Estimation of the crack width and deformation of FRP-reinforced concrete flexural members with and without transverse shear reinforcement

• Published in: Engineering structures 2014-02, Vol.59, p.393-398
• Main Authors: Noël, Martin, Soudki, Khaled
• Format: Article
• Language: English
• Subjects: Applied sciences; Beams; Building failures (cracks, physical changes, etc.); Building structure; Buildings. Public works; Coefficients; Computation methods. Tables. Charts; Concrete; Concrete industry; Construction (buildings and works); Crack width; Cracks; Deflection; Durability. Pathology. Repairing. Maintenance; Exact sciences and technology; Fiber-reinforced polymers; Flexure; Mathematical analysis; Reinforced concrete; Reinforced concrete structure; Reinforcement; Reinforcing steels; Shear; Slabs; Stresses; Stresses. Safety; Structural analysis. Stresses
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2013.11.005

•Accuracy of current crack width equations varies with reinforcement stress level.•Simple modification proposed which increases accuracy at all stress levels.•Most deflection models do not account for deformation caused by shear cracks.•Simple model proposed to predict additional shear deformation for FRP-RC beams. As the general acceptance of FRP reinforcing bars in the concrete construction industry continues to rise, it is increasingly imperative that the structural behavior of FRP-reinforced concrete members be predicted with good accuracy. The current crack width equation used in North American design codes for FRP-reinforced concrete members assumes a constant value of the bond coefficient which results in inconsistent accuracy of crack width predictions depending on the stress level in the reinforcement relative to the stress at which the bond coefficient was calibrated. Meanwhile, effective moment of inertia equations which have been shown to be reasonably accurate for FRP-reinforced concrete members with transverse shear reinforcement do not account for the additional deformation which may result from the vertical displacement of inclined cracks in members without shear reinforcement. Simple modifications are proposed to the current deflection and crack width equations to improve their accuracy at all reinforcement stress levels within the service range and are compared to the experimental results of four full-scale FRP-reinforced concrete slabs tested in flexure.