蔗糖和水玻璃对竹屑–硫氧镁水泥物理性能和水化反应的影响

Effects of Sucrose and Sodium Silicate on the Physical Properties and Hydration Reaction of Bamboo Sawdust-Magnesium Oxysulfate Cement

摘要: 为进一步提高硫氧镁(MOS)水泥的强度和耐水性，研究了竹屑作为填充剂，蔗糖和水玻璃作为分散剂对MOS水泥强度和耐水性的影响，通过采用X射线衍射和扫描电镜(SEM)分析了蔗糖和水玻璃对竹屑–硫氧镁水泥水化反应的影响，并在单掺蔗糖和水玻璃的基础上，复掺柠檬酸以对比探究影响机理。结果表明：蔗糖和水玻璃作为分散剂可以有效提高MgO颗粒的分散性，从而延缓水化反应，促进碱式硫酸镁相的生成，延长了竹屑–硫氧镁水泥的凝结时间，提高了强度和耐水性，柠檬酸的改性机制与蔗糖和水玻璃不同，复掺柠檬酸可以促进水化反应生成更高强度的5·1·7相。

Abstract: To further improve the strength and water resistance of magnesium oxysulfate (MOS) cement, the effects of bamboo sawdust as filler and sucrose and sodium silicate as dispersant on the physical properties and water resistance of MOS cement were investigated, and the effects of sucrose and sodium silicate on the hydration reaction of the bamboo sawdust-magnesium oxysulfate cement were analyzed by using X-ray diffraction (XED) and scanning electron microscopy (SEM), and the citric acid was compounded with the single doping of sucrose and sodium silicate to compare the effects. The results showed that sucrose and sodium silicate as dispersants could effectively improve the dispersion of MgO particles, thus delaying the hydration reaction, promoting the generation of alkali magnesium sulfate phase, prolonging the setting time of bamboo sawdust-magnesium oxysulfate cement, and improving the strength and water resistance, and the modification mechanism of citric acid was different from that of sucrose and sodium silicate. The compound doping of citric acid could promote the generation of a higher-strength phase 5·1·7.