贝利特硫铝酸钙水泥的收缩性能

以碳酸钙、黏土和铝矾土为主要原料制备贝利特-硫铝酸钙(BCSAF)水泥,测定了BCSAF熟料的矿物组成、标准稠度用水量和凝结时间,研究了BCSAF水泥以及基准水泥净浆、砂浆的自收缩和干燥收缩,分析了粉煤灰对BCSAF水泥净浆收缩性能的影响.利用低场核磁技术,研究了BCSAF水泥和基准水泥净浆在早龄期的内部孔结构.结果 表明:BCSAF水泥净浆的自收缩大于基准水泥净浆,干燥收缩小于基准水泥净浆;粉煤灰可以有效减少BCSAF水泥净浆的自收缩和干燥收缩;BCSAF水泥砂浆60d龄期的干燥收缩小于基准水泥砂浆.

Shrinkage of Belite Calcium Sulphoaluminate Cement

Belite calcium sulphoaluminate ferrite(BCSAF) cement was prepared mainly from clay, bauxite and calcium carbonate. The mineral composition, water requirement of normal consistency and setting time of BCSAF clinker were measured. Autogenous and drying shrinkage of BCSAF and reference cement paste and mortar were gauged. The effect of fly ash on the shrinkage of BCSAF cement paste was analyzed. Internal porous structure at early age of two kinds of cement was studied through low field nuclear magnetic resonance technique. The results show that autogenous shrinkage of BCSAF cement paste is larger than that of reference cement paste, but drying shrinkage is smaller due to different hydration products and internal porous structure. Addition of fly ash can effectively lower down autogenous and drying shrinkage of BCSAF cement paste. Fly ash can decrease autogenous shrinkage and drying shrinkage of BCSAF cement paste effectively. Drying shrinkage at 60d of BCSAF cement mortar is better than that of reference cement mortar.