Flexural Fatigue Performance of RC Beams Strengthened with Hybrid Fiber Sheets

2012 ◽  
Vol 166-169 ◽  
pp. 1657-1662
Author(s):  
Xu Jun Chen ◽  
Xiao E Zhu ◽  
Zhong Yang ◽  
Mu Xiang Dai
Keyword(s):  
Fatigue Life ◽  
Basalt Fiber ◽  
Reinforced Concrete Beams ◽  
Fatigue Performance ◽  
Rc Beam ◽  
Rc Beams ◽  
Hybrid Fiber ◽  
Cycle Number ◽  
Flexural Fatigue ◽  
Variation Characteristics

Based on the fatigue test for flexural performance of five reinforced concrete beams, the variation characteristics of the crack development, concrete strain, steel strain, fiber strain with the cycle number of the fatigue load were analyzed, and the effect of hybrid fiber sheets and basalt fiber reinforced polymer(BFRP)sheets on flexural fatigue performance of the strengthened beam was studied. The results show that the accumulated damage of RC beams strengthened with hybrid fiber sheets was slowed down significantly, the anti-crack property was much improved, and the fatigue life was greatly prolonged. Compared with the ordinary RC beam and the RC beam strengthened with double BFRP sheets, the fatigue life of RC beams strengthened with hybrid CFRP/BFRP(C/BFRP) sheets and hybrid CFRP/GFRP(C/GFRP) sheets was increased by 291.26%, 298.63% and 10.73%, 13.53%.

Study on the Evaluation of Fatigue Life of RC Beams Strengthened with FRP Laminates

2011 ◽  
Vol 250-253 ◽  
pp. 2079-2084
Author(s):  
Li Hua Huang ◽  
Tian Qing Li ◽  
Yue Fang Wang
Keyword(s):  
Fatigue Life ◽  
Life Span ◽  
Elastic Stress ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Rc Beam ◽  
Rc Beams ◽  
Stress Strain ◽  
Externally Bonded ◽  
Stress Concentration Factors

Extensive tests have shown that externally bonded fiber reinforced polymer (FRP) laminates are particularly suited for improving the short-term and long-term behavior of deficient reinforced concrete (RC) beam. Fatigue tests conducted to date indicate that fatigue life of RC beam bonded with FRP laminates lies in the response of steel rebar. Study on the method of nominal elastic stress (strain) for evaluating life-span of FRP strengthened beam is carried out in this paper. By analyzing fatigue tests, the acceptable stress concentration factors and S-N curves are suggested to be used to account for the fatigue behavior of RC beams strengthened with FRP laminates. Analytical results are compared with experimental data from two sets of fatigue tests on stresses and life-span, which shows agreeable trend. Based on the findings, the approach of nominal elastic stress (strain) can be extended to evaluate the fatigue life of RC beam bonded with FRP laminates.

Flexural Performance of Corroded RC Beams Strengthened with Hybrid Fiber Reinforced Polymers

2011 ◽  
Vol 243-249 ◽  
pp. 5618-5623
Author(s):  
Jian Hui Li ◽  
Ying Li ◽  
Zong Cai Deng
Keyword(s):  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Rc Beam ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymers ◽  
Displacement Ductility ◽  
Flexural Performance ◽  
Reinforced Polymer

The research program is aimed at investigating the effectiveness of application of good ductile hybrid fiber reinforced polymer (FRP) to upgrade corroded RC beams. A total of 5 RC beams are tested under flexural load, the results show that compared with the un-strengthened corroded RC beam, the crack, yield, maximum and ultimate load of corroded RC beam strengthened with hybrid FRP sheets is increased by 14%, 35%, 102% and 109% respectively, and the displacement ductility factor is only decreased by 11%, which indicate that the hybrid FRP sheets can improve significantly the flexural performance of corroded RC beam.

scholarly journals Investigation on Fatigue Performance of Asphalt Mixture Reinforced by Basalt Fiber

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5596
Author(s):  
Keke Lou ◽  
Xing Wu ◽  
Peng Xiao ◽  
Cong Zhang
Keyword(s):  
Fatigue Life ◽  
Fatigue Failure ◽  
Asphalt Mixture ◽  
Basalt Fiber ◽  
Fatigue Performance ◽  
Control Mode ◽  
Dissipated Energy ◽  
Enhancement Effect ◽  
Stiffness Modulus ◽  
Change Rate

Basalt fiber has been widely used in asphalt mixture due to its excellent mechanical properties and good combination with asphalt. In order to systematically evaluate the enhancement effect of basalt fiber on the fatigue performance of the mixtures, gradations of Stone Mastic Asphalt and Superpave with different nominal maximum aggregate sizes, namely SMA-13, SUP-20 and SUP-25, were prepared, and a four-point bending beam fatigue test was adopted under the strain control mode. The fatigue damage mode was assessed based on the phenomenology theory, energy dissipation theory and change rate of dissipated energy. The results showed that basalt fiber could well increase the fatigue life of the mixtures. Basalt fiber could also increase the cumulative dissipated energy of the mixtures, and it was linearly correlated with the fatigue life in double logarithmic coordinates. In the meantime, adding basalt fiber could increase the change rate of dissipated energy of the mixtures. Furthermore, it is not appropriate to take the stiffness modulus declined to 50% of the original as the fatigue failure criterion of the mixture; this paper suggested that it is reasonable when the stiffness modulus was 15–25% that of the initial. These findings provide a theoretical basis for exploring the fatigue failure of asphalt pavements.

Research on Mechanical Behavior of Reinforced RC Beams Strengthened with Anti-Arch Method

2011 ◽  
Vol 94-96 ◽  
pp. 1395-1401
Author(s):  
Dai Guo Chen ◽  
Yong Yao ◽  
Yong Jun Deng
Keyword(s):  
Numerical Simulation ◽  
Mechanical Property ◽  
Carrying Capacity ◽  
Crack Width ◽  
Concrete Beams ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Rc Beam ◽  
Rc Beams

We analyze the mechanical property of strengthening RC beam by using the method of arch pasting with carbon fiber and directly pasting CFRP through numerical simulation and model test. It explains that strengthening RC girder by using the method of arch can solve the influence of beam's loading by the second time which exists in the method of pasting CFRP in strengthening reinforced concrete beams and it can improve the girder's load when it cracks and the carrying capacity; decreasing the deflection deformation and crack width and gap when the girder carries load; It can make the most use of the character of carbon fiber's high strength. The results play very important role of guiding to engineering.

Effect of overloading on fatigue performance of reinforced concrete beams strengthened with externally post-tensioned carbon-fibre-reinforced polymer tendons

2008 ◽  
Vol 35 (11) ◽  
pp. 1294-1307 ◽  
Author(s):  
Ahmed Elrefai ◽  
Jeffrey S. West ◽  
Khaled A. Soudki
Keyword(s):  
Reinforced Concrete ◽  
Fatigue Life ◽  
Carbon Fibre ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fatigue Performance ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Post Tensioned

This paper presents the results of an experimental and analytical study of the fatigue performance of reinforced concrete beams strengthened with externally post-tensioned carbon-fibre-reinforced polymer (CFRP) tendons. Two loading conditions prior to strengthening the beams were investigated: in-service loading and overloading. A total of 18 beams were tested to failure: three under monotonic loading and fifteen under fatigue loads. The CFRP tendons were post-tensioned to 40% of their ultimate capacity. The results demonstrated that overloading the beams had no discernable effect on the fatigue life of the strengthened beams. The strain-reduction approach for unbonded steel tendons was modified to account for using CFRP tendons and for the permanent deformations resulting from the overloading process. The loading history of the beams prior to and after post-tensioning was incorporated into a strain-life fatigue model to predict the fatigue life of the strengthened beams.

Study on Flexural Fatigue Performance and Damage Laws of Hybrid Fiber Reinforced Concrete

2010 ◽  
Vol 129-131 ◽  
pp. 1138-1141
Author(s):  
Meng Chen ◽  
Zhe An Lu ◽  
Zhi Gang Ren ◽  
You Zou
Keyword(s):  
Reinforced Concrete ◽  
Plain Concrete ◽  
Single Step ◽  
Fiber Reinforced Concrete ◽  
Fatigue Performance ◽  
Fatigue Properties ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Flexural Fatigue ◽  
Fatigue Experiment

The flexural fatigue experiment of plain concrete (C) and Steel - Polypropylene Hybrid Fiber Reinforced Concrete (HFRC) is carried out to study the flexural fatigue performance and damage laws under cyclic loading. With the strain gauges pasted on the bottom of the specimens, the strain is collected by dynamic acquisition instrument.We obtain the fatigue life and the maximum strain - cyclic ratio ( ) curves by counting and analyzing the results of fatigue experiment ,which move forward a single step for analysis of fatigue damage laws of HFRC. The study would provide reference for flexural fatigue properties of HFRC.

scholarly journals Sustainability of Reinforced Concrete Beams with/without BF Influenced by Cracking Capacity and Chloride Diffusion

2020 ◽  
Vol 12 (3) ◽  
pp. 1054 ◽  
Author(s):  
Yurong Zhang ◽  
Chaojun Mao ◽  
Jiandong Wang ◽  
Yanhong Gao ◽  
Junzhi Zhang
Keyword(s):  
Diffusion Coefficient ◽  
Reinforced Concrete ◽  
Basalt Fiber ◽  
Load Level ◽  
Reinforced Concrete Beams ◽  
Chloride Diffusion ◽  
Rc Beam ◽  
Chloride Diffusion Coefficient ◽  
Coupling Interaction ◽  
Chloride Diffusivity

Concrete’s production causes pronounced environmental impacts. It is confirmed that adding basalt fiber (BF) into concrete can improve the mechanical properties and reduce the chloride diffusion coefficient of concrete. Moreover, research on the environmental impact of BF and its application in concrete has gradually emerged in recent years. However, there is little research on the chloride diffusivity of concrete structures with BF under the coupling interaction of external loads and chloride action. Therefore, at first, six beams were cast to obtain the depth-dependent chloride diffusivity of concrete under the coupling interaction of chloride penetration and 50% and 80% of the cracking capacity. Then, a functional unit (FU) combining durability, cracking capacity and volume was proposed to evaluate the sustainability of the concrete structure. In addition, three extra FUs (volume, considering volume and cracking capacity simultaneously and considering volume, cracking capacity and durability simultaneously) were also proposed and compared with the first FU. Results indicate that, regardless of the applied load level, the average chloride diffusion coefficient of a reinforced concrete (RC) beam with BF is larger than that of an ordinary RC beam. Moreover, the sorting of life cycle assessment (LCA) results will vary significantly with the different preset functional units. When taking the cracking capacity into consideration, adding BF into concrete is a suitable solution to improve the sustainability of RC beams.

Static and Fatigue Experimental Research on Reinforced Concrete Beams Strengthened with Pre-Stress CFRP Rods

2011 ◽  
Vol 368-373 ◽  
pp. 2001-2005
Author(s):  
Li Hua Xu ◽  
Hao Zeng ◽  
Feng Xu ◽  
Wen Ke Qin
Keyword(s):  
Reinforced Concrete ◽  
Fatigue Life ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Reinforced Concrete Beams ◽  
Fatigue Performance ◽  
Stress Range ◽  
Reinforcing Bars ◽  
Flexural Capacity ◽  
Novel Technique

In this paper, a total of six reinforced concrete beams including four beams strengthened with externally prestressed CFRP rods and two unstrengthened beams have been tested under monotonic and cylic loads in order to investigate the influence of a novel technique on the flexural static and fatigue behavior of the specimens. The experimental results show that the static and fatigue performance of strengthened members have been improved in terms of that the flexural capacity is greatly enhanced, the fatigue life is increased and the stress range of the internally tensile reinforcing bars is decreased as compared with the unstrengthened ones. It indicates that the developed technique can enhance the flexural capacity as well as improve the fatigue performance of RC members.

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