用于泡沫混凝土的磷酸镁水泥基胶凝材料研究  

Study on the Modification of Magnesium Phosphate Cement by Composite Mineral Admixtures

作　　者：李崇智 彭家蔓 王会新 王琬怡 王坤 任强伟 刘枫 张晓刚 LI Chongzhi;PENG Jiaman;WANG Huixin;WANG Wanyi;WANG Kun;REN Qiangwei;LIU Feng;ZHANG Xiaogang(School of Civil and Transportation Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;China Railway Construction Group Construction Development Company,Beijing 100040,China;Technical Supervision Research Center of Building Materials Industry,Beijing 100020,China)

机构地区：[1]北京建筑大学土木与交通工程学院,北京100044 [2]中铁建设集团建筑发展公司,北京100040 [3]建筑材料工业技术监督研究中心,北京100020

出　　处：《材料导报》2023年第S02期219-222,共4页Materials Reports

基　　金：国家自然科学基金(52378003)。

摘　　要：以偏高岭土、玻化微珠、粉煤灰复合的矿物掺合料等量替代氧化镁,外掺超细SiO_(2),测试磷酸镁水泥净浆的凝结时间、流动性能、力学性能,研究相应胶砂试块的耐水性能,获得一种适用于制备泡沫混凝土的磷酸镁水泥基胶凝材料。结果表明:当偏高岭土、玻化微珠、粉煤灰以质量比7∶1∶2复合(等量替代30%氧化镁),外掺1%超细SiO_(2)时,磷酸镁水泥净浆与砂浆的3 d、7 d、28 d抗压强度、耐水性等均高于对照组无掺合料MPC;使用其制备泡沫混凝土,能够有效解决密度降低过程中的膨胀开裂问题,可以获得密度为500~600 kg/m^(3)的磷酸镁水泥基泡沫混凝土,其7 d抗压强度大于4.0 MPa,强度保留系数大于0.85,力学性能和耐水性能远远优于无掺合料的磷酸镁水泥基泡沫混凝土。The mineral admixture of metakaolin,vitrified microbeads and fly ash were substituted for magnesium oxide in equal parts,and the ultra⁃fine SiO_(2) was added to test the setting time,flow performance and mechanical properties of the net slurry of magnesium phosphate cement,and study the water resistance of the corresponding mortar test block,so as to obtain a magnesium phosphate cement⁃based cementing material suitable for the preparation of foamed concrete.The results show if the mass ratio of metakaolin,vitrified microbeads,fly ash was 7∶1∶2 composite(replacing 30%magnesium oxide with equal amount)and the addition of 1%ultrafine SiO_(2),the compressive strength and water resistance of the magnesium phosphate cement slurry and mortar at 3 d,7 d and 28 d are higher than that of the MPC without admixture in the control group.These could effectively solve the expansion cracking problem of foamed concrete in the process of density reduction.Magnesium phosphate cement⁃based foamed concrete with a density of 500—600 kg/m^(3) can be obtained with a 7 d compressive strength greater than 4.0 MPa and a strength retention coefficient greater than 0.85.The mechanical properties and water resistance are much better than that of MSP foam concrete without admixture.

关 键 词：矿物掺合料 磷酸镁水泥 泡沫混凝土 

分 类 号：TU528[建筑科学—建筑技术科学]