Bond–slip model for CFRP strips near-surface mounted to concrete

A relatively recent method for the strengthening of concrete structures involves the embedding of fiber reinforced polymer (FRP) bars/strips into pre-cut, adhesive-filled grooves in the cover concrete. This paper presents a finite element (FE) study into the bond behavior of NSM CFRP strip-to-concrete bonded joints using a three-dimensional (3-D) meso-scale FE model developed by the authors. The effects of various parameters on the bond behavior of NSM CFRP strips are first clarified with the assistance of FE results, leading to the identification of the groove height-to-width ratio and the concrete strength as the two important parameters for the bond behavior. Based on the results of a FE parametric study on the effects of these two parameters, an analytical bond–slip model is proposed.