| 摘要 |
PURPOSE:To prevent pollution of the natural world such as soil or ocean by performing kneading of cement under the condition of existence of a reducing agent, at building a concrete structure. CONSTITUTION:A reducing agent such as ferrous iron or stannous tin of powder or solution is previously kneaded with cement, aggregate, sand, and the like before kneading, and then a concrete structure is built. By building the concrete structure in this method, hexavalent chromium in the cement is transformed to trivalent chromium by the reducing agent, and it is enclosed and solidified in the structure. Consequently, outflow of trivalent chromium into bleeding water or drain water can be prevented. |
