Using a sledgehammer, proceed to break the damaged place in concrete and get rid of garbage. The edges of the hole are processed with a metal brush (to remove all the remnants of concrete, inseparable with the base).
We process the edges of the holes with the help of a chisel and a hammer so as to give the edges to the center.
We are engaged in laying the reinforcing mesh (its cells should be equal to 10 by 10 cm, and the diameter is 4 mm). The parameters of the grid corresponds to the size of the patch (so that its ends are on the slopes of the concrete opening).
Make a plastic mass, mixing water with dry concrete.
Latex (from butadionostrol) or just PVA glue is applied along the edges of the hole. This helps to preserve concrete of plasticity. Then, with the help of a shovel, lay the concrete inside the hole, tamp it, thereby achieving a tight fit to the edges of the hole and the grid. It is necessary to put a little more concrete so that it performs (after the shrinkage of the mass, its level is equal to the floor level).
By means of Reiki-Ring, we level concrete. Soon a water film is formed on the surface. When the water evaporates, it is necessary to smooth out the surface with a metal ironer.
When concrete hardens, it is moistened with water and covered with polyethylene (preventing evaporation). Within a week, the patch will grab.