PERFORMANCE EVALUATION OF REINFORCED CONCRETE FRAMES WITH ENERGY DISSIPATING HYSTERETIC INFILLS UNDER CYCLIC LOADS

Abstract

The structural interaction mechanism of the reinforced concrete moment resisting frame with the brittle conventional brick infill wall system is a recognized area of concern during severe earthquake excitations. The detachment of the infill from the reinforced concrete frame starts at a low level of drift that triggers a number of undesirable modes of failure of the frame as well as the infill itself. The proposed research discusses the development and construction of an alternative infill wall system that has an efficient lateral resistance mechanism and an improved energy dissipation capacity. A novel energy dissipating hysteretic infill wall system comprising slotted concrete blocks with energy dissipating links made from the ply part of used radial rubber tyres is designed and experimentally tested extensively in full scale reinforced concrete frames. Two sources of energy dissipation mechanism are exploited in the developed system namely friction arising from the rigid surfaces of the blocks in contact and the elastomeric resistance arising out of the yielding of the energy dissipating links. A comprehensive experimental and numerical study is conducted on the energy dissipating hysteretic infill wall system to prove its efficacy and efficiency over the conventional brick infill wall system. Firstly, the load-deformation response of both the infill wall systems is investigated under in-plane directions through cyclic tests conducted on full scale single-storey and two-storey portal frames. There is a significant improvement of the hysteresis behavior of the frames with the proposed infill wall system in terms of failure pattern, degradation of the strength and stiffness and energy dissipation. The energy dissipating infill wall system helps in reducing the stiffening effect and dissipates the energy imparted to the structure. The post-yield response of the frame becomes stable and no collapse condition arises even at large deformations. It also acts as a secondary load resisting system after the formation of plastic hinges in the frame. The energy dissipating hysteretic infill wall system is a kind of passive energy dissipating system that may act as an efficient and versatile solution to minimize the damages in the frame buildings.