Experimental Study on Concrete under Uniaxial and Biaxial Compression

In order to study on mechanical character and damage mechanism of the concrete under different loading conditions, the uniaxial and biaxial compression experiment of concrete is investigated by Isotropic Biaxial Loading System of Henan Polytechnic University. The experimental results show the damage of the concrete under uniaxial compression is shear damage, however the damage of the concrete under biaxial compression is tension-shear damage; biaxial compression stress-strain curves of concrete are similar with those of concrete and can equally be divided into three stage; as the result of the intermediate principal stress, 1:1 biaxial compression strength increased 56.12% and 13.30% than that under 2:1 biaxial compression and uniaxial compression, at the same time 2:1 biaxial compression strength increased 37.80 % than that of the uniaxial compression.