Performance of FRCM composites and FRCM-strengthened RC beams subjected to anodic polarization and cyclic loading
Performance of FRCM composites and FRCM-strengthened RC beams subjected to anodic polarization and cyclic loading
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DOI：
10.1016/j.engstruct.2021.113475
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发表时间：
2021-11-02
影响因子：
5.5
通讯作者：
Matsumoto, Koji
中科院分区：
文献类型：
--
作者：
Wei, Liangliang;Zhu, Ji-Hua;Matsumoto, Koji
纤维增强水泥基材料（FRCM）体系可以对老化钢筋混凝土（RC）结构提供结构加固（SS）。此外，外加电流阴极保护（ICCP）已与FRCM系统集成，以开发ICCP-SS干预系统，以帮助改善FRCM加固RC结构的长期性能。然而，目前对FRCM复合材料及FRCM加固钢筋混凝土构件疲劳性能的研究还很缺乏。研究了碳纤维增强混凝土中的织物层、ICCP过程中的阳极极化以及循环加载条件对碳纤维增强混凝土复合材料拉伸疲劳性能和碳纤维增强混凝土梁弯曲疲劳性能的影响。进行了FRCM试件的循环拉伸试验和梁试件的循环四点弯曲试验。循环拉伸试验结果表明，FRCM的疲劳寿命性能是上级的钢筋和劣于碳纤维增强聚合物（CFRP，通常具有环氧树脂基体的复合材料）。ICCP的阳极极化降低了碳-FRCM在给定应力水平下的疲劳寿命和200万次载荷循环后的疲劳强度。循环弯曲试验结果表明，梁的疲劳性能在很大程度上取决于织物层数在FRCM和轻微的影响，在ICCP-SS的阳极极化。得到了一条新的钢筋应力幅-循环次数曲线（S-N曲线），并给出了满意的疲劳寿命预测。
Fabric reinforced cementitious matrix (FRCM) systems can provide structural strengthening (SS) of aging reinforced concrete (RC) structures. Furthermore, impressed current cathodic protection (ICCP) has been integrated with FRCM systems to develop ICCP-SS intervention systems to help improve the long-term performance of FRCM-strengthened RC structures. However, there is a lack of research regarding the fatigue performance of FRCM composites and FRCM-strengthened RC members. This study investigated the effects of fabric layers in carbon-FRCM, anodic polarization in the process of ICCP, and cyclic loading conditions on the fatigue performance of FRCM composites in tension and FRCM-strengthened RC beams in flexure. Cyclic tensile loading tests of FRCM specimens and cyclic four-point bending tests of beam specimens were conducted. Cyclic tensile test results showed that the fatigue life performance of FRCM was superior to that of steel rebar and inferior to that of carbon fiber reinforced polymer (CFRP, a composite that commonly has an epoxy resin matrix). The anodic polarization of ICCP degraded the fatigue life of carbon-FRCM at a given stress level and fatigue strength after two million loading cycles. The cyclic bending test results indicated that the fatigue performance of the beams was largely dependent on the number of fabric layers in the FRCM and slightly influenced by the anodic polarization in the ICCP-SS. A new curve of the steel stress range versus the number of cycles (S-N curve) for FRCMstrengthened beams was obtained in this study and provided satisfactory fatigue life predictions.