Concrete containing natural pozzolans: New challenges for internal curing

Gaston Espinoza-Hijazin, Álvaro Paul, Mauricio Lopez

Research output: Contribution to journalArticlepeer-review

24 Scopus citations

Abstract

Natural pozzolans (NP) have proven to be an effective supplementary cementitious material; however, the replacement of ordinary portland cement (OPC) with NP might increase the autogenous and drying shrinkage of concrete. Internal curing (IC) might be of great help when using NP because it can promote the pozzolanic reactions and reduce shrinkage. The aim of this research is to assess the effect of IC in concrete containing NP. Results indicate that a 39% replacement of OPC with NP decreased compressive strength by 15%, decreased chloride ion permeability by 66%, and increased autogenous shrinkage by 40%. IC with prewetted lightweight aggregate showed no significant effect in compressive strength or permeability, but it decreased autogenous shrinkage by up to 58%. NP used in this investigation presented higher chemical shrinkage than OPC, making IC less effective as levels of NP increased. The important decrease in permeability attained through the use of NP and the higher chemical shrinkage of NP makes IC a critical technology to consider in concrete mixtures with NP.
Original languageAmerican English
Pages (from-to)981-988
Number of pages8
JournalJournal of Materials in Civil Engineering
Volume24
Issue number8
DOIs
StatePublished - 1 Aug 2012
Externally publishedYes

Keywords

  • Autogenous shrinkage
  • Cement
  • Compressive strength
  • Concrete
  • Curing
  • Internal curing
  • Permeability
  • SCM

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