Effect of water pressure on fracture parameters of concrete

Abstract The effects of water pressure in the crack on the fracture parameters of a concrete beam under three-point bending were discussed. A novel sealing device for hydraulic loading was proposed to simulate the hydraulic load in a test beam. Experimental results showed that the proposed novel sealing device had less effect on the crack propagation in concrete. Then, 12 three-point bending tests of concrete beams with different water pressure in the crack were conducted. A method for determining the fracture parameters of concrete within water pressure was introduced. Moreover, an analytical method based on the relationship of the water pressure and crack width was employed to determine the water pressure distribution along the crack surface. The experimental results indicated that the water pressure applied in the crack had little effect on the initiation fracture toughness but decreased the unstable fracture toughness of concrete. Moreover, as water pressure increased from 0.0 MPa to 0.3 MPa, the unstable fracture toughness decreased by 17.5%, and the cohesive fracture toughness decreased by 21.8%.