- Research Article
2
- 10.1139/cjce-2024-0472
Concrete damage due to pyrrhotite in the Trois-Rivières area (Québec, Canada) – Investigation of existing buildings
- Aug 12, 2025
- Canadian Journal of Civil Engineering
- Marc-André Bérubé + 3 more +3
In the Trois-Rivières area, about 2000 buildings whose the concrete was manufactured with aggregates containing pyrrhotite was the subject of litigation. At the beginning of a trial started in 2009, the experts representing all defendants grouped together and adopted a number of protocols relating to inspection, visual damage assessment, core sampling, and laboratory testing. The aggregate pyrrhotite content is obtained from the concrete sulfur content, the pyrrhotite/pyrite/chalcopyrite ratio and other parameters related to the concrete mixture. In a 2014 judgment, the Court required compensation to all owners whose concrete was made with aggregates containing 0.23 vol% of pyrrhotite or more, whether or not their concrete was damaged. The intrinsic heterogeneity of concrete in terms of sulfur and sulfide contents, from one core to another, but also within a single core, leads to a significant variability of the aggregate pyrrhotite content obtained. Consequently, the 0.23 vol% limit appears highly questionable.
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