| 摘要 |
PROBLEM TO BE SOLVED: To produce a high-strength concrete-molded body which satisfies the initial strengths required for a usual secondary molded body in a steam curing under normal pressure (strength required for demolding after one day of material age, that for transport, assembly and construction after 7 days of material age and the like) and has the total amount of alkali in cement reduced to≤3 kg/m<SP>3</SP>. SOLUTION: Firstly, an available cement is prepared by adding a blast-furnace cement of 0-50 wt% and the balance being a high-early-strength cement of 100-50 wt% based on 100 wt% of total cement (available cement) amount. Then, the aggregate, water, etc. required for the available cement are added, and further the aqueous solution of polycarboxylic acid-based admixture is added in an amount of 0.5-2.0% to compose a substance to be charged into a mold. The substance is charged into the mold, is subjected to centrifugal molding, normal pressure-steam curing and then is demolded to produce a concrete pile having the compression strength of 100 N/mm<SP>2</SP>. COPYRIGHT: (C)2006,JPO&NCIPI |
