The effect of solution chemistry on the behavior of kaolinite in three different situations was investigated: (1) the detachment of kaolinite from glass beads in a fluidized bed, (2) the erosion of kaolinite deposits in a laboratory flume and (3) the determination of the stress-strain rate relationship of concentrated suspensions in a rheometer. The experimental results from these three different approaches could be explained in terms of changes in mode of particle associations which in turn could be characterized in terms of a micromechanical force model which predicts the effect of solution chemistry on the interaction force between adjacent particle surfaces. Understanding the relationship between solution and surface chemistry on the structure, mechanical strength and mechanism of erosion of cohesive sediment deposits is an important step towards developing predictive models of a number of processes including erosion of cohesive sediments in streams and estuaries, and detachment of particles from granular media during filtration and filter backwashing.