PURPOSE: To obtain the soft concrete useful as a material for preventing a water-shielding sheet by compounding a solution comprising a cement, a sandy soil, an emulsifier and fibers with a highly water-absorbable polymer emulsion.

CONSTITUTION: 10-100kg of a cement, 50-200kg of a sandy soil, 50-500kg of an emulsifier, and 0-50kg of fibers are kneaded as the material for the solution A. 1-20Kg of a highly water-absorbable polymer emulsion is added as the material for the solution B to the solution A material and kneaded at the ordinary temperature. The materials A and B are applied by mixing and kneading each other and subsequently pouring the kneaded product into a mold frame, or directly applied as a solid kneaded product to the mold frame. Since the soft concrete holds the softness also after solidified, the soft concrete holds good flexibility even when used for protecting the water-shielding sheet and does not cause breakage on cracks of the sheet. When applied to sidewalks, etc., the soft concrete reduces the extent of the injury of a man when he falls down. The soft concrete gas further water-preventing effect because of its unlikeliness of causing cracks of the soft concrete by its temperature change.