Out-of-Plane Behavior of In-Plane Damaged Masonry Infills Retrofitted with TRM and Thermal Insulation

The effect of in-plane damage on the out-of-plane response of retrofitted and thermally insulated masonry infills was examined in this paper through a set of experiments performed on a medium-scale reinforced concrete frame. Structural reinforcement was realized through the use of textile reinforced mortar (TRM), while expanded polystyrene boards were used for thermal insulation. Various specimen configurations were tested both in- and then out-of-plane sequentially for each infill specimen. Experimental results have shown that the TRM-based strengthening scheme can improve the out-of-plane response of masonry infills both in terms of strength and stiffness, especially in the case of predamaged walls, where strength increases of above 80% were achieved. The addition of insulation arranged in a sandwich configuration resulted in a slight out-of-plane improvement but was not as effective in the case of predamaged infills due to prior in-plane loading, which caused partial debonding of the board. An analytical model is also proposed and validated against the experimental data, which can predict the out-of-plane behavior of a masonry infill while also accounting for the existence of reinforcement and prior damage. Finally, using the same model in a number of case studies, generalized response diagrams are produced and a set of simplified empirical equations is suggested.