Mechanism of superplasticizer adsorption on silicate and aluminate portland cement components

The adsorption regularities of naphthalene-formaldehyde superplasticizer co mponents on Portland cement and Portland cement clinker minerals was studie d. Adsorption values of individual sodium polymethylenenaphthalene sulfonat es (SPMNSs) with degrees of polycondensation from 2 to 17 were compared wit h those of polydisperse superplasticizers, and the change in the superplast icizer molecular-mass distribution in the course of adsorption was studied. It was shown on the basis of the data obtained that the selective bonding of the highest-molecular-weight components occurs in the adsorption on hydr ation products of calcium silicates, whereas the adsorption on hydration pr oducts of calcium aluminates is independent of the molecular mass of SPMNSs in superplasticizer composition.