摘要
试验分析了5种温度梯度下玻化微珠保温混凝土的外观形貌和质量损失,利用扫描电镜（SEM）观察5种温度等级和两种不同冷却方式下保温混凝土的微观结构,定性分析微观物相对质量损失和裂缝开展的影响。试验结果表明：在100~500℃下,保温混凝土中保温骨料玻化微珠性能稳定;经历温度低于300℃时,保温混凝土孔内水分蒸发,质量损失率为4.36%,但基本不出现裂缝;经历温度为300~500℃时,保温混凝土中C-S-H凝胶结构和Ca（OH）2晶体由于失去水分而分解,质量损失率为6.22%,裂缝越来越多;浇水冷却方式下,保温混凝土内部发生水化反应生成C-S-H凝胶和Ca（OH）2晶体,将孔隙填的更加密实,故其裂缝开展小于自然冷却下的裂缝开展。
The morphology and mass loss at five temperature gradients of glazed hollow bead thermal insulation concrete were analyzed, its micro-structure was characterized by scanning elec- tron microscopy（SEM） for five temperature ratings and two cooling modes. The effect of micro- scopic objects on mass loss and crack development was analyzed. The results indicate that. at 100-500 ℃, the performance of glazed hollow bead is stable; after exposed to less than 300 ℃, be- cause of water evaporation of thermal insulation concrete,the mass loss rate is 4.36% and almost no cracks occur on concrete; when exposed to 300-500 ℃, C-S-H structures and Ca（OH）2 crys- tals decompose owing to release of moisture, the mass loss rate is 6.22%, and more cracks occur on concrete with the increase in temperature ; with water cooling, thermal insulation concrete oc- curs new chemical reactions generating C-S-H structures and Ca（OH）2 crystals, filling the pores, so the cracks are less than with natural cooling.
出处
《太原理工大学学报》
CAS
北大核心
2015年第4期419-423,共5页
Journal of Taiyuan University of Technology
基金
国家自然科学基金资助项目:玻化微珠保温砂浆劣化机理及对结构耐久性的影响研究(51308371)
山西省自然科学基金项目(2014011033-1)
关键词
微观结构
扫描电镜
玻化微珠
水泥浆体
界面过渡区
micro-structure
scanning electron microscopy
glazed hollow bead
cement paste interface transition zone
