Numerical meso-model for reinforced concrete frames with retrofitted masonry infill

Several research outcomes have ascertained the need of considering the infill walls in the dynamic response evaluation of reinforced concrete framed buildings. In the case of buildings designed prior the introduction of modern seismic codes, the presence of strong infill might highly influence the failure mode in case of earthquake. Furthermore, considering the increasingly adoption of retrofit techniques aimed at enhancing the in-plane and out-of-plane capacity of the infill walls, its influence on the seismic performance of the structure should be investigated at global and local level. In this study, a numerical model to simulate the response to lateral loads of reinforced concrete frames with retrofitted masonry infill walls is developed. Particularly, since the use of composites is widespread due to the well-known benefits of these materials, the work is focused on the in-plane infill retrofit by fibre-reinforced polymer (FRP). The proposed model for the retrofitted infill is validated by numerical simulation of diagonal compression tests on masonry panels previously conducted at university of Salento. Aiming to analyse the influence of the retrofit on the seismic performance of the frame, the retrofitted infill and unreinforced infill performances are compared. Depending on the infill type considered, the failure modes of the frame members, the energy dissipated under lateral loading and the displacement capacity are analysed.