| 摘要 |
A hydraulic cement mix including hydraulic cement, aggregate, sufficient water to affect hydraulic setting of the cement, and an additive comprising an N-methylol amide, specifically, tri- or tetramethylolglycoluril alone or in combination with other accelerators of set. The additive is present in an amount sufficient to decrease the time necessary for the hardening of the concrete mix. Generally, the additive is present in a total amount of up to about 4.0% by weight based upon the weight of cement in the mix, usually in an amount of between about 0.01% and about 2.50% by weight of cement. The latter concentration is present when complex combinations of accelerators of set for hydraulic cement are employed.
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