Mechanical and environmental loading of concrete beams strengthened with epoxy and polyurethane matrix carbon fiber laminates

    Authors

    Z. B. Haber; K. R. Mackie;L. Zhao

    Comments

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    Abbreviated Journal Title

    Constr. Build. Mater.

    Keywords

    Durability; Environmental conditioning; Cyclic loading; Debonding; Polyurethane composites; DURABILITY EVALUATION; FATIGUE BEHAVIOR; COMPOSITES; SHEETS; Construction & Building Technology; Engineering, Civil; Materials; Science, Multidisciplinary

    Abstract

    Externally-bonded carbon fiber reinforced polymer (CFRP) sheets have become a common material used to retrofit damaged or deteriorated concrete flexural members. This study examines the effects different combinations of cyclic loading, controlled thermal cycling, uncontrolled outdoor environmental exposure, and monotonic loading until failure have on the performance and failure modes of reinforced concrete beams strengthened with externally-bonded CFRP sheets. Twelve large-scale (4.88 m in length) doubly reinforced concrete beams were strengthened with externally-bonded CFRP sheets and tested. Three different unidirectional CFRP strengthening systems were considered; two systems utilizing carbon fiber sheets and epoxy matrices, and a system utilizing pre-impregnated carbon fiber with a water activated polyurethane matrix. Epoxy matrices are commonly used, but polyurethane composite systems have not been rigorously investigated for infrastructure use. Results indicate that moderate cyclic loading and environmental conditioning do not have a significant effect on flexural capacity of strengthened members, but the quality of the field lay-up does have an influence. The performance of the polyurethane system was consistent and insensitive to all loading combinations. (C) 2011 Elsevier Ltd. All rights reserved.

    Journal Title

    Construction and Building Materials

    Volume

    26

    Issue/Number

    1

    Publication Date

    1-1-2012

    Document Type

    Article

    Language

    English

    First Page

    604

    Last Page

    612

    WOS Identifier

    WOS:000295754200072

    ISSN

    0950-0618

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