WORKABILITY, INITIAL SET AND COMPRESSIVE STRENGTH CHARACTERISTICS OF CONCRETE MADE WITH SOUTH AFRICAN CSF AT VARIOUS SUBSTITUTION RATIOS

This paper presents results of a project aimed at characterising the performance of South African CSF in concrete. Concretes were prepared using both densified and undensified CSF (condensed silica fume), at a replacement ratio of 8% and substitution ratios of 1:1, 2:1, 3:1 and 4:1. Concretes containing 300, 400 and 500 kg/cu m were used to prepare control samples. All concretes contained andesite aggregates and no water-reducing admixtures were used. The project was focused on monitoring the effects of the addition of CSF on slump, initial set and compressive strength of concrete. Compressive strength was measured on continuously water cured samples up to 91 days after casting. It was found that the addition of CSF reduces the slump of OPC concrete, with the extent of reduction decreasing as the substitution ratio increased. CSF also causes a delay in the initial setting time, with the extent of delay increasing as the substitution ratio increases. As an aid to the design of CSF concrete mixes, proposed forms of the water/binder ratio vs compressive strength curves for undensified and densified CSF is presented, based on the results of this investigation. The results are also used to determine strength efficiency factors for the 2 forms of CSF over a range of compressive strength grades. (A)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03799824
• Corporate Authors:

  DAVMARK (PTY) LTD

  PO BOX 41412
  HALFWAY HOUSE,   South Africa  2024
• Authors:
  • BALLIM, Y
  • SCOTT, I Y
• Publication Date: 1997-4

Language

• English

Media Info

• Features: References;
• Pagination: p. 5-11
• Serial:
  • CONCRETE BETON
  • Issue Number: 85
  • Publisher: Concrete Society of Southern Africa
  • ISSN: 0379-9824

Subject/Index Terms

• TRT Terms: Mix design; Silica fume; Strength of materials; Workability
• ITRD Terms: 4793: Microsilica; 4714: Mix design; 5544: Strength (mater); 5941: Workability
• Subject Areas: Design; Materials;

Filing Info

• Accession Number: 00743469
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Dec 29 1997 12:00AM