ВЛИЯНИЕ СТРЕССОВОГО ДАВЛЕНИЯ НА ФОРМИРОВАНИЕ СВЯЗАННОЙ ВОДЫ В КАОЛИНОВОЙ ГЛИНЕ

Clays during lithogenesis change the composition, structure and properties, including the physicochemical ones. Some researchers present the results of studying changes in the properties of bound water in clays under the influence of increasing temperatures and pressures. When compaction of water-saturated clays, the “free” water of large pores is removed first, then under loads of 1–3 MPa -- osmotic water, and at a pressure of more than 10 MPa, the removal of “structured hydrated layers” of adsorption-bound water begins. According to the literature, several layers of water closest to a solid surface, corresponding to clay moisture close to “maximum hygroscopic” are not pressed by loads of tens of MPa, and “monolayers” of hundreds of MPa. However, despite existing publications on this issue, experimental information is not enough. The work is devoted to the influence of stress pressure on the formation of bound water in kaolin clay. In the course of experimental studies it was found that stress pressure has a multidirectional effect on the gradient of the removed mass of bound water in clays. This is due to the fact that that when treating kaolin clay with stress pressure, defects are formed on the surface and “inside” of particles (aggregates, colloids and crystallites). Such surface imperfections form the energy potential of the particles, which determines the sorption activity of the clays. During the comparison of direct and indirect criteria, it was found that the most significant influence on the formation of the energy potential of particles is exerted by pressure in the range of P = 0 ÷ 125 MPa. With increasing load up to P = 800 MPa, it is quite difficult to establish the effect of stress pressure on the formation of the energy potential. Thus, under technogenic impact on kaolin clay, its energy potential changes and, as a result, physicochemical properties, including the content of bound water.