scholarly journals Experimental Research on the Flexural Performance of RC Rectangular Beams Strengthened by Reverse-Arch Method

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1666
Author(s):  
Tao Yu ◽  
Quansheng Sun ◽  
Chunwei Li ◽  
Yancheng Liu

Carbon fiber-reinforced polymer (CFRP) reinforcement technology has been widely used in the reinforcement of reinforced concrete (RC) beams. At this stage, high prestressed CFRP board reinforcement is often used in actual reinforcement. However, most reinforced bridges are designed for a long time, and the design value of the protective layer is low, and it is impossible to achieve a large prestressed tension. Therefore, this paper proposes the reverse-arch method to paste the CFRP board and apply low prestress to strengthen the symmetrical RC beam. Through the three-point forward loading test, the cracking load, ultimate load, crack width, mid-span deflection, strain and failure mode of a reverse-arch method-pasted CFRP board-reinforced beam, a directly pasted CFRP board-reinforced beam and an unreinforced beam are compared. The results show that the load-bearing capacity and stiffness of the test beam can be improved by pasting CFRP plates with anti-arch method, but the ductility of the test beam is reduced. Compared with the unreinforced beam, the maximum cracking load and ultimate load are increased by 56% and 63% respectively. The reverse-arch method can produce low prestress, improve the stiffness and bearing capacity of members, and has a good prospect of engineering application.

2014 ◽  
Vol 578-579 ◽  
pp. 1338-1342
Author(s):  
Jin Lin Huang ◽  
Pei Yan Huang ◽  
Jin Hui Xie

Based on experimental research and calculation theory of flexural bearing capacity, a method for calculating the ultimate load bearing of normal section member strengthened with prestressed CFL is proposed. Static load experimental results of two beams show that when prestress level is 20%, the cracking load and yield load of RC beams strengthened with prestressed CFL are 37.5% and 39.3% respectively. It is larger than that of RC beam strengthened with nonprestressed CFL.


2011 ◽  
Vol 250-253 ◽  
pp. 3361-3366
Author(s):  
Hua Chen ◽  
Kan Kang ◽  
Lang Ni Deng ◽  
Peng Zhang

For RC beams strengthened with prestressed carbon fiber reinforced polymer (CFRP) plates, calculate methods for the cracking load, the yield load and the ultimate load are derived base on the analysis of normal section stress. The test of reinforced concrete beams strengthened with prestressed CFRP plates were carried out, and analytical results are compared with experimental results. Comparisons show that the calculated values agree well with the experimental results.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Qingfang Lv ◽  
Ye Liu ◽  
Yi Ding

Inspired by the studies about wooden beam applied with prestressed steel plate and bamboo beam strengthened by fiber-reinforced polymer (FRP), this paper aims to explore the applicability of the prestressed basalt fiber-reinforced polymer (BFRP) sheet to the laminated bamboo beam and the variation of the flexural performance of the laminated bamboo beam applied with prestressed BFRP sheet. Two series of tests were conducted in the present study. In the first series of tests, the prestress loss of the prestressed BFRP sheet was classified and analyzed based on measured strains and deflections, which led to a derivation of the effective prestressed force considering the prestress loss. Analyses showed that the recommended value of prestress loss compared with the initial prestressed force was 22.0% based on the existing test data in the specimen preparation stage. In the second series of tests, the static loading test was performed to investigate the flexural performance of the laminated bamboo beam applied with prestressed BFRP sheet and analyze the difference between the laminated bamboo beams applied with prestressed and non-prestressed BFRP sheets. Test results showed that the no significant variation of the ultimate load and a reduction of the ultimate deformation capacity were caused by the application of the prestressed BFRP sheet.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 795 ◽  
Author(s):  
Fengjie Zhang ◽  
Junwu Xia ◽  
Guo Li ◽  
Zhen Guo ◽  
Hongfei Chang ◽  
...  

This work aimed to investigate the effects of steel tube corrosion on the axial ultimate load-bearing capacity (AULC) of circular thin-walled concrete-filled steel tubular (CFST) members. Circular thin-walled CFST stub column specimens were made of steel tubes with various wall-thicknesses. These CFST column specimens were subjected to an accelerated corrosion test, where the steel tubes were corroded to different degrees of corrosion. Then, these CFST specimens with corroded steel tubes experienced an axial static loading test. Results show that the failure patterns of circular thin-walled CFST stub columns with corroded steel tubes are different from those of the counterpart CFST columns with ordinary wall-thickness steel tubes, which is a typical failure mode of shear bulging with slight local outward buckling. The ultimate strength and plastic deformation capacity of the CFST specimens decreased with the increasing degree of steel corrosion. The failure modes of the specimens still belonged to ductile failure because of the confinement of outer steel tube. The degree of steel tube corrosion, diameter-to-thickness ratio, and confinement coefficient had substantial influences on the AULC and the ultimate compressive strength of circular thin-walled CFST stub columns. A simple AULC prediction model for corroded circular thin-walled CFST stub columns was presented through the regression of the experimental data and parameter analysis.


2010 ◽  
Vol 150-151 ◽  
pp. 198-202
Author(s):  
Zhi Gang Yan ◽  
Yan Huang ◽  
Ming Zhe An

Reactive Powder Concrete (RPC) is a new kind of building material with high strength and other good performance. The combination of RPC and steel tube will compensate the brittleness of RPC and enhance the stability of steel tube, and the loading capacity of the RPC filled steel tube will be improved. Five RPC filled steel tube columns are designed and tested to obtain the ultimate load bearing capacity, the deformation and the strain information. During the loading process, the concrete and the steel tube of the RPC filled steel tube columns are loaded simultaneously. The loading results show that the deformation of the RPC filled steel tube columns are mainly in elastic phase before the loading capacity is up to the ultimate value. The test load decreases to be 80%~90% of the ultimate loading value and then it changes to be smooth. The failure mode of the RPC filled steel tube columns is ductile. The test loading capacity is compared with the formula from the reference. The tested ultimate load bearing capacity of the steam cured RPC filled steel tube columns is higher than the calculated value. The calculated value is safe for the engineering application. The study is useful for the research and application of RPC filled steel tube column.


2009 ◽  
Vol 405-406 ◽  
pp. 343-349 ◽  
Author(s):  
Zong Cai Deng ◽  
Jian Hui Li ◽  
He Fei Lin

In order to investigate the strengthening effects of aramid fiber reinforced polymer (AFRP) sheets on the flexural performance of the corroded beams, the flexural behaviors of corroded RC beams strengthened with AFRP sheets under different degrees of corrosion (minor: reinforcement mass loss is 2.0%, medium: reinforcement mass loss is 6.0%) are researched experimentally in this paper, and compared with that of the control beams (un-corroded) and un-strengthened corroded beams. The results show that,compared with un-strengthened corroded beams under same degrees of corrosion, the cracking load, yield load and ultimate load of minor corroded RC beam strengthened with AFRP sheets is respectively increased by 20%, 27% and 60%, and increased by 15%, 36% and 83% for medium corroded RC beam strengthened with AFRP sheets respectively; The ultimate deflection of the medium corroded beam strengthened with AFRP sheets is 166% larger than that of corroded un-strengthened beam. AFRP sheets can improve significantly the bearing capacity and deformation for corroded RC beams.


2011 ◽  
Vol 194-196 ◽  
pp. 1781-1784
Author(s):  
Hua Wei ◽  
Ji Ye Zhang ◽  
Da Wei Zhu ◽  
Zhi Yuan Peng ◽  
Hai Jun Wang

In order to clear the influence of carbon fiber reinforced polymer (CFRP) on the bearing capacity of reinforced concrete beams, tests of three reinforced concrete beams strengthened with CFRP are carried out. Experimental result shows that CFRP can effectively increase bearing capacity of flexural member, and can restrain the development of crack. Cracking load, yield load and ultimate load are significantly increased. At the same time numerical simulation is done; it is good agreement with experimental results.


2011 ◽  
Vol 243-249 ◽  
pp. 457-460
Author(s):  
Jian Qing Jiang

Combined with the pile foundation engineering of a super-large highway bridge, vertical static loading test of pile with expanded diameter was carried out. The pile’s load-settlement curves, axial forces of the different pile’s section and the pile-soil interaction friction were obtained from the test. The load transfer mechanism and bearing behavior of the pile with expanded diameter under vertical load were studied. The results show that the ultimate load of the testing pile is more than 6000kN. The pile-soil interaction of the pile with expanded diameter behaviors as friction pile, and the bearing capacity of the segment with expanded diameter accounts for 40% of the ultimate load. These studies provide important references for similar projects.


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