Abstract
Mechanically stabilized earth (MSE) walls contain galvanized steel reinforcements that stabilize the fill by means of friction. After some time, the backfill may escape the wall or compact due to water ingress, forming voids that can compromise structural integrity. These voids may be repaired by filling with a cementitious mix known as Controlled Low-Strength Material (CLSM). This practice may have an adverse consequence, as the reinforcement embedded in CLSM passivates due to the high pH of the pore water, while the portion embedded in regular soil may remain active, forming a macrocell that can aggravate corrosion on the soil. To quantify the extent of this effect, small and large scale experiments were carried out to asses by means of electrochemical parameters the extent of the problem. Results of small scale experiments indicate that corrosion of the reinforcement in the backfill side is enhanced up to three times when embedded in CLSM as well, thus reducing durability of the galvanized coating. Large scale experiments confirm this finding, while at the same time indicating that adverse leaching out of the pore water could compromise the reinforcement underneath the patch. Finite element electrochemical modeling of the system supports the findings.
