scholarly journals Experimental Investigation of Reinforced Concrete T-Beams Strengthened in Shear with Externally Bonded CFRP Sheets

2017 ◽  
Vol 21 (2) ◽  
pp. 04016086 ◽  
Author(s):  
Robert M. Foster ◽  
Monika Brindley ◽  
Janet M. Lees ◽  
Tim J. Ibell ◽  
Chris T. Morley ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Reinforced Concrete ◽  
Cfrp Sheets ◽  
Externally Bonded

scholarly journals Mechanical Behavior and Chloride Penetration of Precracked Reinforced Concrete Beams with Externally Bonded CFRP Exposed to Marine Environment

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yan Xie ◽  
Kunhua Guan ◽  
Lei Zhan ◽  
Qichen Wang
Keyword(s):  
Reinforced Concrete ◽  
Marine Environment ◽  
Chloride Penetration ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Chloride Diffusion ◽  
Accelerated Ageing ◽  
Rc Beams ◽  
Cfrp Sheets ◽  
Externally Bonded

Cracked reinforced concrete (RC) beams can be repaired effectively by using externally bonded CFRP sheets. However, when the strengthened beams are subjected to marine environment, long-term performance will be affected by the material and the interface deterioration of concrete and CFRP. Therefore, to evaluate the service life of the strengthened beams, this study investigates the behavior of precracked RC beams strengthened with CFRP sheets exposed to marine environment. Accelerated ageing experiments were carried out by exposing specimens to cyclic wetting in sea water and drying in 40°C air for 3 months and 6 months, respectively. After the environment exposure, four-point bending test was conducted and then the diffusion of chlorides in the strengthened beams was analysed. The results show that the bonding behavior of the adhesive was weakened and the ductility of the strengthened beams was slightly reduced due to the marine environment. But there is no obvious strength difference between the strengthened beams suffered from marine environment for 3 months and 6 months. Besides, the precracks in the RC beams accelerated the chloride diffusion, while CFRP bonding reduced the chloride penetration. In addition, NEL method was employed to validate the effect of the cracks on chloride permeability. The results showed that the chloride diffusion coefficients increased with the depth of the cracks.

scholarly journals Behaviour of Reinforced Concrete Beams Bonded with Glass Fibre Reinforced Polymer and Carbon Fibre Reinforced Polymer Sheets

2020 ◽  
Vol 9 (3) ◽  
pp. 134-138
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Externally Bonded ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

Concrete, a mixture of different aggregates bonded with cement, first developed around 150BC in Rome has been bedrock to the modern Infrastructure. It is used to build everything from roads, bridges, dams to sky scrapers. Strengthening concrete is traditionally done by using steels but the developments in technology in recent decades allowed to use fiber reinforced plastics which are externally bonded to concrete . Such composite materials offer high strength, low weight, corrosion resistance, high fatigue resistance, easy and rapid installation and minimal change in structural geometry. This study investigates the behavior of reinforced concrete beams bonded with fiber composites. A numerical study is conducted to study the behavior of RC beam under Static third point loading. Concrete beam specimens with dimensions of 150 mm width, 300 mm height, and 2600 mm length are modelled. These beams are externally bonded with Glass Fiber Reinforced Polymer (GFRP) sheets and Carbon Fibre Reinforced Polymer (CFRP) sheets. In present study, we examine the performance of reinforced concrete beams which are bonded with GFRP and CFRP sheets with various thicknesses (1, 2 & 3 mm) using ABAQUS in terms of failure modes, enhancement of load capacity, load-deflection analysis and flexural behaviour

BEHAVIOR OF CORRODED RC BEAMS WITHOUT STIRRUPS REPAIRED WITH CFRP SHEETS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Abdullah Al-Saidy ◽  
Sherif El-Gamal ◽  
Khlaifa Al-Jabri ◽  
Bilal Waris
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Strength Loss ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Shear Reinforcement ◽  
Accelerated Corrosion ◽  
Cfrp Sheets ◽  
Externally Bonded

In reinforced concrete structures located in hot and humid areas, steel reinforcement is generally vulnerable to deterioration due to corrosion. Corrosion of reinforcement in many cases is considered the main cause of concrete structures deterioration, which in turn requires large budgets for repair and maintenance. This paper presents the experimental results of damaged/repaired reinforced concrete beams. The experimental program consisted of testing reinforced concrete rectangular beam specimen’s with/without shear reinforcement and exposed to accelerated corrosion of the longitudinal steel reinforcement on the tension side. Bonding external U-shaped CFRP sheets to restore the strength loss due to corrosion repaired corroded beams without shear reinforcement. The test results showed that corroded beams without stirrups failed in a brittle manner with drop in maximum deflection at failure of approximately 60% compared to the uncorroded beam. Corroded beams with stirrups lost some strength, but failed in ductile manner. Using externally bonded U-shaped CFRP sheets restored the ductility of corroded beams without stirrups and prevented bond failure at the steel concrete interface due to the absence of internal stirrups.

scholarly journals Experimental and Analytical Investigation on Flexural Retrofitting of RC T-Section Beams Using CFRP Sheets

2020 ◽  
Vol 10 (4) ◽  
pp. 1233
Author(s):  
Yannian Zhang ◽  
Moncef L. Nehdi
Keyword(s):  
Reinforced Concrete ◽  
Highway Bridges ◽  
Load Resistance ◽  
Analytical Investigation ◽  
Flexural Behavior ◽  
Analytical Models ◽  
Strengthening Effect ◽  
Cfrp Sheets ◽  
Adequate Accuracy ◽  
Externally Bonded

The large portfolio of aging highway bridges worldwide includes many reinforced concrete T-section beams with various levels of damage and degradation. However, there is currently dearth of research on the anchoring behavior of CFRP sheets used for strengthening such RC T-section beams. Moreover, there is a need for rational and accurate analytical models to predict the strengthening effect of CFRP sheets for RC T-section beams. In this study, eight RC T-section beam specimens strengthened with externally bonded CFRP sheets were tested under quasi-static loading. The failure mode, cracking resistance, yielding and ultimate capacity were examined. The effects of U-wrap spacing, flexural reinforcing ratio, and concrete compressive strength on the flexural behavior of the CFRP strengthened RC T-section beams were analyzed and discussed. New analytical models were developed to predict the cracking, yielding and ultimate load resistance of the RC T-section beams strengthened with CFRP sheets. The analytical models were validated through comparing its predictions with experimental results, and they demonstrated adequate accuracy. The findings could be deployed for the retrofitting of a large portfolio of aging highway bridges with deteriorated reinforced concrete T-section beams.

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