| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cement composition which has excellent fluidity, has reduced drying shrinkage and self-shrinkage, has reduced deterioration in fluidity with the lapse of time compared with the conventional ones, also has satisfactory adhesion with existing concrete, and enables operation improved in operability in an inverted construction method, concrete placing for increasing the thickness of the lower face, or the like, and to provide high fluidity self- packing concrete obtained by using the same. SOLUTION: The cement composition contains Portland cement having a dicalcium silicate content of 50 to 70 mass%, an expanding admixture consisting of free lime, calcium aluminoferrite and anhydrous gypsum, a drying shrinkage- reducing agent, and a water-reducing admixture, and has fluidity that packing height in a U type packing test method exceeds 30 cm. The self-packing concrete is obtained by using this cement composition, and in which the unit quantity of the Portland cement is 270 to 900 kg/m<SP>3</SP>. COPYRIGHT: (C)2004,JPO |
