Experimental and numerical studies of improving cyclic behavior of infilled reinforced concrete frame by prefabricated wall panels with sliding joints

This paper aims to introduce a new type of damping infill wall system to alleviate the negative infill-frame interaction of fragile infill walls for reinforced concrete (RC) frames and improve the cyclic behaviors of the entire system. Three tested specimens including specimen BF (a bare RC frame), specimen CWF (an RC frame with ordinary infill walls), and specimen DWF (an RC frame with novel damping infill walls) are designed and fabricated. Quasi-static cyclic tests are conducted to them for exploring and comparing their cyclic behaviors. Experimental results reveal that severe destruction appears upon the conventional infill walls due to the negative infill-frame interaction. On the contrary, no significant cracks or damage are viewed in the new damping wall panels at the inter-story drift ratio of 4.00%. It confirms that the unfavorable infill-frame interaction under horizontal loadings can be mitigated by the developed damping infill systems effectively. The developed innovative infilled RC frame and the bare RC frame exhibit similar cyclic behaviors, including the hysteretic response, loading capacity deterioration, secant stiffness deterioration, and displacement ductility. Furthermore, by using the advanced infill wall system, the RC frame can dissipate energy more efficiently by over 15.71% and ameliorate the degradation of energy dissipation capacity through the stable damping force from the sliding joints. Additionally, numerical models and specimens show similar cyclic behaviors, which testifies to the validity of the pseudostatic experiment and numerical simulation. Parametric results reveal that the influence of developed wall panels made of different strengths of concrete for ameliorating seismic performance of infilled RC frames is very little, whereas the friction factor in the sliding joint is the essential element for enhancing the capacity of infilled RC frames to bear the lateral loadings.