CONFINEMENT TECHNIQUES TO RESIST STATIC AS WELL AS DYNAMIC COMPRESSION OF CONCRETE COLUMNS: A REVIEW PAPER

Abstract

Driven by the concern to identify better technical solutions for the vulnerability of concrete structures to both axial compression and axial compression coupled with lateral pressures caused by events such as earth quake, wind and water forces, a host of relevant literature has been surveyed. Confined concrete structures, to begin with, formed a solution but improvements thereon have lead to experimentations through transverse reinforcement in the form of spirals, circular hoops and rectilinear ties or by encasing the concrete columns in a steel tube or in FRP wraps. The initial works however have looked at only the single layered confinement. The impact of single layered stirrups has been studied under condition of normal strength concrete as well as high strength concrete. Despite capturing models of single layer transverse reinforcement with and without fibrous concrete, the researchers were left
with suboptimal solutions of confinement with single layer configurations. This perhaps has lead to more recent studies suggesting experimentation with double layered stirrups confined concrete columns. These studies including the efforts, though very few in number, to develop analytical models have opened up scope for research in double layered stirrup reinforcement with various configurations, including even confinement using mild steel mesh.