The Induced Heating–Healing of Inductive Warm-Mix Asphalt Mixture Containing Copper-Slag Filler | Journal of Materials in Civil Engineering | Vol 35, No 4

AbstractDue to environmental pollution and the shortage of nonrenewable natural resources in road construction, the use of copper slag as a new material in asphalt pavement has been recently evaluated for its ability to reduce the accumulation of waste and lower the cost of asphalt mixture production. The main purpose of this study was to assess the feasibility of using copper-slag filler as a substitute for lime in warm-mix asphalt (WMA) to enhance its self-healing and thermal/electrical conductivity potential. To this end, an X-ray fluorescence (XRF) test was first conducted to analyze the copper-slag filler constituent elements that affect its microwave heating. Then, the self-healing potential of asphalt samples containing copper-slag filler under microwave heating was investigated using thermal imaging, and an index was presented to analyze the fracture energy and load-bearing capacity at each stage of the fracture-healing test. Moreover, an image processing technique was used to determine its capability for uniform heat transfer. Finally, some tests were performed to study the asphalt mixture heat-transfer potential and determine its thermal/electrical conductivity. The results show that the mixtures containing copper slag had high thermal/electrical conductivity. Thermal conductivity, microwave heating uniformity, and self-healing potential (asphalt resistance against reloading) of asphalt mixtures increased with an increase in the copper-slag filler content. With 40, 50, and 60 s of microwave heating, the samples containing copper slag had an average of 14%, 31%, and 37% better recovery, respectively, than the asphalt samples containing 100% of lime filler.

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