锈蚀RC梁加固前后抗弯性能试验研究

Experimental Study on Flexural Behavior of Corroded RC Beams Before and After Reinforcement

为探究锈蚀RC梁钢板加固前后的抗弯性能,考虑钢板加固、保护层厚度、锈蚀梁的影响,设计了21根试验梁,对比其裂缝、挠度、破坏模式以及承载力的影响。试验结果表明:抗弯性能较弱的锈蚀梁经钢板加固后,其裂缝形态主要表现为稀疏的斜裂缝。未加固梁的裂缝发展速率大,最大裂缝宽度小于加固梁。轻微锈蚀对未加固梁的早期刚度几乎无影响,加固梁的挠度曲线屈服点不明显,屈服阶段缩短,最终破坏的较为突然。加固对梁的破坏形式有着决定性的作用,锈蚀不均匀性对梁破坏形态的影响不容忽视。钢板加固能有效延缓开裂、屈服与破坏,加固梁的屈服挠度略低于对比梁,但其承载力较未加固梁有明显的提升。

In order to explore the flexural behavior of corroded RC beams steel plate before and after reinforcement, considering the influence of steel plate reinforcement, protection layer thickness and corrosion rate, 21 test beams are designed to compare the crack, deflection, failure mode and bearing capacity. Experimental results show that the fracture morphology of corroded beams strengthened by steel plate is mainly manifested by the sparse diagonal cracks as its weak bending performance. The crack growth rate of the reinforced beam is larger, but the maximum crack width is smaller than that of the reinforced beam. Corrosion has little effect on the early stiffness of unreinforced beams. The deflection curve of the strengthened beams is not obvious, and the yield stage is shortened, at lastly, the beams are suddenly destroyed. The reinforcement has a decisive role on the failure mode of beams, and the impact of corrosion heterogeneity on failure mode of beams can not be ignored. The reinforcement by steel plate can effectively delay cracking, yielding and failure, and the yield deflection of the strengthened beams is slightly lower than that of the contrast beams, but the bearing capacity of the strengthened beams is significantly improved compared with unreinforced beam.