Title:
Marine Concrete Durability--Condition Survey of Certain Tensile Crack Exposure Beams at Treat Island, Maine, USA
Author(s):
S. K. Lee, D. V. Reddy, W. H. Hartt, M. Arockiasamy, and E. F. O'Neil
Publication:
Symposium Paper
Volume:
145
Issue:
Appears on pages(s):
371-388
Keywords:
beams (supports); carbonation; corrosion; cracking (fracturing); deterioration; durability; exposure; freeze-thaw durability; surveys; marine atmospheres; reinforcing steels; Structural Research
DOI:
10.14359/4469
Date:
5/1/1994
Abstract:
A joint project of the Reinforced Concrete Research Council (RCRC) and the U.S. Army Corps of Engineers Waterways Experiment Station (WES), covering four field exposure test programs at Treat Island, Maine, was initiated in the 1950s. Two of these addressed tensile crack exposure tests for reinforced concrete to determine the effects of severe natural weathering on the performance of stressed and tensile-cracked reinforced beams. The "Series B" test program, begun in 1954, consisted of 76 reinforced concrete beams. The test variables were location of the reinforcing steel in the concrete beam at the time of casting, its deformation patterns, and the degree of tensile stress. Condition surveys were carried out annually and stopped in 1979. The physical condition and state of corrosion of the ``Series B" beams were investigated by the authors in October 1989 after a period of 10 years of unattended exposure. The overall physical condition of the beams was evaluated as severely damaged, mainly due to the repeated cycles of freezing and thawing. The damage patterns for the yoked (stressed) and control specimens were distinctively different. Six out of the thirty-two sets of yoked pairs had failed, the failure of four sets took place after 1979. Corrosion of reinforcing steel in concrete is considered to be mainly a consequence of the physical deterioration of the concrete. The overall condition of the embedded steel was evaluated as reasonably good considering 35 years of exposure in a severe marine environment.