Effect of Water-Reducing Admixtures and Set-Retarding Admixtures on the Properties of Plastic Concrete

Abstract

Commonly used water reducers and set retarders are divided into four basic categories. The effect of materials from each of these classes on water reduc-tion, set retardation, air entrainment, bleeding, workability and unit weight of plastic concrete is discussed. Data are presented to show the effect of normal dosage and over-dosage of the admixtures at various temperatures. Influence of type and brand of cement, air entraining agents, and other admixtures on properties of plastic concrete is shown. Application and dosage of the admixtures are given. Qualities of plastic concrete containing water reducers or set retarders that may be used to the advantage of the engineer who is seeking to solve a particular problem in the con-struction of a project are discussed.