湿热环境下低吸水率玻化微珠保温砂浆配合比研究

Study on mix ratio of low water absorption vitrifiedbeads insulating mortar in hydrothermal environment

为解决东南沿海地区显著的风驱雨(WDR)现象易引起的建筑外墙渗水、墙体材料劣化等问题,通过两阶段共14组配合比试验,配制了一种低吸水率的外墙玻化微珠水泥基材料,研究了其在湿热环境下累计吸水量与吸水后导热系数的变化规律。研究结果表明:与混凝土相比,玻化微珠水泥基材料可以显著降低材料的导热系数、吸水量,热工性能优异,玻化微珠保温砌块可以有效提高砌块的热工性能,但也会降低材料抗压强度。与混凝土相比,玻化微珠水泥基材料的导热系数、7 d累计吸水量和吸水7 d后导热系数分别为0.336 W/(m·K)、185.8 g和0.483 W/(m·K),分别是混凝土的26.4%、62.4%和30.1%,吸水7 d后导热系数增大0.147W/(m·K),增幅为混凝土的44.3%。

In order to address the significant issue of wind driven rain(WDR)phenomenon in the southeastern coastal areas,which can easily cause water seepage on building exterior walls and deterioration of wall materials,a total of 14 groups of mix proportion tests were carried out in two stages.A low-water-absorption vitrified beads cement-based material for exterior walls was prepared and studies were conducted about the changes in thermal properties such as water absorption rate and thermal conductivity after water absorption in humid and hot environments.Research results indicate that compared with concrete,vitrified beads cement-based materials can significantly reduce the thermal conductivity and water absorption of the material,showing excellent thermal performance.Vitrified beads insulation blocks can effectively improve the thermal performance of blocks,but also reduce the compressive strength of the materials.Compared with ordinary concrete,the thermal conductivity,cumulative water absorption after 7 days,and thermal conductivity after 7 days of water absorption of vitrified microsphere cement-based materials are 0.336 W/(m·K),185.8 g,and 0.483 W/(m·K),respectively,which are 26.4%,62.4%,and 30.1%of those of concrete respectively.After 7 days of water absorption,the thermal conductivity increases by 0.147W/(m·K),which is 44.3%of that of concrete.