Discrete numerical modelling of capsule-asphalt mixture system for self-healing purposes

Gustavo Câmara, Nuno Monteiro Azevedo, Rui Micaelo

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Asphalt mixture faces damage due to vehicle speed, repeated loads, and ultraviolet radiation over time, regardless of being a self-healing material. Induced healing mechanisms are necessary to promote autonomous pavement recovery due to adverse in-service conditions, and the capsule-asphalt mixture system incorporating low-viscosity oils (rejuvenators) has shown to be a possible solution in laboratory tests. This study aims to numerically investigate the effect of rejuvenator-modified mastic (activated capsules) on the stiffness properties of asphalt mixtures within the discrete element method. A three-dimensional model previously validated for rejuvenator-modified mastics with different rejuvenator-to-bitumen ratios (0, 2.5, and 10 wt%) is adopted. A generalised Kelvin contact model represents the time-dependent contacts, and its contact parameters define the rejuvenator amount in the mastic phase. The analysis assesses the impact of the modified mastic amount and the rejuvenator-to-bitumen ratio. Results show that the increasing modified mastic content progressively reduces the mixture dynamic modulus. When the total mastic phase has rejuvenator-modified properties, the mixture stiffness modulus significantly reduces, and the phase angle performs differently from the expected (decrease with frequency) at a 10% rejuvenator-to-bitumen ratio due to the excessively softened state, possibly compromising the pavement mechanical performance. For a 0.30 wt% modified mastic ratio case adopting a local effect, the embedded elements do not significantly influence the mixture rheological properties, especially the stiffness modulus, which may be insufficient for self-healing purposes. Nevertheless, the negligible impact on the phase angle highlights the potential of the rejuvenator-modified asphalt mixture across different traffic and temperature conditions.
Original languageEnglish
Title of host publicationProceedings of the VIII International Conference on Particle-Based Methods
Subtitle of host publicationPARTICLES 2023
EditorsU. Perego, M. Cremonesi, A. Franci
PublisherScipedia S.L
Number of pages12
Publication statusPublished - 2023
EventVIII International Conference on Particle-Based Methods PARTICLES 2023 - Milan, Italy
Duration: 9 Oct 202311 Oct 2023


ConferenceVIII International Conference on Particle-Based Methods PARTICLES 2023


  • Discrete Element Method
  • Rejuvenator-modified Mastic
  • Asphalt Mixtures
  • Self-healing


Dive into the research topics of 'Discrete numerical modelling of capsule-asphalt mixture system for self-healing purposes'. Together they form a unique fingerprint.

Cite this