用菱镁矿尾矿制备的MgO膨胀剂对砂浆强度与膨胀性能的影响  

Effects of MgO expansive agents from magnesite tailings on expansion and strength of mortars

作　　者：刘成龙 邓敏[1,2] 莫立武 恽进进[1] 周保福 严? LIU Chenglong;DENG Min;MO Liwu;YUN Jinjin;ZHOU Baofu;YAN Man(State Key Laboratory of Materials-Oriented Chemical Engineering,College of Materials Science and Engineering,Nanjing Tech University,Nanjing 210009,China;Jiangsu National Synergetic Innovation Center for Advanced Materials,Nanjing 210009,China)

机构地区：[1]南京工业大学材料科学与工程学院材料化学工程国家重点实验室,江苏南京210009 [2]江苏先进生物与化学制造协同创新中心,江苏南京210009

出　　处：《南京工业大学学报（自然科学版）》2018年第6期26-31,共6页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：国家科技支撑计划(2011BAE27B01);国家自然科学基金重点项目(51461135003);国家重点研发计划(2016YFB0303601).

摘　　要：研究海城和莱州菱镁矿尾矿在950℃煅烧1 h制备的MgO膨胀剂(MEA)对砂浆试件膨胀性能和强度的影响规律,并分析掺MgO膨胀剂水泥浆体中MgO的水化程度。结果表明:海城MgO膨胀剂(HC-MEA)中MgO活性高,水化快,掺HC-MEA砂浆90 d膨胀比较大,90～150 d膨胀增长趋势减缓;莱州MgO膨胀剂(LZ-MEA)中MgO活性低,水化慢,掺LZ-MEA砂浆60 d膨胀比较小,60～150 d膨胀发展较快; MEA掺量相同时,掺HC-MEA砂浆试件的膨胀率大于掺LZ-MEA砂浆试件的膨胀率。粉煤灰能抑制掺MEA砂浆试件的膨胀,抑制作用随养护温度的升高或MEA掺量的增加而减小。与未掺MEA砂浆相比,掺8%HC-MEA砂浆的90 d抗压、抗折强度分别提高了5. 84%和1. 12%,掺8%LZ-MEA砂浆的90 d抗压、抗折强度分别提高了1. 84%和4. 24%。The effect of MgO expansive agents(MEA)prepared by calcining Laizhou and Haicheng magnesite tailings at 950℃for 1 h on the expansion and strength of mortars were investigated.The hydration degree of periclase in MEA in cement pastes was also analyzed.Results showed that highly active MgO expansive agents by calcining Haicheng magnesite tailings(HC-MEA)might cause a relatively quick development of expansion of mortars before 90 d and slow development of expansion of mortars during 90 and 150 d.The lowly active MgO expansive agents produced by calcining Laizhou magnesite tailings(LZ-MEA)and incorporated in mortars expanded at a relatively low rate before 60 d and generated a relatively large expansion during 60 and 150 d.The expansion of mortars with HC-MEA was higher than that with LZ-MEA.Fly ash tended to inhibit the expansion of mortars with MEA.Compared with the strength of mortars without MEA,the compressive and flexural strengths at 90 d of mortars with 8%HC-MEA were increased by 5.84%and 1.12%,respectively.The compressive and flexural strengths at 90 d of mortars with 8%LZ-MEA were increased by 1.84%and 4.24%,respectively.

关 键 词：菱镁矿尾矿 MGO膨胀剂 砂浆 膨胀 强度 

分 类 号：TU528[建筑科学—建筑技术科学]