In-plane seismic performance of different infill wall systems in ductile reinforced concrete frames

The seismic response of infilled frames draws considerable interest in the earthquake engineering community for the last decades. Whilst the early studies were concerned with added lateral stiffness and strength, recent studies focused primarily on deformability and performance improvement. In this study, an experimental campaign was conducted to investigate the seismic performance of ductile reinforced concrete (RC) frames infilled with hollow clay bricks and autoclaved aerated concrete blocks. The effectiveness of different infill wall construction techniques, such as the use of isolation joints, mesh overlays, and horizontal sliding joints were evaluated by carrying out cyclic tests on seven half-scale RC frame specimens. Strength and stiffness degradation, energy dissipation and damage propagation of tested infill wall systems obtained by deducing bare frame (BF) response from the infilled frame (IF) were compared. Damage limit states in terms of story drift were proposed based on specific points located on the normalized experimental load-displacement backbone of infill walls. A detailed description of physical damage corresponding to each damage state was reported for visual quantification of the infill wall performance.