Activities per year
Abstract
Samples of four houses showing a degree of damage on the facades from relatively minor to severe have been investigated using scanning electron microscopy with energy-dispersive spectroscopy, image analysis and thermodynamic modelling.
The aggregates used in affected homes in Donegal are mainly phyllites and schist quarried from Dalradian metamorphic formations that contain a high muscovite mica content. However, these aggregates additionally contain iron sulphides, mainly in the form of pyrrhotite. The hydrate assemblage in the concrete blocks shows differing degrees of alteration that can vary considerably on a centimetre scale. Relatively little affected locations show the presence of ettringite in the typical clusters formerly consisting of monosulfate/monocarbonate. In the strongly affected locations the cement paste is nearly completely transformed into thaumasite. Some severely deteriorated concrete blocks are fully carbonated resulting in the formation of CaCO3, silicon-aluminium gel and gypsum. This process obliterates the chemical reactions leading to deterioration.
The alteration of the hydrate assemblage is a clear indication for internal sulfate attack [1,2] with pyrrhotite as the only likely sulphur source. Expansion is typically caused by ettringite formation [1-3], while the complete strength loss of some concrete blocks can be attributed to thaumasite formation [4].
Literature:
[1] I. Casanova, A. Aguado, L. Agulló, Cem Concr. Res. 1997, 27(11) 1627-1632.
[2] Lee, H., Cody, R. D., Cody, A. M., & Spry, P. G. Cem. Concr. Res. 2005, 35(2), 332-343.
[3] W. Kunther, B. Lothenbach, J. Skibsted, Cem. Concr. Res. 2015, 69, 37-49.
[4] M. Romer, L. Holzer, M. Pfiffner, Ceme. Concr. Comp. 2003, 25(8), 1111-1117.
Original language | English |
---|---|
Pages | 1 |
Number of pages | 1 |
Publication status | Unpublished - 26 Sept 2022 |
Event | 4th International Conference on the Chemistry of Construction Materials 2022 - Karlsruhe Institute of Technology, Karlsruhe, Germany Duration: 26 Sept 2022 → 28 Sept 2022 https://veranstaltungen.gdch.de/tms/frontend/index.cfm?l=11018&modus |
Conference
Conference | 4th International Conference on the Chemistry of Construction Materials 2022 |
---|---|
Abbreviated title | ICCCM 2022 |
Country/Territory | Germany |
City | Karlsruhe |
Period | 26/09/22 → 28/09/22 |
Internet address |
Keywords
- pyrrhotite
- sulfate attack
- mica
- concrete
Fingerprint
Dive into the research topics of 'Internal sulfate attack on concrete – a case study from homes in Inishowen, Northwest Donegal, Ireland'. Together they form a unique fingerprint.Activities
- 2 Organising a conference, workshop, ...
-
The Science and Societal Impacts of Defective Concrete
Dunlop, P. (Organiser), Doherty, E. (Organiser), Morgan, J. (Organiser), Rowley, M. (Member of programme committee), Sheeran, E. (Member of programme committee), McGilloway, J. (Member of programme committee) & Kilmartin , J. (Organiser)
15 Nov 2022 → 17 Nov 2022Activity: Participating in or organising an event › Organising a conference, workshop, ...
File -
The impact on family homes of defective concrete products
Dunlop, P. (Member of programme committee) & Doherty, E. (Member of programme committee)
23 Mar 2022Activity: Participating in or organising an event › Organising a conference, workshop, ...
File
Research output
- 1 Article
-
The "mica crisis" in Donegal, Ireland – a case of internal sulfate attack?
Leemann, A., Lothenbach, B., Münch, B., Campbell, T. & Dunlop, P., 15 Mar 2023, (Published online) In: Cement and Concrete Research. 168, June 2023, p. 1-14 14 p., 107149.Research output: Contribution to journal › Article › peer-review
Open AccessFile19 Citations (Scopus)226 Downloads (Pure)
Press/Media
-
Swiss expert 'repulsed' after visiting crumbling Donegal homes
Leemann, A. & Dunlop, P.
20/11/22
1 Media contribution
Press/Media: Research
-
Conference hears ten community centres have defective blocks
19/11/22
1 item of Media coverage
Press/Media: Public Engagement Activities
-
Public Inquiry call for defective concrete blocks scandal
17/11/22
1 item of Media coverage
Press/Media: Research