矿物掺和料对磷酸镁水泥基修补砂浆强度的影响  

Influence of Mineral Admixtures on the Strength of Magnesia Phosphate Cement-Based Rapid Repair Mortar

作　　者：任强[1] 蒋正武[1] 马敬畏[1] 

机构地区：[1]同济大学先进土木工程材料教育部重点实验室,上海201804

出　　处：《建筑材料学报》2016年第6期1062-1067,共6页Journal of Building Materials

基　　金：国家科技支撑计划项目(2014BAL03B02);国家自然科学基金资助项目(51678442;51478348);国家高铁联合基金项目(U1534207);上海市科委重点项目(14DZ1202302;15DZ1205003)

摘　　要：试验研究了粉煤灰、超细粉煤灰及硅灰在单掺和复掺条件下对磷酸镁水泥基快速修补砂浆抗压强度、抗折强度及黏结强度的影响,通过X射线衍射(XRD)和环境扫描电镜(ESEM)对磷酸镁水泥砂浆的水化产物与微观形貌进行分析.结果表明:粉煤灰与超细粉煤灰会降低磷酸镁水泥砂浆的抗压、抗折强度,硅灰对砂浆抗压、抗折强度的发展无不利影响;粉煤灰与超细粉煤灰会降低砂浆的早期黏结强度,但可以提高砂浆后期黏结强度的发展速度;硅灰的掺入可以有效提高砂浆的黏结强度.矿物掺和料参与了磷酸镁水泥的水化进程,生成的无定形物质可对磷酸镁水泥砂浆强度进行补偿;矿物掺和料的火山灰活性是改善磷酸镁水泥砂浆黏结强度的重要原因.Influences of single and combined addition of fly ash, ultra-fine fly ash and silica fume on compressive strength, flexural strength and bonding strength of magnesia phosphate cement-based rapid repair mortar were systematically studied. The hydration products and microstructure of magnesia phosphate ce- ment mortar were analyzed by X-ray di{fraction（XRD） and environment scanning electron microscope（ESEM）. The results show that the addition of fly ash and ultra-fine fly ash results in the decrease of the compressive strength and flexural strength of magnesia phosphate cement mortar, while the addition of silica fume has little negative effect on these strengths. Incorporation of fly ash or ultra-fine fly ash decreases the early bonding strength but improves the later bonding strength development rate, while bonding strength is improved effectively by the incorporation of silica fume at any age. Furthermore, mineral admixtures are involved in the hydration of magnesia phosphate cement and the generated amorphous products compensate for the strength loss, while the pozzolanic activity of mineral admixtures is the main reason for the development of bonding strength.

关 键 词：磷酸镁水泥 矿物掺和料 强度 黏结强度 火山灰活性 

分 类 号：TU528.01[建筑科学—建筑技术科学]