Admixtures and method for accelerating the setting of portland cement compositions

摘要

A method of and compositions for accelerating the setting time of portland cement compositions are disclosed. Certain admixtures, comprising water-soluble carbonates and &agr;-hydroxy carbonyl compounds, are employed as accelerators. Preferred accelerators further comprise water-soluble organic compounds having a plurality of hydroxyl groups. The concentration of admixture relative to cement necessary to achieve acceleration depends upon the identity of the admixture, the water-cement ratio, and the amount and type of aggregate in the composition, among other factors.