Abstract

This paper aims to study the effect of Carbon Fiber Reinforced Polymer (CFRP) strengthening techniques on the fatigue limit of Reinforced Concrete (RC) beams. An accelerated fatigue method was utilized to find the fatigue limit based on the hypothesis of linear cumulative damage as determined by the Palmgren-Miner rule. Six RC beams with dimensions of 152.4 × 152.4 × 1,520 mm were tested under monotonic and cyclic loading using a four-point bending configuration: two non-strengthened RC beams, two RC beams strengthened with Near Surface Mounted (NSM) CFRP rods, and two RC beams strengthened with Externally Bonded (EB) CFRP sheets. Strengthened RC beams had less stiffness degradation and more energy dissipation when compared to the non-strengthened RC beam. The NSM CFRP technique demonstrated a better monotonic flexural strength than the EB CFRP technique. NSM CFRP rods and EB CFRP sheets increase the fatigue limit when compared to the non-strengthened RC beam by 19% and 33%, respectively.

摘要

本文旨在研究碳纤维增强聚合物（CFRP）增强技术对钢筋混凝土（RC）梁疲劳极限的影响。基于由Palmgren-Miner规则确定的线性累积损伤的假设，使用了加速疲劳方法来找到疲劳极限。使用四点弯曲配置在单调和循环载荷下测试了六个尺寸为152.4×152.4×1,520 mm的RC梁：两个非加强型RC梁，两个经近表面安装（NSM）CFRP杆加固的RC梁，以及两个RC梁用外部粘结（EB）CFRP板加固。与未加筋的RC梁相比，加筋的RC梁的刚度降级较小，能量消耗更大。NSM CFRP技术表现出比EB CFRP技术更好的单调抗弯强度。与未加强的RC梁相比，NSM CFRP棒和EB CFRP板分别提高了疲劳极限19％和33％。