MgO细度对磷酸镁水泥性能的影响

摘要

通过将MgO球磨0，10，20，30，60 min，制备出不同细度的MgO，考察不同细度的MgO对磷酸镁水泥净浆强度、凝结时间、流动度、水化温度和收缩性能的影响。结果表明：MgO颗粒存在最佳级配体系；要保证施工的可操作时间和良好的流动性，MgO颗粒比表面积应控制在1700～1800 cm2/g，中值粒径控制在85～90μm；对磷酸镁水泥温度峰值起决定作用的是小于20μm的MgO颗粒；改变MgO颗粒的级配可以降低磷酸镁水泥的收缩率，改善体积稳定性。%By grounding for 0, 10, 20, 30, 60 mins respectively, MgO of different finenesses is prepared. Effects of Magnesium⁃phosphate cement paste on strength, setting time, fluidity, hydration temperature variation and shrinkage performance are ana⁃lyzed. The results show:the optimal gradation system of MgO particles exists;MgO particles should have surface area controlled be⁃tween 1 700-1 800 cm2/g and median particle size controlled in the range of 85-90μm to ensure sufficient operating time and mo⁃bility;the MgO particles which smaller than 20μm in median particle diameter play an essential part in peak temperature of magne⁃sium⁃phosphate cement;changing gradation of MgO particles can reduce shrinkage and improve dimensional stability.