Advanced Self-Healing Asphalt Composites in the Pavement Performance Field: Mechanisms at the Nano Level and New Repairing Methodologies

Abstract

Abstract:In an effort to give a global view of this field of research, in this mini-review we highlight the most recent publications and patents focusing on modified asphalt pavements that contain certain reinforcing nanoparticles which impart desirable thermal, electrical and mechanical properties. In response to the increasing cost of asphalt binder and road maintenance, there is a need to look for alternative technologies and new asphalt composites, able to self-repair, for preserving and renewing the existing pavements. First, we will focus on the self-healing property of asphalt, the evidences that support that healing takes place immediately after the contact between the faces of a crack, and how the amount of healing can be measured in both the laboratory and the field. Next we review the hypothetical mechanisms of healing to understand the material behaviour and establish models to quantify the damage-healing process. Thereafter, we outline different technologies, nanotechnologies and methodologies used for self-healing paying particular attention to embedded micro-capsules, new nano-materials like carbon nanotubes and nano-fibres, ionomers, and microwave and induction heating processes.

Review and analysis of advances in functionalized, smart, and multifunctional asphalt mixtures

“…The difference is that the former results from the rearrangement of the molecules, and the consequence is the wetting and inter-diffusion between the crack faces. The following stages explain the self-healing mechanism: i) both faces of a nano-crack are wetted, ii) immediate strength gain by interfacial cohesion between the crack faces, and iii) long-term strength gain owing to the diffusion and randomization of molecules from one face to the other [88].…”

“…Consequently, microwaves have been used to heat the asphalt mixtures; although they are fast and easy to apply, the high cost and difficulty in controlling heat deepness penetration are the major drawbacks of this technique [88]. In addition, MH increases the temperature of the asphalt binder but not that of the aggregates.…”

Self-healing of asphalt mixes, containing conductive modified bitumen, using microwave heating

“…[3,4] In recent years there has been great interest in developing systems that accelerate and improve the intrinsic self-healing ability of the bitumen in order to increase the durability of roads and controlled asphalt heating is one of the most used approaches. [5] The use of this property allows us to heat only the binder, so that we could tune its temperature, saving energy and preventing accelerated aging.…”

Exploring the Possibility of Using Ionic Copolymer Poly (Ethylene-co-Methacrylic) Acid as Modifier and Self-Healing Agent in Asphalt Binder and Mixture

“…Asphalt binder has been used for many years in paving and roofing constructions because of its great viscoelastic properties [1]. However, with the influence of traffic loading and environmental conditions, the relaxation capability and flexibility of asphalt mixtures gradually decline resulting in more ageing and lower cracking resistance, and this phenomenon is more obvious for virgin asphalt or reclaimed asphalt.…”