This report summarizes the current state of practice for nine alternative backfills. Alternative backfill materials are increasingly used in applications such as retaining walls, bridge abutments, pipes/culverts, embankments, ground improvements, and slopes. The advantages and disadvantages, material characterization, design requirements, design guidelines, placement and construction specifications, cost information, environmental considerations, lifecycle assessment, and case studies/performance records are presented for each material.

The report presents the maturity level of each technology, barriers to the advancement and widespread use of each material, and recommendations for moving forward. The information presented in this report could interest practitioners, designers, and researchers working in roadway geotechnical applications.

Recommended citation: Federal Highway Administration, Alternative Backfills for Highway Applications: State of the Practice (Washington, DC: 2024) https://doi.org/10.21949/1521442