Acid Attack of Concrete caused by Sulfur Bacteria Action, Piedmont and Clendening Lakes Outlet Tunnels, Muskingum Watershed, Ohio.
Abstract
This investigation was conducted to determine the cause of extensive deterioration of concrete above the flow line in the outlet tunnels of two lakes, and to provide guidance in the development of remedial repair schemes if necessary. The cement paste was being reduced to a 'mush' consistency to depths up to 1-1/4 in. Anaerobic bacterial action was indicated by preliminary tests. Physical tests showed the original concrete to be of good quality and that some form of acid attack was in progress. Chemical tests revealed that the water contained high concentrations of sulfates and sulfides. Bacteriological tests confirmed that sulfate-reducing bacteria were present. Data furnished by Huntington District reveal that thermal stratification occurs during the summer causing almost complete depletion of dissolved oxygen at depths greater than 20 ft in both lakes providing an environment where sulfate-reducing bacteria are able to reduce the sulfates present in the water, producing hydrogen sulfide as a waste product. Conditions in the outlet tunnels meet the criteria for the deposition and proliferation of sulfur-oxidizing bacteria which produce sulfuric acid from the hydrogen sulfide. It is concluded that the deterioration is due to acid attack and is the final stage of a corrosive process caused by sulfur bacteria action. Attack by acid water is not indicated, since all the deterioration occurs above the line of normal flow.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1977
- Accession Number
- ADA044840
Entities
People
- Henry T. Thornton Jr.