Bibliographic record
Abstract
Abstract Delayed ettringite formation (DEF) is only one of a number of chemical and physical attack mechanisms related to the presence of sulfur-based compounds existing within the microstructure of concrete. Identification of the various “sulfate” attack mechanisms, both internal and external, is important to guide the development of appropriate performance-based test methods. Such test methods must also recognize and account for the fact that real deterioration processes in concrete often involve a combination of mechanisms; sulfate attack, for example, is often found in combination with other attack mechanisms, such as alkali-aggregate reaction or freezing and thawing. Thus, future tests or suites of tests should be designed to account for acceleration of deterioration that results from the synergy between attack mechanisms. It is suggested that a holistic approach—similar to that proposed by Mehta—whereby the effect of (a) combinations of raw materials and (b) combinations of environmental influences should play a central role in the development of new standards. In this paper, an engineering view of the various mechanisms of sulfate attack is provided. Sulfate-attack mechanisms are categorized and major influences upon these mechanisms are briefly reviewed. The suitability of two key tests related to sulfate attack is examined—ASTM methods C 1012 and C 1038. Available data concerning test method C 1038 are analyzed. Because of the lack of confidence that C 1038 is an adequate performance test, reliance upon prescriptive limits for sulfate and aluminate contents and their relative proportions is currently a better approach to ensure adequate performance of cementitious systems in practice.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".