Mechanical properties of high-performance concrete under triaxial compression

It is well known that the mechanical properties of a material are related to lateral confinement. In this paper, 60 cylindrical high-performance concrete (HPC) specimens with different concrete strength grades were cast and subjected to a conventional triaxial experiment to study the mechanical properties of the material. The experimental results indicated that the specimens exhibited longitudinal splitting failure patterns under uniaxial compression and inclined plane shear failure patterns under triaxial compression. The stress–strain curves were divided into three stages: an elastic rising stage, a plastic rising stage and a softening descending stage. The application of lateral confining pressure effectively increased the triaxial compressive strength. As the concrete strength increased, the descending stage of the stress–strain curves became steeper, indicating an increase in brittleness. Based on the experimental results, the failure criterion of the HPC was analysed using the Drucker–Prager yield criterion and Kotsovos failure theory. The parameters of the Drucker–Prager yield criterion were determined, and the applicable range of the Kotsovos failure theory was also obtained.