三异丙醇胺对石灰石硅酸盐水泥的水化机理及微观结构的影响

Effects of Triisopropanolamine on Hydration and Microstructure of Portland Limestone Cement

通过水泥净浆和砂浆强度试验、测量水化热、硬化水泥浆体的热分析、微观结构的扫描电镜观察和孔结构的测量,研究了三异丙醇胺(triisopropanolamine,TIPA)对石灰石硅酸盐水泥强度、水化过程和硬化水泥浆体的微观结构的影响。结果表明:掺加TIPA能够显著提高石灰石硅酸盐水泥净浆和砂浆的后期强度;TIPA对C4AF的水化和AFt的形成有促进作用,当石膏耗尽,石灰石与水化铝酸钙的反应抑制了AFt向AFm的转化;TIPA可促进石灰石粉的成核效应,使各水化产物均匀交错,凝胶结构致密,是TIPA对石灰石硅酸盐水泥的增强作用的主要机制。

The effect of triisopropanolamine （TIPA） on strength, hydration process and microstructure of portland limestone cement were investigated by measuring heat of hydration, strength of cement paste and motor, thermal analysis of hardened cement pastes, microstructure observation and pore structure measurement. The experimental results indicated that the addition of TIPA increased the strength of the cement at 7 d and 28 d significantly. TIPA promoted the formation of AFt from the hydration of C4AF. When gypsum was used up, the reaction of limestone with hydrated calcium aluminate inhibited the transformation of AFt to AFm. The addition of TIPA resulted in uniformly overlapped hydration products and less porous gel structure as it promoted the nucleus effect of limestone power. This may be the main cause for TIPA to increase the strength of portland limestone cement.