Corrosion Occurring Inside Entirely Enclosed Structures
MARSHALL FIELDS, Orland Park, IL
Detailed and thorough investigation to determine the causes of corrosion damage to this three story concrete retail structure in a suburban Chicago shopping mall. Problems related to corrosion of slabs caused by introduction of calcium chloride in the original concrete mix design, combined with moisture trapped in the deep concrete floor beams by the type of floor covering that existed on the top of the floor systems. Included determination of the potential for similar problems to develop in other areas of this building in the future, and recommendations for repair of the areas that had already developed. Included development and implementation of test programs to assess the potential for drying out the concrete slabs to the point where the corrosion would stop. Included sophisticated rate of corrosion testing and monitoring, and determination of internal relative humidities in various areas of the concrete structure. Unique repairs were then implemented that involved systematic drying of the affected deep beam areas to stop the corrosion, followed by conventional concrete repairs. |
We have investigted a number of structures whre corrosion of reinforcing bars embedded in concrete structres that were totally enclosed from the weather, with no internal source of moisture. These buidlings were typically in the 15 to 20 year age range. Two are descrbied below.
EVANSTON HOSPITAL, Evanston, IL
Investigation to determine the causes of spalling of the top surface of the first floor concrete slabs in this four-story reinforced concrete hospital laboratory building. Problems related to corrosion of slabs caused by inclusion of calcium chloride in the original concrete mix design, combined with moisture trapped in the deep concrete floor beams by the type of floor covering that existed on the top of the floor systems. Included determination of the potential for similar problems to develop in other areas of this building in the future, and recommendations for repair of the areas that have already developed. |