DEFORMATIONAL BEHAVIOR AND CONSTITUTIVE EQUATION OF CONCRETE USING THE ELASTO-PLASTIC AND FRACTURE MODEL.

Biaxial loading tests of concrete under compression-tension stress states were carried out for collecting the fundamental data to formulate the plane stress constitutive equations for concrete. The non-proportional stress paths were newly adopted to make clear the anisotropic behavior of concrete quantitatively. According to the test results, the elasto-plastic and fracture constitutive equations which describe the progress of the plasticity and the fracture are formulated. A new system of flow rules, which describe the directional correlations of the stress and the strain vectors, is also proposed for formulating the anisotropy of concrete.