Abstract
The triaxial testing equipment which is capable of non-axisymmetric loading was developed to investigate damage process under strain softening regime. In these tests, the discontinuous surfaces (damaged zone) can be inspected clearly in the one plane as two dimensional fracture. After triaxial tests, the epoxy resin with fluorescent paint was injected into specimens and the graphic image data of damaged zone were processed to determine the range of damaged zone. In this paper two items are discussed, (1) The Mohr-Coulomb's failure criterion is connected with the actual failure phenomena of concrete considering force transfer mechanism between aggregates. (2) The formation angle and range of damaged zone is quantitatively determined.
