Investigation on the flexural behavior and ductility of reinforced concrete T-beams strengthened with prestressed CFRP sheets

Document Type : Research Paper

Authors

1 Civil engineering faculty- Sahand University of Technology

2 Civil engineering faculty, Sahand University of technology

10.22124/jcr.2024.26364.1642

Abstract

CFRP composites are considered as the one of the most effective methods in strengthening reinforced concrete (RC) members. Although this method has many privileges, the results show that CFRPs use only 30% ~ 40% of their capacity during the loading of a retrofitted concrete beam or slab and suffer from debonding before reaching their maximum capacity. To overcome this issue, prestressing the CFRP composite is proposed and utilized. The aim of this research is to investigate the effect of this strengthening method on the flexural behavior and ductility of RC T-beams. In this regard, eight scaled RC T-beams with dimensions (250×300×3000 mm) in four series, control samples, beams strengthened with non-prestressed CFRP, beams strengthened with CFRP prestressed by 20% and 35%, were produced. For CFRP prestressing, an innovative mechanical arrangement was utilized. Furthermore, the beams were subjected to a four-point bending test and their behavior was investigated. The results indicate that prestressing the composite has significantly increased the bearing capacity of the strengthened beams and improved their failure mechanism compared those of the strengthened by non-prestressed CFRP. Also, the results show that the decrease in beam ductility, when the composite is prestressed by 35%, is less than 10% compared to that of strengthened beam with non-prestressed CFRP. In addition, a numerical method for simulating the behavior of reinforced concrete beams with prestressed CFRP using subroutine coding in ABAQUS is presented.

Keywords

Main Subjects

References

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