Acid Attack - Remedial Measures

Redemption of concrete structures suffering from acid attack may be costly and time consuming. Of particular importance is the redemption of buried sewage transmission structures. Acid attack, due to it’s extremely aggressive nature, may render these buried structures in an unusable state in less than 5-10 years. In this case, the most common method of redemption is the intrusion of a polyethylene or polyvinyl liner inside the existing pipe. This method is costly but much more economical, especially in large metropolitan areas, than pipe replacement. Other methods include the removal of damaged concrete , the application of shotcrete and the roll on application of a protective plastic sheet. Measures for reducing further damage may include freshwater flushing, ventilation, and aeration of sewage.

Shotcrete and commercial concrete patching materials can also be used in the repair of concrete spillway, sluice, and siphon structures in dams. Standard sealant or epoxy coatings are a cost effective means to repair damaged concrete. Raising siphon intake levels may reduce the amount of H₂S exposure. Reducing the H₂S rich bottom environment through systematic reservoir draw downs will also help prevent further damage. Aeration, chemical treatment and dredging are also options but are often more costly and less effective.