Set retardant for hydraulic cement compositions and admixtures therefor

摘要

A zinc-oxide based set retardant additive and admixture for use in Portland cement or other hydraulic cement mixtures. The admixture may comprise silica fume, vitreous calcium aluminosilicate, magnesium aluminum silicate hydrate, a cellulose ether derivative, or their equivalents. The zinc-oxide based set retardant may be interground or pre-blended, pre-packaged, or added on the jobsite, as an admixture, additive, or addition. The zinc-based set retardant may be subsequently added or mixed into a ready mix or wet mixture of portland cement or other hydraulic cement, sand and/or aggregate, with or without fillers, and water, with or without other pozzolans or polymers.

主权项

1. A hydraulic cement composition that achieves a set time of between about 2 to about 5 hours, comprising:
about 50 wt % to about 75 wt % of a hydraulic cement mixture; about 0.01 wt % to about 2 wt % zinc oxide; about 5 wt % to about 45 wt % of one or more pozzolans; and about 0.01 wt % to about 2 wt % cellulosic polymer.