SHAKE TABLE TESTS ON FRP-REHABILITATED RC SHEAR WALLS

摘要

This paper investigates the behaviour of two 8-storey cantilevered reinforced concrete (RC) shear walls rehabilitated using carbon fibre-reinforced polymer (CFRP) composite sheets when subjected to base excitations from a shake table. The two control reduced size walls (1:0.429) were tested on the shake table of Ecole Polytechnique de Montreal in order to investigate the effect of higher modes of vibration on the behaviour of multi-storey RC walls. The walls were subjected to several levels of ground motion excitation that matches the National Building Code of Canada (NBCC 2005) design spectrum of Montreal city in Quebec, Canada. The control walls showed significant inelastic deformations at the 6th storey level in addition to those at the base plastic hinge. After the shake table tests on each of the two control walls, the walls were rehabilitated and re-subjected to the same levels of the ground motion excitations. This paper focuses on the FRP-rehabilitation of the control walls. The rehabilitation scheme for the two walls aimed to increase the flexural and shear capacities of the wall at the 6th storey panel due to the observed increase in demand at that level, whereas the base panel was confined using CFRP sheets in order to increase the ductility capacity without increasing the strength. The rehabilitated walls showed satisfactory performance with improved flexural strength at the 6th storey panel. The rehabilitation scheme resulted in a reduced wall rotation and lower strain values of the flexural steel rebars at the 6th storey panel.