磷酸盐基隧道快速修复材料的长期性能与耐久性

    Durability of Phosphate-based Rapid Repairing Material for Tunnel Engineering

    • 摘要: 为了解决隧道混凝土结构过早劣化,急需快速修复的问题,利用脱硫粉煤灰、凝灰岩机制砂制备磷酸盐快速修复材料(phosphate-based rapid repairing material,简称MKPC),并结合干燥收缩、界面黏结强度、抗蚀系数及抗高温性指标对所制备出的快速修复材料进行长期性能与耐久性研究.试验结果表明:MKPC修复材料具有优异的早期力学性能,1 h抗折强度、抗压强度及黏结强度可分别达9.2、32.6、3.3 MPa;在所模拟的地下水作用下,虽然MKPC修复材料的黏结强度、抗蚀系数有所下降,但黏结强度下降幅度不超过10%,1 a的抗蚀系数仍然大于0.6,表明具有良好的抗地下水腐蚀的能力;最后,MKPC修复材料表现出卓越的高温稳定性,即使在1 000℃的高温阶段,仍保持着完整性.这些表明MKPC修复材料可满足隧道工程快速修复现场施工及耐久性的要求.

       

      Abstract: Concrete structure in tunnel is apt to deteriorate prematurely and hence a prompt restoration is required. In considering this, desulphurization fly ash and machine made tuff sand were employed to fabricate a phosphate-based rapid repairing material. The long term efficiency of the material was evaluated based on combined factors as drying shrinkage, interfacial bonding strength, corrosion resistance and high temperature resistance. Experimental results showed that the fabricated material manifests an excellent mechanical property. The one hour bending stiffness, compressive strength and bending strength were 9.2, 32.6, 3.3 MPa, respectively. A long term underground water flushing simulation demonstrates that only 10 percent bending strength and corrosion resistance is deduced and the corrosion resistance coefficient stays above 0.6, a very good corrosion resistance is thus achieved. What's more, this repairing material retains its stability even at a high temperature of 1 000℃, reveals its good thermo-stability. All these prominent properties make it a prospect material for real restoration applications.

       

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