地铁隧道管片裂缝修补后的抗侵蚀性能研究

Corrosion Resistance of the Metro Tunnel Segments after Repairing of Segment Cracks

  • 摘要: 地铁隧道管片在生产、施工和运营过程中均可能产生裂缝,而管片裂缝修补后的耐久性优劣直接影响隧道安全。文章通过模拟地铁管片裂缝,采用氯离子渗透试验和硫酸盐侵蚀试验,研究了新型修补材料 NR修补不同管片裂缝后的抗侵蚀性能,并与常用环氧树脂修补材料 EC进行了对比分析。结果表明:采用 NR修补不同管片裂缝后其抗Cl-渗透性均明显提高,其中对C60混凝土管片修补效果好于C50混凝土管片;对掺聚丙烯纤维管片的修补效果好于未掺聚丙烯纤维的管片;对 PFC50和 C60混凝土管片的修补效果要优于 EC材料。采用 NR修补后管片的抗硫酸盐侵蚀能力略有下降,C60混凝土管片修补后的抗硫酸盐侵蚀的抗压和抗折强度降幅均较 C50混凝土管片的小,且抗压强度修复效果优于抗折强度;掺聚丙烯纤维管片裂缝修补后的抗硫酸盐侵蚀的抗压和抗折强度降幅均较未掺聚丙烯纤维管片的小,且抗压强度修复效果优于抗折强度;对C50和PFC50混凝土管片抗硫酸盐侵蚀的抗压强度的修补效果要优于EC材料,且对3种混凝土管片抗硫酸盐侵蚀的抗折强度的修补效果均要优于EC材料。

     

    Abstract: Cracks often occur during manufacturing, construction and operation of metro tunnel segments, and the durability of repaired segments has direct effect on tunnel safety. Simulating different subway tunnel segment crack patterns, using the chloride ion permeation test and sulfate attack test, it studied the erosion resistance of the tunnel segments after repairing various segment cracks with innovative repairing material NR, and a comparison with the commonly used epoxy resin repairing material EC was conducted, with the results show that the concrete resistance to chloride ion penetration increases significantly, the repairing effect of C60 segment is better than that of C50; the repairing effect of segment with polypropylene fiber is better than that of the segment without polypropylene fiber;the repairing effect of PFC50 and C60 segments is better compared with the repairing material EC; after using NR repairing material, the resistance to sulfate corrosion of segment decreases slightly, the decreasing amplitude of bending strength and compressive strength of the repaired C60 segment is smaller compared with that of C50 seg? ment, and the remediation effect of compressive strength is better than that of bending strength; the decreasing am? plitude of compressive strength and bending strength against sulfate corrosion of the segment with polypropylene fi? ber is smaller than the one without polypropylene fiber and the remediation effect of compressive strength is better than that of bending strength; compared with the EC repairing material, the remediation effect of compressive strength against sulfate corrosion of C50 and PFC50 concrete segments is better and the remediation effect of bend? ing strength against sulfate corrosion of three kinds of concrete segments is better.

     

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