EFFECTS OF CEMENTITIOUS SLAG CONTENT AND AGGREGATE TYPE ON PROPERTIES AND DURABILITY OF PORTLAND BLAST FURNACE SLAG CEMENT CONCRETES

A series of nine large concrete blocks (750 mm cube), stored outside on an industrial site at the Appleby Frodingham works at Scunthorpe in N.E. England were assessed at 7-8 months, 30 months and 7 1/2 and 10 1/2 years of age. The concrete contained a nominal total cementitious content of 390 kg/m3 and had different levels of ground granulated blast furnace slag in the range 0, 30, 50 and 70% by weight as replacement material for portland cement. Some of the concretes were prepared using gravel and others with crushed limestone as aggregate. The quality and performance of these concretes were determined at each age by testing drilled cores taken from the side face of the blocks, partly protected from driving rain. The assessment involved early heat release compressive strength. Comparisons were made between the different concretes on the basis of their cementitious slag content and aggregate types. The results showed that concretes containing 100% normal portland cement of 50% slag have hardly carbonated, although carbonation had progressed from 5 to 6 mm at 2 1/2 years where 70% slag was used, but there was little change thereafter. Gas permeability decreased slightly as the slag replacement levels were reduced from 70% to 50%, and the coefficient of oxygen permeability (ko) values for the inner concrete were in the range 0.5 to 9 x (10 to the minus 18 m square) by 2 1/2 years, which indicates that all concretes had low permeability. Impressive compressive strength gains were realized with time for the slag cement concretes which at 7 1/2 years were in the range 82.5 to 105 MPa compared with the plain portland cement concrete at 67.5 MPa, clearly demonstrating the beneficial long-term effect of slag on strength development. Benefits were also derived from the use of water reducing admixtures and from using crushed limestone as aggregate. These are discussed in relation to the longer-term performance of the concretes at 10 1/2 years.

• Corporate Authors:

  American Concrete Institute (ACI)

  38800 Country Club Drive
  Farmington Hills, MI  United States  48331
• Authors:
  • Osborne, G J
  • Connell, M D
• Conference:
  • Fifth CANMET/ACI International Conference on Durability of Concrete
  • Location: Barcelona, Spain
  • Date: 2000-6-4 to 2000-6-9
• Publication Date: 2000

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 119-139

Subject/Index Terms

• TRT Terms: Aggregates; Carbonation; Cement; Compressive strength; Concrete; Crushed limestone; Durability; Granulated slag; Gravel; Oxygen; Performance; Permeability; Portland cement concrete; Properties of materials; Slag; Water reducing agents
• Subject Areas: Geotechnology; Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00793934
• Record Type: Publication
• Report/Paper Numbers: SP 192-8
• Files: TRIS
• Created Date: Jun 27 2000 12:00AM