Mechanical characterization and out-of-plane behavior of fabric-reinforced cementitious matrix overlay on clay brick masonry

The mechanical behavior of carbon fiber-reinforced polymer (CFRP) fabric-reinforced cementitious matrix (FRCM) overlay on clay brick masonry was characterized by means of double-shear bond, tensile, and out-of-plane tests. Different bond lengths in the range 55-250 mm were analyzed during the double-shear bond tests. The failure mechanism was slippage of the CFRM mesh, with peak stresses in the fabric around 500 N/mm² per 100 mm bond length. Tensile tests were performed following AC434.13 with FRCM coupons of 10 and 15 mm thickness, where the mechanical behavior was divided into three stages. The four-point bending experiments on FRCM-reinforced prisms showed that the CFRP mesh provided significant added value in both moment capacity (>110%) and deformation capacity (>2800%), when compared to specimens reinforced with solely a cementitious matrix. Additionally, no significant difference was observed between the envelope of the cyclically tested specimen and the statically loaded specimens. A model was proposed where, in contrast to existing design models, the influence of the cementitious matrix layer also was considered. Using the modified tensile test results as input parameters for the model, a good estimation of the experimental results was obtained.