The creep of sealed concrete under multiaxial compressive stresses

Abstract

Synopsis The results of two series of creep tests on sealed concrete are presented. Uni-, bi- and triaxial states of compressive stress were applied to cubical specimens; in the first series, all loaded faces were subjected to the same level of applied stress; in the second series, different levels of stress were applied orthogonally to each specimen. Analysis of the results in terms of the volumetric and deviatoric components of creep shows that the two components can be considered as independent of each other and that both are directly proportional to stress. Their ratio is approximately constant and equal to the elastic value while the concrete is under load; this is equivalent to saying that the effective Poisson's ratio remains constant. After unloading, the ratio changes, the volumetric delayed recovery being initially faster and ceasing sooner than the concurrent deviatoric component.