Bài báo khoa học

In the application of carbon fiber composite sheets (Carbon Fiber Reinforced Polymer-CFRP) to enhance reinforced concrete structures, the bond strength between the CFRP sheets and concrete members plays a crucial role in determining the capacity of the strengthened structures. The paper present an experimental investigation on the influence of concrete compresive strength on the bonding strength between CFRP sheets and concrete substrates. Three groups of specimens with concrete compressive strengths of 20 MPa, 27 MPa, and 36 MPa were prepared. A near-end supported single-shear test was employed to determine the ultimate load that causes debonding between CFRP sheets and concrete substrates. The experimental results revealed the following: (1) Debonding failures depends on the quality (compressive strength) of concrete. Two groups of sprecimen with concrete compressive strengths of 20 MPa and 27 MPa, damage occurs deep into the concrete cover, otherwise, the specimens with the concrete compressive strength of 36 MPa, damage occurs at the contact surface between CFRP sheets and concrete substrates; (2) The bonding load between CFRP sheets and concrete substrates is proportional to the concrete strength. However, when the concrete strength is sufficiently high, the bonding between the CFRP sheet and the concrete will be influenced by the strength of the epoxy adhesive used.