Concrete damage due to pyrrhotite in the Trois-Rivières area (Québec, Canada): risk of future damage to undamaged concrete
Bibliographic record
Abstract
Over 1700 buildings in the Trois-Rivières area (Québec, Canada), with the concrete manufactured with aggregates containing pyrrhotite have been inspected by the defense experts involved in a first trial. Nearly 500 of them, undamaged at the time of a first inspection, were reinspected about every 2 years. Only 23% of these (113/497) showed signs of concrete swelling due to internal sulfate attack with time, but only 8 did so more than 8 years after construction. Among the 384 still undamaged buildings, 99 were over 10 years old despite aggregate pyrrhotite contents of 0.25 to 1.00 vol%. The risk of future damage to undamaged concrete is based on three factors relating to: (1) aggregate pyrrhotite content, (2) type of concrete component and exposure conditions, climatic or other, and (3) age of concrete. Since 2017, the protocol has been applied to many buildings, and proved to be both reliable and conservative.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".