Accuracy Analysis of Design Methods for Concrete Beams Reinforced With Fiber Reinforced Polymer Bars / Kompozitais Armuotų Betoninių Elementų Projektavimo Metodų Tikslumo Analizė

Abstract

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.

Investigation on application of basalt materials as reinforcement for flexural elements of concrete bridges

“…The current study is dedicated to experimental investigation of RC beams with internal and external BFRP reinforcement. The present manuscript investigates deformation behaviour and cracking of flexural elements, i.e., the predominant parameters governing serviceability of the concrete bridges, reinforced with BFRP materials (Timinskas et al 2013). The paper reports new experimental results of 4 BFRP RC beams subjected to a 4-point loading.…”

FRP Reinforcement for Concrete Structures: State-of-the-Art Review of Application and Design

“…Therefore, the deformed surface is more prominent for structural application. Recent investigations by the authors (Gribniak et al 2013;Timinskas et al 2013) have revealed that grooved surface (for instance, Schöck ComBAR) reinforcement is characterized by the high quality (strength) of the bond. It could be explained by a well-balanced shape of the surface of the bar: the shear strength of concrete in the grooves is proportional to bar surface-to-core connection strength (Fig.…”

“…Comparison of characteristic and design tensile strength and elasticity modulus of different types of reinforcement(Timinskas et al 2013) …”

Flexural Response of Reinforced Concrete Waffle Slab with Recycled Polyethylene Terephthalate (PET) in the Topping

“…he search for alternative material in reinforced concrete has led to many discoveries, since steel which has been the major materials in reinforced concrete have been found to get corrode easily when exposed to weather conditions, together with its very high cost. Some of the materials that have been used in place of steel bars in concrete are Fiber Reinforced Polymers (FRP), Glass Fiber Reinforced Polymers (GFRP), (Atutis et al, 2013;Gudonis et al, 2013;Timinskas et al, 2013). Most of these materials have been found to be good but will require some modifications before it can take the place of iron steel in construction.…”