Moisture Susceptibility, Deicing, and Self-Healing Characteristics of Sasobit-Modified Warm Mix Asphalt Containing Basic Oxygen Furnace Filler

Nowadays, regarding the scarcity and non-renewability of natural resources and environmental issues, the use of waste materials in asphalt mixtures has become very popular. Research findings show that the use of Basic Oxygen Furnace (BOF) slag in asphalt mixtures improves mechanical properties and increases economic efficiency. The main objective of this study is to investigate the feasibility of using BOF slag as a filler in Warm Mix Asphalt (WMA) in terms of moisture susceptibility, deicing and self-healing characteristics. The freeze–thaw cycles were employed to evaluate the moisture susceptibility of these mixtures. Moreover, deicing tests using microwave heating, namely ice-melting capability, ice falling time and self-healing during deicing of WMA samples, have been carried out incorporating different BOF contents (0, 35, 70, and 100 by total filler weight). In the next step, self-healing and heat transfer tests were performed using surface thermal imaging method. Based on thermal imaging results, the asphalt mixture’s heat transfer and heating rate increase with increasing BOF content. The results also show that the best self-healing level was achieved by complete filler replacement with BOF. In this regard, the self-healing level of the WMA containing 100% BOF slag improved by 22% on average after five self-healing cycles compared to the control mixture (containing limestone filler). Furthermore, the ice melting speed of WMA containing 100% BOF filler was 56% higher than that of the control mixture.