LAUSR

Abstract Based on the tests among 45 group specimens of five mixes under true tri-axial compressive stress, the characteristics of strain–stress curve, the impact of the stress path and the failure criterion of the plastic concrete were illustrated. The results indicated that the stress - strain curves can be generally divided into four segments, the initial segment was equipped with significantly elastic characteristics, while the last segment indicated severely plastic deformation had occurred. Specimen failure pattern was similar to that of axial compression specimen when the levels of the second and third principal stress were smaller. Otherwise, specimen failure pattern looked like eight diagonal crack. Principal stresses, cohesive forces and angles were influenced dramatically by different stress paths. Based on 93 group test data, three formulas with four parameters, three parameters and two parameters are put forward to express the failure criterion of plastic concrete under true tri-axial compression.