Effective Bond Length Evaluation of Fiber Implantation Methods in EBR Applications Using Particle Image Velocimetry

Document Type : Research Article


1 Graduate Student, Civil Engineering Department, Ferdowsi University of Mashhad

2 َAssistant Professor of Civil Engineering, Ferdowsi University of Mashhad


The bond strength between fiber-reinforced polymer (FRP) laminates and concrete is the main factor affecting the behavior of concrete members strengthened by externally bonded reinforcement (EBR) method. The bond strength depends on several factors, such as surface preparation, concrete strength, FRP stiffness and thickness, and effective bond length. According to previous studies, using a bond length longer than the effective bond length, will not increase load-carrying capacity. Most existing theoretical models estimate bond strength based on the effective bond length. So, in order to achieve a satisfactory performance, it is important to determine the accurate value for the effective bond length of lap joints. In this study, in order to evaluate and compare the effective bond length of fiber implantation method and the conventional EBR method, 12 concrete specimens were prepared and examined. The effective bond length and the bond strength of specimens were determined using single-shear pull test and adopting particle image velocimetry (PIV) method and they were compared with the existing specifications such as ACI and fib. The results showed that using fiber implantation method instead of the conventional EBR method reduced the effective bond length by 20% and increased the bond strength between FRP and concrete substrate by 34%.


Main Subjects

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