Experimental and analytical investigation of using externally bonded, hybrid, fiber-reinforced polymers to repair and strengthen heated, damaged RC beams in flexure

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yousef Al Rjoub ◽  
Ala Obaidat ◽  
Ahmed Ashteyat ◽  
Khalid Alshboul
Keyword(s):  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Fiber Reinforced Polymers ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymers ◽  
Content Type ◽  
Reinforced Polymer ◽  
Damaged Beams

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.

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.

Envelope Response of Corroded RC Circular Columns Strengthened with Hybrid Fiber Reinforced Polymers

2011 ◽  
Vol 255-260 ◽  
pp. 3124-3128
Author(s):  
Jian Hui Li ◽  
Ying Li ◽  
Zong Cai Deng
Keyword(s):  
Seismic Energy ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Envelope Curve ◽  
Rc Columns ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Frp Wrapping

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.

Flexural behavior of fire damaged self-compacting concrete beams strengthened with fiber reinforced polymer (FRP) wrapping

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mervin Ealiyas Mathews ◽  
Anand N ◽  
Diana Andrushia A ◽  
Tattukolla Kiran ◽  
Khalifa Al-Jabri
Keyword(s):  
Elevated Temperature ◽  
Carbon Fiber ◽  
Ultimate Load ◽  
Research Work ◽  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Fiber Reinforced ◽  
Self Compacting Concrete ◽  
Content Type ◽  
Reinforced Polymer

PurposeBuilding elements that are damaged by fire are often strengthened by fiber wrapping techniques. Self-compacting concrete (SCC) is an advanced building material that is widely used in construction due to its ability to flow and pass through congested reinforcement and fill the required areas easily without compaction. The aim of the research work is to examine the flexural behavior of SCC subjected to elevated temperature. This research work examines the effect of natural air cooling (AC) and water cooling (WC) on flexural behavior of M20, M30, M40 and M50 grade fire-affected retro-fitted SCC. The results of the investigation will enable the designers to choose the appropriate repair technique for improving the service life of structures.Design/methodology/approachIn this study, an attempt has been made to evaluate the flexural behavior of fire exposed reinforced SCC beams retrofitted with laminates of carbon fiber reinforced polymer (CFRP), basalt fiber reinforced polymer (BFRP) and glass fiber reinforced polymer (GFRP). Beam specimens were cast with M20, M30, M40 and M50 grades of SCC and heated to 925ºC using an electrical furnace for 60 min duration following ISO 834 standard fire curve. The heated SCC beams were cooled by either natural air or water spraying.FindingsThe reduction in the ultimate load carrying capacity of heated beams was about 42% and 55% for M50 grade specimens that were cooled by air and water, respectively, in comparison with the reference specimens. The increase in the ultimate load was 54%, 38% and 27% for the specimens retrofitted with CFRP, BFRP and GFRP, respectively, compared with the fire-affected specimens cooled by natural air. Water-cooled specimens had shown higher level of damage than the air-cooled specimens. The specimens wrapped with carbon fiber could able to improve the flexural strength than basalt and glass fiber wrapping.Originality/valueSCC, being a high performance concrete, is essential to evaluate the performance under fire conditions. This research work provides the flexural behavior and physical characteristics of SCC subjected to elevated temperature as per ISO rate of heating. In addition attempt has been made to enhance the flexural strength of fire-exposed SCC with wrapping using different fibers. The experimental data will enable the engineers to choose the appropriate material for retrofitting.

Mechanical properties of fiber reinforced polymer composites: A comparative study of conventional and additive manufacturing methods

2018 ◽  
Vol 52 (23) ◽  
pp. 3173-3181 ◽  
Author(s):  
Kuldeep Agarwal ◽  
Suresh K Kuchipudi ◽  
Benoit Girard ◽  
Matthew Houser
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Manufacturing Processes ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Composite Filament

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.

Flexural Behavior of Reinforced-Concrete (RC) Beams Strengthened with Hemp Fiber-Reinforced Polymer (FRP) Composites

2016 ◽  
Vol 860 ◽  
pp. 156-159
Author(s):  
Seyha Yinh ◽  
Qudeer Hussain ◽  
Winyu Rattanapitikon ◽  
Amorn Pimanmas
Keyword(s):  
Reinforced Concrete ◽  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Hemp Fiber ◽  
Flexural Strengthening ◽  
Frp Composites ◽  
Reinforced Polymer ◽  
Fiber Thickness

This experimental study has been conducted on the efficiency of epoxy-bonded hemp fiber reinforced polymer (FRP) composites in flexural strengthening of reinforced concrete (RC) beams. A total of five RC beams were cast and tested up to failure. The test parameters included fiber thickness and strengthening configuration. The experimental results show the capability of hemp FRP composites to increase the loading capacity in flexure of RC beams compared with the un-strengthened beam. The enhancement of ultimate load becomes more significant as the fiber thickness is increased. The effectiveness of strengthened beams in U-wrapped scheme is found greater than strengthened beams in bottom-only scheme. Based on results, it indicates that hemp FRP has a potential to considerably increase the strength and stiffness of the original RC beam.

Compressive behavior of circular and square concrete column externally confined by different types of basalt fiber–reinforced polymer

2020 ◽  
Vol 23 (8) ◽  
pp. 1534-1547 ◽  
Author(s):  
Jingting Huang ◽  
Tao Li ◽  
Dayong Zhu ◽  
Peng Gao ◽  
An Zhou
Keyword(s):  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Compressive Behavior ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Polymer Wrapping ◽  
Basalt Fiber Reinforced Polymer

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.

Tensile Properties of Natural Fiber Reinforced Polymers: An Overview

2015 ◽  
Vol 766-767 ◽  
pp. 133-139 ◽  
Author(s):  
Jeswin Arputhabalan ◽  
K. Palanikumar
Keyword(s):  
Tensile Properties ◽  
Polymer Composites ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites

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].

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