EFFECTS OF FREEZE-THAW EXPOSURE ON PERFORMANCE OF CONCRETE COLUMNS STRENGTHENED WITH ADVANCED COMPOSITES

All research results to date have indicated that the use of fiber reinforced polymers (FRPs) in repair and retrofitting provide deteriorated infrastructure with new life and longevity. This paper presents the results of an experimental study on the performance of concrete columns wrapped with carbon and glass FRP composite sheets subjected to freeze-thaw conditions. The wrapped concrete specimens were conditioned in two different environments: room temperature (23 deg C) and 300 freeze-thaw cycles. The stress-strain behavior in compression of the freeze-thaw exposed specimens was obtained to evaluate their strength, stiffness, and ductility, which were then compared with the performance of unconditioned samples (room temperature). Two sets of tests were conducted using the exposed specimens. In the first set, in which the entire length of the samples was subjected to compression, failure occurred at the top and bottom. It was hypothesized that failure was due to the deterioration of concrete that was exposed rather than failure of the wrapping system. Therefore, the top and bottom parts (75 mm each) were sawed off and the tests were repeated using the shorter specimens. The shorter specimens retained 95% of the strength for the carbon composite wraps and approximately 88% of the strength of the glass composite wraps. Strength values of the wrapped systems before and after exposure were predicted using two different damage factors: one for glass fiber and one for carbon fiber. The predicted strength values compared satisfactorily with the experimental values.

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  • English

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Filing Info

  • Accession Number: 00781635
  • Record Type: Publication
  • Contract Numbers: D CA-96K-0049
  • Files: TRIS
  • Created Date: Jan 7 2000 12:00AM