Developing State-of-the-Art Marine Concrete Repair

The marine environment can be harsh and unforgiving. Over time, chloride ions penetrate to the reinforcing steel of concrete structures exposed to these conditions. Eventually cracks and spalls begin to form throughout the structure, requiring the concrete to be repaired. Too often, those fixes last only a short time, leading to follow-on "repair of repairs". It is a challenging cycle and one that has significant impact for the U.S. Navy; the majority of their piers, wharves and dry docks are reinforced concrete structures. In an attempt to extend the service life of concrete repairs, the U.S. Navy, in collaboration with their A/E consultants, set a goal to develop concrete repairs with a design life approximately equivalent to the original design life of the structure and then plan for subsequent repair projects at approximately 15 year intervals to repair original concrete not repaired. A course of action was developed which included several investigations, studies to identify common areas of concrete failure, and further scrutiny of surface preparation and use of materials with compatible properties to the existing substrate. The result of this effort was the development of "Enhanced Guidelines for Marine Concrete Repair" a specification for concrete spall repairs.