CURRENT PRACTICE SHEETS(MATERIALS)ADMIXTURES

THE ARTICLE IS INTENDED AS A STATEMENT OF CURRENT PRACTICE IN THE USE OF ADMIXTURES TO BASIC CONCRETE MIXES. BRITISH STANDARDS ARE IN PREPARATION TO COVER THE FOLLOWING CLASSES OF ADMIXTURE:- (1) AIR ENTRAINING AGENTS, AND (2) ACCELERATORS, RETARDERS AND PLASTICIZERS. THE MEANS BY WHICH ADMIXTURES ACHIEVE THEIR RESPECTIVE FUNCTIONS IS DESCRIBED. SURFACE ACTIVE AGENTS FORM THE BASIS OF PLASTICIZERS, RETARDERS AND AIR ENTRAINING AGENTS. THE MAKE UP OF THE MOLECULES OF THE VARIOUS ADDITIVES IS EXPLAINED IN TERMS OF THE IONIZED STATE THAT THEY TAKE UP IN SOLUTION. THE COMMONEST TYPE OF ACCELERATOR IS PURELY CHEMICAL IN ACTION - CALCIUM CHLORIDE, BUT MAY BE COMBINED WITH A PLASTICIZER TO IMPROVE COMPACTION IN THE SHORTENED SETTING TIME. THE INCREASED USE OF PUMPED CONCRETE HAS CREATED A NEED FOR FLUIDIZERS TO FORM THE SLIP SURFACE BETWEEN THE "PLUG" OF CONCRETE AND THE PUMP WALLS. THEY ARE RELATED TO PLASTICIZERS EXCEPT FOR THE POLYETHYLENE OXIDE TYPE USED WITH LOW CEMENT CONTENT MIXES. ALSO DISCUSSED ARE GROUT EXPANDERS AND WATERPROOFERS. THESE CONSIST OF ALUMINIUM POWDER AND SOAPS OR FATTY ACIDS. A SET OF TABLES SHOWING THE EFFECTS OF VARIOUS ADMIXTURES ON A RANGE OF PARAMETERS OF CONCRETE BEHAVIOUR IS INCLUDED.

  • Availability:
  • Corporate Authors:

    Cement and Concrete Association

    52 Grosvenor Gardens
    London SW1W 0AQ,   England 
  • Authors:
    • Flatau, A S
  • Publication Date: 1974-2

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 45-47
  • Serial:
    • CONCRETE
    • Volume: 8
    • Issue Number: 2
    • Publisher: THE CONCRETE SOCIETY
    • ISSN: 0010-5317

Subject/Index Terms

Filing Info

  • Accession Number: 00081720
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Feb 27 1975 12:00AM