E-ISSN:2583-2468

Research Article

Reinforced Concrete

Applied Science and Engineering Journal for Advanced Research

2022 Volume 1 Number 1 January
Publisherwww.singhpublication.com

A Study on FRP-Reinforced Concrete Structures

Prabhakar S1*, Amit R2
DOI:10.54741/asejar.1.1.1

1* Sangave Prabhakar, Pg Student, Department of Civil Engineering, Walchand Institute of Technology, Solapur, India.

2 Rao Amit, PG Student, Department of Civil Engineering, Walchand Institute of Technology, Solapur, India.

In civil engineering, fiber reinforced polymer (FRP) bars are commonly employed. As an alternative to reinforcement steel due to their numerous advantages, including great weight-to-strength ratio, light weight, ease of handling electromagnetic neutrality, and lack of rust. Furthermore, as production machinery develops and more becomes industrialized, FRP has evolved into a cost-effective and competitive structural material. This work examines flexural presentation of fiber-reinforced polymer (FRP) bars and concrete reinforced (RC) after beams conditioning for 6, 9, and 12 months simulated seawater in a wet-dry environment cycling. The purpose of this study is to introduce advancements in the research on FRP-reinforced concrete structures based on recent research. The bond presentation of FRP bars flexural behaviour, concrete, compression behaviour, and concrete of ductility structures reinforced with FRP bars in the last few years around the world are among the topics covered in this study. steel-FRP composite bars (SFCBs) and Basalt FRP (BFRP) are the two types of FRP bars used. For comparison, steel bars are used. During the conditioning, the beams are subjected to a steady load. There are a full of 24 simple-supported rays that being verified.

Keywords: FRP-reinforced, concrete structures, reinforce bar, bond strength

Corresponding Author How to Cite this Article To Browse
Sangave Prabhakar, Pg Student, Department of Civil Engineering, Walchand Institute of Technology, Solapur, , India.
Email: 		Prabhakar S, Amit R, A Study on FRP-Reinforced Concrete Structures. Appl. Sci. Eng. J. Adv. Res.. 2022;1(1):1-6.
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https://asejar.singhpublication.com/index.php/ojs/article/view/2

Manuscript Received Review Round 1 Review Round 2 Review Round 3 Accepted
2021-12-22 2022-01-18 2022-01-24
Conflict of Interest Funding Ethical Approval Plagiarism X-checker Note
None Nil Yes 12.23

© 2022by Prabhakar S, Amit Rand Published by Singh Publication. This is an Open Access article licensed under a Creative Commons Attribution 4.0 International License https://creativecommons.org/licenses/by/4.0/ unported [CC BY 4.0].

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INTRODUCTION

Infrastructure deterioration caused by corrosion of embedded reinforcing steel is a major problem all over the world. The use of FRP bars as concrete element reinforcement appears to be a viable approach for solving the corrosion difficulties that plague typical steel-reinforced concrete constructions.

As a result, the use of FRP bars instead of steel is becoming increasingly common around the world. It possesses a great weight-to-strength ratio, no erosion; ease of handling, light weight, electromagnetic neutrality, a low weight-to-strength ratio 1/4 , 1/5 the density of strengthen, non-magnetic properties, and strong longitudinal tensile strength.

Reinforcement FRP is more expensive now reinforcement steel at first, the entire cost cycle of a structural or construction component the cost of using there are two types of applications for FRP bars in civil engineering. The first is to use steel bars instead of concrete regarding the use of bars in concrete buildings second is to strengthen and maintain existing constructions.

FRP to strengthen a structure is reduced. Because structural or structures FRP reinforcements on components require substantially less maintenance. With the advancement of FRP material technology in recent years, an increasing number of academics have begun to focus on FRP application research.

The main focus of this paper is the development of research on material constructions FRP reinforced. The bond presentation of FRP bars in concrete, compressive behaviour, shear resistance, ductility of concrete and flexural behaviour in recent years, FRP bars have been used to strengthen structures around the world are among the topics enclosed in this study.

To prevent unwanted cracking and/or structural failure, schemes reinforcing are often designed to sustain tensile loads in specified sections concrete. Engineers can utilize a wide variety of reinforcing materials in reinforced concrete, polymers, including steel, and alternative composite materials. Reinforced concrete can be permanently stressed to improve the final structure's performance under operational stresses (reinforcement in tension, and concrete in compression).

The United States, the greatest popular systems for achieving this result are post-tensioning and pre-tensioning. Figure 1 illustrates this concept.Solid, flexible, and long-lasting structures require the following qualities in their reinforcing materials Exceptional relative strength.

  • Regardless of pH, wetness, or other conditions, there is a good connection to the concrete.
  • Thermal compatibility, i.e., the ability to withstand unwanted stresses (such as contraction or expansion) as a effect of temperature variations,
  • High tensile strain tolerance
  • The concrete environment durability, regardless of corrosion or long-term stress.


Figure 1: Before and after the concrete was placed in place around the rebar cage of a massive reinforced concrete column

REVIEW LITERATURE

Galati et al. stability of concrete with FRP bars at various temperatures conducted experimental research on specimen’s concrete reinforced with a FRP bar and thermal to subjected cycles with a extreme temperature of 70 °C. When the bars were put at a lower cover, the bond presentation in ultimate terms of load is impaired, the thermal treatment caused a little because of the discrepancy in CTE, and the concrete microcomputer extremely is extended of the concrete and GFRP bars. In addition, Robert and Benmo krane conducted an experiment to determine the longevity of the link together concrete and GFRP bars.


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To accelerate potential degradation, the in concrete, GFRP saloons stood entrenched then tested to tap aquatic at temperatures of 23°C, 40 °C, and 50 °C. The goal of this study was to see how bar age pretentious the pledge between the GFRP bars and the actual, differential scanning calorimetric (DSC), Robert and Benmo krane used transform scanning electron microscopy (SEM), and Fourier infrared spectroscopy (FTIR).

The grades show that, under the conditions used in this investigation, ageing had no result on the endurance of the concrete-bar interface.

COMPONENTS AND PROCEDURES

Reinforcement Bar

As illustrated in Figure 2, the bottom longitudinal reinforcements were made up of three different kinds of reinforcements: BFRP bar, bar steel, and SFCB. Displays table 1 the tensile characteristics as dignified by the authors using ACI440.3R-12.

Fiber Resin  Diameter Nominal (mm) Strength Yield (MPa) Strength Ultimate (Mpa)  Modulus Elastic (GPa) St Ultimate
Bar Steel -  -   11.0   577.7   690.1    212.3   9.2
BFRP Vinylester Bsalt  9.0   NA   1500.1    61.1   2.4
SFCB Vinyl ester Baslt  13.5   245.6   490.0    98.9   5.0

Table 1: Reinforcing bars' properties were put to the test

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Figure 2: In this investigation, there were longitudinal reinforcement bars. Steel, BFRP, and SFCB are the three types of bars available

The SFCB had a rib depth of roughly 1.0 m/m and a nominal diameter of 13.5 mm, respectively. During pultrusion , with a depth of 0.06 d, where d was the trifling length, the BFRP bars' surfaces were ribbed with a nylon laminate. The SFCB has thirty bundles of twenty four thousand tax vinyl ester longitudinal wrapped outside basalt fiber-reinforced polymer and 8.0-m/m steel bar within, similar to the SFCB used by Dong et al Outmoded toughen inns were also used a comparison. The insignificant diameters of steel bars were 9.0 m/m or 11.0 m/m the BFRP, and individually, as stated in Table 1.

Determinants of Bond Strength

Bond stress transfer among concrete and FRP reinforcement has been thoroughly researched. Shearing pressure parallel to FRP bars and concrete have an interface plane is known as bond stress. The connection of an inserted regardless of material. The first is chemical adhesion at the contact point among two resources. The friction bond, on the other hand, is a caused by the coarseness of the bar's surface. The lugs on the reinforcing bars on the concrete surrounding, for example, provide mechanical bearings, is the third mechanism that contributes to the bond. The parameters that determine bond strength can be separated into many divisions based on investigations into concrete reinforced with FRP bars:

The mechanical presentation, deformation, serviceability, failure mode, crack breadth, and structural analysis and design are all influenced by the concrete's basic mechanical properties of FRP bars behaviour.

Concrete

It was created in a lab, much like the concrete itself. The concrete mix design is shown in detail in Table 2. Water to cement was a ratio of 0.42. It was between 5 and 15 millimeters wide in the coarse aggregate. Cube specimens having a compressive strength of 42.7 MPa were used to test the concrete's compressive strengths.

Water(kilogram/milimeters3)W/CSand (kilogram/milimeters3)Cement(kilogram/milimeters3)Corse Aggregate(kilogram/milimeters3)
1930.426244711252

Table 2: Mixture Concrete


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Laboratory with a Controlled Environment

In order to model the load in the service state, a continued shipment was given to two equal beams, as indicated in Figure 3A. The precise procedure of applying the sustained load is described in detail in Dong et al.'s the continued packing regime was the same as in the flexural tests that followed. Many other researchers have used a similar sustained loading mechanism. The applied sustained load for all conditioned beams was set at 30 kN, cracking was a little higher than this load, built proceeding the trial findings the controller rays the shipment on every end strengthen platter was 15 kN, as exposed in Figure 3A about 20 kN. Figure 3B shows the specimens in a dry-wet cycling tank constructed by hand.

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Figure 3: Wet-dry cycling conditions and beam specimens (A) Sustained load coupled with (B) tank conditioning

Tanks for Sea Cycling Water Wet-dry

The automatic cycling wet-dry tanks are depicted in figure 4(A); figure 4(B) depicts the interior structure of the tank. Thermal insulating cotton was put around the walls and floor of the plastic tank. Bamboo wood and waterproof board were used to make the top sandwich cover plate, which had cotton in the centre acts as a heat insulator. To speed up the drying of the specimen, a ventilation hole and fan a in the a cover plate was employed.. A heating rod was also installed in the tank to keep the seawater warm. The water temperature was kept between 20 and 35 degrees Celsius due to the heating rod's power limitations and changes in ambient air temperature over a one-year period, summers are hot, while winters are cold. in winter due to the heating rod's power limitations and changes in ambient air temperature over a one-year period. A surfing pump was also installed in the tank to encourage the flow of saltwater.

Seawater from one side to the other a single drive will transport. other every 12 hours (it takes approximately 10 minutes). Sodium chloride was added a 5 percent bulk fraction of tap waterto create a solution that mimicked saltwater. The concentration was maintained by maintaining a consistent water level.

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Figure 4: Tanks for Sea Water Cycling Wet-dry. (A) Overview and (B) Inner Structure Diagram

REINFORCED CONCRETE WITH FRP

The ability to prevent specimens from bending or deflecting under load referred as stiffness. Under serviceability behaviour, it is one of the most essential properties of RC structures. Furthermore, growing the length bond from 1500 mm to 1800 mm improved the rigidity of 8mm to 10mm GFRP bars by 35% and 15%, respectively. When compared to the controller specimen, growing the size of the bars GFRP from 8 to 10 mm improved stiffness by 100 to 114 percent. Hosen et al. discovered that SNSM-GFRP-strengthened specimens were more rigid than control specimens. The stiffness of the reinforced specimens in this investigation was largely determined by the extent of the SNSM bars. The results also back up the hypothesis that larger diameter rebars have lower binding strengths, especially in higher-grade concrete. According to Baena et al., steel rebars have a great equal of rigidity with no slip, whereas develop FRP rebars slip from the start (obtained slip values for GFRP are greater than those for CFRP bars).

Ductility's Impact on FRP Reinforced Concrete Structures

The supreme volume of the verified samples was overestimated by disregarding the involvement of in the design equation, there are GFRP bars. Smaller spirals GFRP per nearer space are preferred over diameters larger with wider spacing improves ductility and confinement efficiency.


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Sonto et al. discovered that bars GFRP can role play a special function in enhancing for ductility samples with significant eccentricities, but this effect is minor or non-existent for small-eccentricity specimens.

As a result, the author recommends that the stirrup design in strengthened GFRP-RCCs be when employed in a minor compression eccentric environment to ductility improve. Belarbi and Wang, found that adding fibres with a volume fraction of 0.5 percent to concrete increased its characteristics and was found to be an actual technique to improve the ductility of reinforced FRP systems. When contrasting to plain concrete beams, the ductility index of the FRC beams increased by more than 30% for both un weathered and weathered conditions.

Economic Considerations for FRP Reinforced Concrete Construction

The FRP part of the bridge deck performed exceptionally well in trials. The deflections were well within the Canadian code's restrictions, according to the author, and the supreme strains recorded the static truck were only loading 0.14 percent of the final for FRP and only 5% for the facility shipment ended a year.

The strains on the concrete caused by weights truck were much the cracking less than strains predicted. Test ongoing data will be useful for comparing FRP reinforced and steel bridge decks directly.GFRP-based bridges have been studied by Berg and colleagues, with a minor amount of steel also being used. Due to the advantages of GFRP bars over traditional reinforcing steel, researchers all over the world are focusing on their usage in concrete buildings.

Construction time for the reinforced GFRP deck was significantly less than that of the reinforced steel deck, despite the fact that the GFRP deck's original material cost was 60% more. compared to steel, the GFRP deck saved 57 percent on construction costs.

Monitoring long-term bridge and its duplicate will be carried out in order to compare the behavior long-term of GFRP reinforced and steel decks bridge. The reinforced GFRP bridge deck, concrete was poured at a pace of 52.16 m3 per hour. Compared to 30.06 m3 each hour on the reinforced steel deck. When In addition, long-term cost reductions are possible due to a reduced need for maintenance or a longer bridge deck service life.

Details on the Beam and the Test System

As illustrated in Figure 5A, the bar-reinforced steel beams' tensile reinforcements were two steel 10.0-mm bars, the bar-reinforced beams BFRP ' tensile reinforcements were three BFRP bars 8.0mm, and the SFCB-reinforced beams' tensile reinforcements were two 12.5-mm SFCBs, as illustrated in Figure 5B. Diameter with Steel bars 6.0mm and yield 240 MPa strength of were used for the top bars and stirrups. Figure 5 depicts the beam features. The cross-sectional area and span of the beam were 1200 mm and 120 x 200 mm, correspondingly. The cover concrete was 20 millimeters thick. This design was ductile chosen to ensure a failure mode, that concrete crushing is used to control the beams. As demonstrated in implying that the bottom reinforcements will yield before crush concrete. The purpose of this design is to avoid the low section-cross stiffness and rapid failure brittle mode caused by BFRP bar rupture.

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Figure 5: Details on the beam and the test equipment. (A) Filling mechanism and details beam; (B) Test device prearrangement

CONCLUSION

As shown in the findings of this paper's beam tests and the steel bar RC beams appear Macro-mechanical properties should be at their finest for the entire year, however, do not indicate that the steel bar RC concrete beams were adequate in terms of durability. The rate of corrosion for steel bars encased in a concrete cover is extremely quick. The concrete cover will break as a result of the volume expansion caused by rust compounds exposing the inner steel bars to a corrosive environment. According to microscopic examination, the steel bars inner entirely rusted during course of the year. Conversely, as the concrete pore alkalinity of the solution drops as a result of seawater and carbonation flushing, the FRP bars' breakdown rate slows.


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The macro-mechanical properties will then degrade in a non-convergent manner. The degradation FRP bars and RC beams' macro-mechanical properties over time convergent.

According to current research, FRP reinforcement may be employed efficiently in new concrete structural elements such as beams and columns. Great progress has been achieved in the last 20 years of mechanical research on the behaviour of FRP bars in structures RC, and many a variety of design guidelines have been made public all around the world and the accompanying corrosion of constructions, motivated exploration into FRPs as a possible concrete reinforcement. Although much progress has been made in considerate of the FRP behaviour (mainly GFRP) bars in material, the majority of this research has focused on the changes in the shear strength and flexural concrete beams reinforced capacities of with FRP bars. It has also been published on the usefulness of reinforcement FRP as major reinforcement and steel hoop in columns. The understanding of structural behaviour has progressed to the point where various design and codes guides has been established and created all whole worlds. Although the use of reinforcement FRP bars as improves shear behavior and flexure, the examination of the initiation and evolution of FRP reinforced cracking in concrete beams using complementing NDT techniques for mechanical performance characterization remains unexplored. As a result, more research on FRP bar RC structures is needed, particularly on bond behaviours, flexural behaviour, and compressive behaviour.

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