| 摘要 |
PROBLEM TO BE SOLVED: To provide a concrete admixing agent which exhibits high dispersibility and dispersion retainability even in the region with a high water reducing rate, and has high initial dispersibility, good kneadability, excellent workability, and appropriate air-entraining property; and to provide a concrete composition using the same. SOLUTION: The admixing agent contains, as an essential component, a copolymer which includes, as essential constitution units, a constitution unit expressed by general formula (1): CH<SB>2</SB>=CHO(R<SP>1</SP>O)<SB>n</SB>R<SP>2</SP>and a constitution unit originating in a maleic acid-based monomer, and in which the constitution units are each contained in an amount of≥1 mass % in the whole constitution units. The concrete composition contains, as essential components, the admixing agent, cement, fine aggregate, coarse aggregate and water, in which the ratio of the amount of the copolymer added to the amount of cement is 0.01-5 mass %. In the formula, R<SP>2</SP>represents a hydrogen atom or a 1-30C hydrocarbon group; R<SP>1</SP>O represents a 2-18C oxyalkylene group or a mixture of 2-18C oxyalkylene groups; and n represents a number of 50-300. COPYRIGHT: (C)2005,JPO&NCIPI
|
