Relating Corrosion of Mechanically Stabilized Earth Reinforcements with Fluid Conductivity of Backfill Soils

The service life of mechanically stabilized earth (MSE) walls depends on the rate of corrosion of the metallic reinforcements used in their construction. A methodology was designed to monitor and estimate the corrosion rate of galvanized steel in MSE walls with a conductivity sensor coupled with laboratory electrochemical techniques. The fluid conductivity of six coarse-grained backfill soils undergoing either wet-dry cycles or under submerged conditions were measured regularly for up to 120 weeks. The corrosion rates of the galvanized steel were determined indirectly by measuring the conductivities of the leachates from the six backfills. The conductivity of the leach-liquor appears promising to monitor the corrosion rate even though the predicted corroded thickness was less than the actual corroded thickness measured with a scanning electron microscope