Soil aggregate stability typically have a higher water infiltration rate, allowing more water into the soil profile faster, and are not susceptible to water ponding. Soil aggregates are formed due to flocculation and cementation processes, and are enhanced by physical and biological processes. Primary soil particles (sand, silt, and clay) are subjected to these processes, and can stick together to form larger sub-microaggregates (< 250 μm), microaggregates, and macroaggregates (> 250 μm). It has been suggested that soil aggregates form hierarchically, meaning larger less dense aggregates are composed of smaller more dense aggregates (Kay, 1990; Oades, 1993). Flocculation refers to a state when
Dilatancy (granular material) / internal erosion. The use of appropriate filters is critical to managing these materials; I like a #4 sized clear gravel / coarse-grained sand as a commercial aggregate which is generally readily available. Some non- woven filter fabrics are also suitable. As with all filters, D15 and D50 compatibility criteria should be checked. Dilatancy (granular material) Dilatancy is the volume change observed in granular materials when they are subjected to shear deformations. This effect was first described scientifically by Osborne Reynolds in 1885/1886 and is also known as Reynolds dilatancy. Unlike most other solid materials, the tendency of a compacted