Experimental study on the behavior of RC beam-column joint retrofitted with ferrocement jacket under cyclic loading

Abstract

Beam-column joints, being the lateral and vertical load transferring connections in reinforced concrete structures are particularly vulnerable to failures during earthquakes and hence satisfactory performance of these joints is often the key to control the performance of connecting structural members during any seismic event. The present study describes the result of performance of reinforced concrete beam-column joint specimens cast and tested to failure during the experimental work. Two specimens were coated with ferrocement and two were without ferrocement jacket. Reinforcement detailing was as per BNBC 2006. Axial load was applied along the column axis and cyclic loads with gradual increments were applied at tip of cantilever beam till the ultimate capacity was attained accompanied by formation and propagation of crack and failed after formation of hinges. Before formation of first crack ferrocement jacketed specimens experienced 33.26% more lateral load than normal specimens. Maximum deflection before failure was found to be less for ferrocement jacketed specimens. Numbers of cracks were fewer for ferrocement jacketed specimens relative to normal specimens. Hysteresis loops showed higher ductility for ferrocement jacketed specimens than that of normal specimens. Ultimate moment carrying capacity of beam-column joints of specimens with ferrocement jacket found 20% greater than that of normal specimens. Therefore, it may be concluded that ferrocement jacketing may be effectively used to increase the strength and ductility of beam-column joints.