LAUSR

Abstract In this study, a total of 40 concrete blocks were casted and externally strengthened with carbon fiber reinforced polymer (CFRP) composites. The principal objective was to evaluate the influence of special anchoring holes on the bond-slip behavior between CFRP composites and concrete. The bonding surface of each concrete blocks was prepared and then anchoring holes were drilled using rotary drill. The number and pattern of anchoring holes were varied to arrive at the optimum bond-slip behavior. The effects of the CFRP sheet width (10 cm, 15 cm) and length (10 cm, 15 cm) were also investigated. Five different patterns of anchoring holes were assessed including: horizontal pattern, vertical pattern, rectangle pattern, V pattern, and one center holes. The experimental results showed that the pattern of the anchoring holes has a significant effect on the bond-slip behavior. In general, both the bond strength and ultimate slippage increase as the number of holes increases and as the CFRP sheet width or length increase. However, for an equivalent CFRP sheet area, the influence of the width (perpendicular to the direction of loading) is more significant in improving the bond strength than the influence of the length of CFRP sheet. For similar number of anchoring holes, the horizontal pattern was the most effective followed by the rectangular, V-shape, and vertical pattern, respectively.