超细CaCO_3增强硫铝酸盐水泥强度的研究

Strength and Microstructure of Sulphoaluminate Cement Containing Ultra-Fine CaCO_3

在硫铝酸盐水泥硬化体中,钙矾石主要以柱状、棒状而存在,这对水泥的性能产生了不利影响。探讨了超细CaCO3对硫铝酸盐水泥进行改性的研究。试验结果表明,超细CaCO3掺量为3%时,明显改善了硫铝酸盐水泥的强度,其28 d净浆与砂浆抗压强度分别达到100.6 MPa和94.1 MPa,且水泥的28 d砂浆抗折强度高达12.5 MPa。SEM显示掺超细CaCO3硫铝酸盐水泥硬化体中难以发现大颗粒状的水化硫铝酸钙晶体,结构较致密、均匀。

The existence of ettringite in sulphoaluminate cement hardened paste is mainly in the form of pole - like crystal, which causes unfavorable effect on the cement. In this paper the strength and microstructure of the sulphoaluminate cement containing ultra -fine CaCO3 weze discussed. Experimet results show that the strength of sulphoaluminate cement was obviously improved by adding 3% of ultra - fine CaCO3. After curing for 28d, the compressive strength of cement paste and mortar is 100.6MPa and 94.1MPa respectively, and the bending strength of the mortar reached 12.5MPa. SEM study on hardened paste of sulphoaluminate cement containing ultra - fine CaCO3 showed that its structure was dense and homogeneous, there was hardly any massive crystall detected.