加气混凝土吸水特性研究及优化

Investigation on water absorption behavior of autoclaved aerated concrete and optimization

通过统计分析,研究了B06级砂加气混凝土干燥收缩与吸水率的关系及抗压强度与含水率的关系,并利用BSE图像分析了水料比为0.5的砂加气混凝土和粉煤灰加气混凝土的微观特性。结果表明,B06级砂加气混凝土在吸水率小于18%时收缩较小、强度较高;水料比为0.5时,砂加气混凝土和粉煤灰加气混凝土基体的宏观孔体积率分别为3.9%和11.1%,其水化硅酸钙体积率分别为81%和57%;优化后的2种加气混凝土吸水率分别降至3.6%和10.0%;降低水料比、提高晶胶比是改善加气混凝土吸水特性的关键。

Aiming to understand the effect of water absorption behavior on performance of B06 autoclaved aerated concrete（AAC） ,relationship between shrinkage and water absorption ratio, and relationship between compressive strength and water content,of AAC were built by statistical analysis. Microstructural characteristic of sand based AAC with water/binder ratio of 0.5 and flyash based AAC was analyzed by BSE imaging. It is indicated that smaller shrinkage and higher strength may be obtained whenwater absorption ratio of grade B06 AAC is less than 18%. Macro porosity and calcium hydrates of sand based AAC hydrationsystem with water to reactive materials mass ratio of 0.5 are 3.9% and 81% respectively,and those of fly ash based AAC withsimilar water to reactive materials mass ratio are 11.1% and 57% respectively. Water absorption ratio of two kinds AAC falls to3.6% and 10.0% because of optimization. Therefore,mitigation water to reactive materials mass ratio and enhancement crystal/gelratio are key ways to improve water absorption of AAC.