This paper presents the results from a comparative study on the residual bond performance of epoxy and cement-bonded carbon fiber-reinforced polymer (CFRP) reinforcement to concrete interfaces that experienced different levels of elevated temperature exposure. In total twelve groups of concrete beams strengthened with CFRP sheet and grids of the same tensile stiffness, through epoxy and cement-based adhesive bonding, respectively, were carefully prepared and exposed to different test temperature levels from 20 °C to 600 °C. Both polymer cement mortar (PCM) and ductile engineered cementitious composite (ECC) were adopted as the cement binder. The strengthened beams were tested under three-point monotonic bending after different levels of elevated temperature exposure. It was found that with increasing the exposure temperature, the failure modes of the strengthened beams shifted from debonding in a thin layer of concrete substrate to debonding near the fiber-adhesive interface and tearing off of CFRP grids from the ECC matrix. The peak loads of concrete beams strengthened with cement-bonded CFRP grids are at least 50% higher than their counterparts strengthened with epoxy-bonded CFRP sheets given the same temperature exposure.

本文介绍了对环氧树脂和水泥粘结碳纤维增强聚合物 (CFRP) 增强材料对经受不同高温暴露水平的混凝土界面的残余粘结性能的比较研究的结果。共 12 组混凝土梁用具有相同抗拉刚度的 CFRP 板和网格加固，分别通过环氧树脂和水泥基粘合剂粘合，分别经过精心准备，并暴露于 20°C 至 600°C 的不同测试温度水平。采用聚合物水泥砂浆（PCM）和延性工程水泥基复合材料（ECC）作为水泥结合剂。在不同程度的高温暴露后，加固梁在三点单调弯曲下进行了测试。发现随着暴露温度的升高，加固梁的失效模式从在混凝土基材薄层中脱粘转变为在纤维-粘合剂界面附近脱粘以及从 ECC 基体上撕下 CFRP 网格。在相同的温度暴露下，用水泥粘合 CFRP 网格加固的混凝土梁的峰值载荷至少比用环氧树脂粘合 CFRP 板加固的对应梁高 50%。