Experimental study on water fracture interactions in concrete

A novel sealing device that has a minimal effect on the mechanical behaviour of concrete specimens is proposed in this paper. This device connects one side of silicon plates to a specimen using two specially designed clamps, instead of adhesive and screws the other side of the plates together to a steel plate. Several experimental wedge-splitting tests under compact tension are conducted with and without this sealing device to investigate the effect of water pressure on concrete crack propagation. The fracture experiments for concrete under different water pressures and different loading rates are carried out by wedge-splitting tests with the water pressure applied using this novel device. The water distribution is obtained based on experimental data recorded by five pressure transducers present at the tip of a notched crack, and the results show that the internal water pressure consists of a constant curve and a parabolic curve. The water within the crack has sufficient time to enter the crack when the specimen is subjected to a slow split loading, and the water front during slow loading test exceeds that of the fast loadings when reaching the same CMOD. The effect of the water interactions in concrete is severe in quasi-static conditions rather than in fast loading conditions during crack sudden opening. The loading rate plays a dominant role in the water pressure distribution and crack propagation.