硅酸盐耐热混凝土的制备及其性能研究

Research on Preparation and Performance of Heat Resistant Concrete with Portland Cement

利用硅酸盐水泥制备了抗渗等级为P8、耐热度为350℃的混凝土,测试了高温煅烧后混凝土试件尺寸、质量、强度等宏观性能,研究了煅烧制度、矿物掺合料、粗集料种类对混凝土耐热性能的影响,采用扫描电子显微镜(SEM)分析了混凝土经高温处理后微观结构的变化。宏观性能测试结果表明,烘干处理有助于提高混凝土的耐热性能,矿渣混凝土比粉煤灰混凝土更适合用于耐热环境,以破碎卵石为集料的混凝土的耐热性能优于以石灰石碎石为集料的混凝土。SEM分析结果显示,高温煅烧后,矿渣混凝土的内部结构较粉煤灰混凝土更为致密。

Portland cement concrete of 350℃ heat and P8 permeation resistance is manufactured in this investigatior. Some performances, such as dimension change, mass change, and strength change after high temperature calcination are measured. Influences of calcining procedure, mineral additive, and coarse aggregate kind on heat resistance of concrete are tested. Micro-structure of concrete before calcination and after is analyzed by SEM technology. The test results show that oven drying before calcination is benefit to improve the heat resistance of concrete, and ground slag concrete is more suitable than fly ash concrete used in high temperature. It is revealed that heat resistance of concrete using gravel as coarse aggregate is better than that of concrete using crushed limestone. It can be concluded from SEM test that hydration production of concrete with ground slag has more compact micro-structure than that of fly ash concrete.