Accelerated Corrosion of Steel Rebar in Concrete by Electromigration: Effect of Reservoir Length and Concrete Mixes

Two separate binary blended concrete mixes were prepared, one of which contains cement replacement of 50% slag (referred to as SL) and the other of which contains cement replacement of 20% fly ash (termed as FA). Concrete specimens were made using a water to cementitious ratio of 0.41. Different size reservoir lengths ranging from 2.5 cm to 17.5 cm were installed on the top surface of each specimen, and these reservoirs were ponded with 10 percent NaCl solution. Chloride transport was accelerated by electromigration, using an applied potential of 9V initially, and then reduced to 3V after around a week. Steel corrosion parameters were monitored using rebar potential measurements and galvanostatic pulse measurements, over a period of approximately 400 days. Corrosion current values obtained from experimental measurements were then converted to mass loss. Based on the results of experimental findings, the corrosion current values as well as the mass loss values were found to be significantly influenced by the length of the solution reservoirs. This study provides a guideline for subsequent research on accelerated steel corrosion in concrete.