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为了揭示带锈蚀钢箍接头的老旧混凝土电杆经碳纤维布(CFRP)加固后的承载性能及破坏机理,采用南方电网西南线某路段的4根电杆为试验对象(其中2根纵向黏贴两层CFRP,1根纵向黏贴单层CFRP,1根未进行相关加固措施)进行了抗弯承载力试验。通过试验,观察了各试件的受力全过程及破坏形态,获取了荷载-挠度曲线、刚度退化曲线及极限承载力等重要指标。研究结果表明:加固接头试件的破坏主要表现为混凝土与CFRP的表面粘脱失效,过程迅速,具有脆性破坏特点。CFRP加固后试件的截面应变仍符合平截面假定。加固试件的承载力和刚度远大于未加固试件的相应值,黏贴双层CFRP的试件比单层CFRP试件的承载力高,前者的初始刚度和弹塑性刚度均比后者各阶段刚度有所改善。综合考虑后,建议采用纵向黏贴单层碳纤维布较为经济合理,研究成果可供同类服役混凝土电杆的加固设计提供参考。
In order to reveal the bearing capacity and failure mechanism of old concrete poles with corroded steel ferrule joints reinforced with carbon fiber reinforced plastic (CFRP), four poles on one section of Southwest China Southern Power Grid were used as test objects Two-layer CFRP, one longitudinal affixed single-layer CFRP, one without reinforcement measures) for the flexural capacity test. Through the test, the whole process of the stress and failure mode were observed, and the important indexes of load - deflection curve, stiffness degradation curve and ultimate bearing capacity were obtained. The results show that the damage of the specimen is mainly due to the failure of concrete and the surface of CFRP, the process is rapid and has the characteristics of brittle failure. The cross-sectional strain of CFRP strengthened specimens still accords with the assumption of flat section. The bearing capacity and stiffness of the strengthened specimens are much larger than the corresponding values of the unreinforced specimens. The specimens affixed with double-layer CFRP have higher bearing capacity than the single-layer CFRP specimens. The initial stiffness and elastic- Stage stiffness has improved. Considering synthetically, it is more economical and reasonable to adopt the longitudinally-glued single-layer carbon fiber cloth, and the research results can provide a reference for the reinforcement design of the same-type concrete pole.