The project goal was to better understand the extent of air-cooled blast furnace slag (ACBFS) usage for completed INDOT projects, factors that can influence slag leaching, review remediation strategies, and identify applications where future usage restrictions or sitting criteria are needed. A literature review of government documents, peer-review, and trade industry literature was conducted. The project team also conducted a site visit to an ACBFS storage facility and steel mill that generated the ACBFS and reviewed handling and testing procedures. The project team also contacted other state transportation agencies (IL, MD, MI, NY, OH) to determine the degree they incorporated ACBFS into their projects and if product performance tests were required. Results show that changes to Indiana test methods and acceptance criteria are warranted. Indiana Test Method 212 should be revised to extend the test duration, pH acceptance criterion, and add additional material acceptance criteria. Unbound ACBFS should be avoided for construction applications (1) where ground water could contact the material, (2) near environmentally sensitive and populated areas, (3) where a drainage system is not present. Additional work to improve the ability of INDOT to detect ACBFS that would cause short- or long-term chemical leaching problems could include (1) evaluating and optimizing stockpile sampling practices for representative sampling, (2) modifying ITM 212 to better predict worst-case leaching conditions and leachate quality, (3) conduct a head-to-head comparison of bench-scale and field-scale leaching results.

Report Number



ACBFS, air-cooled blast furnace slag, beneficial use, waste

SPR Number


Performing Organization

Joint Transportation Research Program

Publisher Place

West Lafayette, Indiana

Date of this Version