Experimental investigation of reinforced SCC beam-column joint with rectangular spiral reinforcement under cyclic loading

Abstract

This paper presents an experimental study on continuous rectangular spiral reinforced self-compacting concrete (SCC) beam-column subassemblies subjected to cyclic loading. Total three sets of exterior beam-column joint for different flexural strength ratio, with continuous rectangular spiral reinforcement and individual closed stirrups as reference specimen, are considered in the investigation and the flexural strength ratio adopted for three-set were 1.3, 1.5, 2.0. In this work, self-compacting concrete specimens with three different inclinations of stirrups angles (75°, 80°, 85°) are considered for the spiral reinforcement. For better understanding and analysis, all the (twelve) specimens are shrinked to one-third scale. The reinforced beam column sub assemblage has been subjected to cyclic tests to understand its crack propagation and resistive capacity during the seismic excitations. The primary objective of this study is focused on the seismic behaviour of the joint, in terms of load displacement pattern, hysteresis behaviour, failure pattern and energy dissipation. Further more studies are carried out to distinguish and analyse the performances with conventionally closed stirrups. The observed findings are motivating as continuous spiral stirrups outperformed the conventional stirrups in terms of ultimate strength, stiffness degradation, ductility factor and cumulative energy dissipation. These findings would be beneficial to the engineers to build, feasible, suitable and efficient upgrading technique for structural joints in seismic zones.