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

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.

2011 ◽  
Vol 243-249 ◽  
pp. 258-262
Author(s):  
Jun Chen ◽  
Jia Lv ◽  
Qi Lin Zhang ◽  
Zhi Xiong Tao ◽  
Jun Chen

Laminated glass has been increasing widely used in high rise buildings as a kind of safety glass in recent years. So we should analyze its material property. In this paper, we use flexural experiments and ANSYS program to analyze the main factors that affect the flexural capacity of the laminated glass. The test results show that the flexural capacity is closely related to film. And the ANSYS program had got good agreement with the experimental results. Comparison of experimental results with calculated ones indicates that the current design code will lead to conservative results and the equivalent thickness of laminated glasses provided in the code should be further discussed.


2020 ◽  
Vol 984 ◽  
pp. 230-238
Author(s):  
Yun Yan Liu ◽  
Ying Fang Fan

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.


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.


2011 ◽  
Vol 268-270 ◽  
pp. 659-663
Author(s):  
Hua Chen ◽  
Kan Kang ◽  
Lang Ni Deng

The method of applying prestress to CFRP plates can make full use of the characteristics of high-strength, enhance the force properties, prevent peeling damage and reduce the strain lag. Construction technology of prestressed CFRP plates strengthening reinforcement concrete beams was introduce in this paper, and bending test of 6 reinforcement concrete beams strengthened with prestressed CFRP plates were carried out based on the self-developed prestressed CFRP plates supporting anchorages. The test results indicate that the flexural capacity and crack resistance capacity can be increased compared with non-prestressed CFRP plates, and the construction technology can be adopted in practical projects.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Chunyu Fu ◽  
Dawei Tong ◽  
Yuyang Wang

Concrete cracking causes a gradual change in strain distributions along the cross section height of reinforced concrete beams, which will finally affect their instantaneous stiffness. A method for assessing the stiffness is proposed based on the gradual change, which is considered through modeling different strain distributions for key sections in cracked regions. Internal force equilibria are adopted to find a solution to top strains and neutral axes in the models, and then the inertias of the key sections are calculated to assess the beam stiffness. The proposed method has been validated using experimental results obtained from tests on five reinforced concrete beams. The predicted stiffness and displacements are shown to provide a good agreement with experimental data. The instantaneous stiffness is proven to greatly depend on the crack number and depth. This dependence can be exactly reflected by the proposed method through simulating the gradual change in concrete strain distributions.


2011 ◽  
Vol 243-249 ◽  
pp. 621-624
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo

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.


2011 ◽  
Vol 71-78 ◽  
pp. 815-817 ◽  
Author(s):  
Jiong Feng Liang ◽  
Ze Ping Yang ◽  
Zhi Ming Qiu

The mechanical properties of high-strength reinforced concrete beams strengthened with FRP ( fiber reinforce polymer) are further investigated theoretically including it s failure mechanism and loadability,based on earlier theoretical works on RC beams. And the correlation equation of flexural capacity on the cross section of high-strength reinforced concrete beams strengthened with FRP is deduced according to different types of failure.The correlation equation is shown to be in good agreement with the experimental results, which can be referred to engineering application.


2012 ◽  
Vol 166-169 ◽  
pp. 1797-1800
Author(s):  
Hong Chang Qu ◽  
Hong Yuan Li ◽  
Xuan Zhang

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.


2012 ◽  
Vol 184-185 ◽  
pp. 988-991
Author(s):  
Seung Hun Kim

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.


2013 ◽  
Vol 438-439 ◽  
pp. 804-806
Author(s):  
Jiong Feng Liang ◽  
Jian Bao Wang ◽  
Jian Ping Li

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.


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