Title: Fatigue Tests of Reinforced Concrete Beams Strengthened Using Carbon Fiber-Reinforced Polymer Composites

Author(s): Sergio F. Brena, Michael A. Benouaich, Michael E. Kreger, and Sharon L. Wood

Publication: Structural Journal

Volume: 102

Issue: 2

Appears on pages(s): 305-313

Keywords: fatigue; fiber-reinforced; flexural strength; reinforced concrete

DOI: 10.14359/14282

Date: 3/1/2005

Abstract:
In recent years, the need to rehabilitate our aging infrastructure has been recognized. The use of carbon fiber-reinforced polymer (CFRP) composites has been identified as a viable technique for use in strengthening deteriorating or structurally deficient reinforced concrete bridges. Significant research has been conducted to study the static behavior of structural elements strengthened with composites. Comparatively, very little research has been performed on the repeated-load behavior of strengthened elements. This paper presents the results of an experimental program that consisted of fatigue testing ten reinforced concrete beams strengthened using two different types of externally-bonded CFRP composites. Results indicate that bond between the composite laminates and surface of the concrete can degrade at load amplitudes corresponding to extreme load conditions for a bridge. These results indicate that an upper limit on stresses generated along the composite-concrete interface may have to be set during design to avoid premature debonding after a limited number of load cycles.