CFRP strengthened RC beams with pre-strengthening non-uniform reinforcement corrosion subjected to post-strengthening wetting/drying cycles
CFRP strengthened RC beams with pre-strengthening non-uniform reinforcement corrosion subjected to post-strengthening wetting/drying cycles
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DOI：
10.1016/j.engstruct.2016.08.051
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发表时间：
2016-11
影响因子：
5.5
通讯作者：
Dawei Zhang;Yu-Xi Zhao;T. Ueda;Xiangmin Li;Qingfeng Xu
中科院分区：
文献类型：
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作者：
Dawei Zhang;Yu-Xi Zhao;T. Ueda;Xiangmin Li;Qingfeng Xu
在实践中，加固前后的钢筋混凝土（RC）结构通常会受到多种联合作用，可能会对结构造成各种损坏。本研究的主要目的是研究海洋环境中三种类型的预强化和后强化损伤对碳纤维增强聚合物（CFRP）强化RC梁弯曲行为的影响，并开发一种设计方法来预测有或没有CFRP脱粘的屈服载荷、脱粘载荷和峰值载荷。预损坏是由仅持续载荷或持续载荷和腐蚀的组合引起的。后损坏是由持续负载和润湿/干燥 (WD) 循环相结合引起的。记录并比较失效模式、屈服载荷、脱粘载荷和峰值载荷，并讨论相关机理。随后，采用非线性截面分析，检验了钢筋不均匀腐蚀对屈服载荷的影响、WD循环对脱粘载荷和有效CFRP断裂应变的影响，并据此提出了几种模型。所提出的模型可以足够准确地预测梁的屈服强度、脱粘强度和峰值强度。通过现有文献收集的数据库进一步验证了所提出模型的可靠性。
In practice, reinforced concrete (RC) structures before and after strengthening usually is exposed to a wide variety of combined actions, which may cause various damage to the structures. The main objectives of this study are to investigate the effects of three types of pre- and post- strengthening damage in the marine environment on the flexural behaviors of carbon fiber-reinforced polymer (CFRP)-strengthened RC beams and to develop a design methodology for predicting their yielding load, debonding load and peak load with or without CFRP debonding. The pre-damage was induced by either sustained load only or by the combination of sustained load and corrosion. The post-damage was induced by combined sustained load and wetting/drying (WD) cycles. The failure mode, yielding load, debonding load and peak load were recorded and compared, and the related mechanism was discussed. Subsequently, by adopting nonlinear sectional analysis, the effect of non-uniform corrosion of steel reinforcement on the yielding load, the effect of WD cycles on the debonding load and the effective CFRP rupture strain were examined and several models were proposed accordingly. The yielding strength, debonding strength and peak strength of the beams can be predicted by the proposed models with sufficient accuracy. The reliability of the proposed models was further validated with a collected database from the existing literatures.