Effect of superplasticizers on the rheological properties of cements

Title: Effect of superplasticizers on the rheological properties of cements
Author(s): J. Björnström, S. Chandra
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
ISSN: 1359-5997
Publisher: RILEM Publications SARL
Volume: 36
Issue: 264
Issue date: 2003-12-01
Publication year: 2003
Pages: 685 - 692
Total Pages: 8
Nb references: 18
Language: English

Abstract: In this paper, the rheological properties of cement pastes made with different types of cement and superplasticizers are discussed.
As a tool for the discussion, experiments involving dispersion of cement particles, fluidity, viscosity, yield stress and zeta potential have been conducted.
The results obtained show that the chemical compositions of the cements such as C(3)A and sulfate content, alkali and ground lime content are important features controlling the rheology of cement pastes.
Three types of sulfonated superplasticizers (lignosulfonate-based, melamine formaldehyde sulfonic acid, naphthalene formaldehyde sulfonic acid) and one type of polycarboxylic acid polymer were used.
The results revealed that the mechanism by which these polymers disperse cement particles differs fundamentally.
Sulfonated superplasticizers induced a negative charge on cement particles dispersing them by electrostatic repulsion, whereas with the polycarboxylatebased polymer the dispersion mechanism is mainly controlled by steric hindrance.
A model for the adsorption of superplasticizer on a cement particle is proposed.

Online publication: 2003-10-27
Classification: Scientific Reports
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/13912