The in-plane shear behaviour of a new seismic retrofit concept which combines two standalone retrofit measures for in-plane and out-of-plane strengthening of masonry walls was investigated. The in-plane reinforcement consists of a single-sided carbon fabric-reinforced cementitious matrix (FRCM) overlay, while the out-of-plane reinforcement consists of deep mounted carbon fibre reinforced polymer strips embedded in a viscous-elastic epoxy. An experimental program was undertaken in which clay brick masonry wallettes were subjected to the diagonal compression test to assess the effectiveness of the strengthening system on the in-plane behaviour. The obtained results showed that the single-sided carbon FRCM overlay increased the shear capacity with 80%, compared to the unstrengthened control specimens. Moreover, by testing two different FRCM overlay thicknesses it was found that a thicker matrix layer does not increase the shear capacity of wallettes. However, wallettes provided with a thicker FRCM overlay did show a higher level of ductility. Furthermore, the obtained experimental results showed that the presence of only the aforementioned out-of-plane reinforcement does not affect the in-plane strength of masonry wallettes loaded under shear, and even prevented the disintegration after reaching the failure load compared to the unstrengthened control specimens. Finally, an existing analytical model as well as the Eurocode 8 design provisions were compared to the found failure mechanisms and failure loads. The analytical model developed showed good correspondence with the experimental values for both the failure mechanism and failure load, with an experimental/ model ratio () of 0.98, while Eurocode 8 proved to lead to conservative values.

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An experimental program was undertaken to assess the effectiveness of a new retrofit concept to improve the in-plane behavior of unreinforced clay brick walls by means of full-scale static-cyclic in-plane tests. The proposed seismic retrofit system combines two standalone retrofit measures for in-plane and out-of-plane strengthening of masonry walls. The inplane reinforcement consists of a single-sided carbon Fabric-Reinforced Cementitious Matrix (FRCM) overlay, and anchors embedded with a flexible adhesive in the masonry. The out-of-plane reinforcement, which consisted of deep mounted Carbon Fibre Reinforced Polymer (CFRP) strips embedded with a flexible adhesive in the masonry, was included in the study to investigate the possible degrading effects of the deep groove on the in-plane behavior. A total of nine full-scale reinforced masonry walls with three different geometries were tested under three different axial loads. None of the specimens showed shear failure at both the reinforced and the as-built side. Cracking predominantly occurred at the interface between the bottommost bed-joint and the foundation beam. The out-of-plane reinforcement did not affect the in-plane strength, as no vertical shear cracks occurred. Moreover, it was found that the anchors increased both the rocking and sliding resistance of the walls. An analytical model was proposed covering the rocking and sliding resistance of the reinforced walls, providing a good approximation of the experimentally obtained in-plane strengths. Additional pull-out experiments showed that the testing scenario where the tensile forces in the anchor were transferred to CFRP strip, provided a good approximation of the analytically determined anchorage strength.