Soil which fill the voids among sand grains. Silt is mineralogically like sand but with its higher specific surface area it is more chemically and physically active than sand. But it is the clay content of soil, with its very high specific surface area and generally large number of negative charges, that gives a soil its high retention capacity for water and nutrients. Clay soils also resist wind and water erosion better than silty and sandy soils, as the particles bond tightly to each other, and that with a strong mitigation effect of organic matter. Sand is the most stable of
Dilatancy (granular material) new space between the grains. Reynolds dilatancy concept has been brought into the field of geotechnical engineers by Peter Walter Rowe, and is a part of the broader topic of soil mechanics. The phenomenon of dilatancy can be observed in a simple shear test on a sample of dense sand. In the initial stage of deformation, the volumetric strain decreases as the shear strain increases. But as the stress approaches its peak value, the volumetric strain starts to increase. After some more shear, the soil sample has a larger volume than when the test was started. The amount of dilation