Modification of concrete mix during pressing

According to A.V. Satalkina [1], the Americans pointed out the need to remove excess water after the concrete mixture was placed in a mold at the beginning of the century. I.N. Akhverdov [2] indicates that in the process of cement paste compression with (W / C) beginning =- 1.65 [W / C] cement particles, displacing water, approach, and at a relatively low-pressure P = Po = 0.065 MPa, the solvation shells can touch * (The solvation shell is flattened at the places of mutual contacts between the particles *). At large values (P> 0.065 MPa), mainly the diffuse layer of water is squeezed out, and its displacement can continue until only adsorption water remains in the cement-water system (in this case, the system will consist of connected grains zero). The potential energy expended in compressing diffuse water layers can be estimated from the general law of conservation of energy. In the process of concrete compaction, the potential energy of interaction between the surface layers of water and the solid phase is overcome. The convergence of particles of the solid phase will occur at a significant expenditure of energy, which is necessary to overcome the disjoining pressure. When particles approach each other, it is necessary to expend energy, which will be spent on reducing the thickness of the surface layer (work of desorption), which leads to the appearance of significant repulsive forces between the particles.