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Record W1966717244 · doi:10.3141/2126-05

Asphalt Cement Loss Tangent as Surrogate Performance Indicator for Control of Thermal Cracking

2009· article· en· W1966717244 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.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
aboutThe title or abstract carries a Canadian signal from the geographic lexicon.

Bibliographic record

VenueTransportation Research Record Journal of the Transportation Research Board · 2009
Typearticle
Languageen
FieldEngineering
TopicAsphalt Pavement Performance Evaluation
Canadian institutionsQueen's University
Fundersnot available
KeywordsAsphaltCrackingCementRheometerMaterials scienceViscoelasticityAsphalt concreteComposite materialStructural engineeringGeotechnical engineeringRheologyEngineering

Abstract

fetched live from OpenAlex

This paper documents and discusses the field validation of a simple performance indicator for specification grading of asphalt cement for thermal cracking. The loss tangent, tan(δ), as defined by the ratio of the viscous over elastic modulus, G”/ G’, is able to provide a quantitative measure of the sol and gel nature of asphalt cement. As such, tan(δ) relates closely to how well a material is able to relax stress and is therefore investigated as a surrogate performance indicator for thermal cracking. Asphalt cements from 20 contract sites in Ontario, Canada, were tested in torsion bar geometry to determine their viscoelastic properties. The findings show that tan(δ) was able to distinguish good from poor performers for this set of materials with 95% accuracy, which is a considerable improvement over the current bending beam rheometer protocol. In addition to the use of tan(δ), it is suggested that a measure of the critical strain tolerance in the ductile state could be included to provide a significantly improved performance grading method. Most of the worst performing contracts were found to contain zinc. The presence of this element suggests that the use of waste engine oils in asphalt production is likely widespread, since zinc is a universal additive in engine oil and is never found in straight asphalt cement

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)0.006
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.496
Threshold uncertainty score0.835

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0060.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0000.000
Scholarly communication0.0000.001
Open science0.0010.000
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 head0.062
GPT teacher head0.364
Teacher spread0.302 · 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