scholarly journals Stochastic Analysis of Flexural Strength of RC Beams Subjected to Chloride Induced Corrosion

2015 ◽  
Vol 18 (6) ◽  
pp. 1224-1241 ◽  
Author(s):  
Parammal Vatteri Ahsana ◽  
Kanchi Balaji Rao ◽  
Madambikattil Bharathan Anoop
2018 ◽  
Vol 7 (4) ◽  
pp. 2075 ◽  
Author(s):  
Yasmin Murad

 The use of carbon fiber reinforced polymer (CFRP) sheets is becoming a widely accepted solution for strengthening and repairing rein-forced concrete (RC) structures. To date, the behavior of RC beams, strengthened with 60˚ and 45˚ inclined CFRP sheets, has not clearly explained. An experimental program is proposed in this paper to investigate the flexural behavior of RC beams strengthened with CFRP sheets. CFRP sheets were epoxy bonded to the tension face to enhance the flexural strength of beams inducing different orientation angles of 0˚, 45˚, 60˚ and 90˚ with the beam longitudinal axis. The study shows that strengthening RC beams with CFRP sheets is highly influenced by the orientation angle of the sheets. The orientation angle plays a key role in changing the crack pattern and hence the failure mode. The influence of CFRP sheets was adequate on increasing the flexural strength of RC beams but the ductility of the beams was reduced. The best performance was obtained when strengthening RC beam obliquely using 45˚ inclined CFRP sheets where the specimen experienced additional deflection and strength of 56% and 12% respectively and the reduction in its ductility was the least. It is recom-mended to strengthen RC beams, which are weak in flexure, using 45˚ inclined CFRP sheets.  


2007 ◽  
Vol 334-335 ◽  
pp. 429-432
Author(s):  
Takayuki Kusaka ◽  
Keiko Watanabe ◽  
Ken Suke Okubo ◽  
Hironori Namiki

A novel retrofitting method using extremely prestressed carbon fiber sheets, MLML (Multi-Layer Multi-Tensioning) method, was proposed for improving the flexural strength of reinforced concrete structures. The experimental results suggested that the crack initiation strength and the energy absorbing capacity of RC beams could be largely improved by the MLMT method. However, the advantage of the MLMT method was not so clear on the rebars yielding strength and the ultimate flexural strength of RC beams, compared with the conventional methods.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6400
Author(s):  
Binbin Zhou ◽  
Ruo-Yang Wu ◽  
Yangqing Liu ◽  
Xiaohui Zhang ◽  
Shiping Yin

Through proper arranging of a hybrid combination of longitudinal fiber reinforced polymer (FRP) bars and steel bars in the tensile region of the beam, the advantages of both FRP and steel materials can be sufficiently exploited to enhance the flexural capacity and ductility of a concrete beam. In this paper, a methodology for the flexural strength design of hybrid FRP-steel reinforced concrete (RC) beams is proposed. Firstly, based on the mechanical features of reinforcement and concrete and according to the latest codified provisions of longitudinal reinforcement conditions to ensure ductility level, the design-oriented allowable ranges of reinforcement ratio corresponding to three common flexural failure modes are specified. Subsequently, the calculation approach of nominal flexural strength of hybrid FRP-steel RC beams is established following the fundamental principles of equilibrium and compatibility. In addition to the common moderately-reinforced beams, the proposed general calculation approach is also applicable to lightly-reinforced beams and heavily-reinforced beams, which are widely used but rarely studied. Furthermore, the calculation process is properly simplified and the calculation accuracy is validated by the experimental results of hybrid FRP-steel RC beams in the literature. Finally, with the ductility analysis, a novel strength reduction factor represented by net tensile steel strain and reinforcement ratio is proposed for hybrid FRP-steel RC beams.


2020 ◽  
Vol 2 (11) ◽  
Author(s):  
Mohamed El-Zeadani ◽  
Raizal Saifulnaz Muhammad Rashid ◽  
Mugahed Yahya Hussein Amran ◽  
Mohamed Ibrahem Swi

Author(s):  
Nauwal Suki ◽  
Mohd Hisbany Mohd Hashim ◽  
Afidah Abu Bakar

This study investigates the flexural performance of RC beams under the effects of a tropical climate. Effects from the tropical climate, such as heat and rain throughout the year, may cause deterioration to the surface of concrete. Concrete will gradually erode and may expose the steel inside the beam. If the steel is exposed, it may be oxidized, thus decreasing the strength of the RC structure. To avoid this situation from happening, the Near Surface Mounted (NSM) method of strengthening may be applied as an alternative. Three beams with the size of 125 mm x 300 mm x 1800 mm (width; height; length) were constructed for this study. The first one is a beam without strengthening, while the other two beams were strengthened with CFRP plate horizontally positioned on the tension zones, where one beam is placed under room temperature conditions, while the other is left to endure the conditions of the tropical climate for a period of 6 months. All three beams were then tested under a four-point bending test. Results show that the strengthened beam placed under room temperature conditions has 1% more flexural strength compared to the exposed beam. The exposed beam, however, has 21% more flexural strength compared to the control beam. Thus, NSM is proven to strengthen beams even in a tropical climate.


2011 ◽  
Vol 33 (8) ◽  
pp. 2398-2406 ◽  
Author(s):  
K. Girija ◽  
Devdas Menon
Keyword(s):  

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Samson Olalekan Odeyemi ◽  
Rasheed Abdulwahab ◽  
Sefiu Adekunle Bello ◽  
Ahmed Olatunbosun Omoniyi ◽  
Adewale George Adeniyi

In recent years, repair and retrofit of existing structures such as buildings and bridges have been among the most important challenges in Civil Engineering. Strengthening reinforced concrete (RC) members with steel plates is a conventional method that has been adopted for decades. The corrosive nature of steel plates, its weight and the need for many anchor bolts for attachment makes it inefficient for retrofitting damaged structures. Thus, there is a need to source for an alternative material which does not corrode and still be used in the strengthening of reinforced concrete. Bamboo Reinforced Epoxy Composite (BREC) was used to repair five (5) damaged reinforced concrete beams in this research. Two of the beams were preloaded to 40 % and 60 % of the ultimate load before strengthening with BREC and all the beams were loaded to failure. The RC beams implanted with BREC rods experienced a rise in their load carrying capacity when tested. Beams preloaded up to 40 % and 60 % had an increase in flexural strength of 33.7 % and 39.3 % respectively when compared with beams reinforced with steel reinforcements. BREC rods in concrete is an effective method in increasing the flexural strength of RC beams.


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