Experimental response and numerical modelling of two-storey infilled RC frame

Recent devastating earthquakes pointed out the high vulnerability of existing reinforced concrete (RC) buildings and the critical role of infills. The presence of stiff infills may significantly modify the lateral response of RC moment resisting frame buildings and cause severe damage on the surrounding RC members due to seismic actions transmitted at level of beam-column joints. Furthermore, due to their brittle response, they commonly exhibited severe damage often leading to high economic losses. In this context, effective seismic retrofit strategies should aim at both increasing the shear strength of RC members and reducing the damage to infills. However only few tests are available in literature addressing the seismic strengthening of existing RC frames accounting for the infill-to-structure interaction. To fill this gap a comprehensive experimental program of pseudo-dynamic tests on full-scale two-storey infilled RC frames has been designed and is currently ongoing at the full-scale laboratory testing of the University of Napoli Federico II. This paper reports the preliminary experimental results and numerical analyses carried out by using available non-linear models accounting for the infills contribution. The comparison between theoretical predictions and experimental results provides useful insights to improve the numerical models to reproduce the infill-to-strut interaction. Finally, a retrofit strategy to improve the seismic performance of the structural system and reducing the expected damage to infills is herein outlined. © 2021 COMPDYN Proceedings