Publication detail

Long-term mechanical properties of lime-pozzolan mortars: The role of amorphous Al2O3

VYŠVAŘIL, M. ŽIŽLAVSKÝ, T. DVOŘÁK, K. SPYCHAL, E.

Original Title

Long-term mechanical properties of lime-pozzolan mortars: The role of amorphous Al2O3

Type

article in a collection out of WoS and Scopus

Language

English

Original Abstract

Today, lime-pozzolan mortars are being used in the repair of historic buildings, replacing the lime-cement mortars that were previously used in this practice, but were incompatible with historic mortars. It has been observed in laboratory research and also in practice that some lime-pozzolan mortars can lose strength over time. The cause of this behaviour is not fully understood, but the main reason seems to be the instability and breakdown of the aluminate phases. In this paper, the role of amorphous Al2O3 content in pozzolans on the long-term mechanical properties of lime-pozzolan mortars is studied. Lime-pozzolan mortars with 40% replacement of lime with pozzolans with different contents of amorphous Al2O3 (metakaolin, pumice, pozzolanic earth, trass, zeolite) were prepared and the changes in strength, porosity and mineralogical composition of the mortars (determined by XRD and TG/DTA) over time were monitored. Mortars containing pozzolans with a high content of amorphous Al2O3 (over 30% by weight) showed a dramatic decrease in strength, changes in porosity and a decrease in the content of monocarboaluminate (C4AcH11) with a simultaneous increase in the content of vaterite and aragonite. The negative effects of carbonation of the aluminate phases are particularly evident in pozzolans with a high content of amorphous Al2O3.

Keywords

lime-pozzolan mortar; amorphous Al2O3, metakaolin, monocarboaluminate; decrease in strength; carbonation

Authors

VYŠVAŘIL, M.; ŽIŽLAVSKÝ, T.; DVOŘÁK, K.; SPYCHAL, E.

Released

16. 9. 2024

Publisher

MATEC Web of Conferences

ISBN

2261-236X

Periodical

MATEC Web of Conferences

Year of study

403

State

French Republic

Pages count

13

BibTex

@inproceedings{BUT190094,
  author="Martin {Vyšvařil} and Tomáš {Žižlavský} and Karel {Dvořák} and Edyta {Spychal}",
  title="Long-term mechanical properties of lime-pozzolan mortars: The role of amorphous Al2O3",
  booktitle="SUBLime Conference 2024 – Towards the Next Generation of Sustainable Masonry Systems: Mortars, Renders, Plasters and Other Challenges
",
  year="2024",
  journal="MATEC Web of Conferences",
  volume="403",
  pages="13",
  publisher="MATEC Web of Conferences",
  doi="https://doi.org/10.1051/matecconf/202440302009",
  issn="2261-236X"
}