MgO （NH4）2HPO4 K2HPO4 H2O新型磷酸镁水泥

New Magnesia Phosphate Cement Based on MgO （NH4）2HPO4 K2HPO4 H2O System

关键词:  磷酸镁水泥  低酸度磷酸盐  流动特性  凝结时间

Key words:  magnesia phosphate cement  the low acidity phosphates  fluidity  setting time

摘要:

用低酸度磷酸盐（NH4）2HPO4和K2HPO4制备了凝结时间可控、强度高的新型磷酸镁水泥（MPC）.结果表明：由低酸度磷酸盐制备的MPC，在水料比和缓凝剂用量一定的情况下，随着n（（NH4）2HPO4）/n（K2HPO4）的降低，其浆体的流动性增强，凝结时间延长；添加K2HPO4后，MPC的早期抗压强度略有降低，但其28d抗压强度高达70MPa以上；MPC的水化产物为NH4MgPO4·6H2O和KMgPO4·6H2O.

Abstract:

A new type of magnesia phosphate cement（MPC）that has high strength and controllable setting time was prepared by low acidity phosphates （NH4）2HPO4 and K2HPO4 as raw materials. The results show that the new MPC has better fluidity and longer setting time with the decrease in （NH4）2HPO4/K2HPO4 molar ratio in the case of fixed mw/mc ratio and retarder dosage. Early compressive strength of the new MPC after adding K2HPO4 decreases slightly， while 28d compressive strength of the new MPC is all above 70 MPa. The main hydration products of MPC are NH4MgPO4·6H2O and KMgPO4·6H2O.