Modeling of CFRP strengthened RC beams using the SNSM technique, proposed as an alternative to NSM and EBR techniques

Boukhezar Mohcene,Ferhoune Noureddine,Adel Boulebd,Habib Abdelhak Mesbah

doi:10.3221/igf-esis.54.02

Abstract

In this paper, an analytical and numerical study in FEM finite element by the ABAQUS software was conducted. Which aims to study the behaviour of RC beams bending strengthened with SNSM side near surface mounted technique, proposed as a solution to avoid the failure mode by debonding of the strengthening, the disadvantage of the EBR externally bonded reinforced technique, and the failure mode by separation of the concrete cover relative to the NSM near surface mounted technique, by comparing the behaviour of the three techniques, the effect of the quantity of strengthening and confirm the results with the literature. The results of this study show that the numerical and analytical model can predict the behaviour of strengthened RC beams according to the three techniques, a clear improvement of the bending capacity of beams strengthened is noticed. A good preservation of the ductility of SNSM beams with a better failure mode.

Highlights

I n the last years, the fibre-reinforced polymer (FRP) has emerged as the material of choice for structural strengthening, due to its strengthening efficiency and light weight
FRP was applied for the strengthening of the reinforced concrete (RC) beams according to the external bonded reinforced (EBR) technique
The side near surface mounted (SNSM) technique has been proposed as an alternative approach for strengthening RC beams to overcome the limitations of EBR and NSM techniques

Summary

Introduction

I n the last years, the fibre-reinforced polymer (FRP) has emerged as the material of choice for structural strengthening, due to its strengthening efficiency and light weight. To overcome the failure mode of EBR techniques, the near surface mounted (NSM) technique was proposed [8,9,10] It differs from the previous one by anchoring bars or rods in grooves recessed in the tensioned part of the RC beams, filled using an epoxy resin. The SNSM implementation process is similar to that of the NSM, except for the FRP strengthening, which is inserted in the lateral sides of the beam instead of the bottom part Several researchers, such as Al-Mahmoud F et al [17], Bilotta et al [11] and Sharaky et al [12], have studied the behaviour of the NSM technique. Their experimental investigations have shown a significant increase in the bending capacity of RC beams These studies have proved that the most frequent failure mode for the NSM technique is failure by separation of the concrete covering. In a second experimental and analytical study of Hosen et al [19], the results showed that the SNSM strengthening technique significantly increases the first cracking capacities by 153%, the yield by 108% and the extreme load by 147% compared to the control RC beam

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Conclusion