Environmental and Economic Assessment of Engineered Water Repellency for Frost Mitigation in Low-Volume Flexible Pavements in Minnesota

Engineered water repellency (EWR) using organosilanes provides a promising approach for mitigating frost heave by preventing ice lens formation. This study evaluates the environmental and economic impacts of typical flexible pavement structures used in Minnesota, as well as three EWR-treated variants. Primary data for the life cycle assessment (LCA) were collected from the Minnesota Department of Transportation (MnDOT) and Minnesota Road Research Facility and analyzed with the Federal Highway Administration LCA PAVE tool. The life cycle cost analysis (LCCA) was performed with the MnDOT tool to calculate the net present value per the ISO 15686-5 standard. The MnDOT soil replacement method (SRM) with EWR emerged as the most sustainable and cost-effective, showing a 23% reduction in global warming potential compared with the traditional SRM. The primary sources of emissions and expenses were hot mix asphalt activities, accounting for 58%–71% of the total. The LCA contributed less than 8% to the overall integrated cost, underscoring the predominance of LCCA in decision-making. Further field evaluations are recommended to confirm the long-term performance of EWR technologies and to optimize their integration into pavement design.