It is this characteristic of the water molecule which weakly attracts one molecule to an other and gives water it's surface tension. Water, which is a conductor, is electrostatically attracted to the surface of the cohesive clay particles. In fact cohesive clay particles are surrounded by a layer of water electrostatically bound to the cohesive clay. The properties of cohesive clay that attract water, and therefore create plasticity, are unique. Sand, silt and other soils do not possess these properties.
Cohesive clay is usually a deterrent to road-building.
However, cohesive clay is an ideal component of an EcoCrete road because it lends itself well to combination with this product. EcoCrete is an unusual product. It can be combined with inadequate road building substances like cohesive clay to create a hard-packed road base. It combines with cohesive clay and other fines on a microscopic level to create a dense material which is impervious to water. That unique characteristic becomes more defined as the road becomes more dense.