Durability And Behavior Of Prestressed Concrete Beams Report 3 Laboratory Tests Of Weathered Pretensioned Beams

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ISBN 13 :
Total Pages : 43 pages
Book Rating : 4.:/5 (227 download)

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Download or read book Durability and Behavior of Prestressed Concrete Beams. Report 3. Laboratory Tests of Weathered Pretensioned Beams written by and published by . This book was released on 1971 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work describes laboratory tests which were conducted on four prestressed concrete beams which had been exposed to tidal weathering for a considerable period of time. Two of the beams had been exposed in an unloaded condition at the Treat Island, Maine, severe weathering exposure station and the other two had been exposed for 9 years in a flexurally loaded condition at the St. Augustine, Florida, mild weathering exposure station. The laboratory tests conducted on these beams consisted of the examination and tensile testing of the steel prestressing strands after removal from the beams and tests for depth of carbonation and chloride penetration in the test beams. The steel prestressing strands were found to be corroded externally for 20 to 100 percent of their length. Internal strand corrosion was generally more extensive than the external corrosion; the corrosion seemed to progress along the center wire of each strand. Only 8 of the 25 strand sections tested met the tensile strength and elongation requirements of ASTM Designation: A 416-68. Corrosion on the steel strands at the ends of all beams showed that the epoxy pads used as end protection were not effective in protecting the ends of the strands. Depth of carbonation tests indicated that carbonation was not a factor in the corrosion of the steel strands. Depth of chloride penetration tests revealed that sufficient chlorides were present in the test beams to cause corrosion on the prestressing strands. The steel strands taken from the St. Augustine beams were in poorer condition than those from the Treat Island beams.