1374420 - Effect on Mixture Composition on Performance, Cost, and Emission of Micro-Surfacing Containing RAP and Electric Arc Furnace Steel Slag

For the road infrastructure, prolonging the life of pavement structure to prevent rehabilitation/ reconstruction can be achieved with adequate cold-emulsion-based preservation treatment that can minimize the carbon footprint. In addition, the circular economy is a vital part of decarbonization efforts. Many industrial waste/ by-products such as waste glass, steel slag, waste ceramic, fly ash, crumb rubber powder, and recycled asphalt pavement (RAP) has been used in the micro-surfacing mixture to diversify waste and possibly reduce cost. However, incorporating recycling materials may change the mixture's performance. The sustainable engineering decision requires considering the economic, environmental, and engineering performance together. The objective of this study is to address this issue by quantifying the engineering performance, cost, and carbon footprint of the micro-surfacing incorporated with reclaimed asphalt pavement (RAP) and electric arc furnace slag (EAFS). Mixtures of EAFS and RAP with varying proportions were designed, and evaluate their engineering performance (short/long term abrasion and vertical/ lateral deformation), carbon footprint, and cost. Analytical hierarchy process (AHP) analysis was incorporated to determine the optimal sustainable micro-surfacing mixtures.
RAP incorporated micro-surfacing mix showed superior performance in short-term abrasion resistance but inferior performance in vertical and lateral deformation resistance compared to the control mixture. EAFS incorporated micro-surfacing mix showed superior performance in long-term abrasion resistance, vertical and lateral deformation resistance but inferior performance in short-term abrasion resistance compared to the control mixture. In terms of carbon footprint and cost analysis, the mixture containing EAFS results in better emission and cost reduction.
The AHP analysis results indicated that the optimal sustainable micro-surfacing mixture is 100% EAFS mixture which balanced the cost, carbon footprint, short-and long-term abrasion resistance, as well as vertical and lateral deformation resistance.