抄録
It is important to clarify the variation of particle contact angle of fresh concrete with shear deformation for understanding its deformation resistance and mechanical behaviors. In this study, using X-ray CT imaging, the authors investigated mean particle contact angles (θ) of fresh mortar before and after sheared in a ring shear device, which was composed of alumina powder, sand, and water, etc. As a result, the mean particle contact angle increases with increasing the shear deformation, but when reaching a peak, it decreases with the shear deformation. The increase and the decrease of θ are respectively the characteristics before and in shear failure state. Also, the greater the vertical stress on the shear plane, the smaller the increase or decrease of θ with the shear deformation.