| abstract |
A cementitious mixture comprises a hydraulic cement; greater than about 10% by weight of a pozzolanic cement replacement selected from fly ash, slag, natural pozzolans, and mixtures thereof, based on the weight of said hydraulic cement and cement replacement; and a compatabilizing admixture, wherein the compatabilizing admixture comprises a compatabilizing derivatized polycarboxylate polymer dispersant capable of acting as a water reducer, in combination with an accelerator. The derivatized polycarboxylate dispersant, alone or in combination with other derivatized polycarboxylate dispersants, is a polymer comprising units derived from at least one of a substituted carboxylic acid monomer and a substituted ethylenically unsaturated monomer, at least one of an N-polyoxyalkylene maleimide and a condensation product of an unsubstituted carboxylic acid monomer and an alkoxypolyoxyalkylene primary amine substituted carboxylic acid monomer, and optionally including an unsaturated hydrocarbon. The derivatized polycarboxylate dispersant provides for a longer shelf life dispersant, improved dispersability of cementitious mixtures, water reduction in cementitious mixtures, and is an effective dispersant in high pozzolan replaced cementitious mixtures. |