On Poisson’s Ratio and Volumetric Strain in Concrete

A new procedure is proposed for identifying uniaxial stress-strain relationship and Poisson’s ratio in compressed plain concrete. The procedure is based on the assumption of an internal core of intact material always present inside a specimen in uniaxial-compression. This involves a modification of the traditionally identified uniaxial stress-strain relationship and Poisson’s ratio, which turns out to be almost independent of the loading step. The main finding concerns the volumetric strain, since it appears to be no real increase in the volume of a concrete solid when the solid is placed under pressure.