In the previous tests performed of cubic specimens of cement mortar, the authors showed that the material would turn anisotropic with increase of the deviatoric stress component, and that the texture of the material underwent changes with increase of its hydrostatic stress component. From these results it is supposed that cement mortar which seems to be macroscopically homogeneous and isotropic will exhibit anisotropy not by the intrinsic property of the material, but by the transition of

more »

... in state, and that the internal change of the texture of the material depends upon the degree of porosity contained in the material. The triaxial compression tests by experiments I and II were therefore performed of cement mortar and marble specimens with considerable difference in porosity in them respectively under various states of stress, in order to investigate the relationship between the textural change and the characteristics of deformation due to the transition of stress from isotropic state to anisotropic state. From the results of these tests the authors found the following facts. (1) The internal texture of the material undergoes changes and resistance against deformation decreases with increase of hydrostatic stress under different levels of stress on mortar and marble. The characteristics of deformation tend also to be anisotropic as deviatoric stress increase. (2) The characteristics of deformation are definitely determined by the state of stress regardless of its path if the given stress of the material is below its yield stress.