Freeze-thaw resistance of pozzolanic hydrated lime mortars

Su-Cadirci T. B., Calabria-Holley J., Ince C., Ball R. J.

Construction and Building Materials, vol.394, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 394
  • Publication Date: 2023
  • Doi Number: 10.1016/j.conbuildmat.2023.131993
  • Journal Name: Construction and Building Materials
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, CAB Abstracts, Communication Abstracts, INSPEC, Metadex, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Conservation, Hydrated lime mortars, Lime mortars, Pozzolan
  • Middle East Technical University Affiliated: Yes

Abstract

Degradation of hydrated lime mortars subjected to freezing and thawing is common in historic building conservation. The pozzolanic additions, Argical M1000, diatomite (diatomaceous earth) and brick dust, were evaluated for their ability to improve performance for up to 720 days. Pozzolanic reactions influenced the pore structure evolution, mechanical performance, and chemical reactivity of the mortar matrix. Argical-lime mortars exhibited a sudden failure, while a gradual reduction in mechanical strength was observed for mortars containing brick dust. A slower rate of failure in diatomite mortars was attributed to pore refinement, which was associated with superior freeze thaw performance. This study has advanced the current state of the art regarding how pore structure affects lime mortars' freeze and thaw resistance. Therefore it provides spesifications on how to optimise mortars for historic masonry. A key impact is the more effective use of lime mortars for conservation, thereby protecting heritage structures from degredation.