The Role of Calcium Ions and Lignosulphonate Plasticiser in the Hydration of Cement

Cement admixtures are used as plasticizers to reduce the water requirement in mixing concrete. Lignosulphonate base is used as a retarder; it prolongs the hydration period of cements. This article reports on experiments involving equilibrium dialysis, conductivity, X-ray diffraction analysis (XRD), differential thermal analysis (DTA) and isothermal titration calorimetry (ITC) that were carried out to investigate the role of calcium ions and polymeric plasticizers in cement/admixture hydration. The results show that plasticizers have two roles: one mainly as a kinetic inhibitor (poison) in cement hydration and the other as a dispersant (which improves the hardening properties of hydrated cements). The authors conclude that the admixture's action as a kinetic inhibitor explains the crucial morphology change from ettringite gel to ettringite crystalline during hydration.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00088846
• Authors:
  • Grierson, L H
  • Knight, J C
  • Maharaj, R
• Publication Date: 2005-4

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References;
• Pagination: pp 631-636
• Serial:
  • Cement and Concrete Research
  • Volume: 35
  • Issue Number: 4
  • Publisher: Elsevier
  • ISSN: 0008-8846
  • Serial URL: http://www.sciencedirect.com/science/journal/00088846

Subject/Index Terms

• TRT Terms: Admixtures; Calcium; Cement; Curing and setting agents; Ettringite; Hydration; Kinetics; Lignosulfonate; Plasticizers; Portland cement; Thermal properties
• Uncontrolled Terms: Thermodynamic calculations
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 01000505
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 2 2005 12:39PM