Modelling of the in-plane behaviour of masonry walls strengthened with polymeric grids embedded in cementitious mortar layers

The seismic reinforcement of masonry walls needs to be carried out through appropriate and effective techniques aiming at providing both adequate strength and displacement capacity. The present research concerns experimental results about the in-plane behaviour of masonry walls strengthened through an innovative technique employing polymeric grids embedded in cementitious mortar layers applied on the wall surface. The behaviour of strengthened masonry walls subjected to cyclic shear-compression tests is examined in order to quantify the strength and displacement capacity increment provided by the reinforcement. A Finite Element Model of the unreinforced and reinforced panels has been developed and parameters defining masonry and strengthening materials have been calibrated by means of comparisons with the experimental results. The effectiveness of the strengthening system has been then numerically investigated through a wide parametric analysis varying the masonry strength, the wall shape, the axial stiffness of the strengthening grid and the strength of the mortar. Finally, a comparison of the effectiveness of the polymeric grid with a traditional steel one embedded in the same mortar layer is also reported.