Mechanical Properties and Rapid Chloride Permeability of Concrete With Ground Fly Ash

The objective of this study was to optimize the design of high-strength, high-volume fly ash concretes. Eight concrete mixtures were prepared using the same batch of ordinary portland cement (OPC) and ground low-lime fly ash. The aggregate grading used in the mixtures of concrete, water-binder ratio, and the maximum particle size of aggregate were kept constant in all concretes, however, the partial replacement of cement by fly ash was varied from 0% to 70% OPC concrete, in steps of 10%. The replacement was on a one-to-one weight basis. At 28 days, there was little reduction in compressive strength up to 40% cement replacement by ground fly ash; then a significant decrease was recorded for the further fly ash dosages. At 56 and 120 days, however, the compressive strength up to 40% cement replacement by fly ash was found to be almost identical to that of the no fly ash concrete, and for one year it was even higher. Beyond 40% replacement, the compressive strength decreased significantly. It was shown that the brittleness index increases substantially with increasing compressive strength of concrete. The results of the rapid chloride penetration tests revealed that high volume ground fly ash concrete had better resistance to the penetration of chloride ions. The mortar phases of these concretes were also prepared. As the dosage of fly ash increased, 2, 7, and 28-day compressive strengths of the mortars decreased. However, at later ages at 56, 120, and 365 days, nearly 40% cement replacement by ground fly ash, the compressive strength of mortar with fly ash was about equal to that of mortar without fly ash. The pozzolanic effectiveness ratio increased with increasing curing time and fly ash content.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/13846872
• Authors:
  • Sengul, Ozkan
  • Tasdemir, Canan
  • Tasdemir, Mehmet Ali
• Publication Date: 2005-11

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 414-421
• Serial:
  • ACI Materials Journal
  • Volume: 102
  • Issue Number: 6
  • Publisher: American Concrete Institute (ACI)
  • ISSN: 0889-325X
  • Serial URL: https://www.concrete.org/publications/acimaterialsjournal.aspx

Subject/Index Terms

• TRT Terms: Brittleness; Chlorides; Compressive strength; Concrete aggregates; Concrete curing; Fly ash; High strength concrete; Ions; Mechanical properties; Mortar; Portland cement; Pozzolan; Soil penetration test
• Uncontrolled Terms: Cement replacement; Chloride permeability
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 01014852
• Record Type: Publication
• Files: TRIS
• Created Date: Dec 29 2005 3:05PM