Experimental Study on the Behaviour of Short Columns Confined by Waste Plastic Bags-Epoxy Composites

Abstract

An experimental study was carried out to investigate the behaviour of short column confined by waste plastic bags and nylon strips and findings of this study are presented in this paper. Eight reinforced concrete (RC) short columns were casted. Among them two specimens were named as control, while remaining six specimens were divided into three groups [two specimens for each group] based on different confinement techniques investigated in this study. In retrofitting technique 1 (RT-1), RC short columns were externally confined by full wrap of plastic bags, while in retrofitting techniques 2 (RT-2) and 3 (RT-3), confinement was provided to the short columns by stirrups of nylon and plastic bags with 25 mm clear spacing, respectively. The testing under compression loading was performed on UTM of 100T capacity. From the results obtained, seismic parameters such as ductility, fracture energy before peak and after peak, factor k* and load-displacement response were studied. The results indicated that RC short column confined by RT-1 (full wrap) gives better performance in terms of ductility and fracture energy after peak. Increase in the ductility of RT-1 specimen was about 25% as compared to the control one. Moreover, post-peak fracture energy exhibited by short column confined through techniques RT-1 and RT-2 was 132 and 125 N/mm as compared to control one with 14 N/mm of fracture energy. The experimental observations further indicated that the failure of control specimen was sudden showing high brittleness while the failure of confined specimens by RT-1 and RT-2 techniques was observed to be gradual giving some warning before final failure.