Case Study: Condition Assessment of a 36-Year-Old Mechanically Stabilized Earth Wall in Virginia

AbstractIn 2012, a mechanically stabilized earth (MSE) wall was demolished in Virginia due to road realignment activities, providing an opportunity to assess the condition of the steel-bar mat reinforcement after 36 years in service. Steel and backfill samples were collected from various locations throughout the wall. The remaining zinc thickness from the galvanized steel was measured utilizing three different techniques; the electrochemical properties of the backfill were also measured. It was found that corrosion was highest at the joint between the pavement and moment slab and in locations downstream of a drainage pipe through the wall. By industry design standards, the electrochemical properties of the backfill, specifically the chlorides and resistivity, indicate the backfill collected is aggressive; however, the wall was in good condition, with an estimated service life of 150 years based on the measured corrosion. This article provides an overview of this case study, the testing performed, and the results; it also examines methods to estimate initial thickness of the zinc coating for insights on the performance of galvanized steel used in earthwork applications.