Experimental Evaluation of Reinforced Concrete Frames with Unreinforced Masonry Infills under Monotonic and Cyclic Loadings

Abstract

Despite numerous studies on seismic performance of masonry infilled reinforced concrete frames have been conducted, experimental study on effect of type of lateral load on masonry infilled reinforced concrete frames is sparse. This paper investigates the seismic performance of masonry infilled reinforced concrete frames with different aspect ratios subjected to monotonic and cyclic loadings. Six half-scale, single-storey, single-bay frame specimens designed according to code provisions commonly adopted in Malaysia were tested. Behaviours of frames were assessed based on observed failure modes, strength, stiffness, ductility and energy dissipation capacity. Experimental result reveals that typical infilled frame in Malaysia has high tendency to fail under shear on columns. Type of loading does not affect strength of both bare frames and infilled frames. However, the drift to reach peak strength drops about 40–52% for infilled frames subjected to cyclic loading as compared to monotonic loading. Initial stiffness of infilled frames is found elevated with slower stiffness degradation under the influence of cyclic loading. Ductility of infilled frames subjected to cyclic loading is 48% higher than those subjected to monotonic loading, regardless of aspect ratio. A total of 84% increase in energy dissipation is observed with 60% of increment in bay length.