粉煤灰和矿粉对磷酸镁水泥性能的影响

发布时间：2018-01-24 19:46

本文关键词： 磷酸镁水泥粉煤灰矿粉凝结时间性能　出处：《硅酸盐通报》2016年02期 　论文类型：期刊论文

【摘要】：磷酸镁水泥(magnesium phosphate cement,MPC)是一种新型气硬性胶凝材料,在其中掺入矿物掺合料可改善其性能。本文采用高纯度死烧Mg O、磷酸二氢铵及硼砂配制了磷酸镁水泥,掺入一定量粉煤灰或矿粉,研究了这两种矿物掺合料对磷酸镁水泥凝结时间、力学性能及耐水性能的影响。结果表明:随着粉煤灰和矿粉掺量的增加,MPC凝结时间缩短;砂浆试件抗压强度呈先升高后降低趋势,当掺量为10%时,抗压强度最高,同等掺量的矿粉对MPC早期和后期强度的贡献均优于粉煤灰的贡献;粉煤灰的掺入提高了MPC的耐水性,而矿粉的掺入却有降低MPC的耐水性的趋势;XRD测试表明,不掺掺合料、掺粉煤灰、掺矿粉的MPC的主要反应产物均为Mg NH4PO4·6H2O和一些非晶相,掺矿粉的MPC试件浸水28 d后,表面浸出物主要为Mg NH4PO4·6H2O。
[Abstract]:Magnesium phosphate cement (phosphate) is a new type of gas-hard cementing material. The properties of the cement can be improved by adding mineral admixture. In this paper, magnesium phosphate cement is prepared with high purity dead burned MgO, ammonium dihydrogen phosphate and borax, and a certain amount of fly ash or mineral powder is added. The effects of the two mineral admixtures on the setting time, mechanical properties and water resistance of magnesium phosphate cement were studied. The results showed that the setting time of MPC was shortened with the increase of the content of fly ash and mineral powder. The compressive strength of mortar increased first and then decreased. When the content was 10, the compressive strength was the highest, and the contribution of the same amount of mineral powder to the early and late strength of MPC was better than that of fly ash. The addition of fly ash improved the water resistance of MPC, while the addition of mineral powder decreased the water resistance of MPC. XRD test showed that mg NH4PO4 路6H2O and some amorphous phases were the main reaction products of MPC with no admixture, fly ash and mineral powder. Mg NH4PO4 路6H _ 2O was the main extractant on the surface of the MPC sample doped with mineral powder after 28 days of soaking.
【作者单位】：西安建筑科技大学;
【基金】：陕西省教育厅专项科研计划项目(2013JK0975)
【分类号】：TQ172.1
【正文快照】： 1引言磷酸镁水泥(MPC)是由重烧氧化镁、磷酸盐、缓凝剂及矿物掺合料等按照一定比例混合,通过酸碱中和反应及物理作用而形成的新型气硬性胶凝材料[1,2]。与传统硅酸盐水泥相比,MPC主要有以下优点[3-5]:快凝、快硬早高强,粘结强度高,体积变形小,低温下凝结硬化快。因此,MPC主要

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