The Influence of Reinforcement Ratio on the Shear Behaviour of Sand Coated Basalt FRP Bars Reinforced Beams

FRP bars were used to improve the mechanical properties of bamboo beams for civil engineering without changing the existing bamboo processing technology in this paper. Three bamboo beams, including one control beam and two FRP-reinforced beams were tested. The effects of various types of FRP bars were compared, including CFRP and BFRP. The results show that the ultimate displacements of reinforced specimens are less than the control specimen. The FRP bars can enhance effectively the cross-section stiffness of bamboo beams. CFRP bars can reduce about 30% strain and BFRP bars can also reduce about 10% strain for the tensile bamboo fiber. The FRP bars in the tension zone can share tensile stress of bamboo fiber. The cross-section stiffness still controls the structure design for the FRP bars reinforced bamboo beams.

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Experimental Study on Reinforced Concrete Beam with Embed in Basalt FRP Bars

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.204-208.3827 ◽

2012 ◽

Vol 204-208 ◽

pp. 3827-3830

Author(s):

Bai Ru Zhu ◽

Yang Song

Keyword(s):

Reinforced Concrete ◽

Bearing Capacity ◽

Reinforced Concrete Beam ◽

Reinforced Concrete Beams ◽

Failure Characteristics ◽

Flexural Failure ◽

Reinforced Beams ◽

Frp Bar ◽

Mode 3 ◽

Frp Bars

Many tests were carried out to study flexural failure characteristics, ultimate bearing capacity, and stiffness etc of reinforced concrete beams which are embed in basalt FRP bar. The results show that:（1）Basalt FRP bars greatly enhance load bearing capacity. (2) Beam failure characteristic is interfacial bond failure mode. (3) Reinforced beams’ integrity and stiffness are greatly improved, the beam crack resistance significantly improved.

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Shear Behavior of Fiber Reinforced Concrete Beams with Basalt FRP Reinforcing Bars and Glass FRP Stirrups

University of the Future: Re-Imagining Research and Higher Education ◽

10.29117/quarfe.2020.0081 ◽

2020 ◽

Author(s):

Abathar AL-Hamrani ◽

Wael Alnahhal

Keyword(s):

Reinforced Concrete ◽

Carbon Fibers ◽

Glass Fibers ◽

Construction Materials ◽

Steel Reinforcement ◽

Reinforcement Ratio ◽

Reinforced Concrete Beams ◽

Fiber Reinforced ◽

Reinforcing Bars ◽

Frp Bars

The State of Qatar suffers from a harsh environment in the form of high temperature that prevails almost all year round in addition to severe humidity and coastal conditions. This exposure leads to the rapid deterioration and the reduction of the life span of reinforced concrete (RC) infrastructure. The full functionality and safe use of the infrastructure in such environments can only be maintained by holistic approaches including the use of advanced materials for new construction.With the developments in materials science, the advanced composites, especially fiber reinforced polymer (FRP) materials are becoming viable alternatives to the traditional construction materials. Having superior durability against corrosion, versatility for easy in-situ applications and enhanced weight-to-strength ratios compared to their counterpart conventional materials, FRPs are promising to be the future of construction materials. More recently, FRP composites made of basalt FRP (BFRP) have been introduced as an alternative to traditional steel reinforcement at a price comparable to glass fibers of about $2.5–5.0 per kg, which is significantly lower than carbon fibers. BFRP bars are characterized by their corrosion resistance, greater strain at failure than carbon fibers, and better chemical resistant than glass fibers, particularly in a strongly alkaline environment. Knowing that FRP bars are anisotropic materials with weaker strength in the transverse direction compared with the longitudinal direction, and having a relatively low modulus of elasticity compared with steel reinforcement, it is important to investigate the concrete contribution to shear strength for beams reinforced with BFRP bars. In addition, due to the elastic performance of the FRP reinforcing bars compared with steel bars, FRP bars fail in a brittle manner. Moreover, concrete itself is a brittle material. Previous investigations have shown that using discrete fibers in concrete increases its ductility due to the large compressive strains exhibited at failure. Therefore, basalt macro-fibers is proposed in this study. A total of 14 concrete beam specimens were tested under four point loading until failure. The parameters investigated included the reinforcement ratio (2rb, 3.1rb, and 4.53rb, where rb is the balanced reinforcement ratio), the span to depth ratio (a/d=2.5, and a/d=3.3), the spacing between stirrups (S1=170mm, and S2=250mm) and the basalt fiber volume fraction (0%, 0.75% and 1.5%). Test results clearly showed that both BFRP bars and basalt macro-fibers can be used as sustainable and eco-friendly alternative materials in Concrete Structures in Qatar.

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Parametric Study on Moment Redistribution of Fiber Reinforced Concrete Continuous Beams with Basalt FRP Bars

University of the Future: Re-Imagining Research and Higher Education ◽

10.29117/quarfe.2020.0084 ◽

2020 ◽

Author(s):

Abdelrahman Hamdi Abushanab ◽

Wael I Alnahhal

Keyword(s):

Reinforced Concrete ◽

Parametric Study ◽

Steel Reinforcement ◽

Reinforcement Ratio ◽

Fiber Reinforced Concrete ◽

Elastic Behaviour ◽

Fiber Reinforced ◽

Moment Redistribution ◽

Continuous Beams ◽

Frp Bars

The state of Qatar is suffering from its harsh environment and coastal conditions, which stand for most of the year. As a result, steel-reinforced concrete structures are subjected to rapid corrosion and deterioration. Therefore, there is a necessity to replace the conventional steel reinforcement by fiber-reinforced polymers (FRP) bars. Apart from FRP bars corrosion resistance, their strength to weight ratio is higher than steel reinforcement, which made the FRP, bars a viable alternative to steel reinforcement. Continuous concrete beams are commonly used elements in structures such as parking garages and overpasses. In such structures, forces could be distributed between the critical sections after cracking. This phenomenon is called moment redistribution. It reduces the congested rebars in connections and enhances the ductility of the members. However, the linear-elastic behaviour of FRP materials makes the ability of continuous beams to redistribute loads and moments questionable. This study aims to investigate the capability of moment redistribution of basalt fiber reinforced concrete (BFRC) continuous beams reinforced with basalt FRP (BFRP) bars. Eleven reinforced concrete (RC) continuous beams of 200 x 300 x 4000 mm were tested up to failure under fivepoint loading. The main investigated parameters were the reinforcement ratio (0.6rb, 1.0rb, 1.8rb and 2.8rb; where rb is the balanced reinforcement ratio), stirrups spacing (80 and 120 mm) and volume fractions of Basalt-macro fibers (BMF) (0.75 and 1.5%). A parametric study was then conducted using a validated finite element (FE) model to extend the investigated parameters that may affect the moment redistribution of RC continuous beams. It was concluded that moment redistribution occurs in beams that have at least a ratio of bottom to top reinforcement of 0.3.

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Flexural Strength Design of Hybrid FRP-Steel Reinforced Concrete Beams

Materials ◽

10.3390/ma14216400 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6400

Author(s):

Binbin Zhou ◽

Ruo-Yang Wu ◽

Yangqing Liu ◽

Xiaohui Zhang ◽

Shiping Yin

Keyword(s):

Reinforced Concrete ◽

Flexural Strength ◽

Failure Modes ◽

Reinforcement Ratio ◽

Reinforced Concrete Beams ◽

Rc Beams ◽

Strength Reduction Factor ◽

Steel Reinforced Concrete ◽

Strength Design ◽

Reinforced Beams

Through proper arranging of a hybrid combination of longitudinal fiber reinforced polymer (FRP) bars and steel bars in the tensile region of the beam, the advantages of both FRP and steel materials can be sufficiently exploited to enhance the flexural capacity and ductility of a concrete beam. In this paper, a methodology for the flexural strength design of hybrid FRP-steel reinforced concrete (RC) beams is proposed. Firstly, based on the mechanical features of reinforcement and concrete and according to the latest codified provisions of longitudinal reinforcement conditions to ensure ductility level, the design-oriented allowable ranges of reinforcement ratio corresponding to three common flexural failure modes are specified. Subsequently, the calculation approach of nominal flexural strength of hybrid FRP-steel RC beams is established following the fundamental principles of equilibrium and compatibility. In addition to the common moderately-reinforced beams, the proposed general calculation approach is also applicable to lightly-reinforced beams and heavily-reinforced beams, which are widely used but rarely studied. Furthermore, the calculation process is properly simplified and the calculation accuracy is validated by the experimental results of hybrid FRP-steel RC beams in the literature. Finally, with the ductility analysis, a novel strength reduction factor represented by net tensile steel strain and reinforcement ratio is proposed for hybrid FRP-steel RC beams.

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Comparison of the Flexural Performance and Behaviour of Fly-Ash-Based Geopolymer Concrete Beams Reinforced with CFRP and GFRP Bars

Advances in Materials Science and Engineering ◽

10.1155/2020/3495276 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Hemn Qader Ahmed ◽

Dilshad Kakasor Jaf ◽

Sinan Abdulkhaleq Yaseen

Keyword(s):

Crack Width ◽

Ultimate Load ◽

Load Capacity ◽

Reinforcement Ratio ◽

Geopolymer Concrete ◽

Ultimate Load Capacity ◽

Gfrp Bars ◽

Reinforced Polymer ◽

Fibre Reinforced Polymer ◽

Frp Bars

A construction system with high sustainability, high durability, and appropriate strength can be supplied by geopolymer concrete (GPC) reinforced with glass fibre-reinforced polymer (GFRP) bars and carbon fibre-reinforced polymer (CFRP) bars. Few studies deal with a combination of GPC and FRP bars, especially CFRP bars. The present investigation presents the flexural capacity and behaviour of fly-ash-based GPC beam reinforced with two different types of FRP bars: six reinforced geopolymer concrete (RGPC) beams consisting of three specimens reinforced with GFRP bars and the rest with CFRP bars. The beams were tested under four-point bending with a clear span of 2000 mm. The test parameters included the longitudinal-reinforcement ratio and the longitudinal-reinforcement type, including GFRP and CFRP. Ultimate load, first crack load, load-deflection behaviour, load-strain curve, crack width, and the modes of failure were studied. The experimental results were compared with the equations recommended by ACI 440.1R-15 and CSA S806-12 for flexural strength and midspan deflection of the beams. The results show that the reinforcement ratio had a significant effect on the ultimate load capacity and failure mode. The ultimate load capacity of CFRP-RGPC beams was higher than that of GFRP-RGPC, more crack formations were observed in the CFRP-RGPC beams than in the GFRP-RGPC beams, and the crack width in the GFRP-RGPC beams was more extensive than that in the CFRP-RGPC beams. Beams with lower reinforcement ratios experienced a fewer number of crack and a higher value of crack width, while numerous cracks and less value of crack width were observed in beams with higher reinforcement ratio. Beams with the lower reinforcement ratios were more affected by the type of FRP bars, and the deflection in GFRP-RGPC beams was higher than that in CFRP-RGPC beams for the same corresponding load level. ACI 440.1R-15 and CSA S806-12 underestimated the flexural strength and midspan deflection of RGPC beams; however, CSA S806-12 predicted more accurately.

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