Evaluation of the Freeze and Thaw Durability of Road Soils Stabilized with a Biofuel Co-Product

In the past decade, the biofuel industry has seen significant development in the United States and all over the world. Based on a review of recent bioenergy literature, it appears the by-products derived during biofuel production may play a positive role in value-added engineering applications. Recent studies at Iowa State University (ISU) demonstrated the successful utilization of biofuel co-products (BCPs) in pavement subgrade stabilization. This paper discusses the effect of three types of BCPs containing different lignin content from lignocellulosic biorefineries on a typical Iowa soil called loess in terms of freeze and thaw durability. Emphasis is given to detailed data analysis of laboratory test results in comparing three types of BCPs treated soils with untreated and cement treated soils. Results reveal that the BCPs investigated in this study are promising materials to improve freeze and thaw durability of the Iowa loess classified as CL-ML or A-4 for geotechnical applications.