scholarly journals Evaluating Flexural Strength of RC Beams Strengthened by CFRP using Different Analytical Models

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Riyam J. Abed ◽  
Mohammed A. Mashrei ◽  
Ali A. Sultan
Keyword(s):  
Flexural Strength ◽  
Prediction Models ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Analytical Models ◽  
Rc Beams ◽  
Test Results ◽  
Related Field ◽  
Cfrp Sheet ◽  
Externally Bonded

Abstract This paper deals with reinforced concrete beams strengthened by CFRP in flexure. The debonding between CFRP and the surface of the beam is the main problem. Many researchers around the world have made extensive efforts to study the phenomenon of debonding for efficient applications. Based on these efforts and different related field applications, code previsions and various models have been proposed for predicting debonding failure. Two code previsions and three typical models are presented in the current study. ACI-440.2R 17, CNR-DT 200 R1/2013, Said and Wu, Lu et al., and Teng et al. have been used to estimate the flexural strength of RC beams strengthened by CFRP with and without grooves. Test results of eleven flexural beams strengthened by CFRP sheet/laminate using externally bonded reinforcement (EBR) and externally bonded reinforcement on grooves (EBROG) methods were used in the current paper. The performance and accuracy of each model were evaluated based on these test results. Most of the prediction models that used in this study give a closer prediction of the flexural strength of beams strengthened by EBR compared to that of the beams strengthened by EBROG. Finally, the prediction results of CNR-DT 200 R1/2013 were the most accurate and approval with test results compared with other models in the current study

Test Analysis for RC Beams Strengthened with Externally Bonded Prestressed CFRP Laminates

2008 ◽  
Vol 385-387 ◽  
pp. 41-44 ◽  
Author(s):  
Shi Qi Cui ◽  
Jin Shan Wang ◽  
Zhao Zhen Pei ◽  
Zhi Liu
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Test Results ◽  
Test Analysis ◽  
Cfrp Laminates ◽  
Cfrp Sheet ◽  
Externally Bonded

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.

Deflection Prediction of FRP-Strengthened Reinforced Concrete Beams

2011 ◽  
Vol 243-249 ◽  
pp. 621-624
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo
Keyword(s):  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Test Results ◽  
Structural Members ◽  
Modified Model ◽  
Reinforced Polymer ◽  
Service Load ◽  
Good Agreement

Bonding fiber reinforced polymer (FRP) laminates to the tension face of RC members has been proven to be an effective method to improve the flexural strength. However, structural members are not only needed to have adequate strength, but also to have adequate performance of deformation at service load levels. To evaluate the deflection of externally FRP-strengthened RC beams, a total of 18 RC beams, including 16 beams strengthened with CFRP laminate under different preload levels and 2 control beams, were tested. Based on the assumption that the section of the beam behaves a tri-linear moment-curvature response characterized by pre-crack stage, post-crack stage and failure stage and the test results, this paper presents a modified model to evaluate the deflection of CFRP-strengthened RC beams. The present modified model was verified by the similar test results, and shows a good agreement with the test results.

scholarly journals Debonding-Related Strain Limits for Externally Bonded FRP Sheets in Flexurally Strengthened Reinforced Concrete Beams

2013 ◽  
Vol 7 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Guibing Li ◽  
Aihui Zhang ◽  
Yugang Guo
Keyword(s):  
Reinforced Concrete ◽  
Tensile Strain ◽  
Concrete Beams ◽  
Experimental Tests ◽  
Critical Issue ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Externally Bonded ◽  
Strengthening Technique ◽  
Code Provisions

Debonding problems of externally bonded fiber reinforced polymer (FRP) sheets in flexurally FRP-strengthened reinforced concrete (RC) beams have been a concern and a research challenge since their application of this strengthening technique. Intermediate crack induced debonding is the most common failure mode which is that the debonding initiates at the critical flexural-shear or flexural cracks and propagates towards the direction of moment decrease. To mitigate debonding failure, most Codes and proposed models take the method by limiting the allowable tensile strain in FRP laminates. This paper presents experimental tests of concrete beams flexurally strengthened with externally bonded CFRP sheets to investigate debonding initiation and tensile strain of FRP laminates. The allowable tensile strain of FRP sheets in flexurally FRP-strengthened RC beams proposed by prevalent Code provisions and models was assessed based on the data obtained from experimental programs. It has beenshown that the allowable tensile strains provided by these provisions and models have a great difference with that of experimental results and exhibit a high level of dispersion. Furthermore, the FRP laminates of most tested RC beams were debonded before reaching the proposed allowable tensile strain. The Code provisions and models are inadequate to effectively prevent intermediate crack induced debonding failure in flexurally FRP-strengthened RC members. This is known to be a critical issue in engineering design and application of RC beams flexurally strengthened by FRP sheets.

The Experimental Study on Bearing Capacity of Reinforced Concrete Structure with Different Reinforce Methods

2014 ◽  
Vol 936 ◽  
pp. 1438-1441
Author(s):  
Qing Yi Liu ◽  
Xiao Mei Liu
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Steel Plate ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Test Results ◽  
Reinforced Concrete Structure ◽  
Fiber Sheet

Three reinforcement materials with steel plate, epoxies resin sheet, and glass fiber sheet adhering to failed reinforced concrete beams (RC beams) were used to improve the bearing capacity of Reinforced Concrete beams in the paper. The test results shows all the three materials were proved satisfied with bearing capacity increasing request. Strengthening effects with steel plate and epoxies resin sheet were more obvious.

Experimental Study of Strengthening of Reinforced Concrete Beams with Externally Bonded GFRP Sheets

2014 ◽  
Vol 919-921 ◽  
pp. 115-118
Author(s):  
Hai Ying Hu ◽  
Yu Cheng Zhang ◽  
Zhong Ming Huang
Keyword(s):  
Experimental Study ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Strengthening Effect ◽  
Rc Beams ◽  
Reinforced Plastics ◽  
Glass Fiber Reinforced ◽  
Bending Resistance ◽  
Externally Bonded ◽  
Fiber Reinforced Plastics

A test of bending resistance and reinforcement is carried out on RC beams by applying sheet of glass fiber reinforced plastics (GFRP). A study and analysis is given to the traits of bending and rupture of RC beams reinforced by applying GFRP and to the effect of GFRP on ultimate bearing capacity and stiffness of the beams. The strengthening effect is investigated to give guidance in practice work.

Experimental Study of Cyclic Loading Behaviors of Reinforced Concrete Beams Strengthening with Externally Bonded Steel Frame

2012 ◽  
Vol 201-202 ◽  
pp. 304-307
Author(s):  
Li Yun Pan ◽  
Cheng Chen ◽  
Shun Bo Zhao ◽  
Chang Yong Li
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Steel Plate ◽  
Concrete Beams ◽  
Steel Frame ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Service Load ◽  
Externally Bonded ◽  
Ultimate Resistance

Two large impaired reinforced concrete beams with pre-loading cracks were strengthened by the externally bonded steel frame composed with bottom steel plate and side hoop steel belts. The cyclic loading behaviors of these beams were tested to verify the effectiveness of this strengthening method specified in current Chinese design code. Based on the analyses of test results, the steel plate worked well with bonded concrete under normal service load, the hoop steel belts were necessary to prevent the peeling of bottom steel plate. The strengthened beams were effectively enhanced in flexural stiffness and ultimate resistance, and no new cracks appeared under the normal service load.

scholarly journals REPAIR OF FLEXURAL DAMAGED REINFORCED CONCRETE BEAMS USING EMBEDDED BAMBOO REINFORCED EPOXY COMPOSITE

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Samson Olalekan Odeyemi ◽  
Rasheed Abdulwahab ◽  
Sefiu Adekunle Bello ◽  
Ahmed Olatunbosun Omoniyi ◽  
Adewale George Adeniyi
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Concrete Beams ◽  
Epoxy Composite ◽  
Reinforced Concrete Beams ◽  
Steel Plates ◽  
Rc Beams ◽  
Existing Structures ◽  
Load Carrying ◽  
Alternative Material

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.

Experimental Study of Strengthening of Reinforced Concrete Beams with Externally Bonded GFRP Sheets

2013 ◽  
Vol 790 ◽  
pp. 333-336
Author(s):  
Hui Kang Liu ◽  
Ze Fan ◽  
Yu Cheng Zhang
Keyword(s):  
Experimental Study ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Strengthening Effect ◽  
Rc Beams ◽  
Reinforced Plastics ◽  
Glass Fiber Reinforced ◽  
Bending Resistance ◽  
Externally Bonded ◽  
Fiber Reinforced Plastics

A test of bending resistance and reinforcement is carried out on RC beams reinforced by applying sheet of glass fiber reinforced plastics (GFRP). A study and analysis is given to the traits of bending and rupture of RC beams reinforced by applying GFRP and to the effect of GFRP on ultimate bearing capacity and stiffness of the beams. The strengthening effect is investigated to give guidance in practice work.

scholarly journals Influence of flange on the shear capacity of reinforced concrete beams

2018 ◽  
Vol 162 ◽  
pp. 04003
Author(s):  
Kaiss Sarsam ◽  
Raid Khalel ◽  
Nisreen Mohammed
Keyword(s):  
Structural Engineering ◽  
Shear Failure ◽  
Concrete Beams ◽  
Design Method ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Test Results ◽  
Web Reinforcement ◽  
The Web

In structural engineering (RC, steel, etc.) it is usual to base the shear strength of members on the web only- e.g. in RC the stirrups used are usually called “web reinforcement”. Presently all codes, and several researches, base the strength of members on the capacity of the web alone. 93 tests of T-beams failing in shear available from the literature are studied in this work to estimate the influence of flanges on the shear capacity of RC beams. These include 32 ones without web reinforcement and 61 with stirrups. Comparison between test results and theoretical shear capacity show that all available equations conservatively estimate the occurrence of shear failure. In this work an equation for predicting the contribution of the flange to shear capacity in T-beams is presented. The best available design method obtained from the literature leads to a coefficient of variation (COV) of 17.58% compared to 13.46% for the proposed design method in this work.

An Experimental Study on Flexural Behavior of Reinforced Concrete Beams Strengthened with High-Performance Ferrocement

2010 ◽  
Vol 163-167 ◽  
pp. 3772-3776 ◽  
Author(s):  
Hua Ping Liao ◽  
Shi Sheng Fang
Keyword(s):  
Reinforced Concrete ◽  
Comparative Analysis ◽  
High Performance ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Rc Beams ◽  
Test Results ◽  
Flexural Capacity ◽  
Engineering Designs

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.

Sign in / Sign up

Export Citation Format

Share Document