【摘要】 为验证磷酸盐水泥(Magnesium Phosphate Cement，MPC)在桥梁伸缩缝修复中的可行性，通过MPC快硬高强砂浆的凝结时间、力学性能来评估其工作性能，通过压汞法检测MPC砂浆的孔隙结构，同时进行快速氯离子渗透试验，评估其耐久性。结果表明，MPC砂浆的抗压强度在12 h内达到最大值。其中，重烧氧化镁与磷酸二氢钾的质量比为4.0时，MPC砂浆的最大抗压强度为31.4 MPa，而普通硅酸盐水泥(Ordinary Portland Cement，OPC)制备的砂浆为4.2 MPa。同时，MPC砂浆与修补面的黏结性能更好，其拉伸黏结强度和弯曲黏结强度更高，分别为1.9 MPa和1.7 MPa，而OPC砂浆分别为1.5 MPa和1.2 MPa。除此以外，MPC快硬高强砂浆孔隙类型以空气孔隙为主，而不是毛细孔隙，因此相比OPC砂浆，MPC砂浆在电通量试验中表现出较低的渗透性。实际工程应用表明，MPC配制的快硬高强修补材料优于OPC配制的修补材料。更多还原

【Abstract】 In order to verify the feasibility of Magnesium Phosphate Cement (MPC) in bridge expansion joint repair,its working performance is evaluated by the setting time and mechanical properties of MPC fast hardening high-strength mortar,and the pore structure of MPC mortar is detected by mercury intrusion method,and rapid chloride ion penetration test is conducted to evaluate its durability.The results indicate that the compressive strength of MPC mortar reaches its maximum value within 12 h.Among them,when the mass ratio of calcined magnesium oxide to potassium dihydrogen phosphate is 4.0,the maximum compressive strength of MPC mortar is 31.4 MPa,while the mortar prepared with Ordinary Portland Cement (OPC) is 4.2 MPa.At the same time,MPC mortar has better bonding performance with the repair surface,with higher tensile bonding strength and bending bonding strength of 1.9 MPa and 1.7 MPa,respectively,while OPC mortar has 1.5 MPa and 1.2 MPa,respectively.In addition,the pore type of MPC fast hardening high-strength mortar is mainly air pores,rather than capillary pores,therefore,compared to OPC mortar,MPC mortar shows lower permeability in electrical flux tests.Practical engineering applications have shown that the fast hardening and high-strength repair material prepared by MPC is superior to the repair material prepared by OPC.更多还原