摘要
研究了有机酸CA改性的硫氧镁水泥物相组成、抗压强度及耐水性能。改性后的硫氧镁水泥出现了大量新相,且Mg(OH)2的生成量明显减少。利用化学元素分析方法确定了该新相的组成为5Mg(OH)2.MgSO4.5H2O(515相)。采用SEM确定515相是一种针状晶体。利用TG-DSC方法研究了其分解规律。利用XRD跟踪试验确定了515相的生成过程并结合改性剂对氧化镁水化后pH值的影响,探讨了改性剂对硫氧镁水泥的改性机理。改性后水泥相的抗压强度和耐水性能明显提高。
Phase compositions,compressive strength and water resistance of magnesium oxysulphate cement modified by organic acid CA were studied. Mass of new phase appears and the content of Mg（OH）2 decreases in modified cement. This new phase can be expressed by 5Mg（OH）：·MgSO4·5H2O（515 phase） determined by chemical element analysis. SEM analysis has proved that the microstructure of the 515 phase is needle-like crystal. The law of thermal＇decomposition of this new phase has been studied by TG-DSC method. The process of formation of 515 phase has been studied by data of XRD tracking and the modification mechanism of the additive on the magnesium oxysulphate cement has been discussed based on the influences of additive CA on pH changes of magnesia hydration. The compressive strength and water resistance can be improved by the addition of CA.
出处
《新型建筑材料》
2013年第5期68-72,共5页
New Building Materials
关键词
硫氧镁水泥
改性剂
物相组成
抗压强度
耐水性
magnesium oxysulphate cement
additives
phase compositions
compressive strength
water resistance
