Update on Condition of Reinforced Earthwall Straps

摘要

Mechanically stabilized earth (MSE) walls are in widespread use but durability is a concern. Corrosion of reinforcement in walls using metallic components is a potentially important limitation as strips are often then (e.g. only 4 mm). A 1994-8 FDOT investigation of 10 MSE structures determined that corrosion rates were low as expected for soils meeting specifications. At that time the walls were instruments for future corrosion measurements and non-destructive monitoring. The walls had accumulated another decade of service by the start of the present survey, conducted to provide an indication of corrosion-related aging and improve long term performance projections. Surface appearance of coupons extracted from actual reinforcement elements in five of the walls showed little evidence of distress. Metallographic examination showed only moderate wastage of the galvanized layer, corresponding to low corrosion rates. A statistical model that takes into account the estimated galvanized steel and plain steel corrosion rates and their variability was applied to project the evolution of corrosion damage in a generic Florida MSE wall, using data developed in the present and previous surveys.