Design and evaluation of a new bond-type anchorage system for fiber reinforced polymer tendons

2004 ◽  
Vol 31 (1) ◽  
pp. 14-26 ◽  
Author(s):  
Burong Zhang ◽  
Brahim Benmokrane
Keyword(s):  
Tensile Strength ◽  
Bond Length ◽  
Weight Ratio ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Bond Type ◽  
Reinforced Polymer ◽  
Anchorage System ◽  
Mm Bond

Corrosion resistance, high strength, and advantageous strength-to-weight ratio enable fiber reinforced polymers (FRPs) to have substantial potential to replace steel tendons in prestressed applications. One of the main technical obstacles to wide use of FRPs in the construction industry is the methodology to anchor FRP tendons to achieve their full strength. High tensile to compression and shear strength ratios make it necessary to develop a new anchorage design concept for FRP tendons. This paper gives a literature review of bond-type anchorage systems and the mechanics of stress transfer by bond from FRP tendons to grout and reports an experimental study on a newly developed bond-type anchorage system with carbon fiber reinforced polymer (CFRP) Leadline 8-mm-diameter rods. The test program consisted of nine monotonic tensile tests, two pullout tests, and two proving tests on the anchorage system with Leadline single- or 9-rod tendons. The test results showed that the developed anchorage system with 250-mm bond length ensures full development of the tensile strength of Leadline mono-rod tendons. The bond strength of Leadline 9-rod tendons is 14 MPa for a bond length of 95 mm, 62% of that of mono-rod ones with a bond length of 80 mm. The anchorage system with a 400-mm bond length gives at least 90% of the tensile strength of Leadline 9-rod tendons and also demonstrates an acceptable sustained loading behaviour in accordance with existing codes.Key words: anchorage, bond stress, creep, grout, polymers, rod, slip, tendon.

scholarly journals Experimental investigation of the microstructures and tensile properties of polyacrylonitrile-based carbon fibers exposed to elevated temperatures in air

2019 ◽  
Vol 14 ◽  
pp. 155892501985001 ◽  
Author(s):  
Chenggao Li ◽  
Guijun Xian
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Elevated Temperatures ◽  
Tensile Modulus ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

The elevated temperature resistance and even fire resistance of carbon fiber-reinforced polymer composites were critical concerns in many applications. These properties of a carbon fiber-reinforced polymer depend not only on the degradation of the polymer matrix but also on that of the carbon fibers under elevated temperatures. In this study, influences of elevated temperatures (by 700°C for 30 min) in air on the mechanical properties and microstructures of a carbon fiber were investigated experimentally. It was found that the tensile strength and modulus as well as the diameters of the carbon fibers were reduced remarkably when the treatment temperatures exceeded 500°C. At the same time, the content of the structurally ordered carbonaceous components on the surface of carbon fibers and the graphite microcrystal size were reduced, while the graphite interlayer spacing ( d002) was enhanced. The deteriorated tensile modulus was attributed to the reduced graphite microcrystal size and the reduced thickness of the skin layer of the carbon fiber, while the degraded tensile strength was mainly attributed to the weakened cross-linking between the graphite planes.

scholarly journals Buckling Analysis of Pultruded Glass Fiber Reinforced Polymer (GFRP) Angle Sections

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2532
Author(s):  
Rahima Shabeen Sirajudeen ◽  
Rajesh Sekar
Keyword(s):  
Glass Fiber ◽  
Slenderness Ratio ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Fe Model ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced Polymer ◽  
Buckling Mode ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced

Glass fiber reinforced polymers (GFRP), with their advantage of corrosion resistance, have potential to be used as structural members in civil engineering constructions. Pultruded GFRP angle section trusses could be used instead of steel sections in remote areas and in areas prone to corrosion. The objective of this paper is to study the strength of GFRP angle sections under concentric axial load. Glass fiber reinforced polymer (GFRP) made of E-glass and Isophthalic polyester resin and manufactured by pultrusion process was used for the experimental study. Two GFRP angle sections of size 50 × 50 × 6 mm and 50 × 50 × 4 mm and lengths 500 mm, 750 mm, and 1000 mm were chosen for the study. Further, finite experimental element analysis of the GFRP angle sections was done using ANSYS software and validated with the experimental results. The validated FE model was used for parametric studies varying the slenderness ratio and flange width to thickness ratio (b/t) ratio. It was observed that length of the specimen and thickness influenced the buckling load and buckling mode. An increase in b/t ratio from 8.3 to 12.5 decreases the load carrying capacity by almost 60% at a slenderness ratio of 50.

Technological Advances for Improved Performance and Operation of Fiber-Reinforced Polymer Piping

2010 ◽  
Author(s):  
Pierre Mertiny ◽  
Mohammad Bashar ◽  
Avinash Parashar ◽  
Kulvinder Juss
Keyword(s):  
Weight Ratio ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Damage Resistance ◽  
Reinforced Polymer ◽  
Initial Cost ◽  
Excellent Corrosion Resistance ◽  
Operational Capabilities ◽  
Technological Advances ◽  
Improved Performance

Fiber-reinforced polymer (FRP) piping has been recognized for excellent corrosion resistance and high specific properties such as its strength-to-weight ratio. Despite the positive characteristics, FRP piping has limited, albeit growing utilization in industrial service. This is in part due to initial cost when compared to conventional metallic pipe. Reduced life cycle expenditures in conjunction with operational advantages may foster an increased implementation of FRP piping. This may be achieved through installation procedures, longevity and operational capabilities that are superior to those related to metallic piping. The present article reviews recent technological advances relating to these attributes, namely improved joining methods; enhanced wear, corrosion and damage resistance; and embedded monitoring systems for wear and other parameters.

Mechanical properties of fiber reinforced polymer composites: A comparative study of conventional and additive manufacturing methods

2018 ◽  
Vol 52 (23) ◽  
pp. 3173-3181 ◽  
Author(s):  
Kuldeep Agarwal ◽  
Suresh K Kuchipudi ◽  
Benoit Girard ◽  
Matthew Houser
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Manufacturing Processes ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Composite Filament

Fiber reinforced polymer composites have been around for many decades but recently their use has started to increase in multiple industries such as automotive, aerospace, and construction. The conventional composite manufacturing processes such as wet lay-up, resin transfer molding, automatic lay ups etc. suffer from a lot of practical and material issues which have limited their use. The mechanical properties of the parts produced by such processes also suffer from variation that causes problems downstream. Composites based additive manufacturing processes such as Fused Deposition Modeling and Composite Filament Fabrication are trying to remove some of the barriers to the use of composites. Additive manufacturing processes offer more design and material freedom than conventional composite manufacturing processes. This paper compares conventional composite processes for the manufacturing of Epoxy-Fiberglass fiber reinforced polymers with composite filament fabrication based Nylon-Fiberglass fiber reinforced polymers. Mechanical properties such as tensile strength, elastic modulus, and fatigue life are compared for the different processes. The effect of process parameters on these mechanical properties for the composite filament fabrication based process is also examined in this work. It is found that the composite filament fabrication based process is very versatile and the parts manufactured by this process can be used in various applications.

Experimental study on the bond behavior of the CFRP-steel interface under the freeze–thaw cycles

2019 ◽  
Vol 54 (1) ◽  
pp. 13-29 ◽  
Author(s):  
Yu-Yang Pang ◽  
Gang Wu ◽  
Hai-Tao Wang ◽  
Zhi-Long Su ◽  
Xiao-Yuan He
Keyword(s):  
Carbon Fiber ◽  
Bond Length ◽  
Ultimate Load ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Bond Slip ◽  
Freeze Thaw ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

The bond–slip degradation relationship between carbon fiber-reinforced polymer and steel in a freeze–thaw environment is crucial to evaluate the long-term service performance of steel structures strengthened with carbon fiber-reinforced polymer plates. However, limited studies on the durability and long-term performance of the carbon fiber-reinforced polymer-steel-bonded interface are the major obstacle for the application of carbon fiber-reinforced polymer plates in strengthening steel structures. This paper reports an experimental study to investigate the effects of the carbon fiber-reinforced polymer bond length and the freeze–thaw cycles on the bond behavior of the carbon fiber-reinforced polymer-steel-bonded interface. The three-dimensional digital image correlation technique is applied to obtain displacements and strains on the surface of the single-shear specimen. The experimental results present herein include the failure mode, the ultimate load, the carbon fiber-reinforced polymer strain distribution, the displacement distribution, and the bond–slip relationship. The results show that the ultimate load increases with increasing bond length until a certain bond length value is reached, after which the ultimate load remained approximately constant, and the ultimate loads of carbon fiber-reinforced polymer-steel interface decrease gradually under freeze–thaw cycles. The bond–slip parameters degradation models are proposed, and the bond–slip degradation relationship under the freeze–thaw cycles is established. Finally, the bond–slip degradation relationship is confirmed through comparisons with the experimental results.

scholarly journals Experimental and Numerical Research on Open-Hole Strength and Damage Mechanism of Regularly Arrayed Short Fiber Reinforced Polymer Composite

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1622
Author(s):  
Junfeng Hu ◽  
Xutong Zhang ◽  
Zhou Chen ◽  
Wenkang Guo ◽  
Hang Li ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Damage Mechanism ◽  
Short Fiber ◽  
Numerical Control ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Open Hole ◽  
Continuous Carbon Fiber

Laminates with unidirectionally arrayed chopped strands (UACS) are one of the advanced short fiber reinforced polymer composites (SFRP) with significant application prospect, which greatly improves mechanical properties compared to the traditional SFRP, meanwhile ensuring excellent flowability. In practice, composite laminate with an open hole is one of the typical connective components, and it is necessary to clarify the allowable load and damage tolerance performance of notched structures. In the present study, UACS laminates were fabricated using the continuous carbon fiber reinforced polymer (CFRP) prepreg, on which regularly arrayed bi-angled slits were introduced by a commercial numerical control cutter. The tensile strength and strain distribution around the open hole of the notched UACS laminate were experimentally investigated, while the damage progression near the open hole of the notched UACS laminate was analyzed by the finite element method (FEM). The tensile strength of the notched UACS laminate was measured at 298 MPa, which is about 60% of the strength of the unnotched UACS laminate. The simulation results match well with the experimental results, although there is a little overestimate on strength, by about 5% and 7%, for unnotched and notched UACS laminates, respectively. The final critical failure mode for the notched UACS laminate is mainly dominated by the delamination instead of the fiber breakage in the unnotched UACS laminate.

scholarly journals Anodic and Mechanical Behavior of Carbon Fiber Reinforced Polymer as a Dual-Functional Material in Chloride-Contaminated Concrete

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 222
Author(s):  
Liangliang Wei ◽  
Ji-Hua Zhu ◽  
Zhijun Dong ◽  
Jun Liu ◽  
Wei Liu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Mechanical Behavior ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Functional Material ◽  
Dual Functional ◽  
Reinforced Polymer ◽  
Chloride Contaminated

Carbon fiber reinforced polymer (CFRP) has been used as a dual-functional material in a hybrid intervention system (ICCP-SS) which integrates the impressed current cathodic protection (ICCP) and structural strengthening (SS). The mechanical behavior of CFRP as an anode has been investigated in some solution environments. However, the anodic and mechanical behavior of CFRP bonded to concrete is unclear. This paper focuses on the anodic and mechanical performance of CFRP bonded to the chloride-contaminated concrete by conducting an electrochemical (EC) test. The method of bonding the CFRP to the concrete and the shape of the steel embedded in the concrete were considered. The current densities of 20 mA/m2 and 100 mA/m2 were applied during 120-day and 310-day EC tests. The electrode potentials and driving voltages were recorded, and the bond interfaces of the CFRP were inspected after EC test. The residual tensile strength and failure modes of the CFRP were analyzed after tensile tests. Finally, the long-term performance of CFRP as a dual-functional material in ICCP-SS system was discussed. Results show that the externally bonding CFRP in ICCP-SS system can not only protect the steel in chloride-contaminated concrete effectively but also maintain 70% of the original tensile strength of CFRP at a charge density of 744 A·h/m2. The expected service period of CFRP as a dual-functional material bonded to the chloride-contaminated concrete was determined to be more than 42.5 years.

scholarly journals Experimental Study on Bond Performance of Carbon- and Glass-Fiber Reinforced Polymer (CFRP/GFRP) Bars and Steel Strands to Concrete

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1268
Author(s):  
Jun Zhao ◽  
Xin Luo ◽  
Zike Wang ◽  
Shuaikai Feng ◽  
Xinglong Gong ◽  
...  
Keyword(s):  
Bond Strength ◽  
Bond Length ◽  
Retention Rate ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Bond Performance ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Gfrp Bar ◽  
Strength Retention

FRP bars and steel strands are widely used in civil engineering. In this study, three different types of high-strength reinforcement materials, carbon fiber reinforced polymer (CFRP) bar, glass fiber reinforced polymer (GFRP) bar, and steel strand, were investigated for their interfacial bond performance with concrete. A total of 90 sets of specimens were conducted to analyze the effects of various parameters such as the diameter of reinforcement, bond length, the grade of concrete and stirrup on the bond strength and residual bond strength. The results show that CFRP bars possess a higher bond strength retention rate than steel bars in the residual section. In addition, with the increase in bond length and diameter of the CFRP bar, the residual bond strength decreases, and the bond strength retention rate decreases. Furthermore, the bond strength retention rate of GFRP bars was found to be higher than that of CFRP bars. With the increase in grade of concrete, the bond strength and residual bond strength between GFRP bars and concrete increases, but the bond strength retention rate decreases. With an increase in bond length and diameter of the GFRP bar, the bond strength starts to decrease. Further, stirrup can also increase the bond strength and reduce the slip at the free end of GFRP bars. Moreover, the bond strength retention rate of the steel strand was found to be lower than CFRP and GFRP bar.

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