Shake Table Tests of Infilled RC Frames with Different Column-to-infill Connections

Masonry infill walls are widely used as partitions in RC frames and usually considered as nonstructural elements in design. However, observations from the recent major earthquakes have shown that the structural interaction between columns and infill walls of RC frames under seismic excitation can significantly alter the structural behaviour, thus causing catastrophic consequences. This paper presents shake table tests on 1/3-scale RC frame specimens with infill wall under real earthquake excitation inputs, with the aim at verifying the effectiveness and applicability of proposed flexible connection details at column-to-infill interface. Taking into account of similitude requirements, the artificial mass simulation model has been utilised during specimen design process. The first frame specimen is fully infilled by masonry wall, while the second one is constructed by separating the infill panel from columns with two finite width vertical gaps. Columns and infill walls are connected by spaced mild steel bars, and the gaps between them are filled with polystyrene foam. The test results indicate that the proposed flexible column-infill connection details can effectively improve the seismic performance of masonry-infilled RC frame structures by reducing the undesirable interaction between columns and infill wall. In addition, the displacement ductility and energy dispassion capacity of the frame system can be considerably improved.