MECHANICAL PROPERTY AND FAILURE CRITERION FOR CONCRETE UNDER BIAXIAL COMPRESSIVE STRESSES AFTER CYCLIC FREEZING AND THAWING

The tests of concrete specimens under 5 biaxial compressive stress states suffering 0,25,50 and 75 cycles of freezing and thawing were completed using a large static-dynamic triaxial test system for concrete in the State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology. The strength of concrete and the curve of stress-strain were measured. The microstructure of concrete after different freezing and thawing cycles were inspected using electron microscope. The mechanical properties, such as biaxial compressive strength and deformation under different proportional loadings are analysed based on the experimental results. Failure criterion of concrete under the biaxial compressive stresses after cyclic freezing and thawing is established in stress space. It serves as a reference for the design and analysis of dams, concrete roads, bridges which are subjected to biaxial compressive load in northern cold region.