MgO对C_3S形成过程影响及其固溶效应研究

利用化学分析、XRD及DTA分析,研究MgO对C3S形成过程影响及其固化效应。结果表明,MgO因其优先与SiO2反应形成固溶体的特性,fCaO随MgO质量分数递增而增大,又因CaO-SiO2-MgO形成共熔融物的特性,MgO质量分数大于其固溶极限时,fCaO变化呈相反趋势,此时促进C3S形成效应明显。通过最小二乘法及MgO固溶度的精确界定,可推导出MgO在C3S中的固溶反应分子式为:(Ca3-0.15xMg0.15x)(Si1-0.85xMg0.85x)O5-0.85x(x≤0.179)。

By means of chemical analysis,XRD and differential thermal analysis,the effect and solid solution mechanism of MgO during C3S formation were studied.The results showed that because the priority of the reaction between SiO2 and MgO to form solid solution the fCaO content increased gradually with MgO content increased.On the other hand if the content of MgO exceed its solid solubility limit for CaO-SiO2-MgO congruent melting compound formation the effect of MgO on fCaO content would be reversed.By means of least square method and the accurate definition of MgO solid solubility,the molecular formula that MgO solidifies in C3S was deduced：（Ca3-0.15xMg0.15x）（Si1-0.85xMg0.85x）O5-0.85x（x≤0.17 9）.