原料摩尔比对硫氧镁胶凝材料性能的影响

摘要

Effects of n (MgO) (MgSO4),n (H2 O) (MgSO4) on the properties and micro-structural mechanism of magnesium oxysulfate(MOS) cemented materials were investigated.The results show that the most optimal mechanical properties are obtained when n(H2O)(MgSO4) is fixed to be 19 ∶ 1 and n(MgO)(MgSO4) equals to 14 ∶ 1.Micro-structural analysis shows that once n(MgO)(MgSO4) is over 14 ∶ 1,the content of residual MgO and Mg(OH)2 in hardened paste of MOS will increase,which will loosen the structure of the hardened MOS and reduce its mechanical properties;With the increase of n(H2O)(MgSO4) the formation of basic-magnesium-sulfate phase in hardened MOS will be retarded,resulting in a large amount of pores in microstructure and decrease of mechanical properties,when n(MgO)(MgSO4) is 14 ∶ 1.%研究了氧化镁-硫酸镁摩尔比n(MgO) (MgSO4),水-硫酸镁摩尔比n(H2O)(MgSO4)对硫氧镁胶凝材料性能的影响及其微观机理.结果表明:固定n(H2O)(MgSO4)为19∶1,n(MgO)(MgSO4)为14:1时硫氧镁胶凝材料力学性能最优;n(MgO)(MgSO4)超过14∶1后,硫氧镁胶硬化浆体中剩余MgO和Mg(OH)2的含量会增大,使硬化结构疏松,从而降低其力学性能;固定n(MgO) (MgSO4)为14:1时,n(H2O)(MgSO4)的增大会延缓硬化硫氧镁浆体中碱式硫酸镁相的生成,造成微观结构中产生大量孔隙,从而导致其力学性能下降.