Performance-based specifications for concrete
Bibliographic record
Abstract
Abstract This chapter mainly deals with performance specifications from the North American perspective, although the international literature has also been reviewed. The increase in demand for improved concrete durability and the simultaneous growing complexity of concrete mixture design and proportioning lead us to the debate regarding prescription or performance specifications. Interest is further fuelled by the changes in construction techniques that have accompanied the developments of newer concrete materials. Although there have been some recent advances, from the review of standards and the literature published since the previous edition, it became clear that while there was an almost universal interest in performance, primarily for durability, there were few specifications that contained any pure performance criteria. Most specifications defined exposure conditions that pertained to each country or region and then tabulated concrete mixture contents and limits that had been shown by previous studies to likely result in the desired durability. These include maximum limits for the water-to-cement or water-to-cementitious ratio, minimum cement contents and an acceptable range of air contents. The chapter concludes that a multi-step plan is needed, with possibly nine steps, to realise the transition from prescription to performance specifications.
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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) | 0.002 | 0.001 |
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; both teacher heads agree on what is shown here.
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".