Assessing Corrosivity of Galvanized Soil Reinforcements from Electrochemical Tests
The accurate estimation of the service lives of mechanically stabilized earth (MSE) walls requires a proper evaluation of the corrosion potential through electrochemical test methods. Robust field tests are required to assess the corrosivity of galvanized metal used in MSE walls. To simulate an environment similar to an MSE wall, cylindrical soil specimens about 12 in. (300 mm) in diameter and 10 in. (250 mm) in height were constructed. For every specimen, two instruments were used. The first instrument measured the polarization resistance corrosion tests carried out on galvanized strips and meshes, as well as epoxy-coated rebars. The second instrument measured the soil resistivity of the specimen. Tests were conducted at moist and wet (submerged) states on materials that exhibited high, medium, and low resistivity values. A coarse and a fine aggregate gradation were considered to study the impact of the grain size distribution on the corrosivity. Five analytical models were prepared to estimate the rate of corrosion using the corrosion tests. Cumulative corrosion was measured on sacrificial coupons using SEM and an electronic thickness gauge. Test results confirmed that materials with high resistivity exhibit low corrosion rate. Fine-grained backfill displayed higher corrosion rates due to their high fines content.
Cabrera, Diana Alejandra, "Assessing Corrosivity of Galvanized Soil Reinforcements from Electrochemical Tests" (2018). ETD Collection for University of Texas, El Paso. AAI10929706.