Flexural Performance and Failure Modes of NSM CFRP-Strengthened Concrete Beams: A Parametric Study

  • Rami H. HaddadEmail author
  • Oubaida A. Almomani
Research paper


The flexural performance and failure modes of concrete beams, strengthened with near-surface mounted (NSM) carbon fiber-reinforced polymer (CFRP) strips were investigated. For this, reinforced concrete beams (150 × 250 × 1400 mm) were cast, and cured for 28 days, then strengthened with NSM CFRP strips at varying numbers (1–3), lateral spacing (50–100 mm), and embedment lengths (150–450 mm). The impact of staggering of NSM CFRP strips upon strengthening efficiency was tackled, as well. The flexural mechanical response, strain in strips at failure, and cracking and failure modes were evaluated for all concrete beams under a four-point loading test setup. The findings indicated that inserting NSM CFRP strips at a certain lateral distance from the main steel bars prevented end-cover peeling-off. Furthermore, staggering NSM CFRP strips contributed to increasing the residual flexural capacity and toughness of strengthened beams by as much as 30 and 51%, respectively, although it led to a slight reduction in their ductility. In general, the present study confirmed the findings of different literature works with regard to the effect of key repair parameters using NSM CFRP strips.


Strengthening NSM CFRP strips Peeling off Analytical prediction Strain 



The authors acknowledge the technical and financial support provided by the research deanship at Jordan University of Science and Technology (project number 153/2015) and the assistance by the technicians at the structural and materials laboratory via the Department of Civil Engineering.


Dean of Scientific Research, Jordan University of Science and Technology, P.O. Box 3030, 22110 Irbid, Jordan.


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Copyright information

© Iran University of Science and Technology 2018

Authors and Affiliations

  1. 1.Civil Engineering DepartmentJordan University of Science and TechnologyIrbidJordan

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