Guidelines for mix proportioning of fly ash/GGBS based alkali activated concretes

Ali Rafeet, Raffaele Vinai, Marios Soutsos, Wei Sha

Research output: Contribution to journalArticle

33 Citations (Scopus)
442 Downloads (Pure)

Abstract

The effects of paste volume, water content and precursor blend on consistency, setting time and compressive strength of alkali activated concrete (AAC) produced with fly ash (FA) and ground granulated blast furnace slag (GGBS) have been investigated with the aim of developing a suitable mix design procedure. Paste volumes in the range 30–33% were found not to influence the compressive strength but did influence the consistency of the mixes. The water-to-solid ratio was found to influence compressive strength and setting time. Increasing GGBS content in the binder blend resulted in an increase of the compressive strength, but higher GGBS content caused also early setting which may be undesirable. A mix design procedure has been developed and has been used to determine the constituent mix proportions for three classes of concretes, i.e. (a) a ready-mix concrete with nominal strength 35 MPa, (b) a typical structural concrete with nominal strength 50 MPa, and (c) a high strength concrete for precast applications with nominal strength 70 MPa. Cost analysis was carried out to compare the AAC with Portland cement concretes with similar properties. Normal strength Portland cement concrete (PC), as typically used in ready mix industry has been shown to be less expensive than AAC. However, alkali activated concrete can be competitively priced for high strength concretes. An empirical step-by-step procedure is presented for selecting trial mix proportions for concretes with a range of consistency values, setting times and cube compressive strengths.
Original languageEnglish
Pages (from-to)130-142
Number of pages13
JournalConstruction and Building Materials
Volume147
Early online date26 Apr 2017
DOIs
Publication statusPublished - 30 Aug 2017

Keywords

  • Selection of mix proportions
  • Alkali activated binders/concretes
  • Fly ash
  • Ground granulated blast furnace slag

Fingerprint Dive into the research topics of 'Guidelines for mix proportioning of fly ash/GGBS based alkali activated concretes'. Together they form a unique fingerprint.

  • Cite this