Performance of Plant-Produced Asphalt Containing Cellular Capsules

Materials (Basel). 2022 Nov 25;15(23):8404. doi: 10.3390/ma15238404.

Abstract

This paper aims to assess the influence of encapsulated rejuvenators on plant-produced asphalt's performance. The polymeric capsules are evaluated as cellular materials that deform and absorb energy while they experience a progressive collapse of their porous structure, rather than a simply means to release the rejuvenator. Additionally, variables during asphalt manufacturing that may affect their plastic deformation under loading are assessed too. Firstly, plant-produced asphalt's mechanical and morphological properties were evaluated, including the capsules' distribution and integrity after mixing. Then, results were contrasted with lab-produced asphalt under controlled conditions. Lastly, the capsules' deformation was qualitatively evaluated using a FE model to verify findings from the testing campaign. It was concluded that (i) cellular capsules can resist mixing at an asphalt plant without compromising their performance; (ii) the deformation of the capsules affected asphalt's stability by up to 13%, reduced the particle loss by up to 25% and increased asphalt's macrotexture by 10%; (iii) to maximize their energy absorption, the cellular capsules must be part of the aggregate skeleton.

Keywords: cellular materials; encapsulated rejuvenators; energy-absorption; macrotexture; polymeric capsules; ravelling; rutting; stone mastic asphalt.

Grants and funding

This project was funded by Connect Plus M25 Ltd.