Effects of lateral reinforcement upon the strength and deformation properties of concrete

Abstract

Synopsis Confinement of concrete by rectilinear lateral reinforcement is discussed. An experimental investigation is described in which the main variables were: concrete strength; size, spacing and grade of lateral reinforcement; strain gradient; and thickness of cover. In the analysis of test results, laterally reinforced specimens are treated as composite members consisting of core and cover. The parameters of an analytical stress-strain relationship, which was found to describe the mechanical properties of plain and laterally reinforced concrete adequately, are determined from a regression analysis of the test results. The experimental results are compared with the strength of confined concrete as predicted by (1) a formula based on a theoretical analysis, and (2) an equation which unifies several previously proposed formulae giving the strength of laterally reinforced concrete.