| 摘要 |
PROBLEM TO BE SOLVED: To improve a soil containing a hydraulic cement, its cured product or a lime-based soil additive into a soil capable of growing plant by mixing the soil with an inorganic buffering agent. SOLUTION: The inorganic buffering agent is prepared by using an inorganic weak acid or an inorganic weak base. The kind of the buffering agent is selected while considering the influences on plants, human bodies, or natural environments in addition to the buffering capability. From these viewpoints, the buffering agent is prepared by combining an inorganic weak acid with an inorganic weak base. Phosphoric acid, carbonic acid or boric acid is used as the inorganic weak acid, phosphoric acid being excellent from the viewpoints of buffering capability, influence on living organisms, and price. An alkali metal ion, especially potassium ion, is preferable as the inorganic weak base. The inorganic buffering agent is used in the form of an aqueous solution and is adjusted to a concentration of 0.001 to 0.1 mol/1. A soil containing a hydraulic cement or its cured product is generally a waste construction soil. Though the quality of the waste soil varies with construction sites, the method of the invention is not specifically limited by the quality of waste construction soil. |
