The main part of the road is a «pillow». This is far from a homogeneous mass of crushed stone and mineral supplement. The constructive layer, which is at the very bottom, performs the functions of protection and provides frost resistance not only to the canvas itself, but to all structures. Depending on the geographical location, the main layer is made either from the rock, or from slag and cement products. It all depends on what is cheaper in this region. Gravel, crushed stone and soil, which are the basis, are impregnated with astringent compositions. Each layer has its own fraction, wedging and complementing, thereby protecting the previous.
