Too fast setting and hardening rate as well as concentrative hydration heat of magnesium potassium phosphate cements restrict its extensive engineering application seriously.Endothermic energy storage of phase change material offers a new way for solving the problems.Effect of inorganic phase change material Na2SO4 · 10H2O(NS) on hydration temperature,work perfor mances and compressive strength of magnesium potassium phosphate cement(MKPC) were investigated.Moreover,influence mechanism of NS on properties of MKPC were researched with the aids of XRD,FT-IR,SEM analyses and hydration heat release rate.The result showed that solution and phase change process of NS absorbed a multitude of hydration heat and released crystalliferous water,which attenuated solution rate and concentration of Mg2+,PO43-and H+ in system of MKPC.So rate of interior hydration of MKPC reaction diminished,causing prolonged setting time,increased fluidity,and mild hydration heat release and temperature rise.In early hydration process,with NS content increase,early strength of MKPC diminish slightly.Under a certain content of NS (≤ 4％),the crystallinity of hydration products increased,and the long-term strength of MKPC increased steadily.28 d compressive strength of MKPC with 2％ NS was higher than that of the reference group.%磷酸钾镁水泥凝结硬化过快及水化放热集中的问题严重制约着其大规模工程应用,相变材料的吸热储能功能为解决这一问题提供新途径.研究了无机水合盐Na2SO4·10H2O(NS)对磷酸钾镁水泥(MKPC)水化温升、工作性能和抗压强度的影响,并结合XRD、FT-IR、SEM等分析手段及其水化放热速率曲线探究了NS对MKPC性能的影响机制.结果表明:NS的溶解和相变过程吸收大量热,同时释放出结晶水,降低了MKPC体系中Mg2+、PO43和H+的溶出速率及浓度,MKPC系统内部水化反应速率降低,凝结时间延长,流动度增大,水化放热和水化温升变得更加平缓,在水化早期,MKPC的硬化体强度随NS掺量增加略有降低.在一定的NS掺量(≤4％)内,MKPC水化产物的结晶度提高,后期强度稳定增长,掺有2％NS的MKPC的28 d强度将高于基准组.
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