Construction use of vitrified chromium-contaminated soils

This paper describes the test results of a demonstration study on the use of vitrified soils as highway construction aggregates. It is based on a bench- and pilot-scale feasibility study of the remediation of chromium-contaminated soil through cold top ex situ vitrification, making glass from wastes. Based on bench-scale tests, approximately six tons of chromium-contaminated soil from two different sites were vitrified. To determine the suitability as construction aggregate, vitrified soils were subjected to several tests. The bench- and pilot-scale test results were compared with New Jersey Department of Transportation (NJDOT) and ASTM specifications for construction aggregates. The results showed that the vitrified soils could be accepted as an aggregate material. Then the vitrified chromium-contaminated soils were used as aggregate in hot mix asphalt (HMA). Mix designs were performed to determine the maximum amount of vitrified chromium-contaminated soils that can be added to make satisfactory hot mix asphalt concrete mixes. The test showed that it is possible to include up to 58.8% of vitrified chromium-contaminated soils from both sites in HMA mixes. In order to evaluate the performance of HMA made with vitrified chromium-contaminated soils, the Marshall test, the durability test, and the hydraulic conductivity test were performed. The hot mix asphalt concrete mixes made with vitrified soil performed very well, suggesting the suitability of using vitrified chromium-contaminated soils in construction.