Heating asphalt mixtures with microwaves to promote self-healing

This paper presents the results of a research into the technical viability of heating asphalt mixtures with microwaves and how the microwaves influence the heating process of the different variables involved. Various past studies have established that elevated temperatures during rest periods of an asphalt mixture promote self-healing. In addition, recent investigations have been done regarding the heating of asphalt mixtures by means of electromagnetic induction: steel wool and graphite additives where introduced to the mixtures, improving their conductivity and thus increasing their susceptibility to electromagnetic induction.In this study, heating to promote self-healing is achieved with microwaves. The optimal steel wool content established for this study is around ten times less than that recommended for heating by electromagnetic induction, which in practice could mean an important reduction in costs. Additionally, the amount of electricity used by microwave devices is much less than that required to produce a similar effect by electromagnetic induction.

► We present the heating of asphalt mixes to promote the self-healing process.
► The novelty is the use of microwaves instead of electromagnetic induction.
► Microwaves could be advantageous when compared to the electromagnetic induction.
► Content of additives are smaller than those in the case of electromagnetic induction.
► Microwaves appear to be a promising technique to in situ heat asphalt layers.