Abstract
The particle dispersion effect of superplasticizers (SP) containing polycarboxylate polymers of different molecule structure was examined under the conditions of extended mixing time. The particle dispersion effect of SP, represented by the ratio of the relative flow area rate of the mortar to the relative funnel speed rate of the mortar, increases in a straight line as the dosage of SP increases. Depending on the molecule structure of the SP, the apparent adsorption to cement particles scarcely increases as dosage is increased; in other words, only the amount remaining in the liquid phase increases. The decrease in the particle dispersion effect of SP, as a result of mixing, can be divided into the following two types: 1) decrease corresponding with the remaining amount when the dosage of SP is decreased, and 2) a greater decrease in the particle dispersion effect compared to the decrease in remaining amount. The main factor responsible for this phenomenon is the influence of the molecular structure of the SP on the adsorption speed of the SP to the cement particles.
