Experimental Investigation of the Influence of Concrete Strength on the Bond Interface between CFRP Sheets and Concrete Members

CFRP to concrete bond behavior has a significant role in transferring the stress between the concrete and the CFRP sheets and has a direct influence on the failure mode of a CFRP- strengthened RC beams. The bond behavior is influenced by several factors, including concrete compressive strength, stiffness of CFRP sheets, adhesive resin, CFRP-to-concrete width ratio. This paper presents an experimental investigation on the influence of concrete strength on the bonding strength of concrete - CFRP sheet using a near-end supported single-shear pull test. Experiments were performed on nine specimens using three concrete mix proportions. The test results indicated that the strain of CFRP sheet is proportional to the concrete compressive strength. Additionally, the failure modes were found to be dependent on the concrete compressive strength.