Environmental performance and functional analysis of chip seals with recycled basic oxygen furnace slag as aggregate.

Resource utilization of industrial waste is a significant global challenge. Steel slag, a typical industrial by-product in the steel-making process, pollutes the environment and causes ecological deterioration. In this study, steel slag was recycled in chip seals as the aggregate, and the functional and environmental performance of the chip seal with recycled steel slag was determined. Economic costs were also discussed and compared with conventional surface layers. The results indicated that recycling steel slag as the aggregate in chip seal has a lower pollution risk and higher environmental benefits compared with those used for landfilling and dumping. Steel slag can significantly increase the heating and de-icing efficiencies of chip seal compared with basalt, particularly for microwave heating. The self-bonded function represented by the durability of aggregate retention can be enhanced by steel slag. The cost of the chip seal containing steel slag and steel fiber is only increased by 0.14 USD/m2 than that of ordinary chip seal, indicating a remarkable economic efficiency of chip seal with de-icing and self-bonded functions.