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| Content Provider | Springer Nature Link |
|---|---|
| Author | Björnström, J. Chandra, S. |
| Copyright Year | 2003 |
| 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 (lignosulonate-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 polycarboxylate-based polymer the dispersion mechanism is mainly controlled by steric hindrance. A model for the adsorption of superplasticizer on a cement particle is proposed.Dans ce rapport, les propriétés rhéologiques des pâtes de ciment fabriquées avec différents types de ciment et de superplastifiants sont discutées. Outils de cette discussion, des expériences impliquant la dispersion des particules de ciment, la fluidité, la viscosité, la fonction de ce seuil et le potentiel zêta ont été conduites. Les résultats obtenus montrent que la composition chimique du ciment, comme les teneurs en C$_{3}$A et en sulfate, ainsi que les teneurs en alcali et en chaux, sont des particularités importantes afin de contrôler la rhéologie des pâtes de ciment. Trois types de superplastifiants avec sulfate (lignosulfonate, acide sulfonique formaldèhyde mélamine, acide sulfonique formaldéhyde naphthalène) et un type de polymère acide poly-carboxilique ont été utilisés. Les résultats ont révélé que le mécanisme, par lequel ces polymères dispersent les particules de ciment, est fondamentalement différent. Les superplastifiants avec sulfate ont entraîné une charge négative sur les particules de ciment, les dipersant par la répulsion électrostatique, tandis qu’avec le polymère poly-carboxylate, le mécanisme de dispersion est principlalement contrôlé par un encombrement stérique. Un modèle pour l’adsorption de superplastifiants par une particule de ciment est proposé. |
| Starting Page | 685 |
| Ending Page | 692 |
| Page Count | 8 |
| File Format | |
| ISSN | 13595997 |
| Journal | Materials and Structures |
| Volume Number | 36 |
| Issue Number | 10 |
| e-ISSN | 18716873 |
| Language | English |
| Publisher | Kluwer Academic Publishers |
| Publisher Date | 2003-01-01 |
| Publisher Place | Dordrecht |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Theoretical and Applied Mechanics Structural Mechanics Mechanical Engineering Operating Procedures, Materials Treatment Civil Engineering Building Materials |
| Content Type | Text |
| Resource Type | Article |
| Subject | Building and Construction Mechanics of Materials Materials Science Civil and Structural Engineering |
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