Mining materials to generate magnetically-triggered induction healing of bitumen on smart road pavements

Around the globe, maintenance costs to repair asphalt roads during their service life often exceed the available budget of road authorities and municipalities. In this research, a novel approach is presented to generate engineered healing capabilities in iron ore particles (magnetite)-bitumen composites through induction heating. This approach is expected to contribute in decreasing the amount of maintenance needs on road pavements. A comprehensive experimental campaign was conducted to evaluate the possible use of mining material as healing promoter for road pavement systems, reducing maintenance needs during the road service life hence saving agency and user costs. Two different types of magnetite were mixed with bitumen according to three different filler/bitumen ratios. Rheology of bitumen was firstly evaluated to characterise its viscoelastic response at different temperature, then induction heating principles were applied to generate an alternative magnetic field to rapidly heat bitumen-magnetite samples, melt the surrounding bitumen and heal the crack. Experimental measurements also included optical, calorimetric and chemical evaluation of the samples. Results showed that the temperature of the composite samples increased under the alternative magnetic field, reaching high temperature values in a very small amount of time. The heating rate (up to 50 degrees C/s) depended on the intensity of the electric current in the induction heating machine and on filler/bitumen ratio, among others. (C) 2018 Elsevier Ltd. All rights reserved.