DEGRADATION KINETICS OF PULTRUDED E-GLASS/VINYLESTER IN ALKALINE MEDIA

The use of fiber-reinforced polymer (FRP) composites, in the form of externally bonded reinforcement for rehabilitation or in the form of externally bonded reinforcement for rehabilitation of in the form of reinforcing bars and tendons for new reinforcement, provides a potential means of slowing or even preventing, the deterioration seen in conventional materials such as steel and concrete. However, there is a concern regarding the long-term durability of E-glass reinforced FRP with concrete. This article presents the results from a 75-week investigation aimed at characterization of deterioration mechanisms and performance of E-glass/vinylester in an alkaline environment. The study used dynamic mechanical thermal analysis, Fourier-transform infrared spectroscopy, gravimetric moisture uptake, tensile and short-beam-shear tests, and microscopy. Results show a range of deterioration mechanisms initiating with reversible plasticization of the resin and transitioning to irreversible fiber-matrix debonding, hydrolysis, and chain scission of the resin, and pitting and material loss of the fiber. Reconditioning, following periods of immersion, results in some regain in tensile strength over at least half the exposure period, whereas after 15 weeks there is almost no regain in interlaminar shear strength. The authors predict that long-term response will match fairly closely with experimental results at the 75-week level. Under self-similar continuation of deterioration, 26.89% of the original tensile strength and 58.24% of the short-beam-shear strength can be expected to be retained after 50 years. The authors conclude with a brief discussion of real-life conditions versus the testing conditions.

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  • English

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  • Accession Number: 00986586
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 28 2005 12:00AM