Experimental Study of Bond Behavior of CFRP-to-Brick Joints

Carbon fiber–reinforced polymer (CFRP) composite materials have been widely used to strengthen masonry constructions. The bond between CFRP and substrate strongly conditions the performance of reinforced masonry structures. Characterization of shear bond mechanical behavior of masonry-CFRP interface thus becomes a crucial factor. The paper presents the results of an extensive experimental investigation aimed at evaluating the bond between clay brick and CFRP sheet. Specimens with varying width and length of the bonded CFRP sheet were subjected to shear test by three different testing setups. Results allowed comparison of the effectiveness of the three types of setup and pointed out the influence of the dimensions of the bonded sheet on ultimate load and ultimate slip, load-displacement diagram, and failure modes. Measurement of local strain along the CFRP sheet also allowed an investigation on the transfer mode of the stresses from the reinforcement to the brick and the determination of the local shear stress-slip relationship.