Bridges are critical components of transportation infrastructure. This research addresses the need to extend the service life of bridges by improving the safety and reliability of bridge abutments and reducing their life-cycle cost and footprints. Mechanically stabilized earth (MSE) is a known strategy to enhance the economy and performance of bridge abutments. In addition, the application of rotary-kiln-manufactured lightweight aggregate backfills improves the performance of MSE bridge abutments with a leaner structural system. Such improvements include a reduction of structural demands due to a lower density, free drainage of granular materials, a high internal friction angle, less settlement with no consolidation, and accelerated construction requiring less compaction effort. This project aims to assess the electrochemical properties of expanded shale, clay, and slate (ESCS) aggregates and their influence on the corrosion of embedded steel strips. The experimental methodology involves evaluating current testing methods to measure electrical resistivity, pH, sulfate, chloride, and corrosion considering various gradation, moisture, dilution, and curing conditions. Samples represent available sources of ESCS with one source of normal weight aggregates for comparison. Results indicate the appropriateness of ESCS for addressing corrosion in MSE backfills. Further, outcomes provide guidelines to categorically predict the corrosivity of steel reinforcement when ESCS is employed as fill within MSE systems. These guidelines can help optimize the design and reduce the need to maintain and rehabilitate bridges, abutments, and approach and departure slabs on roadways to keep transportation systems safe and cost-efficient for sustainable infrastructure.

Publication Date


Publication Type



Transportation Engineering

Digital Object Identifier


MTI Project



Corrosion, Lightweight aggregate, Mechanically stabilized earth, Bridge abutments, Electrical resistivity, pH, Sulfates, Chloride, Backfills


Transportation | Transportation Engineering