SUPERPLASTICIZED CONCRETE. PROPERTIES, WORK TECHNIQUE AND FIELDS OF APPLICATION

FLYTBETONG. EGENSKAPER, ARBETSTEKNIK OCH ANVAENDNINGSMOEJLIGHETER

Superplasticisers may be based on (1) sulphite waste liquor, (2) formaldehyde resins, (3) others. In fresh concrete they mainly act as a lubricant. The principal effect is a considerable change in consistency from 8 cm to about 22 cm slump, enabling reductions of 10-40% to be made in water/cement ratio. Fluidity time varies according to additive, from 1/2 hour up to 6 hours. Stability is good, and there is less tendency for the aggregate to separate. Strength at 28 days is the same as in ordinary concrete, but melamine additives produce 20% higher one-day strengths. Shrinkage is a little higher. There seems to be a reduction in air content when superplasticisers and air entraining agents are used together. Pumping is easier, but for very high slumps there is a risk of pump stoppage. To avoid segregation during transport, grading should be more continuous than in ordinary concrete. Superplasticised concrete generally needs less compaction than ordinary concrete; overcompaction tends to cause segregation. In Sweden superplasticised concrete is mainly used by precasting works, either only for difficult sections or for the whole production range. At present, the cost of additive is about 15% of ordinary concrete price, and this limits application. Environmental advantages may however outweigh this.

  • Corporate Authors:

    Tidskriffen Cement och Betong

    Fack
    S-20110 Malmoe 1,   Sweden 
  • Authors:
    • JOHANSSON, A
  • Publication Date: 1979

Language

  • Swedish

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 101 p.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00316945
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • Report/Paper Numbers: CBI Forskning Monograph
  • Files: ITRD, TRIS
  • Created Date: Feb 6 1981 12:00AM