Work

Development and optimization of sustainable asphalt self-healing systems for SMA mix

Year: 2025

Type: article

Abstract: Premature failure of asphalt pavements caused by climate change, high temperatures, increased rain fall and freezing temperatures, as well as increased traffic loading present a big challenge for road engineers. Microcracking is a prevalent asphalt pavement damage mechanism, which leads to premature pavement failure, such as: formation of larger cracks, ravelling and potholes. The concept of self-healing asphalt has been developed to implement an extrinsic crack repair system, reduce maintenance efforts, and extend the service life of asphalt pavements. This paper presents a laboratory evaluation of the four extrinsic self-healing asphalt systems in SMA mix, including: alginate capsule system, conductive alginate capsule system, induction system (with steel fibres) and hybrid system (alginate capsule & induction). The SMA mix designs were adjusted by incorporating healing systems within the mix design. In total four SMA mix designs containing different extrinsic self-healing technology were created and two mixtures without self-healing system were used as control mixtures. Indirect Tensile Test (ITT), Water Sensitivity test (WS), Binder Drainage test (BD) and Triaxial test were employed to investigate the physical performance of the asphalt mix. A Semi-circular bending (SCB) and healing programme was adopted to evaluate the healing efficiency of the asphalt mix with various healing systems. The results show that incorporation of self-healing additives can affect the physical performance of asphalt mixture, therefore requires a comprehensive evaluation before being applied into construction site. The study results showed that induction healing system and hybris healing system are most efficient healing systems for the SMA mix.

Source: Construction and Building Materials

DOI: 10.1016/j.conbuildmat.2025.143054