Abstract
The size effects and the shape effects (square or circular cross-section) on the flexural strength of concrete are investigated through experiments and numerical analysis with fracture mechanics concepts. Based on the numerical results, we proposed equations for estimating the flexural strength of concrete beams with square or circular cross-section. The beam depth, the tensile strength and the characteristic length of concrete are the variables in the proposed equations. The estimated values of the flexural strength through the equation are in good accordance with the experimental results especially for the square beams. The equation gives moderate values for the flexural strengths of various kinds of concrete including normal concrete, high strength concrete, lightweight concrete, mortar and polyester resin concrete.
