Evaluation of CSA Prequalification Procedures of UHPC Materials for Bridge Construction
Bibliographic record
Abstract
Canadian Bridges are particularly vulnerable to corrosion and long-term durability problems initiated by the easy fracture and delamination of concrete under combined stress and climatic exposure. UHPC is an alternative construction material that holds great promise to alleviate many of those durability and strength problems both in new construction and in retrofitting. While only recently it was considered an emerging material, UHPC is now implemented in infrastructure, necessitating full understanding of material behavior with ultimate goal to exploit its unique properties in design practices. In this study, a proprietary UHPC mix produced by DURA Canada is used to assess the material characterization techniques prescribed by Canadian Standards Association (CSA) for UHPC materials. This research serves as a case study for proof testing the repeatability and robustness of the prequalification procedures specified by the2019 CSA Standards, in light of the fact that these procedures have only been recently drafted and introduced in the Code. Additional objective is to evaluate the material’s compliance with requirements for abrasion, salt scaling, absorption, chloride ion penetration, and freeze thaw resistance according to the different standards used by the Canadian Industry as well as time dependent properties such as creep, shrinkage, and coefficient of thermal expansion. Finally, this paper will present in detail the specimen preparation and testing, as well as the challenges encountered, lessons learnt and recommendations for future editions of the code.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.007 | 0.016 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".