Experimental Evaluation of Masonry-Infilled RC Frames

The influence of masonry infill panels on the seismic performance of reinforced concrete (RC) frames that were designed in accordance with current code provisions are investigated. Two types of frames are considered. One was designed for wind loads and the other for strong eqrthquake forces. Twelve 1/2-scale, single-story, single-bay, frame specimens were tested. The parameters investigated included the strength of infill panels with respect to that of the bounding frame, the panel aspect ratio, the distribution of vertical loads, and the lateral-load history. The experimental results indicate that infill panels can significantly improve the performance of RC frames. However, specimens with strong frames and strong panels exhibited a better performance than those with weak frames and weak panels in terms of the load resistance and energy-dissipation capability. The lateral loads developed by the infilled frame specimens were always higher than that of the bare frame. This is even true for the least ductile specimen deforming up to a drift level of 2%.