FORMATE DURABILITY OF ROAD PAVEMENTS - LITERATURE SURVEY AND LABORATORY TESTS
Notice bibliographique
Résumé
Based on literature, the influences of formate de-icing chemicals into the characteristics of road asphalt are investigated only somewhat in airfield conditions e.g. in Sweden, Norway, Canada and in Finland. Differences between normal road asphalt paving concrete, AC16 in Finland compared to airfield asphalt paving concrete are, however, so small that the results obtained from the airfield conditions are well applied also in road conditions. Wear influences are not existing on airfields like in normal road conditions. That is why the wear of normal asphalt paving mixtures, influenced by potassium formate de-icing chemical, was researched in laboratory. Based on present opinions, formates influenced the quality of asphalt pavements. Formates influenced in different ways road binder, bitumen, aggregates and resistance of adhesion between aggregate and bitumen. Influence in bitumen is determined by softness of bitumen. Potassium formate is penetrating to surface of soft bitumen, B160/220, during the laboratory storage test, so effectively that the bitumen film is separating into the surface of this de-icing chemical. In compacted asphalt pavement the influence in adhesion between aggregate and bitumen seams to be smaller and is due to the tightness of the asphalt pavement. The precise influence mechanism of formate into the bitumen consistency and into the asphalt pavement characteristics has so far, however, been unknown and not well researched. Influences of formates should be prevented by the improved mix-design of the consistency of the road pavements. Influences of formate in road bitumen are decreased with the harder road bitumen. The road bitumen, B160/220 is proved at least to be too soft as the road bitumen with formate chemical. When using potassiumformate the hard road bitumen, B70/100 should be selected. When avoiding cold-cracking in pavements, it should be better to select the polymer-modified bitumen (PmB) with the formates. PmBs are, however, in normal road asphalt use, compared to normal bitumen, more expensive. The preliminary wear tests of road asphalt concretes after 2 months storage in 50% potassium formate water solution were carried out in laboratory. The wear test was the Prall wear test based on standard prEN 12697-16. Road asphalt concrete, AC16 (B70/100) and stone mastic asphalt concrete, SMA16 (B70/100) were worn less than the corresponding samples stored in normal water. Wear results showed that any immediate wear risk with potassium formate was not detected. Influences of the other de-icing chemicals in wear were not researched. Because of the small data in wear results final conclusions regarding wear influence could not be made. In the literature, the abrasions type wear of the acid aggregate, quartzite. by icing and melting cycle wear tests were researched. The wear of quartzite in this abrasion test was greatest when 2% sodium formate water solution was used in storage of the aggregate particles. That is why wear of road pavements and adhesion of bitumen to aggregate should be tested with formates more, also with the Finnish road aggregates. Interpretation of the results obtained from formates in literature was not such that it actually could prevent the use of potassium formate in de-icing on the road surfaces. Both formates and acetates in the literature survey behaved in de-icing of asphalt pavements, additionally, rather equally and better than urea chemicals. Certain criteria, connected to possible use of potassium formate in de-icing on the road surfaces must, however, still be studied more during the mix-design procedure of the road pavements. On the sensitive ground water areas, the selection of potassium formate for de-icing needs still more results on the real degradation of the chemical. When using potassium on the sensitive ground water areas the mix-design of asphalt pavement layer should be done so that the maximum void content is 3% by volume. This improves adhesion between aggregate and bitumen. Formate will then dissipate and evaporate directly from the asphalt concrete surface preventing penetration of formate into the pavement structure. Asphalt pavement structure, during the use of formate, should then be as dense as possible and remain without cold-cracking. The asphalt pavements consist sometimes also of new and old asphalt pavement wearing layers and the acid bitumen emulsion is used as the glueing agent between these layers.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,002 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».