Experimental Research on the Flexural Performance of the Strengthened Concrete Beams with Prestressed CFRP

2011 ◽  
Vol 255-260 ◽  
pp. 105-108
Author(s):  
Guo Wen Yao ◽  
Yan Li Wei ◽  
Shi Ya Li
Keyword(s):  
Failure Modes ◽  
Concrete Beams ◽  
Flexural Stiffness ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Flexural Performance ◽  
Load Carrying ◽  
Cycle Loading ◽  
Strengthened Beam ◽  
Three Stages

Three-bending experiments were performed on RC beams strengthened with prestressed CFRP under static and cycle loading. Prestressed CFRP obviously increases the load-carrying capacity and fatigue life of strengthened RC beam. And it greatly increases the flexural stiffness of strengthened beam. The failure modes of the beams go through concrete cracking, CFRP debonding from concrete and beam fractured. The vertical flexibility history at midspan is decomposed into three stages. And then fatigue damage is defined by flexural stiffness and its evolvement shows three stages of nucleation, growth and mutation.

Flexural Performance of Reinforced Concrete Built-up Beams with SIFCON

2020 ◽  
Vol 38 (5A) ◽  
pp. 669-680
Author(s):  
Ghazwan K. Mohammed ◽  
Kaiss F. Sarsam ◽  
Ikbal N. Gorgis
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Conventional Concrete ◽  
Flexural Performance ◽  
Load Carrying ◽  
Fiber Concrete

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.

scholarly journals Experimental assessment of the performance of reinforced concrete beams strengthened with carbon fiber reinforced polymer laminates

2020 ◽  
Vol 39 (1) ◽  
pp. 105-112
Author(s):  
N. Yusuf ◽  
J.M. Kaura ◽  
A. Ocholi ◽  
M. Abbas
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Rc Beams ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Flexural Performance ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity

In this study, experimental research is carried out to assess the flexural performance of RC beams strengthened with different amount of CFRP laminates at the tension face. Twelve rectangular RC beams were fabricated and three are un-strengthened and used as reference beams and the remaining nine are strengthened with different amount of CFRP varying from single to triple layers and all are tested to failure under three points bending test. The increase of ultimate strength provided by the bonded CFRP laminates is assessed and failure modes is identified and compared to the un-strengthened RC beams. The results indicated that the flexural capacity of the beams was significantly improved as the amount of the laminates increases that ranged from 20% to 52% increased for single to triple layers laminates. It is concluded that the attachment of CFRP laminates has substantial influence on the performance of CFRP strengthened RC beams. Based on the observed results, recommendations are made that externally application of CFRP laminates can be used for a significant enhancement of the strength deficient RC beams in increasing the ultimate load carrying capacity. Keywords: CPRP laminate, Reinforced concrete, ductility, index, epoxy resin, flexural strengthening

Effect of CFRP Thickness on Load-Carrying Capacities and Failure Modes of Strengthened RC Beams

2011 ◽  
Vol 255-260 ◽  
pp. 109-112
Author(s):  
Guo Wen Yao ◽  
Mao Sheng Li ◽  
Shi Ya Li
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Mechanical Analysis ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Bending Load ◽  
Load Carrying ◽  
Carbon Fiber Laminate ◽  
Externally Bonded ◽  
Ultimate Loading

The effect of thickness of externally bonded carbon fiber laminate (CFRP) on load-carrying capacity and failure modes was analyzed for the strengthened reinforced concrete (RC) beams under bending load. According to the balance equations of applied force and moment, the relation was obtained between ultimate loading of strengthened beam and thickness of CFRP, and the failure modes were predicted for the CFRP strengthened beams. The load-carrying capacity of strengthened RC beam is higher with thicker externally bonded CFRP until it reaches the ultimate loading. The mechanical analysis is in good agreement with the three-point bending experiments performed on CFRP strengthened RC beams.

Nonlinear Finite Element Analysis for the Flexural Behavior of Concrete Beams Strengthened with NSM CFRP-PCPs Composite Bars

2014 ◽  
Vol 584-586 ◽  
pp. 925-928
Author(s):  
Jiong Feng Liang ◽  
Ze Ping Yang ◽  
Ping Hua Yi ◽  
Jian Bao Wang
Keyword(s):  
Finite Element ◽  
Concrete Beams ◽  
Nonlinear Finite Element ◽  
Flexural Behavior ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Element Analysis ◽  
Four Point Bending ◽  
Load Carrying ◽  
Bending Loading

This paper presents the development of a detailed 3D nonlinear finite element (FE) numerical model that can accurately predict the load-carrying capacity and response of RC beams strengthened with NSM CFRP-PCPs composite bars subjected to four-point bending loading. The predicted FE mid-span deflection responses agreed very well with the corresponding measured experimental tested data at all stages of flexural loading.

Numerical Analysis on the Load-Carrying Capacity for the FRP Reinforced Four-Point Bending Concrete Beam

2011 ◽  
Vol 287-290 ◽  
pp. 1130-1134
Author(s):  
Hong Chang Qu ◽  
Chang Qing Wu ◽  
Ling Ling Chen
Keyword(s):  
Finite Element ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Cracking Behavior ◽  
Four Point Bending ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Different Types

In this paper, different types of debonding failure modes are described. Study of concrete cracking behavior and interfacial debonding fracture in fiber reinforced polymer (FRP)-strengthened concrete beams are carried out. A finite element analysis is performed to investigate the different types of debonding propagation along FRP–concrete interface and crack distribution in concrete. The proposed FE, denoted as FRP–FB (force-based) beam, is used to predict the load-carrying capacity and the applied load-midspan deflection response of RC beams subjected to four-point bending loading. Numerical simulations and experimental measurements are compared based on numerous tests available in the literatures and published by different authors. The numerically simulated responses agree remarkably well with the corresponding experimental results. It demonstrates that the proposed two-dimensional frame finite element (FE) is able to accurately estimate the load-carrying capacity of reinforced concrete (RC) beams flexurally strengthened with externally bonded fibre reinforced polymer (FRP) strips and plates.

scholarly journals Concrete Beams Strengthened with Jute Fibers

2019 ◽  
Vol 5 (4) ◽  
pp. 767-776 ◽  
Author(s):  
Yaseen Ali Salih ◽  
Nadia Nazhat Sabeeh ◽  
Mohammed Faeq Yass ◽  
Ahmed Shihab Ahmed ◽  
Ektiffa Saleh Khudhurr
Keyword(s):  
Carrying Capacity ◽  
Concrete Beams ◽  
Natural Fibers ◽  
The Other ◽  
Jute Fiber ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
The Third ◽  
Load Carrying ◽  
Reference Specimens

Nowadays, the reinforcement of concrete with natural fibers can consider being an effectual scheme to achieve the global demand for sustainable development. Due to sustainability, bio degradability, and environmental friendly, natural fibers are preferred as compared to synthetic fibers. The present study investigated the effect of width and thickness of jute fiber strips on the mechanical properties of reinforced concrete beams (RC beams). The experimental program consisted testing of twenty-four RC beams (150*150*1000 mm) comprised of four groups. The first group consisted of three reference RC beams, the second group consisted of three RC beams strengthened longitudinally with carbon fiber strip (CFRP) of 15 cm width, the third group included nine RC beams strengthened longitudinally with one layer of jute fiber strips (JFRP) having variable width, 5, 10, and 15 cm, and lastly the fourth group which was same as the third group except using double layer of jute fiber strips. Generally, the results showed that toughness, ultimate flexural strength, and load carrying capacity of RC beams strengthened with JFRP were increased with the increase of the strip width and thickness. On the other hand, ductility and stiffness were decreased with the increase of the strip width. Test results showed that load carrying capacity was improved by 5.56 and 11.1% for one layer of jute fiber strips of 5 and 15 cm width respectively as compared with the reference specimens. On the other hand, the load carrying capacity was improved by 3.95 and 8.75 % for two layers of jute fiber strips of 10 and 15 cm width respectively as compared with the one layer strengthened specimens. Concerning the CFRP strengthening, the load carrying capacity was improved by 77.76% as compared with the reference specimens. 

scholarly journals Flexural Performance of Cross-Laminated Bamboo (CLB) Slabs and CFRP Grid Composite CLB Slabs

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Qingfang Lv ◽  
Weiyang Wang ◽  
Ye Liu
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Strain Analysis ◽  
Manufacturing Processes ◽  
Load Carrying Capacity ◽  
Layer Number ◽  
Flexural Performance ◽  
Number Of Layers ◽  
Laminated Bamboo ◽  
Load Carrying

In order to accord well with the requirements of sustainable development and green construction, a cross-laminated bamboo composed of an odd number of orthogonally oriented layers of bamboo scrimber is proposed in this paper. Adjacent bamboo layers are face-bonded by structural adhesives under pressure. The uniform mechanical and physical properties can be obtained through the orthogonal layup. Flexural performances of three groups of one-way CLB slabs and two groups of one-way CLB slabs strengthened with CFRP grids were investigated via four-point monotonic loading configuration until failure. Experimental parameters of thickness of the layer, number of layers, and manufacturing processes of CFRP grids were taken into consideration. Experimental observations showed that the failure of the CLB slab was brittle, and different failure modes were found in the CLB slab with CFRP grids via different manufacturing processes. Test results showed that the load-carrying capacity increased with the thickness of the layer, number of layers, and application of CFRP grids pressed in the bamboo layer, but the CFRP grids pressed in the interface of adjacent bamboo layers weakened the load-carrying capacity. The strain analysis demonstrated that the compression region was utilized with more efficiency via CFRP grids pressed in the bamboo layer, and the plane cross section assumption is suitable for both CLB slab and CLB slab strengthened with CFRP grids. A theoretical calculation method of flexural load-carrying capacity was proposed for the CLB slab, the accuracy of which was proved.

scholarly journals Effect of Preload Level on Flexural Load-carrying Capacity of RC Beams Strengthened by Externally Bonded FRP Sheets

2015 ◽  
Vol 9 (1) ◽  
pp. 426-434 ◽  
Author(s):  
Guibing Li ◽  
Aihui Zhang ◽  
Yugang Guo
Keyword(s):  
Carrying Capacity ◽  
Concrete Strength ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Test Results ◽  
Damage Level ◽  
Cfrp Sheets ◽  
Flexural Performance ◽  
Load Carrying ◽  
Externally Bonded

Most of the laboratory tests investigated the flexural performance of un-preloaded or undamaged RC beams strengthened with CFRP composites. However, in engineering applications, the structural member must carry a certain load or damage. There is a lack of systematical investigations on the effects of preload or damage level on the flexural load-carrying capacity of CFRP-strengthened RC beams. This paper tested 22 RC beams to investigate the influence of preload level on flexural load-carrying capacity of CFRP-strengthened RC beams. The test variables are preload level, amount of CFRP sheets, tension rebar ratio, and concrete strength. The test results show that if the preload level is not more than 80% of the yielding strength of the original beam, the preload or damage level does not influence the flexural load-carrying capacity of CFRP-strengthened RC beams. However, the ultimate flexural load-carrying capacity is significantly poor than that of RC beam strengthened under a preload level not more than 80% of the yielding strength, if the RC beams are strengthened under a preload level more than 90% of the yielding strength.

Experimental Study on Shear Strengthening of Reinforced Concrete Beams Using Different Techniques of Concrete Jacketing

2021 ◽  
Vol 21 (2) ◽  
pp. 53-61
Author(s):  
Mohammed F. Ojaimi
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Shear Failure ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Load Carrying

A large number of RC structures or at least some of their members need strengthening or rehabilitation. Among the typical failure modes, the shear failure is more dangerous and less predictable, because of usually brittle behavior and sudden collapse. Therefore, there are necessities for upgrading the shear capacity and the local ductility of reinforced concrete beams. In this study, four different techniques of concrete jacketing were used to improve the behaviors of the shear deficiencies beams. The four techniques used in this study to enhance the behavior of the beams were by using a Self-Compacted Fiber Reinforced Concrete jacket without stirrups (S.-J. + Steel Fiber), a concrete jacket of Self Compacted Concrete with stirrups (S.-J. + Stirrups), a concrete jacket of ferrocement jacket (S.-J. + Ferrocement), and a concrete jacket of ferrocement jacket with external steel reinforcing bars (S.-J. + Ferrocement + R). These techniques contributed to enhancing the load-carrying capacity and delaying the appearance of the first crack in tested beams compared with the control beam by a percentage of (35, 59, 30, 6) % and (18, 35, 81, 80) %, respectively. The specimen (S.-J. + Stirrups) showed the best performance in comparison with the other used strengthening techniques used in this study in terms of stiffness and the ultimate load-carrying capacity. The ferrocement jacket (S.-J. + Ferrocement) was found to be the most suitable jacketing system used to enhance the shear capacity in terms of cracking load.

scholarly journals RC BEAMS STRENGTHENED WITH HPFRCC: EXPERIMENTAL AND NUMERICAL RESULTS

2016 ◽  
Vol 22 (2) ◽  
pp. 254-270 ◽  
Author(s):  
Mykolas DAUGEVIČIUS ◽  
Juozas VALIVONIS ◽  
Tomas SKUTURNA ◽  
Vladimir POPOV
Keyword(s):  
Carrying Capacity ◽  
High Performance ◽  
Concrete Beams ◽  
Numerical Results ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Cementitious Composite ◽  
Negative Effects ◽  
Load Carrying

The study analyses the behaviour of reinforced concrete beams strengthened with high-performance fibre-reinforced cementitious composite (HPFRCC). Six beams were divided into two equal groups and strengthened. In total, nine beams were tested, including three control beams that were not strengthened. Control beams were over-reinforced. The beams of the first group were strengthened in the compressed part while those of the second group were strength­ened in the compressed and tensioned parts of the section. The experimental results of all tested beams were compared with numerical results. The positive and negative effects of strengthening the resistance and serviceability of the beams were experimentally determined. The obtained results showed that the load-carrying capacity of all strengthened beams increased and their deflections decreased; however, crack width in the beams of the second group increased while that of the beams of the first group decreased. The width of cracks increased because the number of cracks decreased. The findings of this study show a comparison of strains, deflections, cracking and load-carrying capacity and indicate that strengthening changed the failure of the beams.

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