Fatigue life of RC beams strengthened with FRP systems

• Published in: Structural concrete : journal of the FIB 2014-06, Vol.15 (2), p.219-228
• Main Authors: Meneghetti, Leila Cristina, Garcez, Mônica Regina, da Silva Filho, Luiz Carlos Pinto, Gastal, Francisco de Paula Simões Lopes, Bittencourt, Túlio Nogueira
• Format: Article
• Language: English
• Subjects: Applied sciences; aramid; Aramids; Beams (structural); Building structure; Buildings. Public works; Carbon; Construction (buildings and works); Cracks; Deflection; Durability. Pathology. Repairing. Maintenance; Exact sciences and technology; fatigue; Fatigue (materials); Fatigue life; fib Model Code 2010; Fiber reinforced plastics; fibre-reinforced polymers; RC beams; Reinforced concrete; Reinforced concrete structure; Repair (reinforcement, strenthening); Strength of materials (elasticity, plasticity, buckling, etc.); Structural analysis. Stresses; testing / experiments
• ISSN: 1464-4177; 1751-7648
• DOI: 10.1002/suco.201300017

Fibre‐reinforced polymers (FRP) in the form of externally bonded reinforcement have been used successfully in the rehabilitation of concrete structures. Although considerable data has been produced on the performance of strengthened RC structures, the reliability of strengthened structures can be significantly reduced due to the variability in the FRP properties, especially when the wet layup technique is used. In addition to this, structural engineers are concerned about the durability of FRP‐strengthened structures under extreme loading conditions. Nonetheless, knowledge of the behaviour of strengthened elements under fatigue loading may be important to raise confidence in the strengthening systems. This paper presents the results of an experimental programme developed to investigate the behaviour up to failure of RC beams strengthened with high‐performance carbon and aramid fibre sheets and subjected to static and cyclic loadings in terms of ultimate loads, deflections, cracking behaviour, failure modes and fatigue life by means of loading, crack width and deflection monitoring. Experimental data on fatigue life were used to validate analytical models developed for strengthened and unstrengthened beams.