基于混料实验研究矿物外加剂对氯氧镁水泥性能的影响  

The Studies of the Mineral Admixtures Impact on the Properties of Magnesium Oxychloride Cement Based on Mixture Design

作　　者：丁向群[1] 张冷庆[1] 孙艳丽[2] 

机构地区：[1]沈阳建筑大学材料科学与工程学院,辽宁沈阳110168 [2]沈阳建筑大学商学院,辽宁沈阳110168

出　　处：《沈阳建筑大学学报（自然科学版）》2016年第3期476-485,共10页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(51078241);中国建材联合会项目(2103-M3-8)

摘　　要：目的研究矿物外加剂对氯氧镁水泥(简称镁水泥)强度和耐水性的影响,以解决镁水泥耐水性差、浸水后强度严重损失的问题.方法以粉煤灰、硅灰和铁尾矿为矿物外加剂,利用SEM和XRD观察分析改性后的镁水泥的微观结构和相组成;运用单纯形重心混料设计分析矿物外加剂复掺对镁水泥抗压强度和软化系数的影响;通过回归模型分析矿物外加剂对MgO-MgCl_2-H_2O三元体系抗压强度和软化系数影响的显著性.结果随着粉煤灰掺量的增加,镁水泥的抗压强度逐渐降低,软化系数逐渐提高;随着硅灰掺量的增加,镁水泥抗压强度逐渐降低,软化系数先升高后降低,当硅灰掺量为15%时,软化系数为0.85;随着铁尾矿掺量的增加,镁水泥抗压强度基本保持不变,软化系数降低;当m(粉煤灰)∶m(硅灰)=0.51∶0.49时,镁水泥抗压强度为39.99 MPa,软化系数为0.73.结论矿物外加剂能有效地改善镁水泥的耐水性,提高软化系数;矿物外加剂对镁水泥的改性机理基本相同;混料设计能够有效的分析复掺条件下各组分对镁水泥性能的影响.The influence of mineral admixtures for magnesium oxychloride cement was studied to deal with the bad water-resistance and strength loss problems of magnesium oxychloride cement（MOC）,using fly ash,silica fume and iron tailings as admixtures. Based on the XRD and SEM observations on microstructure and phase composite of modified MOC,the influence of compoundmineral admixtures on MOC compressive strength and softening coefficient were analyzed using simple centroid mixture design. The significant effects of mineral admixtures on compressive strength and soften coefficients of the MgO-MgCl_2-H_2 O ternary system were investigated by regression model. With fly ash content increasing,compressive strength of MOC decreased while softening coefficient gradually increased. With silicon fume content increasing,compressive strength of MOC gradually reduced while softening coefficient first increased and then decreased. When silica fume content was 15%,the softening coefficient was 0. 85. With iron tailings content increasing,compressive strength of MOC changed lightly while softening coefficient decreases. When the mass ratio of fly ash and silica fume was 0. 51 to 0. 49,the compressive strength of MOC was39. 99 MPa while softening coefficient was 0. 73. The results showed that the mineral admixtures could effectively improve the water resistance and softening coefficient of MOC with similar modified mechanism,and mixture design can effectively analyze the performance of each composite group in complex conditions.

关 键 词：氯氧镁水泥 混料设计 矿物外加剂 抗压强度 软化系数 

分 类 号：TU526[建筑科学—建筑技术科学]