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Prevents Corrosion Before it Begins!
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Grand Rapids, Michigan
“The proof is in the pudding,” but in this case it was in the concrete. Even sewer systems in the upper Midwest experience corrosion in sanitary sewer systems and Grand Rapids, Michigan is no exception. The City wanted to determine what could be done to protect concrete pipe and manholes in its sewer system from corrosion generated by hydrogen sulfide gas.
With the cooperation of Premarc Industries, a local precaster, the City had a test manhole installed in August 1999 on a highly corrosive sanitary sewer line to evaluate different products by direct comparison.
Complete Case Study (pdf) |
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Hampton, Virginia
In 2000, the manholes near City Hall in Hampton, Virginia, were identified as being severely deteriorated from high levels of hydrogen sulfide gas which fed bacteria to form Microbiologically Induced Corrosion. When unprotected concrete is exposed to Hydrogen Sulfide Gas, bacteria can quickly grow creating sulfuric acid which allows structural damage in just a few short years. This was the case in the City of Hampton.
Complete Case Study (pdf) |
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Miami-Dade, Florida
Miami-Dade, Florida, has an area where levels of Hydrogen Sulfide Gas are extremely high. When unprotected concrete is exposed to hydrogen sulfide gas, Thiobacillus bacteria can create sulfuric acid that causes severe levels of structural damage from corrosion in a very short time.
One of their manholes on Key Biscayne had to be replaced every three years because of the Microbiologically Induced Corrosion (MIC) generated by turbulence and high levels of hydrogen sulfide gas.
Complete Case Study (pdf) |
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Maline Structure, St. Louis, MO
The Maline Drop Shaft located near the Chain of Rocks Bridge is just like concrete sewer structures everywhere. They corrode when hydrogen sulfide gas is present. Moderately-high temperatures, long retention times, high biological oxygen demand (BOD) levels, and turbulence contribute to elevated levels of hydrogen sulfide gas which, in turn, provide the food for acid-producing bacteria.
The technical name for this process is Microbiologically Induced Corrosion (MIC). This 40-year oldconcrete structure was severely deteriorated from MIC. The upper portion of the walls were mushy with more than two inches of the original wall missing; in the lower half of this 50-feet-deep structure, more than five inches of the walls had corroded away.
Complete Case Study (pdf) |
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