Fracture Behaviors of Dam and Wet-screening Concrete by Direct Tensile Test

The emphasis of this paper is to experimentally study the fracture behaviors of dam and wet-screening concrete such as softening curve, uniaxial tensile strength f(1), maximum crack width w(o) and fracture energy G(F). The direct tension tests were performed on prismatic specimens with no initial notch include dam concrete specimens which size is 250 mm x 250 mm x 500 mm and wet-screening concrete specimens which size is 150 mm x 150 mm x 300 mm by employing a servo-hydraulic closed-loop testing machine with large stiffness. The uniaxial tensile load-strain curves, uniaxial tensile stress-strain curves, uniaxial tensile stress-deformation curves were acquired. On the basis of principle of fracture mechanics of concrete, the stress-crack width curves and the relative stress-relative crack width curves were obtained. Finally, the expressions of softening curves and fracture parameters such as f(1), w(o) and G(F) of dam and wet-screening concrete were achieved. The relationships of the foregoing fracture parameters between dam concrete and wet-screening concrete were discussed in this paper. The achieved softening curves and fracture parameters can provide input data for the fracture simulating analysis of dam and wet-screening concrete.