Particle loss mitigation in asphalt by the addition of polyethylene foam

This paper evaluates the feasibility of using a cellular foam as a substitute for capsules containing rejuvenators to mitigate the ravelling of Stone Mastic Asphalt and enhance its durability. While encapsulated rejuvenators have been shown to effectively release the rejuvenator and partially restore asphalt viscosity, recent research has found that the capsules exhibited a porous structure that has a non-negligible effect on the arrangement of the aggregate skeleton in SMA mixtures, which might impact the asphalt performance in mitigating ravelling by absorbing the energy from the external loads. To address this, a Polyethylene Terephthalate (PET) foam with three different densities is used in this study to assess the effect of an energy-absorbing cellular structure on asphalt performance and ravelling mitigation. Mechanical tests have been conducted on SMA mixtures containing 1 % and 5 % of the total volume of the mixture to determine the resistance to rutting, fatigue and particle loss. Results indicate that foam density influences particle loss and rutting resistance, with higher foam content enhancing fatigue life. Moreover, all foam types exhibit improved surface ravelling resistance, suggesting that integrating porous particles with inherent energy absorption capabilities could enhance SMA mixture durability.