Flexural strengthening of RC beams with externally bonded CFRP systems: Test results and 3D nonlinear FE analysis

Renata Kotynia, Hussien Abdel Baky, Kenneth W. Neale, Usama A. Ebead

Research output: Contribution to journalArticlepeer-review

147 Citations (Scopus)


This paper presents experimental results and a numerical analysis of the reinforced concrete (RC) beams strengthened in flexure with various externally bonded carbon fiber-reinforced polymer (CFRP) configurations. The aim of the experimental work was to investigate the parameters that may delay the intermediate crack debonding of the bottom CFRP laminate, and increase the load carrying capacity and CFRP strength utilization ratio. Ten rectangular RC specimens with a clear span of 4.2 m, categorized in two series, were tested to evaluate the effect of using the additional U-shaped CFRP systems on the intermediate crack debonding of the bottom laminate. Two different configurations of the additional systems were proposed, namely, continuous U-shaped wet layup sheets and spaced side-bonded CFRP L-shaped laminates. The fiber orientation effect of the side-bonded sheets was also investigated. A numerical analysis using an incremental nonlinear displacement-controlled 3D finite-element (FE) model was developed to investigate the flexural and CFRP/concrete interfacial responses of the tested beams. The finite-element model accounts for the orthotropic behavior of the CFRP laminates. An appropriate bond-slip model was adopted to characterize the behavior of the CFRP/concrete interface. Comparisons between the FE predictions and experimental results show very good agreement in terms of the load-deflection and load-strain relationships, ultimate capacities, and failure modes of the beams.

Original languageEnglish
Pages (from-to)190-201
Number of pages12
JournalJournal of Composites for Construction
Issue number2
Publication statusPublished - 2008


  • Concrete beams
  • Concrete, reinforced
  • Fiber reinforced polymers
  • Finite element method
  • Flexural strength

ASJC Scopus subject areas

  • Ceramics and Composites
  • Civil and Structural Engineering
  • Building and Construction
  • Mechanics of Materials
  • Mechanical Engineering


Dive into the research topics of 'Flexural strengthening of RC beams with externally bonded CFRP systems: Test results and 3D nonlinear FE analysis'. Together they form a unique fingerprint.

Cite this