Concrete strength criteria for biaxial and triaxial state of stress

Abstract

Based on the experiments conducted by the authors, a concrete strength criteria has been developed, which allows us to take into account biaxial and triaxial states of stress in strength calculations of massive concrete and reinforced concrete structures. The developed strength criteria is adapted to a spatial eight-node finite element (solid type) and implemented in the PrinCe programme. In order to conduct the developed criteria operational check, both experimental data and calculation results of other widely used strength criteria for concrete were compared. Thus, to verify the proposed criteria under triaxial compression, the calculation results were compared with experimental data as well as with the Willam-Warnke criterion and the modified Drucker-Prager criterion. The comparison shows that in the low hydrostatic stresses mode results of the above criteria converge both with each other and with the experimental data. In the medium hydrostatic stress mode , the criteria proposed by the authors and the Willam-Warnke criterion show close results, while the modified Drucker-Prager criterion, on the contrary, gives 20 % overestimation of concrete strength. Comparison of the results of concrete biaxial tests shows good agreement with the criteria developed by the authors. Thus, for heavy coarse concrete the differences in strength values were not more than 3,5 %, for heavy fineconcrete and expanded clay concrete — not more than 4 %.