Haroon Muhammad, Moon Jae Sang, Kim Changhyuk
Department of Architectural Engineering, Sungkyunkwan University, Suwon 16419, Korea.
Department of Civil Engineering, Balochistan University of Engineering and Technology, Khuzdar 89100, Pakistan.
Materials (Basel). 2021 Oct 7;14(19):5866. doi: 10.3390/ma14195866.
Carbon fiber reinforced polymers (CFRP) have shown considerable potential in the repair and rehabilitation of deficient reinforced concrete (RC) structures. To date, several CFRP strengthening schemes have been studied and employed practically. In particular, strengthening of shear damaged RC members with CFRP materials has received much attention as an effective repair and strengthening approach. Most existing studies on strengthening shear-deficient RC members have used unidirectional CFRP strips. Recent studies on strengthened T-beams demonstrated that a bidirectional CFRP layout was more effective than a unidirectional layout. As such studies are limited, in this study, the feasibility of bidirectional CFRP layouts for the shear strengthening of rectangular RC beams was experimentally evaluated. Bidirectional layout details with CFRP anchors as well as rehabilitation timing were considered and investigated. The test results showed that the members with a bidirectional CFRP layout carried less shear strength capacity than those with unidirectional layouts for the same quantity of CFRP material. Nevertheless, the bidirectional CFRP layout allowed for a uniformly distributed stirrup strain compared to the unidirectional CFRP layout at the same load level, which increased the efficiency of the transverse reinforcement. Additionally, the shear contribution of CFRP material according to the CFRP strengthening timing was verified.
碳纤维增强聚合物（CFRP）在缺陷钢筋混凝土（RC）结构的修复和加固方面已显示出巨大潜力。迄今为止，已经对几种CFRP加固方案进行了研究并实际应用。特别是，用CFRP材料加固受剪损坏的RC构件作为一种有效的修复和加固方法受到了广泛关注。大多数现有的关于加固抗剪能力不足的RC构件的研究都使用了单向CFRP条带。最近对加固T梁的研究表明，双向CFRP布置比单向布置更有效。由于此类研究有限，在本研究中，通过试验评估了双向CFRP布置用于矩形RC梁抗剪加固的可行性。考虑并研究了带有CFRP锚固件的双向布置细节以及修复时机。试验结果表明，对于相同数量的CFRP材料，双向CFRP布置的构件的抗剪强度比单向布置的构件低。然而，与相同荷载水平下的单向CFRP布置相比，双向CFRP布置能使箍筋应变均匀分布，从而提高了横向配筋的效率。此外，还验证了根据CFRP加固时机CFRP材料的抗剪贡献。
