-400 μm, the greater the residual flexural strength of the foamed concrete is.