Development and Evaluation of Crumb Rubber-Modified Binders for High-Performance Asphalt Concrete
Notice bibliographique
Résumé
Asphalt pavements, or asphalt concrete (AC), are viscoelastic composites designed for modern transportation but often exceed their design limits, leading to distresses like rutting, moisture damage, and cracking. To address these issues, high-modulus asphalt concrete (HMAC) was developed in France in the 1960s as enrobé à module élevé (EME), using stiff asphalt binders to enhance rutting and moisture resistance. However, increased stiffness reduces stress dissipation, making HMAC prone to fatigue and thermal cracking, a primary concern in cold regions like Canada, where extreme temperature fluctuations accelerate pavement deterioration. This thesis explores a novel approach to pavement design that addresses the limitations of hard-grade asphalt binders in HMAC, particularly in cold climates. By incorporating crumb rubber-modified binder (CRMB), a sustainable and performance-enhancing alternative, this research aims to develop high-performance asphalt concrete (HPAC). This advanced mixture retains or improves the superior dynamic stiffness of HMAC while significantly improving cracking resistance, ensuring long-term durability. Additionally, HPAC is tailored explicitly for base course applications in full-depth asphalt pavements, where tensile and compressive stresses are at their highest. Moreover, this research incorporates a comprehensive asphalt binder modification technique using a crumb rubber modifier (CRM) and its effect on AC mixtures regarding resistance to prevalent pavement distresses, such as rutting, moisture damage, and cracking. The study is divided into five key sections. The first section introduces asphalt pavement technologies, highlighting advancements and the challenges posed by increasing traffic loads and climate change, along with the study’s objectives and methodology. The second section reviews existing literature on AC design methodologies, the rheological behaviour of conventional and modified binders, and the evolution of HMAC to HPAC. This review identifies research gaps from relevant literature and emphasizes the need for HPAC solutions suited to Canada’s extreme climatic conditions and growing traffic demands. The third section evaluates the rheological performance of CRMB by examining the effects of crumb rubber modifier (CRM) content and blending time on asphalt binder properties, notably achieving a high Performance-Grade (PG) 82 intended for HPAC application. A 30-mesh CRM was mixed into a PG 64-22 unmodified binder at varying concentrations (3%, 6%, 9%, 12%, and 15%) and blending times (30, 60, and 90 minutes) at 180°C. Results indicated a 12% CRM content with a 60-minute blending time optimized polymerization, achieving PG 82-22, demonstrated superior high-temperature performance while maintaining adequate elasticity and low-temperature stress relaxation properties. Intermediate-temperature results suggested improved fatigue resistance, while aging analysis revealed lower stiffness gains over time, indicating enhanced resistance to oxidative and physical hardening. Consequently, the optimized CRMB suitability for HPAC application was validated with the dynamic modulus test, exceeding the requirement (≥14,000MPa @10°C, 10 Hz). However, phase separation remained a challenge, emphasizing the need for improved storage stability techniques. The fourth section incorporates the optimized CRMB into AC mixtures to assess its suitability for HPAC applications through performance-based evaluations. Comparative analysis with unmodified AC confirmed that crumb rubber-modified asphalt concrete (CRMAC) mixtures demonstrated superior rutting resistance and moisture durability in the Hamburg wheel tracking (HWT) test and exhibited enhanced stress redistribution, effectively delaying crack initiation at low temperatures in the disc-shaped compact tension (DCT) test. The performance space diagram (PSD), developed within the balanced mix design (BMD) framework, further illustrated this improvement by positioning CRMAC mixtures in a more balanced performance zone and reinforcing their potential for base course applications in cold regions. The final section presents the key findings of the study, including a summary, conclusions, and future research directions. The results emphasize CRMB’s potential to enhance the durability and structural integrity of HPAC mixtures, positioning them as a promising alternative for base course layers in extreme climates. While CRMAC demonstrates significant performance improvements, further research is recommended to evaluate its long-term field performance and optimize mix designs to mitigate temperature and traffic-induced distress.
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,001 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 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 source (Gemma direct ou Codex distillé), 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 ».