FRACTURE RESISTANCE AND SELF-HEALING POTENTIAL OF VERY THIN ASPHALT OVERLAY ENHANCED BY MICROWAVE HEATING
Öz
Very-thin asphalt overlay mixtures require a careful balance of competing demands, such as enhancing skid resistance, reducing noise, and improving rutting resistance, due to their reduced thickness. Achieving this balance involves reducing the nominal maximum aggregate size (NMAS) and incorporating coarser aggregate gradations. This design complexity is particularly critical for semi-dense graded very-thin overlays, which are more susceptible to cracking. In this context, investigating the healing potential of very-thin asphalt overlays through microwave heating offers a promising opportunity to extend pavement life while minimizing economic and environmental impacts. This study investigates and compares the cracking resistance and self-healing capabilities of two mixtures by applying Fracture–Healing–Fracture (FHF) cycles using Semi-Circular Bending (SCB) testing under microwave heating. The mixtures examined include a semi-dense aggregate gradation (BBTM8) designed for very-thin overlays, and a dense-graded aggregate mixture (ACL 16+) intended for binder courses and containing 50% reclaimed asphalt pavement (RAP). As a result, the ACL mixture exhibited a fracture toughness (KIC) value of 37.1 N/mm³⁄², attributed to its denser gradation, larger NMAS, higher stiffness, and greater RAP content. In contrast, the initial KIC value of the BBTM8 mixture was 18.4 N/mm³⁄². However, following microwave heating, the KIC value of the BBTM8 mixture increased significantly and approached that of the ACL mixture, aided by its higher air void content. The FHF cycle results revealed that the BBTM8 mixture demonstrated higher fracture resistance and more efficient recovery performance than the ACL mixture.
Anahtar Kelimeler
self-healing, fracture resistance, microwave heating, ultra-thin asphalt overlay, SCB test
Destekleyen Kurum
Czech Technical University in Prague
Proje Numarası
The part of the activities provided by CTU in Prague was supported by project No. GA22-04047K funded by The Czech Scientific Foundation (GACR)
Etik Beyan
No conflict of interest was declared by the authors.
Teşekkür
We would like to thank the Czech Technical University in Prague, Road Structures Department for providing us with the opportunity to use their laboratory facilities. The part of the activities provided by CTU in Prague was supported by project No. GA22-04047K funded by The Czech Scientific Foundation (GACR).
Kaynakça
- Atakan, M., and Yıldız, K. (2024). Effect of aggregate damage on self-healing characteristics of asphalt concrete: An image processing-based method. Construction Building Materials, 425, 135924.
- Bui, H. H., and Saleh, M. J. E. F. M. (2021). Effects of specimen size and loading conditions on the fracture behaviour of asphalt concretes in the SCB test. 242, 107452.
- Chen, X., and Solaimanian, M. (2019). Effect of long-term aging on fracture properties of virgin and recycled asphalt concrete. Advances in Civil Engineering Materials, 8(1), 527-543.
- Eren, E., Valentin, J., and Ahmedzade, P. (2024). Assessment of the Effects of Induction Heating Induced-Healing on the Fracture Properties of Very Thin Asphalt Concrete. Paper presented at the International Conference on Maintenance and Rehabilitation of Pavements.
- Fernández-Sánchez, G., Berzosa, Á., Barandica, J. M., Cornejo, E., and Serrano, J. M. (2015). Opportunities for GHG emissions reduction in road projects: a comparative evaluation of emissions scenarios using CO2NSTRUCT. Journal of Cleaner Production, 104, 156-167.
- Gallego, J., del Val, M. A., Contreras, V., Páez, A. J. C., and Materials, B. (2013). Heating asphalt mixtures with microwaves to promote self-healing. 42, 1-4.
- Garcia-Gil, L., Miró, R., and Pérez-Jiménez, F. E. J. A. S. (2019). Evaluating the role of aggregate gradation on cracking performance of asphalt concrete for thin overlays. 9(4), 628.
- Gómez-Meijide, B., Ajam, H., Lastra-González, P., Garcia, A. J. C., and Materials, B. (2016). Effect of air voids content on asphalt self-healing via induction and infrared heating. 126, 957-966.
- Guo, M., Zhang, R., Du, X., and Liu, P. J. E. (2024). A state-of-the-art review on the functionality of ultra-thin overlays towards a future low carbon road maintenance. 32, 82-98.
- He, L., Zhou, Z., Ling, F., Alexiadis, A., Van den Bergh, W., Cannone Falchetto, A., . . . Kowalski, K. J. (2022). A Coarse-Grained Molecular Model for Simulating Self-Healing of Bitumen. Applied Sciences, 12(20), 10360.