Tangential Adhesion Strength between Clay and Steel for Various Soil Softnesses

Abstract

To investigate the adhesion at the interface between clay and steel, a rotary shear apparatus was adopted to perform rotation shearing tests on clay materials including bentonite, kaolin and their mixture. The tangential adhesion strength between clay and steel was determined for different normal pressures and consistency indexes. The effects of the consistency index, normal pressure and clay plasticity on the tangential adhesion strength were analyzed. The slope of the curve of the tangential adhesion strength and normal pressure decreased as the consistency index decreased (i.e., an increase in the saturation degree), indicating that the influence of the normal pressure on the tangential strength weakened. With an increase in the consistency index, the tangential adhesion strength of the clay first increased and then decreased, reaching a maximum value at a consistency index of 0.85–1.25. The consistency index corresponding to the maximum tangential adhesion strength increased as the normal pressure increased. No major differences in the tangential adhesion strengths were observed among the clays that were sheared under the same normal pressure and consistency index.