Experimental study on mechanical behavior of high-strength high-performance concrete under biaxial loading

This study presents the mechanical response of different types of high-strength high-performance concrete (HSHPC) with uniaxial compressive strengths of 47–90 MPa under uniaxial and biaxial loading conditions. In this experimental study, 72 specimens with dimensions of 100 mm × 100 mm × 100 mm were loaded under uniaxial and biaxial compressive loading conditions, and 144 platen specimens with dimensions of 150 mm × 150 mm × 50 mm were tested under biaxial tensile, biaxial compressive–tensile, and uniaxial tensile loading conditions. A true triaxial loading system was employed to evaluate the response of the HSHPC specimens under various stress combinations. The stresses, deformations, and failure characteristics were recorded and analyzed for all HSHPC specimens. The experimental results revealed that the uniaxial strength and stress ratios had a remarkable effect on the strength and deformation of HSHPC specimens bearing biaxial compressive and biaxial compressive–tensile loading but no evident influence on the specimens under biaxial tension. A novel failure criterion considering the influence of uniaxial compressive strength was proposed for HSHPC specimens subjected to biaxial loading. This investigation is valuable for the design and finite element analysis of structures using HSHPC materials.