Influence of fly ash as a cement addition on the hardened properties of recycled aggregate concrete

Shi Cong Kou, Chi Sun Poon, Dixon Chan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

118 Citations (Scopus)

Abstract

The effects of the use of Class F fly ash as a cement addition on the hardened properties of recycled aggregate concrete were determined. In this study, four series of concrete mixtures were prepared with water-to-cement (w/c) ratios of 0.55, 0.50, 0.45 and 0.40. The recycled aggregate was used as 0%, 20%, 50% and 100% replacements of coarse natural aggregate. Furthermore, fly ash was employed as 0% and 25% addition of cement. Although the use of recycled aggregate had a negative effect on the mechanical properties of concrete, it was found that the addition of fly ash was able to mitigate this detrimental effect. Also, the addition of fly ash reduced the drying shrinkage and enhanced the resistance to chloride ion penetration of concrete prepared with recycled aggregate. Moreover, it was found that the drying shrinkage and chloride ion penetration decreased as the compressive strength increased. Compared with the results of our previous study, the present study has quantified the advantages of using fly ash as an additional cementitious material in recycled aggregate concrete over the use of fly use as a replacement of cement.
Original languageEnglish
Pages (from-to)1191-1201
Number of pages11
JournalMaterials and Structures/Materiaux et Constructions
Volume41
Issue number7
DOIs
Publication statusPublished - 1 Aug 2008

Keywords

  • Chloride ion penetration
  • Drying shrinkage
  • Fly ash
  • Mechanical properties
  • Recycled aggregate

ASJC Scopus subject areas

  • Building and Construction
  • Civil and Structural Engineering
  • Materials Science(all)

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