Non-destructive analysis of fiber reinforced polymer (FRP) composites is important for confirming the long-term safety and durability of concrete structures. In this study, a pulse-heating infrared thermography technique was used to detect and characterize bonding defects of externally bonded carbon fiber reinforced polymers (CFRP) on concrete surface structures. The CFRP composite contains various bonding defects of three different sizes located at five different depths. Sequential thermal images were obtained to describe the temperature contrast and shapes of the bonding defects. Through analysis of the maximum temperature response, we investigated the effects of defect size and depth on the defect temperature response. The relationship between the defect depth and maximum temperature response was used to quantitatively estimate the defect depth. In addition, finite element simulations were performed on the CFRP composites with bonding defects to investigate the temperature response of various defects, which showed good agreement with the experimental results. This confirms the effectiveness of the infrared thermography method to detect and characterize bonding defects of FRP composites bonded on concrete structures.

纤维增强聚合物（FRP）复合材料的无损分析对于确认混凝土结构的长期安全性和耐久性非常重要。在这项研究中，采用脉冲加热红外热成像技术来检测和表征混凝土表面结构上外部粘合碳纤维增强聚合物（CFRP）的粘合缺陷。CFRP 复合材料包含位于五个不同深度的三种不同尺寸的各种粘合缺陷。获得连续的热图像来描述温度对比和键合缺陷的形状。通过对最大温度响应的分析，我们研究了缺陷尺寸和深度对缺陷温度响应的影响。利用缺陷深度与最大温度响应之​​间的关系来定量估计缺陷深度。此外，对存在粘结缺陷的CFRP复合材料进行了有限元模拟，研究了各种缺陷的温度响应，结果与实验结果吻合良好。这证实了红外热成像方法检测和表征粘合在混凝土结构上的 FRP 复合材料粘合缺陷的有效性。