Performance of steel fiber-reinforced alkali-activated slag-fly ash blended concrete incorporating recycled concrete aggregates and dune sand

Hilal El-Hassan, Abdalla Hussein, Jamal Medljy, Tamer El-Maaddawy

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

This study evaluates the performance of alkali-activated slag-fly ash blended concrete made with recycled concrete aggregates (RCA) and reinforced with steel fibers. Two blends of concrete with ground granulated blast furnace slag-to-fly ash ratios of 3:1 and 1:1 were used. Natural aggregates were substituted with RCA, while macro steel fibers with 35 mm of length and aspect ratio of 65 were incorporated in RCA-based mixtures at various volume fractions. Fine aggregates were in the form of desert dune sand. Mechanical and durability characteristics were investigated. Experimental results revealed that RCA replacement decreased the compressive strength of plain concrete mixtures with more pronounced reductions being perceived at higher replacement percentages. Mixtures made with 30%, 70%, and 100% RCA could be produced with limited loss in the design compressive strength upon incorporating 1%, 2%, and 2% steel fibers, by volume, respectively. In turn, splitting tensile strength was comparable to the NA-based control while adding at least 1% steel fiber, by volume. Moreover, higher water absorption and capillary sorptivity and lower ultrasonic pulse velocity, bulk resistivity, and abrasion resistance were reported during RCA replacement. Meanwhile, incorporation of steel fibers densified the concrete and enhanced its resistance to abrasive forces, water permeation, and water transport. Analytical regression models were developed to correlate hardened concrete properties to the 28-day cylinder compressive strength.

Original languageEnglish
Article number327
JournalBuildings
Volume11
Issue number8
DOIs
Publication statusPublished - Aug 2021

Keywords

  • Alkali-activated concrete
  • Analytical regression model
  • Dune sand
  • Fly ash
  • Hardened properties
  • Recycled concrete aggregate
  • Slag
  • Steel fibers

ASJC Scopus subject areas

  • Architecture
  • Civil and Structural Engineering
  • Building and Construction

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