Environmental Impact Assessment and Total Cost Analysis of BOF and BSSF Slag in Asphalt Concrete

Abstract

Dense grade asphalt concrete (DGAC), a popular surface material in Taiwan, allows for the design of the new recycling materials to reduce the use of natural aggregate. Basic oxygen-furnace (BOF) and Baosteel slag short-flow (BSSF) slag as steel byproduct are rarely used and generally disposed of. This study explores the environmental impact of replacing some of the coarse aggregates with steel slag in DGAC. Four levels of aggregate replacement (10, 20, 30, and 100%) were analyzed. Simulation results indicate that the replacement of coarse aggregate with BOF and BSSF slag increases the global warming potential (GWP) up to 7.13% compared to traditional DGAC during the production phase due to its specific gravity. However, using BOF and BSSF slag saves up to 36.41% of total cost included and reduces the environmental impact by decreasing the use of natural aggregate and the disposal of slag. Based on this result, replacement of a coarse natural aggregate with BOF and BSSF slag in DGAC is feasible and worthy of further research.