Experimental Study on Flexural Behavior of CFRP Reinforced Pre-Stressed Concrete Beams with Initial Cracks

2020 ◽  
Vol 984 ◽  
pp. 230-238
Author(s):  
Yun Yan Liu ◽  
Ying Fang Fan
Keyword(s):  
Ultimate Load ◽  
Concrete Beams ◽  
Flexural Behavior ◽  
Test Results ◽  
Bending Tests ◽  
Reinforced Beams ◽  
Beam Section ◽  
Non Destructive ◽  
Initial Cracks ◽  
Good Agreement

In order to explore the flexural behavior of CFRP reinforced pre-stressed concrete (PC) beams with initial cracks, 6 pre-tensioned beams were manufactured. Then the beams were pre-loaded to crack with 40% and 60% ultimate load respectively, and the beams were strengthened by CFRP under the conditions of load holding and fully unloaded. After that, the four-points bending tests were performed, and beam section strains, flexural capacities and cracks were analyzed. The results demonstrate that the ultimate load of CFRP reinforced beams increased by 10%~18%, and the ultimate loads of CFRP reinforced load holding beams were 3% and 6% lower than that of CFRP reinforced non-destructive beam, and the inhibiting effect of CFRP on cracks was weakened, the hysteresis strains should be considered for them. In this paper, the fiber hysteresis strains were calculated by the method of full section decompression moment, and the flexural capacities of CFRP reinforced PC beams were calculated, which are in good agreement with the test results.

Experimental Research on Ceramsite Concrete Beams

2012 ◽  
Vol 166-169 ◽  
pp. 708-711
Author(s):  
Chuang Du ◽  
Wen Ling Tian ◽  
Xiao Wei Wang ◽  
De Jun Wang
Keyword(s):  
Concrete Beam ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Polypropylene Fiber ◽  
Flexural Behavior ◽  
Polypropylene Fibers ◽  
Test Results ◽  
Normal Concrete ◽  
Ordinary Concrete ◽  
Cover Thickness

Six specimens, including 4 ceramsite concrete beams(one of beams mixed into the polypropylene fiber ) and 2 normal concrete beams, were tested to investigate the flexural behavior. The test results show that cracking load of ceramsite concrete beams is slightly smaller than the ordinary concrete beam and cracking load of ceramsite concrete beams has significantly improved after mixing into the polypropylene fibers. The ultimate load of ceramsite concrete beams are no less than ordinary concrete beam,and fibers have not effects on the increase of ultimate load. Load-deflection curves were compared,and the results show that stiffness of ceramsite concrete beam is less than ordinary concrete beam. Ductility of ceramsite concrete beam is poorer than ordinary concrete beam. Fibers improve the stiffness of ceramsite concrete beam. Cover thickness of concrete beam has little effect on the performance of ceramsite concrete beam.

Analysis on Flexural Behavior of Concrete Beams with CFRP-GFRP Bars

2010 ◽  
Vol 163-167 ◽  
pp. 1565-1568 ◽  
Author(s):  
Jiang Yong Cai ◽  
Yan Tao He ◽  
Ying Ying Liu ◽  
Jing Liang Xiong
Keyword(s):  
Concrete Beams ◽  
Experimental Results ◽  
Flexural Behavior ◽  
Test Results ◽  
Flexural Capacity ◽  
Excellent Performance ◽  
Gfrp Bars ◽  
Good Agreement

This paper presents a method for designing and predicting the flexural behavior and capacity of concrete beams with mixed CFRP-GFRP bars. The design of the section with CFRP-GFRP bars is expected to obtain better performance in serviceability and deformability comparing with the section with only CFRP bars or GFRP bars by realizing successive rupture of CFRP and GFRP bars in the section. The corresponding equations are proposed to calculate the flexural capacity, strain and stress of the section. The calculating values of flexural capacity are compared to existing test results and it is found that the calculating values are in good agreement with the experimental results. Further analysis on a calculating example shows that the section with CFRP-GFRP bars designed appropriately presents excellent performance.

Flexural Analysis of Simply Supported Concrete Beam Reinforced with FRP Bars

2012 ◽  
Vol 182-183 ◽  
pp. 1617-1621
Author(s):  
Hong Chang Qu ◽  
Ling Ling Chen ◽  
Sheng Li Zhang
Keyword(s):  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Test Results ◽  
Simply Supported ◽  
Reinforced Polymer ◽  
Reinforced Beams ◽  
Theoretical Predictions ◽  
Flexural Analysis ◽  
Frp Bars

The purpose of this paper is to experimentally and theoretically study the flexural behavior of concrete beams reinforced with fiber reinforced polymer (FRP) bars. In this research, two series of concrete beams reinforced with GFRP and CFRP were tested up to failure. Beam stiffness was the same for all beams until the appearance of first cracks. Deflection at failure was identical for beams reinforced with GFRP and CFRP bars, but force at failure of CFRP reinforced beams bars was greater. The theoretical analysis for calculating deflections was carried out. The theoretical results were compared to the test results for the simply supported beam deflections, and the theoretical predictions agree well with the test results.

Capacity Calculation on Reinforced Concrete Beams Strengthened by Externally Prestressed Transverse Tensioning Method

2013 ◽  
Vol 671-674 ◽  
pp. 636-641
Author(s):  
You Zhi Tong ◽  
Tian Wen Wang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Reinforced Beams ◽  
Secondary Load ◽  
Capacity Calculation ◽  
Flexural Bearing Capacity ◽  
Improvement Measures ◽  
Good Agreement

Eight reinforced concrete beams (six externally reinforced and two contrast beams) were tested under the primary or secondary load experiment. According to the test results, the existing formulas and specifications were applied to make calculations on reinforced beams. Besides, comparisons were made between test and calculation value, the differences were pointed out and improvement measures were proposed. Comparisons were made between test and calculation value on normal section flexural bearing capacity of reinforced concrete beams strengthened by externally prestressed transverse tensioning method and they are in good agreement.

scholarly journals Flexural Behavior of Rubberized Reinforced Concrete Beams

2018 ◽  
Vol 7 (4.20) ◽  
pp. 316 ◽  
Author(s):  
Adel A. Al-Azzawi ◽  
Dalia Shakir ◽  
Noora Saad
Keyword(s):  
Ultimate Load ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Fiber Content ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Rubberized Concrete ◽  
Normal Concrete ◽  
Rubber Material ◽  
Rubber Waste

In Iraq, the use of rubber waste material in concrete is an interesting topic due to its availability in large volumes. Researches of applications of rubber waste in concrete have been increased since 2003. Many studies carried out to investigate the performance of concrete using different ratios of rubber as a replacement to fine or coarse aggregate. In this research, rubber wastes from scrapped tires have been added as fiber to concrete mix with presence of 0.5% superplasticizer. The flexural behavior of concrete beams, mechanical properties of concrete and workability of concrete mixes have been studied. Rubber fibers ranging from (2-4) mm were added in percentages of 0.5% and 1%) of the cement weight. The results have demonstrated that the addition of rubber material as fibers in natural aggregate concrete enhances its ductility, compressive strength and tensile strength compared to the normal concrete. The effect of rubber fiber content is found to be significant on the behavior of tested beams. If the fiber content increased from 0 to 0.5% the cracking load increased by 60 % and ultimate load increased by 21%. For rubberized concrete, if the fiber content increased from 0.5 to 1.0%, the cracking load decreased 7% and ultimate load increased by 4%.   

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.

Flexural Tests of Fiber-Reinforced-Concrete Beams Reinforced with FRP Rebars

2012 ◽  
Vol 166-169 ◽  
pp. 1797-1800
Author(s):  
Hong Chang Qu ◽  
Hong Yuan Li ◽  
Xuan Zhang
Keyword(s):  
Concrete Beams ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Test Results ◽  
Flexural Performance ◽  
Flexural Tests ◽  
Hybrid Reinforcement ◽  
Brittle Mode

This paper investigates the flexural performance of FRP/FRC hybrid reinforcement system as well as FRP/plain concrete beams. Test results showed that the crack widths of FRP/FRC beams were smaller than those of FRP/plain concrete beams at the different corresponding load. With the increase of load, the crack spacing slightly decreased. The plain concrete beams failed in a more brittle mode than the FRC beams. Once they reached their ultimate moments, the load dropped fleetly. Compared to the companion beam, the addition of fibers improved the flexural behavior.

Flexural Behavior of Void Reinforced Concrete Slab with CFRP Reinforcing Bars

2012 ◽  
Vol 184-185 ◽  
pp. 988-991
Author(s):  
Seung Hun Kim
Keyword(s):  
Concrete Slab ◽  
Flexural Behavior ◽  
Test Results ◽  
Compression Zone ◽  
Reinforcing Bars ◽  
Flexural Capacity ◽  
Reinforced Concrete Slab ◽  
Bending Tests ◽  
Bending Performance ◽  
Flexural Members

Use of hollow material in slab can reduce self-weight and deflection than solid slab with CFRP reinforcement. This study was intended to evaluate the bending performance of void flexural members with CFRP reinforcements by bending tests. Test results showed that specimens with void and solid section had the similar failure mode by concrete crushing at the compression zone, and that there was a big flexural capacity difference between the two section. Flexural capacity of solid section with CFRP bars was increased by 55% for void section. Thus, for the design of flexural members with CFRP bars by concrete crushing failure, it is important to calculate the exact distribution of strains and stresses, and to consider the reduction of flexural strength of void section.

Experimental Research on Bending Performance of Concrete Beams Reinforced with CFRP-PCPs Composite Rebars

2013 ◽  
Vol 438-439 ◽  
pp. 804-806
Author(s):  
Jiong Feng Liang ◽  
Jian Bao Wang ◽  
Jian Ping Li
Keyword(s):  
Experimental Research ◽  
Prestressed Concrete ◽  
Crack Width ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Experimental Results ◽  
Flexural Behavior ◽  
Bending Performance ◽  
Reinforced Beams

The flexural behavior of concrete beams reinforced with CFRP-PCPs composite rebars was studied. Experimental results showed that the deflection of beams reinforced with highly prestressed prisms is at service loads coMParable to deflection of steel reinforced beam. Flexural cracks of CFRP-PCPs composite rebars reinforced beams are hairline before prism cracking, and widened after the prism cracking. When the concrete beam was reinforced with the prestressed concrete prisms, the crack width decreased as the prestress in the prism increased.

Experiment Research of Flexural Behavior of Reinforced RC Beams Strengthened with the External Prestressed CFRP Plates

2012 ◽  
Vol 466-467 ◽  
pp. 225-228
Author(s):  
Kan Kang ◽  
Peng Zhang ◽  
Feng Tao Liu
Keyword(s):  
Flexural Behavior ◽  
Utilization Rate ◽  
Rc Beams ◽  
Test Results ◽  
Experiment Research ◽  
Flexural Performance ◽  
Cfrp Plate ◽  
Reinforced Beams ◽  
Bending Capacity ◽  
Prestressed Anchor

Based on the the self-developed prestressed CFRP plate anchorage,the test specimens comprised 5 RC beams strengthened with the way the external prestressed CFRP plates,the research on the different prestressed tension and different span beam about the influence of the bending capacity , ultimate bearing capacity,cross section strain, CFRP strain and deflection of the test reinforced beams on the research. The test results showed that: the externally prestressed CFRP plate can obviously increase of the flexural performance of RC beams, and improve the utilization rate of the strength of the CFRP plate, through the external prestressed anchor of CFRP plate for a tension, reducing the RC beams crack, and improving the ductility of the RC beams.

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