Flexural Strengthening of RC Continuous T-Beams Using CFRP

In this paper, experimental investigations for strengthening reinforced concrete (RC) continuous beams were performed. Eighteen T-beams were cast, twelve of which were inverted T-beams where the flange portion of the T-beam was subjected to positive flexure to represent the support region of a conti...

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Main Authors: Ayssar Al-Khafaji, Hani Salim
Format: Article
Language:English
Published: MDPI AG 2020-06-01
Series:Fibers
Subjects:
Online Access:https://www.mdpi.com/2079-6439/8/6/41
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author Ayssar Al-Khafaji
Hani Salim
author_facet Ayssar Al-Khafaji
Hani Salim
author_sort Ayssar Al-Khafaji
collection DOAJ
description In this paper, experimental investigations for strengthening reinforced concrete (RC) continuous beams were performed. Eighteen T-beams were cast, twelve of which were inverted T-beams where the flange portion of the T-beam was subjected to positive flexure to represent the support region of a continuous beam. Six of the T-beams were non-inverted where the web is subjected to positive flexure. Carbon fiber reinforced polymer (CFRP) sheets with different widths were considered, and different strengthening configurations with the same area of CFRP were investigated. The use of one-layer, multiple layers, or multiple strips of CFRP were evaluated to investigate the effect of these configurations on the ultimate capacity and ductility of the strengthened beams. From the experimental observation of the non-inverted beams, it was found that the ultimate load capacities of the CFRP-strengthened beams were enhanced by 4% to 90% compared to the control beam. Using multiple layers of CFRP sheets enhanced the stiffness of the beams by 4% to 46%, depending on the CFRP area and configurations. The debonding of CFRP before the ultimate failure provided additional ductility to the tested beams. For the strengthening of the inverted beams, it was found that the addition of CFRP strips did not increase the strength of the beams when the width of CFRP to beam width ratio was less than 0.25, but the ductility of the beam was enhanced slightly. The use of multiple strips was found to be a more effective way for the strengthening of the negative moment region than using multiple layers. This can also provide more desirable modes of failure than when applying CFRP in multiple layers. Ductility was found to be lower if multiple layers were used compared to other configurations. Moreover, it was observed that as the compressive strength of concrete increased the addition of the CFRP improved the beams ductility.
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spelling doaj.art-62bb14a5cc27464e86876d9ec1d1c4f32023-11-20T04:28:32ZengMDPI AGFibers2079-64392020-06-01864110.3390/fib8060041Flexural Strengthening of RC Continuous T-Beams Using CFRPAyssar Al-Khafaji0Hani Salim1Civil and Environmental Engineering, University of Missouri, Columbia, MO 65211-2200, USACivil and Environmental Engineering, University of Missouri, Columbia, MO 65211-2200, USAIn this paper, experimental investigations for strengthening reinforced concrete (RC) continuous beams were performed. Eighteen T-beams were cast, twelve of which were inverted T-beams where the flange portion of the T-beam was subjected to positive flexure to represent the support region of a continuous beam. Six of the T-beams were non-inverted where the web is subjected to positive flexure. Carbon fiber reinforced polymer (CFRP) sheets with different widths were considered, and different strengthening configurations with the same area of CFRP were investigated. The use of one-layer, multiple layers, or multiple strips of CFRP were evaluated to investigate the effect of these configurations on the ultimate capacity and ductility of the strengthened beams. From the experimental observation of the non-inverted beams, it was found that the ultimate load capacities of the CFRP-strengthened beams were enhanced by 4% to 90% compared to the control beam. Using multiple layers of CFRP sheets enhanced the stiffness of the beams by 4% to 46%, depending on the CFRP area and configurations. The debonding of CFRP before the ultimate failure provided additional ductility to the tested beams. For the strengthening of the inverted beams, it was found that the addition of CFRP strips did not increase the strength of the beams when the width of CFRP to beam width ratio was less than 0.25, but the ductility of the beam was enhanced slightly. The use of multiple strips was found to be a more effective way for the strengthening of the negative moment region than using multiple layers. This can also provide more desirable modes of failure than when applying CFRP in multiple layers. Ductility was found to be lower if multiple layers were used compared to other configurations. Moreover, it was observed that as the compressive strength of concrete increased the addition of the CFRP improved the beams ductility.https://www.mdpi.com/2079-6439/8/6/41reinforced concretecontinuous beamsCFRP strengtheningexperimental
spellingShingle Ayssar Al-Khafaji
Hani Salim
Flexural Strengthening of RC Continuous T-Beams Using CFRP
Fibers
reinforced concrete
continuous beams
CFRP strengthening
experimental
title Flexural Strengthening of RC Continuous T-Beams Using CFRP
title_full Flexural Strengthening of RC Continuous T-Beams Using CFRP
title_fullStr Flexural Strengthening of RC Continuous T-Beams Using CFRP
title_full_unstemmed Flexural Strengthening of RC Continuous T-Beams Using CFRP
title_short Flexural Strengthening of RC Continuous T-Beams Using CFRP
title_sort flexural strengthening of rc continuous t beams using cfrp
topic reinforced concrete
continuous beams
CFRP strengthening
experimental
url https://www.mdpi.com/2079-6439/8/6/41
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