Trade Journals for the Concrete Industry

In 1999 the city of Grand Rapids, Michigan, under the direction of Chuck Schroeder, city engineer, embarked on a study to determine the optimal method for preventing concrete corrosion in sanitary manholes due to hydrogen sulfide gas. Turbulence, moderately-high temperatures, and septic sewage create conditions that are ideal for sulfuric acid (H2SO4) production. Sulfuric acid is formed when aerobic (air-breathing) bacteria on the walls of the manholes metabolize hydrogen sulfide gas and oxygen. Their waste by-product is sulfuric acid, which results in the rapid decay of concrete. The technical name of this process is microbiologically induced corrosion (MIC).