A probabilistic source assessment framework for leaching from secondary materials in highway applications

Recovered materials from the transportation sector or secondary or by-product materials from the industrial, municipal, or mining sector can be used as substitutes for natural materials in the construction of highway infrastructure. The environmental impact of traditional and newer secondary materials needs to be determined for the conditions of their expected use. The purpose of this paper is to introduce a probabilistic framework for evaluating the environmental acceptability of candidate secondary materials based on the risk of soil and groundwater contamination from leached metals and organics from the pavement. The proposed framework provides a structured guidance for selecting the appropriate model, incorporating uncertainty, variability, and expert opinion, and interpreting results for decision making. This new approach is illustrated by a probabilistic analysis of arsenic leaching from Portland cement concrete and asphalt concrete materials that were constructed using virgin and secondary products.