Performance of volcanic ash and pumice-based blended cements in sulphate and sulphate–chloride environments
Bibliographic record
Abstract
The deterioration of concrete structures due to sulphate and mixed sulphate—chloride in soils, groundwater and marine environments is a well-known phenomenon. The use of blended cements incorporating supplementary cementing materials and cements with low C 3 A content is becoming common in such aggressive environments. This paper presents the results of an investigation on the performance of volcanic ash (VA)- and finely ground volcanic pumice (VP)-based ASTM Type I and Type V (low C 3 A) blended cements (using 20% VA or VP as cement replacement) with varying immersion periods of up to 80 weeks in environments characterised by the conjoint presence of chlorides and sulphates. The effect of sulphate and sulphate—chloride environments on the strength and expansion characteristics of mortar specimens was evaluated. X-ray diffraction analysis and differential scanning calorimetry tests were also conducted to determine phase composition, pozzolanic activity and chloride binding of plain and blended cements. The performance of blended cements was found to be better in comparison with plain cements in terms of strength reduction and expansion characteristics and the performance was also found to depend on the type of cement (Type I or Type V). Results also indicate that the presence of chloride ions in the sulphate environment mitigates the sulphate attack in both plain and blended cements.
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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 | 0.001 | 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".