| 摘要 |
PROBLEM TO BE SOLVED: To enable the carbonation of a formed cement to a deeper part by forming a composition obtained by kneading a cement, water and an alcohol and hardening the formed cement by carbonating with carbon dioxide of supercritical state. SOLUTION: Any kind of cement forming calcium hydroxide by hydration such as ordinary Portland cement, special Portland cement and alumina cement can be used in the present process, and the use of Portland cement having high densifying effect in carbonation is preferable. The composition may be incorporated with aggregate e.g. cement mortar aggregate such as silica sand and river sand, calcium carbonate, etc. The alcohol is the one compatible with carbon dioxide fluid of supercritical state and water, preferably ethanol. The carbonation treatment is preferably carried out at the initial stage of the hydration of cement, e.g. within 24 hr after the kneading of cement with water in the case of curing at 20 deg.C. |
