scholarly journals Debonding Failure Analysis of Reinforced Concrete Beams Strengthened with CFRP Plates

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2738
Author(s):  
Rendy Thamrin ◽  
Zaidir Zaidir ◽  
Silvy Desharma

In this study, experimental work was carried out on reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymers (CFRP) plates. This study aims to examine the effect of the reinforcement ratio on the flexural behavior of these beams and propose a new model for predicting the debonding moment. Six RC beams consisting of three control beams and three beams strengthened with CFRP plates were tested. The beams were simply supported and loaded with four-point bending. The test variable was the tensile reinforcement ratio (1%, 1.5%, and 2.5%). Analytical prediction using the fiber element method was also carried out to obtain the complete theoretical response of the beam due to flexural loads. The test results show that the reinforcement ratio affected the bending performance of RC beams with CFRP plates. Following this, the experimental data from 60 beam test results from published literature and this study were analyzed. From these data, it was found that the ratio of tensile reinforcement, the ratio of modulus of elasticity of concrete, the modulus of elasticity of the plate, and plate thickness all affect the value of debonding moment. A parametric study using fiber elements and the two-dimensional finite element method was also carried out to confirm the effect of these variables on debonding failure. These variables were then used to develop an equation to predict the debonding moment of RC beams strengthened with CFRP plates, using simple statistical analysis. This analysis resulted in a simple model for predicting the debonding moment. Then the model is entered into a computer program, and the complete response of the cross-section due to debonding failure can be obtained.

Author(s):  
Rendy Thamrin ◽  
Zaidir Zaidir ◽  
Silvy Desharma

In this study, experimental work was carried out on reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymers (CFRP) plates. This study aims to examine the effect of the reinforcement ratio on the flexural behavior of these beams and propose a new model for predicting the debonding moment. Six RC beams consisting of three control beams and three beams strengthened with CFRP plates were tested. The beams were simply supported and loaded with four-point bending. The test variable was the tensile reinforcement ratio (1%, 1.5%, and 2.5%). Analytical prediction using the fiber element method was also carried out to obtain the complete theoretical response of the beam due to flexural loads. The test results show that the reinforcement ratio affected the bending performance of RC beams with CFRP plates. Following this, the experimental data from 60 beam test results from published literature and this study were analyzed. From these data, it was found that the ratio of tensile reinforcement, the ratio of modulus of elasticity of concrete, the modulus of elasticity of the plate, and plate thickness all affect the value of debonding moment. A parametric study using fiber element and two-dimensional finite element method was also carried out to confirm the effect of these parameters on debonding failure. These parameters were then used to develop an equation to predict the debonding moment of RC beams strengthened with CFRP plates using simple statistical analysis. This analysis resulted in a simple model for predicting the debonding moment. Then the model is entered into a computer program, and the complete response of the cross-section due to debonding failure can be obtained.


2010 ◽  
Vol 163-167 ◽  
pp. 3772-3776 ◽  
Author(s):  
Hua Ping Liao ◽  
Shi Sheng Fang

Three reinforced concrete (RC) beams strengthened by high-performance ferrocement and two control specimens without strengthened are investigated when RC beams have low compressive strength. Flexural behaviors of strengthened RC beams with high-performance ferrocement are evaluated based on comparative analysis with RC beams. The strengthening results of steel meshes with U-shape (i.e. ferrocements are put onto the tension face and two profile faces) are analyzed. The flexural capacity, deflection and crack width of RC flexural beams are measured, and then comparative analysis is carried out for deformation performance and law of crack development. The test results show that ferrocement contributes greatly to increase the flexural capacity and raise crack-resisting capacity. The experimental results can provide a theoretical reference for actual engineering designs.


2020 ◽  
pp. 136943322097478
Author(s):  
Abu Sayed Mohammad Akid ◽  
Qudrati Al Wasiew ◽  
Md. Habibur Rahman Sobuz ◽  
Touhidur Rahman ◽  
Vivian WY Tam

Fiber-reinforced polymer (FRP) is a revolutionary breakthrough in the history of structural engineering innovation due to its unique characteristics to strengthen and repair the deficient reinforced concrete structures. This paper aimed at evaluating the flexural characteristics of jute fiber reinforced polymer (JFRP) bonded reinforced concrete beams. The influence of the test variables comprised of strengthening scheme and corrosion rate for reinforced concrete (RC) beams. The experimental study comprised of casting six RC beams and testing them in flexure loading. To determine the flexural response of RC beams, three beams were fabricated with JFRP laminate having a level of corrosion of 0%, 7.5%, and 15%, whereas three beams were designated as control beams having same corrosion levels with no JFRP. Test results indicated that all JFRP strengthened beams exhibited increased ultimate load, yield load, first cracking load, and lower ductility index compared to control beams. The results also revealed that JFRP strengthening technique improved the flexural strength of the corroded beams efficiently, albeit the ultimate load of the beams diminished with higher corrosion level. Analytical calculations were carried out for quantifying the flexural characteristics and mass loss of beams which provided a good agreement with the test results.


2010 ◽  
Vol 163-167 ◽  
pp. 1451-1455
Author(s):  
Gui Bing Li ◽  
Ai Hui Zhang ◽  
Wei Liang Jin

Externally bonding fiber reinforcement polymer (FRP)laminate to the soffit of reinforced concrete (RC) beam is an effective way to increase its flexural strength. However, there is little investigation on flexural behavior of RC beam by side-bonding FRP laminates.To investigate the difference of flexural behavior between soffit-bonding and side-binding FRP laminates RC beams,a total of 9RC beams were tested, including 8 strengthened beams and 1 control beam. The test results showedthat:1) As fiber reinforced concrete, side-bonding FRP laminates can also effectively increase the first crack strength of RC beams.The first crack load improved significantly; 2) side-bonding FRP laminates is not a good method to improve the flexural behavior of RC beam at the yield stage and the post yield stage. 3) Side-bonding of CFRP laminates is a good way for existing RC beams to control its crack width and deflection.


Author(s):  
Nguyen Trung Hieu ◽  
Nguyen Van Tuan

The elasto-plastic characteristics of plain concrete are inevitably affected by the loading rate. This paper presents an experimental investigation on the effect of loading rate on flexural behavior of concrete and reinforced concrete (RC) beams, which was carried out with Walter+bai electro-hydraulic servo system. Three-point bending tests on 100 × 100 × 400 mm prismatic concrete samples and 80 × 120 × 1100 mm RC beams with different displacement controlled loading rates of 0.01 mm/min, 0.1 mm/min, and 3 mm/min were imposed. Based on the test results, the effects of loading rates on the load-displacement curve, cracking, and ultimate load-carrying capacities of RC beams were evaluated.


2016 ◽  
Vol 22 (2) ◽  
pp. 146-153 ◽  
Author(s):  
Rizwan AZAM ◽  
Ahmed K. EL-SAYED ◽  
Khaled SOUDKI

The effect of corrosion on the structural behaviour of reinforced concrete (RC) beams without stirrups was experimentally investigated. A total of seven medium-scale RC beams without stirrups were constructed. The beams measured 150 mm wide, 250 mm deep and 1700 mm long. The test variables included: three different longitudinal reinforcement ratios (0.91%, 1.21%, and 1.82%) and two different corrosion levels (3% and 10%). Four beams were subjected to artificial corrosion whereas three beams acted as control un-corroded. Following the corrosion phase, all beams were tested to failure in three point bending. Corrosion crack widths and cracking patterns were recorded at different stages of corrosion. The effect of different longitudinal reinforcement ratios on the rate of corrosion was observed. Test results revealed that the beams with higher reinforcement ratios experienced slower corrosion rate compared to beams with lower reinforcement ratios. All control beams failed in shear whereas corroded beams failed in bond. There was a significant reduction in the load carrying capacity of the corroded beams without stirrups compared to the control beams.


2008 ◽  
Vol 385-387 ◽  
pp. 41-44 ◽  
Author(s):  
Shi Qi Cui ◽  
Jin Shan Wang ◽  
Zhao Zhen Pei ◽  
Zhi Liu

Reinforced concrete beams strengthened with externally bonded CFRP sheet and prestressed CFRP are analyzed in this paper. Crack developments and displacements with curvatures for different beams are analyzed. Test results show that prestressed CFRP are able to control the development of macro cracks in concrete and prestressed CFRP is an effective method to improve the toughness of concrete, reduce strengthening cost and meanwhile enhance bearing capacity of concrete beams.


2021 ◽  
Vol 921 (1) ◽  
pp. 012022
Author(s):  
S Kala ◽  
H Parung ◽  
A A Amiruddin

Abstract The length of reinforced concrete blocks varies widely, while in general the reinforcement produced in Indonesia is 12 m. Therefore, the use of reinforcement in a long stretch is done to be connected. The through connection is the most economical connection [2]. Lap splice can be made by overlapping the reinforcement which is touching or separate [3]. Splicing reinforcement can cause the strength of reinforced concrete beams to be reduced or even damaged so that rehabilitation measures are needed which can be in the form of retrofit (repair). Retrofitting with wiremesh and self compacting concrete (SCC) is considered to improve building structures. Reinforcement overlapping on reinforced concrete beams retrofit with wiremesh and self compacting concrete can be analyzed by numerical methods to determine their effect on bending behavior. Now, to analyze a structural behavior, it can be done using finite element method based program. The application of the finite element method is used in several programs, including ABAQUS, ADINA, Atena, ANSYS, etc. This study aims to analyze the overlapping of reinforcement in retrofit reinforced concrete beams against the flexural behavior, overlapping is made at one-third and one-third of the beam span using finite element method based analysis software.


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