Experimental Investigations on Seismic Retrofitting of Reinforced Concrete Beam-Column Joints
Beam-column joints are recognized as the critical and vulnerable zone of a Reinforced Concrete (RC) moment resisting structure subjected to seismic loads. During an earthquake, the global response of the structure is mainly governed by the behaviour of the joints. If the joints behave in a ductile manner, the global behaviour generally will be ductile, whereas if the joints behave in a brittle fashion then the structure will display a brittle behaviour. The joints of old and non-seismically detailed structures are more vulnerable and behave poorly under the earthquakes compared to the joints of new and seismically detailed structures. Therefore, more often than not, the joints of such old structures require retrofitting in order to deliver better performance during earthquakes. Various researchers have proposed different methods to retrofit the beam-column joints of existing RC structures. This paper reports a few experimental investigations carried out for seismic retrofitting of RC beam-column joints using different techniques. The concepts behind each of them and their practical usefulness have been brought out.