Production Method ballast

Method of production of ballast for railway construction, road construction, dam construction and shore protection, wherein 1) ballast stones are spread out to form ballast and 2) a reaction mixture for the preparation of a polyurethane foam, produced from components by a process of low pressure, is applied between the stones extended ballast, wherein the reaction mixture is prepared in a pressure range of from 2 to 20 bar from components present at least two component streams.