Seismic performance of masonry infilled RC frames designed for gravity loads

The common practice considers the masonry infills as non-structural elements neglecting their influence in the evaluation of the seismic performance. However, the damages observed during past earthquakes, as well as the experimental studies carried out in the last decades, pointed out the influence of masonry infills in the loss assessment of reinforced concrete buildings. The interaction between the infill panels and the surrounding frame significantly affects both stiffness and strength of masonry infilled reinforced concrete frames. The aim of this work is to investigate about the influence of masonry infills on the seismic performance of multi-storey reinforced concreteframes designed for gravity loads both in terms of elastic and inelastic response. The macro-modelling approach is followed assuming consolidated formulations available in the literature. The mechanical properties of masonry infills are varied in a wide range, aiming to cover the usual materials used in Italy. The Incremental Dynamic Analysis is carried out in order to study the fragility curves, the collapse mechanisms and the ductility of the analysed frames