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

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.

Flexural behaviour of geopolymer concrete beams reinforced with BFRP and GFRP polymer composites

2022 ◽  
pp. 136943322110542
Author(s):  
Nagajothi Subramanian ◽  
Elavenil Solaiyan ◽  
Angalaeswari Sendrayaperumal ◽  
Natrayan Lakshmaiya
Keyword(s):  
Crack Width ◽  
Concrete Beams ◽  
Bending Test ◽  
Geopolymer Concrete ◽  
Flexural Behaviour ◽  
Premature Failure ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Fibre Reinforced Polymer ◽  
Frp Bars

The paper presents the experimental investigations on the flexural behaviour of geopolymer concrete beams reinforced with Basalt Fibre Reinforced Polymer (BFRP)/Glass Fibre Reinforced Polymer (GFRP) rebars and the effect of inclusion of the new adhesively bonded BFRP/GFRP stirrups. M30 grade geopolymer and conventional concrete beams with the dimension of 100 × 160 × 1700 mm were cast to investigae the flexural behaviour of BFRP/GFRP and steel bars. This study also examined the mode of failure, deflection behaviour, curvature moment capacity, crack width, pattern, propagation, strains and average crack width of the BFRP/GFRP bars with stirrups in the geopolymer concretes using a four-point static bending test. The results were compared to that of conventional steel-reinforced concrete, and it was found that the Basalt and Glass reinforced polymer beams demonstrated premature failure and sudden shear failure. Further, the FRP bars exhibited higher mid-span deflection, crack width and crack propagation than steel bars. Crack spacing of the FRP bars decreased with an increase in the number of cracks. The correlation between the load and the deflection behaviour of the beams was determined using statistical analysis of multi variables regression.

scholarly journals Enhancing Stability of Thin-Walled Short Steel Channel Using CFRP under Eccentric Compression

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Hongyuan Tang ◽  
Canjun Wang ◽  
Ruijiao Wang
Keyword(s):  
Analytical Study ◽  
Ultimate Load ◽  
Load Capacity ◽  
Local Buckling ◽  
Fiber Reinforced Polymer ◽  
Actual Behavior ◽  
Thin Wall ◽  
Ultimate Load Capacity ◽  
Reinforced Polymer ◽  
Global Buckling

This paper presents the experimental and analytical results of eccentrically loaded short cold-formed thin-wall steel channels strengthened with transversely oriented carbon fiber reinforced polymer (CFRP) strips around their web and flange. Seven specimens, each 750 mm long, were fabricated; the main parameters were the number of CFRP plies (one or two) and the space between the CFRP strips (50, 100, or 150 mm). The application of the CFRP strips results in increases in ultimate load capacity and, with the exception of the most heavily reinforced (2 plies at 50 and 100 mm), local buckling was observed prior to global buckling. To extend and better understand the experimental work, a companion analytical study was conducted. Comparisons between experimental observations and computed results show that the analyses provided good correlation to actual behavior. In addition, the numerical results explained the observed phenomenon that flange local buckling was constrained to regions between the CFRP strips.

scholarly journals Experiment on RC Beams Reinforced with Glass Fibre Reinforced Polymer Reinforcements

2019 ◽  
Vol 8 (6S4) ◽  
pp. 35-41
Keyword(s):  
Glass Fibre ◽  
Failure Modes ◽  
Load Capacity ◽  
Ultimate Load Capacity ◽  
Conventional Steel ◽  
Reinforced Polymer ◽  
Experimental Prediction ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced

This study presents the flexural behaviour of rectangular concrete beams reinforced with surface treated Glass Fibre Reinforced Polymer (GFRP), Grooved bars and Sand sprinkled reinforcing bars. Beams cast with standard mix of M30 grade concrete, with a reinforcement ratios of 0.73%, and compared with that of conventional steel reinforced beams. Totally five rectangular beams of size 125 mm x 250 mm x 3200 mm were cast. The flexural study was carried under static two point loading. The experimental prediction was focused on observation of ultimate load capacity, cracks propagation and crack widths and failure modes of beams. The results indicate that both type of GFRP reinforcements are at par with the conventional steel reinforcements.

Numerical analysis of reinforced concrete beams strengthened in shear using carbon fiber reinforced polymer materials

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sabiha Barour ◽  
Abdesselam Zergua
Keyword(s):  
Finite Element ◽  
Ultimate Load ◽  
Load Capacity ◽  
Nonlinear Finite Element ◽  
Fiber Reinforced Polymer ◽  
Analytical Models ◽  
Ultimate Load Capacity ◽  
Content Type ◽  
Reinforced Polymer ◽  
The Difference

Purpose This paper aims to analyze the performance of reinforced concrete (RC) beams strengthened in shear with carbon fiber-reinforced polymer (CFRP) sheets subjected to four-point bending. Design/methodology/approach ANSYS software is used to build six models. In addition, SOILD65, LINK180, SHELL181 and SOLID185 elements are used, respectively, to model concrete, steel reinforcement, polymer and steel plate support. A comparative study between the nonlinear finite element and analytical models, including the ACI 440.2 R-08 and FIB14 models as well as experimental data, is also carried out. Findings The comparative study of the nonlinear finite element results with analytical models shows that the difference between the predicted load capacity ranges from 4.44%–24.49% in the case of the ACI 440.2 R-08 model, while the difference for FIB14 code ranges from 2.69%–26.03%. It is clear that there is a good agreement between the nonlinear finite element analysis (NLFEA) results and the different expected CFRP codes. Practical implications This model can be used to explore the behavior and predict the RC beams strengthened in shear with different CFRP properties. They could be used as a numerical platform in contrast to expensive and time-consuming experimental tests. Originality/value On the basis of the results, a good match is found between the model results and the experimental data at all stages of loading the tested samples. Load capacities as well as load deflection curves are also presented. It is concluded that the differences between the loads at failure ranged from 0.09%–6.16% and 0.56%–4.98%, comparing with experimental study. In addition, the increase in compressive strength produces an increase in the ultimate load capacity of the beam. The difference in the ultimate load capacity was less than 30% when compared with the American Concrete Institute and FIB14 codes.

A review on experimental flexural cracking in FRP reinforced concrete members

2019 ◽  
Author(s):  
Cristina Barris ◽  
Paula Zubillaga ◽  
Lluis Torres
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Design Guidelines ◽  
Flexural Members ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Maximum Crack ◽  
The Relationship ◽  
Frp Bars

<p>This paper aims to assess the relationship among crack width and several influencing parameters of Fibre Reinforced Polymer (FRP) Reinforced Concrete (RC) flexural members. A database with the results of 133 concrete specimens reinforced with different types of FRP bars available in the literature has been collected and analysed. A bond coefficient <i>k</i>b has been adjusted for the maximum crack width of all specimens by using ACI-440 and ISIS Canada design guidelines in the service range, obtaining a mean bond coefficient of 1.11 and 0.72, respectively. The effect of the surface treatment and modulus of elasticity of the FRP rebar, and the <i>n·</i> ratio on the bond coefficient have been studied, obtaining no significant influence of the studied parameters due to the high scatter of results.</p>

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.

Minimum thickness of concrete members reinforced with fibre reinforced polymer bars

2001 ◽  
Vol 28 (4) ◽  
pp. 583-592 ◽  
Author(s):  
Amin Ghali ◽  
Tara Hall ◽  
William Bobey
Keyword(s):  
Reinforced Concrete ◽  
Minimum Thickness ◽  
Reinforced Polymers ◽  
Flexural Members ◽  
Steel Reinforced Concrete ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Fibre Reinforced Polymer ◽  
Frp Bars

To avoid excessive deflection most design codes specify the ratio (l/h)s, the span to minimum thickness of concrete members without prestressing. Use of the values of (l/h)s specified by the codes, in selecting the thickness of members, usually yields satisfactory results when the members are reinforced with steel bars. Fibre reinforced polymer (FRP) bars have an elastic modulus lower than that of steel. As a result, the values of (l/h)s specified in codes for steel-reinforced concrete would lead to excessive deflection if adopted for FRP-reinforced concrete. In this paper, an equation is developed giving the ratio (l/h)f for use with FRP bars in terms of (l/h)s and (εs/εf), where εs and εf are the maximum strain allowed at service in steel and FRP bars, respectively. To control the width of cracks, ACI 318-99 specifies εs = 1200 × 10–6 for steel bars having a modulus of elasticity, Es, of 200 GPa and a yield strength, fy, of 400 MPa. At present, there is no value specified for εf; a value is recommended in this paper.Key words: concrete, cracking, deflection, fibre reinforced polymers, flexural members, minimum thickness.

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.

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