硼砂对磷酸镁水泥性能影响及微观作用机理分析

Influence of Borax on Properties of Magnesium Phosphate Cement and Its Microscopic Mechanism

研究了硼砂对磷酸镁水泥凝结时间与抗压强度的影响，分析了硼砂对水泥陛能影响的微观作用机制。研究发现：随着硼砂对MgO质量分数增加，磷酸镁水泥凝结时间延长，其早期抗压强度迅速降低，后期抗压强度所受影响相对较小；磷酸镁水泥应用于快速修补及抢修抢建时，硼砂质量为氧化镁质量的5％～10％为宜；硼砂对磷酸镁水泥水化产物的早期生成量及组织结构有一定影响，硼砂对MgO质量分数越大，影响越大。

The influence of the borax as a retarding admixture on magnesium phosphate cement＇ s setting time and compressive strength is researched. The microscopic mechanism of borax influencing on the properties of cement is analyzed. The results show that with the increase of borax content, the setting time of magnesium phosphate cement （ MPC ） increased and the early compressive strength decreased quickly, while the late compressive strength is less affected. When MPC is used in rapid repairing and building, the appropriate mass ratio of borax to magnesium oxide is 5% - 10%. Borax is of certain influence on the early formation and organizational structure of MPC ＇ s hydration products. The more borax content is, the greater the impact will he.