Failure Criterion of Cement Mortar Under Triaxial Compression

Abstract

In the first half of this paper, two-dimensional Griffith type fracture criteria were extended into three dimensions. Based on the result, a possible failure criterion of macroscopically homogeneous and isotropic brittle materials was proposed. The criterion is expressed in the principal stress space (σ₁, σ₂, σ₃) by a convex surface with the space diagonal of its axis. The surface consists of the following two types ; one is expressed by Max. (σ₁, σ₂, σ₃)=K (uniaxial tensile strength), and the other is such that the right sections of the surface are slightly bulged from an equilateral triangle and almost isotropically expand with an increase of hydrostatic pressure. In the second half, experimental work for cement mortar was treated. In the compressive range examined here the failure criterion of cement mortar is found to be very similar to that described above. It is also found that the criterion is independent of the loading path and little affected by the intermediate stress in the experimental range.