抄録
A gas pressure difference of 0.2N/mm2 was maintained between the cross sections of concrete with simultaneous increase of loading in the split tensile strength test configuration. A single crack that formed in the longitudinal direction parallel to the loading increased the gas permeability of the concrete. It was found that gas permeability was gradually increased at a crack opening of about 0.02mm and then rapidly increased until the crack opening reached 0.08mm. The degree of water saturation of concrete had significant effect on the formation of the crack and hence failure of the concrete under investigation. Oven dried concrete exhibited gradual increase of the gas permeability while water saturated concrete showed rapid increase of the gas permeability at the crack opening of 0.02mm. In this way the gas permeability of concrete subjected to the split tensile strength test was controlled by the failure mechanism.
