Abstract. In the practice of building of capital types of pavements eventually established the principle of one-time capital investment, according to which the physical and mechanical properties of structural layers to be formed largely under construction and start of operation of the road to take the calculated value. According to this principle calculated characteristics of soil reinforced with inorganic binders, defined in the standard period of solidification, which is taken for 28 days just as is customary during testing of cement products. It is assumed that after 28 days of hardening of soil samples fortified gaining at least 70% of maximum strength.

Consistent implementation of this principle encourages use for strengthening of soil-early type of inorganic binders cement and virtually eliminates the possibility of a wide use for these purposes is slowly hardening of mineral binders which, for example, steel slags.