The effects of infill wall on dynamic characteristics of reinforced concrete frame systems

This study presents an experimental investigation on the dynamic characteristics of infilled Reinforced Concrete (RC) frames. For this purpose, a 1/3-scaled, one-bay, three-storey RC frame was produced and tested by using ambient vibration test. The experiments were performed on sequentially produced three specimens which use the same single reinforced frame. The infill walls were made of hollow clay brick. The frequency, mode shapes and damping ratios in the in-plane direction of patterns were obtained by six accelerometers. Fifteen-minute records under ambient vibration were taken for each model, and the dynamic characteristics were determined using the ambient response testing and modal identification software (ARTeMIS) program. The experiments showed that the infill walls significantly affected the frequency values and damping ratios of the frame system. As a result of this study, the presence of damaged/undamaged infill walls lead to an increase in the frequency values and the damping ratios for the first three modes of the frame systems. On the other hand, the natural frequency of the first three modes of with undamaged infill walls is more than those with damaged ones. While the damping ratios for undamaged infill walls were increased at first two modes and it was decreased at the third mode.