Supercritical carbonation of calcareous composites: influence of mix design

Elham Farahi, Phil Purnell, Neil R. Short

Research output: Contribution to journalArticlepeer-review


This work combined compression moulding with subsequent super-critical carbonation treatment (100 bar, 60 °C, 24 h) to fabricate cement and/or lime based ceramic composites with various aggregates. Composites were examined using mechanical testing, XRD, He pycnometry and thin-section petrography. Composites with lime-only binders were significantly weaker than those with cement-lime binders regardless of the degree of carbonation. Flexural strengths in excess of >10 MPa were routinely achieved in large (>100 mm) specimens. Aggregate type (calcareous vs. siliceous) had a significant effect on the microstructure and properties of the composites. Calcareous aggregates appear to augment the strength enhancement effected during super-critical carbonation by encouraging preferential precipitation of calcite at the binder-aggregate interface.
Original languageEnglish
Pages (from-to)12-19
Number of pages8
JournalCement and Concrete Composites
Early online date21 Jun 2013
Publication statusPublished - 31 Oct 2013


  • super-critical carbonation
  • mechanical processing
  • lime
  • cement
  • flexural testing
  • petrography


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