Bond Behavior of CFRP/Steel Double Strap Joints: An Experimental Study

The performance of steel elements retrofitted with carbon fiber-reinforced polymer (CFRP) relies on the bond behavior of the interface between CFRP and steel substrate, as the adhesive is typically the weakest link of the retrofitting system. Therefore, understanding the bond behavior between CFRP and steel substrate is crucial for retrofitting design of steel structures. This necessity has been the main impetus for conducting the present experimental study on the bond behavior of CFRP/steel double strap joints under static loadings. To that end, the adhesive type, CFRP-bonded length, and surface preparation are the parameters considered in this research. Additionally, the effect of CFRP elastic modulus on the bond behavior is examined by using Normal Modulus (NM) and Ultra-High Modulus (UHM) CFRP with approximately the same tensile capacity. Failure modes, bond strength, effective bond length, and bond–slip curves are some of the key issues that will be thoroughly discussed in this study.