| 摘要 |
PROBLEM TO BE SOLVED: To obtain a member into which large chemical prestress is introduced with little loss in the chemical prestress by kneading a cement compsn. containing a cement and an expanding material to prepare a concrete, forming the obtd. concrete and ageing it in hot water at a specified temp. SOLUTION: A cement compsn. containing a cement preferably of 100 pts.wt. and an expanding material (e.g. hauyne-base, calcium oxide-base material) preferably of 2 to 16 pts.wt. is kneaded to prepare a concrete, which is formed and aged in a hot water at >100 deg.C, preferably at 120 to 200 deg.C, preferably in a vertical pressure chamber. As a result, large expansion strain and compression strength can be obtd. at a lower temp. and in a shorter retention time compared to the process of autoclave ageing. Since hardening of the cement is significantly accelerated, specified compression strength can be obtd. in a short time. Further, specified chemical prestress can be introduced so that the use amt. of the expanding material can be suppressed. |
