Abstract

In this article, an experimental program was carried out to investigate the flexural behaviour of RC beams strengthened using side and bottom near-surface mounted (NSM) CFRP strip and rope. Thirteen reinforced concrete beams (150x250x1600mm) with flexural deficiency were cast. Different configurations have been used for strengthening RC beams, including side NSM, bottom NSM and both of them. Test results have shown that specimens strengthened with NSM CFRP strips have higher load carrying capacity and higher ultimate deflection than that strengthened with NSM CFRP ropes for the same configuration. FRP debonding, concrete cracks and concrete cover separations are more depicted in specimens strengthened with NSM CFRP ropes than that strengthened with NSM CFRP strips. Using NSM CFRP ropes or strips has increased the elastic stiffness of the strengthened specimens. Flexural strengthening of RC beams using CFRP ropes and strips has increased the load-carrying capacity NSM in a range of (18%–51%) and (30%–80%), respectively, compared to the control specimen. It is also found that beams with bottom strengthening increased the flexural capacity by (25%–32%) compared to RC beams with side strengthening

摘要

在本文中，开展了一项实验计划，以研究使用侧面和底部近表面安装 (NSM) 碳纤维增强塑料条带和绳索加固的 RC 梁的弯曲性能。浇筑了 13 根存在抗弯缺陷的钢筋混凝土梁 (150x250x1600mm)。不同的配置已用于加固 RC 梁，包括侧面 NSM、底部 NSM 以及两者。测试结果表明，对于相同配置，使用 NSM CFRP 条加固的试件比使用 NSM CFRP 绳加固的试件具有更高的承载能力和更高的极限挠度。FRP 剥离、混凝土裂缝和混凝土保护层分离在用 NSM CFRP 绳索加固的试件中比用 NSM CFRP 条加固的试件更容易描述。使用 NSM CFRP 绳索或条带增加了加固试样的弹性刚度。与对照样本相比，使用 CFRP 绳索和条带对 RC 梁进行抗弯加固，承载能力 NSM 分别提高了 (18%–51%) 和 (30%–80%)。还发现，与侧面加固的 RC 梁相比，底部加固的梁的抗弯能力提高了 (25%–32%)