To eliminate the unequal spraying of silicone and to prevent the generation of powder dust at the time of earth cover execution by using an emulsion obtd. by stirring the reactive silicone and methanol, then mixing water with this mixture.

The silicone is put at 10 liter into a stirring vessel and the industrial methanol is added at 10 liter into this vessel where both are stirred for 2 minutes. Further, 80 liter water is put into the vessel and the mixture is stirred for 5 minutes. The resulted silicone emulsion is sprayed and mixed in a mixing tank with a measure of 20 liter per ton in the case of dried and decomposed granite sand, 30 liter per ton in the case of dry and granulated construction sludge and 10 liter in the case of No.4 silica sand while the raw materials are kept rotated. The mixture is heated for 20 minutes at 160 to 180°C. The purpose of the heating is to vaporize the water and the methanol and simultaneously to accelerate the dehydrogenation reaction of the reactive silicone. The reason why the methanol is used lies in that the methanol does not leave residues in spite of drying at low temp., is harmless to the environment and health and is easily available.