Tangent Poisson's ratio of high-strength concrete in triaxial compression

Abstract

Based on a carefully arranged experimental programme, the paper studies the variation of the tangent Poisson's ratio of high-strength concrete with a uniaxial compressive strength of 67 MPa (100 × 200 mm cylinder) under various confining pressures in triaxial compression. It shows that the high lateral confinement can significantly reduce the initial value of the tangent Poisson's ratio as compared with that of the uniaxial compression, and the tangent Poisson's ratio at failure also decreases notably with the increase of the lateral confining pressure. Therefore the tangent Poisson's ratio of high-strength concrete depends on not only the axial stress but also the lateral confinement. A simplified expression based on the experimental results is then proposed to define this variation. The influence of cyclic loading in triaxial compression is also investigated; this shows that the lateral versus axial strain relation of high-strength concrete during the cyclic loading essentially follows the general trend of the monotonic loading.