To prepare a high-durability cement composition capable of lowering contraction without impairing resistance to freezing and thawing by adding an admixture having air entrainment property to a composition containing water, cement and aggregate, by blending them and by kneading them, and then by conducting secondary blending through adding an organic shrinkage- decreasing agent.
This high-durability cement composition is prepared by including an admixture having air antrainment property which can entrain (pref. 3-6 vol.%) minute closed cell (pref. having 20-200 μm cell diameter) to a cement composition. An organic shrinkage-decreasing agent which decreases the shrinkage in drying a cement composition is pref. a polyoxyalkylene compound of the formula: E-[(A1O)x-R1]n [E is a compound moiety having (n) atoms of active hydrogen; A1Os are each a 2-4C oxyalkylene; R1 is H or a 1-4c alkyl; (x) is 1-10; (n) is a integer of 1-8].
ISHIKAWA KOZO
UCHIDA YOSHIO
KINOSHITA SEIGO
HONDA SUSUMU
NOF CORP