To provide a cement admixture capable of improving a strength and durability of a hardened matter by improving a water reduction property of a cement composition or the like, giving viscosity easy to work in a site where the cement composition or the like is handled and sufficiently exhibiting a strength expressing property of a hardened cement composition, especially early strength expressing properety and to provide the cement composition containing such a cement admixture.
In the cement admixture containing two kinds polymers of a polycarboxylic acid based copolymer (A) and a polycarboxylic acid based copolymer (B) in a specific mass ratio, the polycarboxylic acid based copolymer (A) has a repeating unit originated from an unsaturated polyalkylene glycol based monomer having a specific hydrophobic part and a repeating unit originated from an unsaturated polycarboxylic acid based monomer and has a weight average molecular weight within a specific range.
Takanori Tamai