Mechanical properties, and microstructure of ASR-affected concrete subjected to freeze-thaw cycles
Bibliographic record
Abstract
In cold climates, concrete structures made with reactive aggregates in cold climates can experience both alkali-silica reaction (ASR) and freeze-thaw (FT) cycles, accelerating deterioration beyond the effects of either mechanism alone. Combined exposure can accelerate concrete deterioration, highlighting the need to investigate the resistance of concrete against coupled mechanisms of ASR and FT cycles but is relatively scarcely studied which speaks to the need/novelty of this work. The primary objectives of this study are to: develop two exposure schemes that capture coupled modes of ASR followed by FT cycles, and FT cycles followed by ASR inducing conditions; and to interpret the role of exposure sequence on the degree of physical damage. Mix designs in accordance with ASTM C1293, but also with ∼5 % air entrainment were used for all mixes. Different levels of ASR damage were generated by using different reactive aggregates (Sudbury, Spratt and Jobe), exposure temperature (23 °C and 50 °C) and exposure duration (up to 6 months). Key findings are: (i) for exposure scheme of ASR followed by FT cycles, a nearly linear relationship was established between ASR-induced expansion and reduction in FT durability factor, demonstrating preceding ASR’s weakening effect on FT resistance; (ii) for exposure scheme of FT cycles followed by ASR, the expansion curves of concrete with or without FT cycles are similar for all aggregate types; (iii) concrete subjected to FT cycles followed by ASR had 78.9 % (Sudbury), 51.4 % (Spratt) and 43.1 % (Jobe) lower expansion compared to expansion due to ASR followed by FT cycles; and (iv) although ASR products partially filled entrained air voids, the contribution of damage due to: physical pre-cracking due to ASR and partially filled air voids by ASR product leading to a compromised freeze-thaw resistant air void system could not be decoupled. • Two exposure schemes are developed to understand ASR and FT. • ASR expansion and durability factor are linearly proportional when ASR exposure precedes FT cycles. • Physical pre-cracking due to ASR and partially filled air voids by ASR product leads to a compromised freeze-thaw resistant air void system could not be decoupled.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".