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Record W24356974

Effect of fly ash replacement on alkali and sulphate resistance of mortars

2007· dissertation· en· W24356974 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

aboutThe title or abstract carries a Canadian signal from the geographic lexicon.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueSpectrum Research Repository (Concordia University) · 2007
Typedissertation
Languageen
FieldEngineering
TopicConcrete and Cement Materials Research
Canadian institutionsnot available
Fundersnot available
KeywordsFly ashAlkali–silica reactionMortarSulfateSilica fumeCementMaterials scienceAlkali–aggregate reactionDurabilityWaste managementComposite materialMetallurgyEngineering
DOInot available

Abstract

fetched live from OpenAlex

The use of fly ash as a supplementary cementing material in concrete and mortar has dramatically increased in recent years due to its improvement of concrete and mortar properties and its environmentally friendly impact. In this thesis, the sulfate resistance and alkali-silica reaction in mortars containing 0, 20, 40, 60, and 80% fly ash replacement levels were investigated to determine the effect of fly ash content on durability. Four types of cement and two types of fly ash were used in the tests, the cements used were of different alkali contents and with and without blended silica fume. The fly ashes consisted of medium and high calcium contents. The results showed that the expansion resulting from sulfate attack as well as the alkali-silica reaction considerably decreased with the increase of fly ash content, but the strength of the mortar samples greatly decreased as well. The effectiveness of fly ash in both tests was highly dependent on their CaO content and on the chemistry of cements utilized. 20% Sundance fly ash replacement was sufficient to maintain the sulfate expansion after six months of exposure below CSA allowable expansion limit of 0.05% for high sulfate resistance cement and also below the Canadian limit of 0.1% in the ASR test. For Rockport fly ash, replacement levels at 40% were needed to maintain the expansion below the limit of 0.1% in ASR and sulfate test. The presence of silica fume blends significantly reduced the expansion due to alkali-silica reaction and sulfate attack; addition of fly ash to silica fume blended cements did not significantly improve performance.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.002
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.074
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0020.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0010.001
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.012
GPT teacher head0.281
Teacher spread0.268 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it