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

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.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yousef Al Rjoub ◽  
Ala Obaidat ◽  
Ahmed Ashteyat ◽  
Khalid Alshboul

PurposeThis study aims to conduct an experimental study and finite element model (FEM) to investigate the flexural behavior of heat-damaged beams strengthened/repaired by hybrid fiber-reinforced polymers (HFRP).Design/methodology/approachTwo groups of beams of (150 × 250 × 1,200) mm were cast, strengthened and repaired using different configurations of HFRP and tested under four-point loadings. The first group was kept at room temperature, while the second group was exposed to a temperature of 400°C.FindingsIt was found that using multiple layers of carbon fiber-reinforced polymer (CFRP) and glass fiber-reinforced polymer (GFRP) enhanced the strength more than a single layer. Also, the order of two layers of FRP showed no effect on flexural behavior of beams. Using a three-layer scheme (attaching the GFRP first and followed by two layers of CFRP) exhibited increase in ultimate load more than the scheme attached by CFRP first. Furthermore, the scheme HGC (heated beam repaired with glass and carbon, in sequence) allowed to achieve residual flexural capacity of specimen exposed to 400°C. Typical flexural failure was observed in control and heat-damaged beams, whereas the strengthened/repaired beams failed by cover separation and FRP debonding, however, specimen repaired with two layers of GFRP failed by FRP rupture. The FEM results showed good agreement with experimental results.Originality/valueFew researchers have studied the effects of HFRP on strengthening and repair of heated, damaged reinforced concrete (RC) beams. This paper investigates, both experimentally and analytically, the performance of externally strengthened and repaired RC beams, in flexure, with different FRP configurations of CFRP and GFRP.


2011 ◽  
Vol 255-260 ◽  
pp. 3124-3128
Author(s):  
Jian Hui Li ◽  
Ying Li ◽  
Zong Cai Deng

Corroded RC columns do not possess necessary ductility to dissipate seismic energy during a major earthquake, the study investigates the use of hybrid fiber reinforced polymer (FRP) wrapping as a method of retrofitting non-ductile corroded RC columns, and a model to determine the envelope response of RC corroded columns strengthened with hybrid FRP are presented based on cross-section analysis for undamaged RC element. The results show that the technique of strengthening corroded RC column with hybrid FRP is quite effective, the envelope curve estimated using the linear plane assumption with modification by reinforcement slip model, may still be used as the envelope curve of RC corroded columns strengthened with hybrid FRP, a good agreement between analytical and experimental results is observed.


2018 ◽  
Vol 52 (23) ◽  
pp. 3173-3181 ◽  
Author(s):  
Kuldeep Agarwal ◽  
Suresh K Kuchipudi ◽  
Benoit Girard ◽  
Matthew Houser

Fiber reinforced polymer composites have been around for many decades but recently their use has started to increase in multiple industries such as automotive, aerospace, and construction. The conventional composite manufacturing processes such as wet lay-up, resin transfer molding, automatic lay ups etc. suffer from a lot of practical and material issues which have limited their use. The mechanical properties of the parts produced by such processes also suffer from variation that causes problems downstream. Composites based additive manufacturing processes such as Fused Deposition Modeling and Composite Filament Fabrication are trying to remove some of the barriers to the use of composites. Additive manufacturing processes offer more design and material freedom than conventional composite manufacturing processes. This paper compares conventional composite processes for the manufacturing of Epoxy-Fiberglass fiber reinforced polymers with composite filament fabrication based Nylon-Fiberglass fiber reinforced polymers. Mechanical properties such as tensile strength, elastic modulus, and fatigue life are compared for the different processes. The effect of process parameters on these mechanical properties for the composite filament fabrication based process is also examined in this work. It is found that the composite filament fabrication based process is very versatile and the parts manufactured by this process can be used in various applications.


2020 ◽  
Vol 23 (8) ◽  
pp. 1534-1547 ◽  
Author(s):  
Jingting Huang ◽  
Tao Li ◽  
Dayong Zhu ◽  
Peng Gao ◽  
An Zhou

This article studies the compressive behavior of concrete columns confined by different basalt fiber–reinforced polymers. A total of 30 columns were divided into 10 groups according to section shapes (circular and square), basalt fiber–reinforced polymer types (unidirectional basalt fiber–reinforced polymer, bidirectional basalt fiber–reinforced polymer, and hybrid basalt fiber–reinforced polymer/carbon fiber–reinforced polymers), and number of layers (0, 1, and 2). The test results showed that the compressive strengths of confined specimens increased by 20%–71% for circular columns and by 23%–41% for square columns. Similarly, the ultimate strains improved by 49%–296% for circular specimens and by 45%–145% for square specimens. The two-layer basalt fiber–reinforced polymer jacket had the best confinement effect, whereas the confining effect of bidirectional basalt fiber–reinforced polymer wrapping was relatively lower than that of unidirectional basalt fiber–reinforced polymer wrapping. Moreover, both the strength and ultimate strain of confined concrete improved with increasing number of basalt fiber–reinforced polymer layers. Finite element numerical models were also developed and verified by experimental results, and then the stress distributions of basalt fiber–reinforced polymer jackets and cross-sectional concrete were presented. Based on the test results and experimental data from several existing studies, modified strength and ultimate strain models were further developed for basalt fiber–reinforced polymer-confined circular and square columns.


2015 ◽  
Vol 766-767 ◽  
pp. 133-139 ◽  
Author(s):  
Jeswin Arputhabalan ◽  
K. Palanikumar

This paper deals with tensile properties of natural fiber reinforced polymer composites. Natural fibers have recently found increasing use in various fields as an alternative to synthetic fiber reinforced polymers. Due to this they have become attractive to engineers, researchers and scientists. Natural fibers are replacing conventional fibers such as glass, aramid and carbon due to their eco-friendly nature, lesser cost, good mechanical properties, better specific strength, bio-degradability and non-abrasive characteristics. The adhesion between the fibers and the matrix highly influence the tensile properties of both thermoset and thermoplastic natural fiber reinforced polymer composites. In order to enhance the tensile properties by improving the strength of fiber and matrix bond many chemical modifications are normally employed. In most cases the tensile strengths of natural fiber reinforced polymer composites are found to increase with higher fiber content, up to a maximum level and then drop, whereas the Young’s modulus continuously increases with increasing fiber loading. It has been experimentally found that tensile strength and Young’s modulus of reinforced composites increased with increase in fiber content [1].


2011 ◽  
Vol 266 ◽  
pp. 192-195
Author(s):  
Jian Hui Li ◽  
Zhao Zhong Chang ◽  
Ying Li ◽  
Zong Cai Deng

In order to research the seismic performance of strengthening corroded RC circular columns with hybrid Fiber Reinforced Polymer (FRP) sheets, ten RC columns were tested under cyclic load and constant axial. Test phenomena are described, experimental data are analyzed and compared, and the effect of the axial compression ratio and stirrup reinforcement ratio on the seismic behavior is studied. Results show that the corrosion of steel bars may introduce the brittle failure for RC columns in some extent, and the seismic performance can be enhanced effectively for RC columns strengthened with hybrid FRP. Ductility and energy dissipation are improved significantly, but the bearing capacity can be only increased within limits. When the degree of rebar corrosion is 5.1%, the maximum displacement ductility factor and accumulated energy dissipation of the strengthened corroded columns are 123% and 12.5 times larger respectively than that of the un-strengthened corroded columns.


2019 ◽  
Vol 299 ◽  
pp. 06005 ◽  
Author(s):  
Paul Bere ◽  
Emilia Sabău ◽  
Cristian Dudescu ◽  
Calin Neamtu ◽  
Marius Fărtan

The fiber reinforced polymers (FRP) represent a group of materials with a very impressive development in the last time. There are used in different applications from aerospace to sports or medicine. Carbon fiber reinforced polymer (CFRP) has special properties and tend to replace traditional materials like steel, aluminum alloys or wood. Different procedures were developed to manufacture the CFRP. Autoclave processing can be considered the most important way to obtain the best mechanical properties of this kind of material. In this paper it is presented the autoclave manufacturing process to obtain theCFRP plates. The autoclave polymerization process steps are indicated for the CFRP made of Twill textile prepreg material. The stacking sequence of the layers is [0/90]. To determine the mechanical properties of the material tensile test on standardized specimens was employed. The obtained mechanical material’s properties are comparable with steel but its density was reduced 5.5 times.


2019 ◽  
Vol 53 (24) ◽  
pp. 3469-3481
Author(s):  
Hong Yu ◽  
Suresh Advani ◽  
Dirk Heider

Increasing applications of carbon fiber reinforced polymers exploiting its electrical properties demand a good understanding of the electrical conduction mechanisms of carbon fiber reinforced polymer. Resin-rich interface, which is not uncommon to exist between composite laminae, not only affect the mechanical properties, but also the electrical conduction behavior. This study focuses on the impact of resin-rich layer on the through-thickness resistivity of carbon fiber reinforced polymer. Electrical characterizations are carried out on dry fiber tow systems as well as cured composites. Through-thickness resistivity changes of dry fibers with the sizing are compared against fibers without the sizing layer, and cured composites with added resin-rich layer against the composite laminates without the resin-rich layer. A localized Joule heating theory is proposed to explain the difference in the electrical responses. The theoretical and experimental investigations should prove useful for the development of quantitative models with Joule heating to describe electrical resistivity behavior of carbon fiber reinforced polymer.


2016 ◽  
Vol 845 ◽  
pp. 154-157
Author(s):  
Sri Tudjono ◽  
Himawan Indarto ◽  
Monica Devi

Shear reinforcement for retrofitting an RC beam using unidirectional Carbon Fiber Reinforced Polymer (CFRP) woven can only be applied on the beam’s body below the concrete floor slab. Thus, it cannot fully curb like the way stirrups do, in which it will affect the shear capacity. The CFRP can only be ‘n’or ‘u’ shaped, taking into consideration the direction of shear force. Herein, the experimental study of the shear capacity ofshear capacity the beam strengthened by FRP is carried out.shear capacity The beams are RC beams of width 150 mm, height 300 mm, span of 1000 mm, f'c = 26 MPa having 2 bar of 19 mm diameter (fy = 403.65 MPa) and stirrups 6 mm diameter of 250 mm spacing (fy=375 MPa). The shear capacity measured is then compared with the shear capacity calculated using ACI 440. The result shows that the shear capacity measured from experiment is greater than the shear capacity calculated by ACI 440. Also, theshear capacity of RC beam with CFRP reinforcement n shape is greater than u shape.


Author(s):  
Mulugeta H Woldemariam ◽  
Giovanni Belingardi ◽  
Alem T Beyene ◽  
Daniel T Reda ◽  
Ermias G Koricho

In this work the effect of nanoclay, Cloisite 20B inclusion on the mechanical behavior of a woven-type glass fiber reinforced polymer composite was experimentally investigated. Specifically, the study examined the effect of nanoclay with various weight percentages on the tensile, compressive strengths, and modulus of elasticity of glass fiber reinforced polymers in both weft and warp directions. Results showed that depending on the warp and weft directions, the inclusion of nanoclay, Cloisite 20B, significantly improved the mechanical behavior of glass fiber reinforced polymers. A better understanding of nanoclay fillers and their contribution to mechanical behaviors can lead to better design of novel structural composites.


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