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|Title:||Durability of concrete exposed to natural weathering : concrete research : third interim report|
|Authors:||United States. Mississippi River Commission.|
U.S. Army Engineer Waterways Experiment Station.
|Publisher:||U.S. Army Engineer Waterways Experiment Station.|
Engineer Research and Development Center (U.S.)
Synopsis: The resistance of concrete to severe natural weathering has been studied since 1936 at an experimental exposure installation at Treat Island, Cobscook Bay, Maine. Since 1940 concrete specimens have been exposed to mild natural weathering and to warm sea-water at a second experimental: exposure installation at Salt Run, St. A-Augustine, Florida. Additional specimens have been exposed to natural weathering in two locations in New York State and, in certain cases, companion specimens have been stored indoors. In connection with 18 different programs of investigation, more than two thousand specimens have been exposed and studied. In every case, the purpose for which specimens were exposed was to evaluate the effects of certain variable characteristics of manufacture of the concrete on its resistance to natural weathering. Such characteristics are: type, source, and minor-alkali content of the Portland cement; type and source of the aggregates: air-entraining and other types of admixtures; liquid membrane curing compounds; types and methods of forming: and methods of preparing horizontal construction joints. Whenever it has been found possible to do so, changes in the condition of the concrete during exposure have been evaluated in terms of changes in the dynamic modulus of elasticity of the specimen. This report has been prepared to present in a single volume a brief but up-to-date summary of the data developed in these programs on the resistance of the concrete specimens to natural weathering, and to present in more detail such data as have not previously been made generally available. Much of the data derived from the exposure of these specimens has been given in previously published technical reports issued by the Central Concrete Laboratory, North Atlantic Division*, CE. Such reports are cited by references in Part III of this report and are listed in Appendix A. In a number of cases, groups of specimens have been continued in the exposure subsequent to the issuance of the report of the investigation. In other cases, the results of the exposure have been given in reports of very limited distribution. It is proposed that as additional data become available further interim reports will be issued. A brief summarization of the results obtained is contained in Part IV of this report.
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|WES-Technical-Memorandum-No.6-226-Report-3.pdf||3.83 MB||Adobe PDF|