Induction heating of asphalt mixtures with waste steel shavings

Abstract

Waste steel improves the induction heating efficiency of asphalt mixtures. However, the heating performance of the asphalt mixture with waste steel suffers from overheating and non-uniform temperature distribution. To prevent these issues, the induction heating performance was evaluated in this research. Under different electro-magnetic induction operational conditions, such as power (P) and frequency (f), induction heating tests were conducted in asphalt mixtures with different waste steel shavings content (WSS content). The induction heating efficiency (IHE) was defined by the achieved induction heating rate (IHR), and induction heating uniformity (IHU), which was determined by the temperature square deviation. IHE and IHU were proposed as the criteria to evaluate the heating performance. In this way, the influences of the WSS content, P and f on the IHE and IHU were analyzed, and the results showed that high IHE and IHU cannot be achieved simultaneously. Thus, a comprehensive evaluation method was proposed, which can mitigate overheating and non-uniform temperature distribution problems. Finally, to obtain the greater heating performance, the less energy consumption, and the more efficient utilization of waste steel, it is recommended to use as optimum scheme 3 kW frequency, 55 kHz power and 10% wt of WWS content.