Shear strengthening and rehabilitating of reinforced concrete T-beams using externally carbon fiber reinforced polymer sheets

Mervat Beramly,Hasan Katkhuda,Nasim Shatarat,Mutasim Abdel-Jaber,Malak Al-Diseet

doi:10.5937/jaes0-34390

Abstract

The shear behavior of reinforced concrete (RC) T-beams using externally bonded carbon fiber-reinforced polymers (CFRPs) composites is investigated experimentally and theoretically in this research. Nine RC T-beams were cast and tested under monotonic one-point loading. The variables used in this study are: the situation of specimens (strengthened or rehabilitated); type of CFRPs material (laminate or sheet); and the CFRPs configuration (inclined or horizontal). The experimental results were compared to theoretical results from nonlinear finite element (FE) models for T-beams using ABAQUS software. The experimental results showed that using different CFRPs materials in various configurations effectively improved shear capacity for strengthening and rehabilitating RC T-beams. Compared to the control beam, the three schemes used to strengthen the shear of RC T-beams were successful in increasing the maximum load capacity by a range of 13.6 to 36.4%, and by 4.6 to 27.3% for rehabilitate T-beams. The included horizontal strips of CFRPs laminates achieved the highest increase in the shear capacity for strengthened T-beams. While, for the rehabilitated T-beams the results showed that the CFRP scheme that included full wrap of the Web with CFRPs sheets was the best. A good agreement was found between the experimental and theoretical results. The differences in the ultimate loads and mid-span deflections were in the range of 0.33% to 26%, and 0.32% to 6.6%, respectively.

Highlights

Large number of buildings designed using reinforced concrete (RC) in recent decades is currently facing a number of problems, many of which have reached the end of their expected service life
All the experimental results showed that using external Carbon fiber-reinforced polymers (CFRPs) materials with different arrangements increased the ultimate load-carrying capacity by 13.6%, 36.4%, and 31.8% for beams SB1, SB2 and SB3 of the group three respectively, and by 4.6%, 9.1% and 27.3% for beams RB1, RB2 and RB3 of the group four, respectively, compared to the result of the CB1 beam
In group three; the horizontal CFRP laminates showed the highest increase in the experimental shear capacity

Summary

Introduction

Large number of buildings designed using reinforced concrete (RC) in recent decades is currently facing a number of problems, many of which have reached the end of their expected service life. Shear strengthening appeared to be more effective when two horizontal CFRPs strips were applied over the shear span and Mervat Beramly, et al - Shear strengthening and rehabilitating of reinforced concrete Т-beams using externally carbon fiber reinforced polymer sheets tension region. As the shear span ratio increased, the effect of CFRPs strip spacing on specimen shear capability decreased. The main variables in the testing program were: shear span to depth ratio, amount of transverse steel, the layout and amount of CFRPs laminates, bond between the CFRPs laminates and the beam surface, and inclination of CFRPs anchors. The variables used in this study were: the situation of specimens (strengthened or rehabilitated); type of CFRPs material (laminate or sheet); and the CFRPs configuration (inclined or horizontal). The experimental results were compared with the theoretical results by modeling the T-beams using ABAQUS FE software

Methods

Results

Conclusion