Experimental study on compressive strength of high strength concrete core samples

Two types of core samples with dimension of  100 mm and  70 mm in diameter are prepared,which were cored from high strength concrete of 50～90 MPa compressive strength.Then,their compressive strength were measured and compared with cubic compressive strength of concrete under same curing conditions.Results indicate that compressive strength of core samples with various dimensions was influenced little by type of aggregate.The compressive strength of core samples with dimension of  100 mm in diameter is almost the same as cubic compressive strength of concrete with dimension of 100 mm in sides.However,the compressive strength of core samples with dimension of  70 mm in diameter is higher by 13% than the cubic compressive strength of concrete with dimension of 100 mm in sides.This shows that it is necessary to modify the compressive strength advisably when small core sample was used to evaluate the compressive strength of high strength concrete.