scholarly journals ACCURACY ANALYSIS OF DESIGN METHODS FOR CONCRETE BEAMS REINFORCED WITH FIBER REINFORCED POLYMER BARS / KOMPOZITAIS ARMUOTŲ BETONINIŲ ELEMENTŲ PROJEKTAVIMO METODŲ TIKSLUMO ANALIZĖ

2014 ◽  
Vol 5 (3) ◽  
pp. 123-133 ◽  
Author(s):  
Edgaras Timinskas ◽  
Rūta Jakštaitė ◽  
Viktor Gribniak ◽  
Vytautas Tamulėnas ◽  
Gintaris Kaklauskas
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Design Methods ◽  
Steel Reinforcement ◽  
Design Codes ◽  
Basalt Fibre ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Innovative Materials ◽  
The Moment

Traditional steel reinforcement does not resist corrosion and its resources are limited; therefore, carbon, glass, aramid and basalt fibre reinforced polymer bars were developed. The composite reinforcement has a high tensile strength and resistance to electromagnetic fields. Different kinds of materials and application of various surface coatings are used in the production of the composite bars. This results in different adhesion to concrete and mechanical properties of composite bars. In comparison with steel reinforcement, glass, aramid and basalt fibre reinforced polymer bars have a lower modulus of elasticity. Thus, structural rigidity provided by these bars is smaller in respect to reinforced concrete elements. Current reinforced concrete design codes and recommendations are based on empirical and simplified methods of strain evaluation, which may be inadequate for design of structures with composite bars. In this paper, an adequacy of the empirical models was checked against the experimental data of concrete beams reinforced with composite bars. The moment-curvature data of 52 beams reported in the literature and conducted by the authors were used for assessment of accuracy of design methods. In order to perform the analysis, different methods from design codes (European (LST 2007), American (ACI Committee 318 2011) and Russian (NIIZhB 2006)) and recommendations (Italian (CNR 2007) and American (ACI Committee 440 2006)) have been selected. The results of the investigation will provide engineers with more information on design of concrete beams with fibre reinforced polymer bars. This will encourage an extensive use of these innovative materials in different types of structures. Santrauka Tradicinė plieninė armatūra nėra atspari korozijai, jos iŠtekliai yra riboti, todėl buvo sukurti polimeriniai strypai, armuoti anglies, stiklo, bazalto arba aramido pluoŠtu. Ši kompozitinė armatūra pasižymi dideliu tempiamuoju stipriu ir atsparumu elektromagnetiniam laukui. Kompozitinių strypų gamyboje naudojamos skirtingos medžiagos ir taikomi įvairūs pavirŠiaus dengimo būdai, skiriasi jų mechaninės bei sukibimo su betonu savybės. Lyginant su plienine armatūra, stiklo, aramido ir bazalto kompozitiniai strypų tamprumo modulis yra mažesnis, todėl tokiais strypais armuotų konstrukcijų standumas taip pat yra mažesnis nei gelžbetoninių konstrukcijų. Dabartiniuose gelžbetoninių konstrukcijų projektavimo reglamentuose taikomi empiriniai supaprastinti deformacijų nustatymo metodai gali būti netinkami konstrukcijoms, armuotoms polimerine armatūra, projektuoti. Šiame darbe, naudojant mokslinėse publikacijose surinktų 46 eksperimentinių tyrimų ir autorių atliktų 6 sijų bandymų duomenis, buvo įvertintas kompozitais armuoto betono elementų įlinkių skaičiavimo metodų tikslumas. Analizei atlikti buvo pasirinkti Europos (LST EN 1992-1-1:2005), JAV (ACI 318M-11) ir Rusijos (SP 52-101-2003) armuotojo betono konstrukcijų projektavimo normų bei Italijos (CNR-DT 203/2006) ir JAV (ACI 440.1R-06) projektavimo rekomendacijų metodai. Gauti analizės rezultatai suteiks projektuotojams iŠsamesnę informaciją apie kompozitais armuotų betoninių elementų projektavimą, skatins didins Šių inovatyvių medžiagų naudojimo apimtį įvairiose statybinėse konstrukcijose.

Review of shear design methods for reinforced concrete beams strengthened with fibre reinforced polymer sheets

2001 ◽  
Vol 28 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Christophe Deniaud ◽  
JJ Roger Cheng
Keyword(s):  
Reinforced Concrete ◽  
Glass Fibre ◽  
Mechanical Model ◽  
Concrete Beams ◽  
Design Methods ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Shear Design ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper reviews the different shear design methods found in the literature for reinforced concrete beams strengthened externally with fibre reinforced polymer (FRP) sheets and compares the adequacy of each method by using the test results from the University of Alberta. The FRP shear design methods presented include the effective FRP strain and the bond mechanism criteria, the strut-and-tie model, the modified compression field theory, and a mechanical model based on the strip method with shear friction approach. Sixteen full-scale T-beam test results were used in the evaluation. Two web heights of 250 and 450 mm and two ready mix concrete batches of 29 and 44 MPa were used in the test specimens. Closed stirrups were used with three spacings: 200 mm, 400 mm, and no stirrups. Three types of FRP were used to strengthen externally the web of the T-beams: (i) uniaxial glass fibre, (ii) triaxial (0/60/–60) glass fibre, and (iii) uniaxial carbon fibre. The results showed that the mechanical model using the strip method with shear friction approach evaluates better the FRP shear contribution. The predicted capacities from this mechanical model are also found conservative and in excellent agreement with the test results.Key words: beams, carbon fibres, composite materials, fibre reinforced polymers, glass fibres, rehabilitation, reinforced concrete, shear strength, sheets, tests.

scholarly journals Moment - curvature behavior of basalt fibred concrete beams made with basalt fibre reinforced polymer bars

2021 ◽  
Vol 309 ◽  
pp. 01059
Author(s):  
V Saikrishna ◽  
V Srinivasa Reddy ◽  
M V Seshagiri Rao ◽  
S Shrihari
Keyword(s):  
Crack Width ◽  
Concrete Beams ◽  
Gauge Length ◽  
Reinforced Concrete Beams ◽  
Flexural Properties ◽  
Basalt Fibre ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
The Moment ◽  
Steel Rebars

In the current study the moment - curvature behavior of basalt fibred concrete beams made with basalt fibre reinforced polymer bars and normal beams with steel rebars are evaluated. Basalt fibred reinforced concrete beams of M30 grade were casted with steel and BFRP rebars separately to study the flexural properties of basalt fibre and BFRP bars. From the load –deflection plots, flexural characteristics such as load at first crack, ultimate flexural strength, deflection at the centre and crack width at failure are evaluated. Deflections were measured at the central point and under the load using the deflection meters. The values of moments and curvatures are obtained. Moment curvature relationships are very important to assess out ductility of the structure and the amount of possible redistribution of stresses. The deformations measured are divided by the gauge length (200mm) to obtain the strains at the particular level. From the top and bottom strains, the average curvatures were calculated. From these results, M-Ф diagrams are plotted.

scholarly journals Flexural behaviour of reinforced concrete beams strengthened with pre-stressed and near surface mounted steel–basalt-fibre composite bars

2019 ◽  
Vol 23 (6) ◽  
pp. 1154-1167
Author(s):  
Yajun Zhao ◽  
Yimiao Huang ◽  
Haiyang Du ◽  
Guowei Ma
Keyword(s):  
Reinforced Concrete ◽  
Polymer Composite ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Basalt Fibre ◽  
Near Surface ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Fibre Reinforced Polymer ◽  
Near Surface Mounted

Fibre-reinforced polymer bars have been widely used for strengthening concrete members due to their high strength, light weight and strong corrosion resistance. A near-surface mounted strengthening system has been adopted to protect the fibre-reinforced polymer bars from external hazards. To make up the lower stiffness and ductility of fibre-reinforced polymer bar compared to steel rebar, this study proposed to use a pre-stressed near-surface mounted steel–basalt-fibre-reinforced polymer composite bar. The steel–basalt-fibre-reinforced polymer composite bar is manufactured through wrapping a steel rod by a basalt-fibre-reinforced polymer cover. A total of nine reinforced concrete beams, including one control or calibration and eight others strengthened by pre-stressed near-surface mounted steel–basalt-fibre-reinforced polymer composite bars, are fabricated and tested. Results show that the proposed steel–basalt-fibre-reinforced polymer composite bar strengthening method can improve both the strength and ductility of the reinforced concrete beams. Pre-stressing of the steel–basalt-fibre-reinforced polymer composite bars further increases substantially the beams’ load-carrying capacity by restraining crack propagation in concrete. Standard-based load analysis correctly predicts the cracking load, however, underestimates the ultimate strength of the beams. Finite element method modelling is conducted to provide a more effective load-carrying capacity prediction and a case study is carried out with regard to the amount of the strengthening steel–basalt-fibre-reinforced polymer composite bars.

Analisa Pola Kegagalan Balok Beton Menggunakan GFRP Bar Tanpa Selimut Beton

2020 ◽  
Vol 24 (1) ◽  
pp. 11-16
Author(s):  
Saddam - Husein ◽  
Rudy Djamaluddin ◽  
Rita Irmawaty ◽  
Kusnadi Kusnadi
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Cover ◽  
Steel Reinforcement ◽  
Fiber Reinforced Polymer ◽  
Mode Analysis ◽  
Flexural Capacity ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Gfrp Bar

SADDAM HUSEIN. Analisa Pola Kegagalan Balok Beton Menggunakan GFRP Bar Tanpa Selimut Beton (dibimbing oleh Rudi Djamaluddin dan Rita Irmawaty) Struktur beton bertulang yang menggunakan tulangan baja pada daerah korosif, menjadi rawan terhadap kerusakan atau penurunan kekuatannya akibat korosi.Korosi pada tulangan baja merupakan salah satu faktor penyebab menurunnya kekuatan struktur beton bertulang. Salah satu material yang dikembangkan mengatasi korosi adalah penggunaan material tulangan GFRP (Glass Fiber Reinforced Polymer). Penelitian ini bertujuan untuk menganalisa kapasitas lentur dan pola kegagalan balok beton tanpa selimut dengan menggunakan material tulangan GFRP bar.   Desain penelitian merupakan eksperimental laboratorium dengan rekapitulasi sebanyak 6 sampel yang terdiri dari 2 Balok beton menggunakan tulangan baja dengan selimut beton, 2 balok beton menggunakan tulangan GFRP bar dengan selimut beton, 2 balok beton menggunakan GFRP bar tanpa selimut beton. Metode pengujian dilakukan dengan dengan pengujian lentur statik monotonik dan Analisis data menggunakan uji kondisi retak awal dan kondisi ultimit.   Hasil penelitian ini menunjukkan bahwa kapasitas lentur pada balok dengan tulangan GFRP bar lebih besar dibandingkan dengan balok tulangan baja dan mampu meningkatkan kapasitas lentur balok dalam menahan beban sebesar 39.76 %, pola kegagalan beton yang terjadi pada balok tulangan baja mengalami kegagalan lentur tekan ditandai dengan retakan yang terjadi pada sisi tertekan dan membentuk retakan tegak dengan sumbu netral beton yang tertekan, sedangkan pada balok beton tulangan GFRP tanpa selimut mengalami kegagalan keruntuhan tekan geser dengan kondisi tulangan berdeformasi (bi-linear) dengan retak miring dan secara tiba-tiba menjalar menuju sumbu netral beton yang tertekan sehingga terjadilah keruntuhan secara tiba-tiba.     SADDAM HUSEIN.Failure mode analysis of concrete Beams Using GFRP rebar Without concrete cover (supervised by Rudi Djamaluddin and Rita Irmawaty)   Reinforced concrete that uses rebar steel in corrosive areas, are prone to damage or decreased strength due to corrosion. Corrosion in the steel reinforcement is one of the factors that decreasing strength of reinforced concrete. One of the materials developed to overcome corrosion is the use of GFRP (Glass Fiber Reinforced Polymer) reinforcement material. This study aims to analyze the flexural capacity and failure mode of concrete beams without concrete cover using material GFRP bar as reinforcement.   The research design was an experimental laboratory with a recapitulation of 6 samples consisting of 2 beams using steel reinforcement with concrete cover.2 concrete beams using reinforcement GFRP bar with concrete cover, 2 beams using GFRP bars without concrete cover. The  research method uses the monotonic static flexure and analyzing the data using the initial crack condition and ultimate conditions test.   The results of the research indicate the flexural capacity of the beams with GFRP bar reinforcement is higher than steel reinforcement beams and can increase 39.76% of the flexural capacity of the beams in holding loads , the failure mode analysis occurs in steel reinforcing beam experiences compressive failure. Failure was characterized  by cracks that occur on the depressing side and form an upright crack with the neutral axis of the compressed concrete, whereas in GFRP reinforced concrete beams without concrete cover, failure of shear compression with conditions of deformed reinforcement (bi-linear) with sloping cracks and suddenly spread towards the neutral axis of the compressed concrete so that there was a sudden collapse.

Behaviour of reinforced GFRP bars concrete beams having strengthened splices using CFRP sheets

2021 ◽  
pp. 136943322110015
Author(s):  
Akram S. Mahmoud ◽  
Ziadoon M. Ali
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
New Method ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Strength Capacity ◽  
Cfrp Sheet ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

When glass fibre-reinforced polymer (GFRP) bar splices are used in reinforced concrete sections, they affect the structural performance in two different ways: through the stress concentration in the section, and through the configuration of the GFRP–concrete bond. This study experimentally investigated a new method for increasing the bond strength of a GFRP lap (two GFRP bars connected together) using a carbon fibre-reinforced polymer (CFRP) sheet coated in epoxy resin. A new splicing method was investigated to quantify the effect of the bar surface bond on the development length, with reinforced concrete beams cast with laps in the concrete reinforcing bars at a known bending span length. Specimens were tested in four-point flexure tests to assess the strength capacity and failure mode. The results were summarised and compared within a standard lap made according to the ACI 318 specifications. The new method for splicing was more efficient for GFRP splice laps than the standard lap method. It could also be used for head-to-head reinforcement bar splices with the appropriate CFRP lapping sheets.

Durability of coral-reef-sand concrete beams reinforced with basalt fibre-reinforced polymer bars in seawater

2021 ◽  
pp. 136943322098166
Author(s):  
Wang Xin ◽  
Shi Jianzhe ◽  
Ding Lining ◽  
Jin Yundong ◽  
Wu Zhishen
Keyword(s):  
Coral Reef ◽  
Marine Environment ◽  
Failure Modes ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Initial Stiffness ◽  
Basalt Fibre ◽  
Rc Structures ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

A combination of coral reef sand (CRS) concrete and fibre-reinforced polymer (FRP) bars provides an effective solution to the durability deficiency in conventional RC structures. This study experimentally investigates the durability of CRS concrete beams reinforced with basalt FRP (BFRP) bars in a simulated marine environment. Flexural tests are conducted on a total of fourteen CRS concrete beams aged in a cyclic wet-dry saline solution at temperatures of 25, 40 and 55°C. The variables comprise the types of reinforcement (steel and BFRP), the aging duration and the temperature. The failure modes, capacities, deflections and crack development of the beams are analysed and discussed. The results indicate that the ultimate load of the beams exhibits no degradation after aging, whereas the failure mode of the BFRP-CRS concrete beams transition from flexure to shear, which is caused by the degradation in the mechanical properties of the stirrups. The aged BFRP-CRS concrete beams show a substantial increase of over 70% in their initial stiffness compared with the control beams (beams without aging) and a substantial decrease in their crack width after aging due to the prolonged maturation of the concrete. Furthermore, a formula for calculating the shear capacity in the existing code is modified by a partial factor equal to 2, which can predict the capacity of a CRS concrete beam reinforced with BFRP bars in a marine environment.

scholarly journals FLEXURAL CAPACITY OF CONCRETE BEAMS REINFORCED WITH STEEL AND FIBRE‐REINFORCED POLYMER (FRP) BARS

2004 ◽  
Vol 10 (3) ◽  
pp. 209-215
Author(s):  
Hau Yan Leung
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Beam Design ◽  
Reinforced Concrete Member ◽  
Current Design ◽  
Fibre Reinforced Polymer ◽  
Steel Rebars ◽  
Frp Bars

Although much research on concrete beams reinforced with fibre‐reinforced polymer (FRP) rods has been conducted in recent years, their use still does not receive the attention it deserves from practicising engineers. This is attributed to the fact that FRP is brittle in nature and the collapse of FRP‐reinforced concrete member may be catastrophic. A rational beam design can incorporate a hybrid use of FRP rods and steel rods. Current design codes only deal with steel‐reinforced or FRP‐reinforced concrete members. Therefore in this study some design charts and equations for concrete beam sections reinforced with FRP rods and steel rebars were generated. Results from the theoretical derivations agreed well with experimental data.

Strengthening of Concrete Beams with Basalt Fibre Reinforced Polymer

2020 ◽  
Author(s):  
Eric Hughes ◽  
Adeyemi Adesina ◽  
Bruno Paini ◽  
Sreekanta Das ◽  
Niel Van Engelen
Keyword(s):  
Concrete Beams ◽  
Basalt Fibre ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer
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