Title:
Experimental Study of Plain Concrete
under Triaxial Stress
Author(s):
I. lmran and S. J. Pantazopoulou
Publication:
Materials Journal
Volume:
93
Issue:
6
Appears on pages(s):
589-601
Keywords:
concretes; damage; deformation; moisture content (of aggre-gate,
hardened concrete, etc.); triaxial stresses.
DOI:
10.14359/9865
Date:
11/1/1996
Abstract:
The mechanical behavior of plain concrete under triaxial stress states was investigated experimentally to establish the sensitivity of the mechanical properties to an array of physical and experimental variables, and to enhance the available database of such tests for the benefit of improved understanding and modeling of the constitutive behavior of the material. The test program was particularly focused on the deformation aspects of the response and the process of damage buildup, and consisted of 130 dif-ferent tests. Parameters of the experimental program were the porosity of concrete, the moisture content at the time of testing, and the load path used in the tests. The most important response index was the history of damage accumulated in the microstructure, which was measured in terms of volumetric expansion and plastic deformation of the material. A simple strain-based model was formulated to represent the experimental trends. It was shown that the expansive strain of the cross section supporting the com-pressive strut best organized the experimental data. This result indicates that expansion due to damage is responsible for the stiffness degradation and the softening of resistance that is observed in concrete with increasing deformation levels; hence, this is one of the most important state variables characterizing the constitutive behavior of the material.