scholarly journals Centrifugally-cast concrete poles with non-metallic reinforcement

2021 ◽  
Vol 73 (06) ◽  
pp. 579-590
Keyword(s):  
Transmission Lines ◽  
Power Transmission ◽  
Steel Corrosion ◽  
High Strength ◽  
Load Testing ◽  
Shear Reinforcement ◽  
Centrifugally Cast ◽  
Reinforced Polymer ◽  
Cast Concrete ◽  
Fibre Reinforced Polymer

The article describes the testing of poles for electric power transmission lines, which are made of centrifugally-cast concrete and ultra-high strength concrete, and which are prestressed with Carbon Fibre Reinforced Polymer tendons (CFRP). The presented results of pole ultimate load testing suggest the potential for usage of this construction product, particularly in aggressive environments with high probability of steel corrosion. Part of the tested poles had shear reinforcement in the form of confined Glass Fibre Reinforced Polymer (GFRP) grid, while one share of samples had no shear reinforcement, but the concrete matrix was strengthened with synthetic macro fibres. A review is given on similar product testing, calculation methods, and guidance is provided for further research.

Steel-free hybrid reinforcing bars for concrete structures

2018 ◽  
Vol 21 (16) ◽  
pp. 2617-2622 ◽  
Author(s):  
Jin-Guang Teng ◽  
Bing Zhang ◽  
Shishun Zhang ◽  
Bing Fu
Keyword(s):  
Concrete Structures ◽  
Steel Corrosion ◽  
High Strength ◽  
Reinforcing Bars ◽  
Reinforced Polymer ◽  
Steel Bar ◽  
Annular Layer ◽  
Fibre Reinforced Polymer ◽  
Corrosion Problem ◽  
Bar Buckling

Extensive research has been conducted on the replacement of steel rebars with fibre-reinforced polymer rebars to eliminate the steel corrosion problem in conventional steel bar–reinforced concrete structures. However, as the performance of fibre-reinforced polymer rebars is substantially inferior in compression (due to issues such as fibre micro-buckling) than in tension, their use in concrete columns is generally not recommended; this poses a significant challenge when a steel-free structure is needed. This article presents a novel steel-free hybrid rebar developed at The Hong Kong Polytechnic University that overcomes the above-mentioned problem. Such a hybrid rebar typically consists of a central fibre-reinforced polymer rebar, an external fibre-reinforced polymer confining tube and an annular layer of high-strength cementitious material such as ultrahigh-performance concrete. To demonstrate the performance of these hybrid rebars, results from a series of preliminary tests and associated modelling work are presented in the article. These results indicate that (1) the fibre-reinforced polymer rebar at the centre is well supported against bar buckling and fibre micro-buckling, (2) the compressive strength of the fibre-reinforced polymer material can be fully mobilized and (3) the stress–strain response of hybrid rebars can be designed to resemble an elastic–plastic response with some post-yielding hardening.

scholarly journals Sequential Laser–Mechanical Drilling of Thick Carbon Fibre Reinforced Polymer Composites (CFRP) for Industrial Applications

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2136
Author(s):  
Sharizal Ahmad Sobri ◽  
Robert Heinemann ◽  
David Whitehead
Keyword(s):  
Carbon Fibre ◽  
Polymer Composites ◽  
Weight Ratio ◽  
High Strength ◽  
Industrial Applications ◽  
Fibre Laser ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Thrust And Torque

Carbon fibre reinforced polymer composites (CFRPs) can be costly to manufacture, but they are typically used anywhere a high strength-to-weight ratio and a high steadiness (rigidity) are needed in many industrial applications, particularly in aerospace. Drilling composites with a laser tends to be a feasible method since one of the composite phases is often in the form of a polymer, and polymers in general have a very high absorption coefficient for infrared radiation. The feasibility of sequential laser–mechanical drilling for a thick CFRP is discussed in this article. A 1 kW fibre laser was chosen as a pre-drilling instrument (or initial stage), and mechanical drilling was the final step. The sequential drilling method dropped the overall thrust and torque by an average of 61%, which greatly increased the productivity and reduced the mechanical stress on the cutting tool while also increasing the lifespan of the bit. The sequential drilling (i.e., laser 8 mm and mechanical 8 mm) for both drill bits (i.e., 2- and 3-flute uncoated tungsten carbide) and the laser pre-drilling techniques has demonstrated the highest delamination factor (SFDSR) ratios. A new laser–mechanical sequence drilling technique is thus established, assessed, and tested when thick CFRP composites are drilled.

scholarly journals Processing and Mechanical Behavior of Banana Fibre Reinforced Epoxy based Composite with Alumina and silicon Carbide

2021 ◽  
pp. 434-441
Author(s):  
Kaushal Arrawatia ◽  
Kedar Narayan Bairwa ◽  
Raj Kumar
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Glass Fibre ◽  
High Strength ◽  
Fibre Reinforcement ◽  
Fixed Amount ◽  
Reinforced Polymer ◽  
Banana Fibre ◽  
Percentage Weight ◽  
Fibre Reinforced Polymer

Polymer composites have outstanding qualities such as high strength, flexibility, stiffness, and lightweight. Currently, research is being performed to develop innovative polymer composites that may be used in many operational situations and contain a variety of fibre and filler combinations. Banana fibre has low density compared to glass fibre and it is a lingo-cellulosic fibre having relatively good mechanical properties compared to glass fibre. Because of their outstanding qualities, banana fibre reinforced polymer composites are now widely used in various industries. The primary goal of this study is to determine the effect of the wt.% of banana fibre, the wt.% of SiC, and the wt.% of Al2O3 in banana fibre reinforcement composites on the mechanical and physical properties of banana fibre reinforcement composites. Tensile strength and flexural strength of unfilled banana fibre epoxy composite increased with the increase in wt. of banana fibre from 0 wt.% to 12 wt.%. Further, an increase in wt.% banana fibre drop in mechanical property was observed. It has been concluded from the study that the variation in percentage weight of filler material with fixed amount (12 wt.%) of banana fibre affects the mechanical properties of filled banana reinforcement composites. Optimum mechanical properties were obtained for BHEC5 (72 wt.% Epoxy + Hardener, 12 wt.% banana fibre and 16 wt.% Al2O3).

Performance of High-Pressure Fibre-Reinforced Polymer Composite Pipe Structures

2006 ◽  
Author(s):  
Pierre Mertiny ◽  
Fernand Ellyin
Keyword(s):  
High Pressure ◽  
Polymer Composite ◽  
High Strength ◽  
Fiber Reinforced Polymer ◽  
Damage Mechanisms ◽  
Reinforced Polymer ◽  
Composite Pipe ◽  
Fibre Reinforced Polymer ◽  
Superior Corrosion Resistance ◽  
Composite Pipes

Advanced fiber-reinforced polymer composite pipes offer high strength and superior corrosion resistance properties compared to conventional metallic pipeline materials. However, damage mechanisms in composite pipes are not fully understood and failure prediction methodologies are currently inadequate. Research is required to resolve these deficiencies which are an encumbrance to the certification of high-pressure composite pipe and its introduction into service. This is underlined by the findings reviewed in the present paper which derive from a comprehensive study on the performance and damage mechanisms in composite pipes and joint modules.

Model's Calibration for Masonry Reinforced with FRP Mesh-Bars

2014 ◽  
Vol 919-921 ◽  
pp. 421-425
Author(s):  
Alessandra Dal Cin
Keyword(s):  
Shear Strength ◽  
Polymer Material ◽  
Shear Reinforcement ◽  
Reinforced Polymer ◽  
Masonry Material ◽  
Fibre Reinforced Polymer ◽  
Steel Joints

The paper presents some considerations on the reliability of the available formulas to determine the shear strength of masonry reinforced with FRP (fibre reinforced polymer) material. In detail the outcomes of a model related to the Eurocode 6 is prepared in presence of not usual shear reinforcement as FRP mesh bars jointed to ten surface masonry through steel joints. The model considers the basic contribution due to the masonry material and then add the contribution related to the presence of a material as carbon bars that is characterized by higher behaviour in term of stiffness.

Shear behavior of reinforced concrete beams strengthened in flexure with bonded carbon fibre reinforced polymers laminates

2005 ◽  
Vol 32 (5) ◽  
pp. 812-824 ◽  
Author(s):  
Francesco Bencardino ◽  
Vincenzo Colotti ◽  
Giuseppe Spadea ◽  
Ramnath Narayan Swamy
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Shear Behavior ◽  
Structural Performance ◽  
Rc Beams ◽  
Shear Reinforcement ◽  
Brittle Behavior ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

The aim of this paper is to clarify the structural performance of reinforced concrete (RC) beams with weak or without any internal shear reinforcement and externally strengthened in flexure with carbon fibre reinforced polymer (CFRP) laminates, when subjected to a shear-dominant-loading regime. Seven RC beams were specifically designed, without and with an external anchorage system, which was carefully detailed to enhance the benefits of the strengthening laminate and counteract the destructive effects of shear forces. All the beams were identical in terms of their geometry, longitudinal internal reinforcement, and concrete strength but varied, to highlight the role of shear behavior, in terms of their internal and external shear reinforcement as well as in their loading test regime. The beams were tested under four-point bending and extensively instrumented to monitor strains, deflection, cracking, load carrying capacity, and failure modes. The structural response of the tested beams has, then, been critically analyzed in terms of deformability, strength, and failure processes that occur under a shear-dominant loading regime. It is shown that with a carefully designed anchorage system, a brittle behavior without yielding of tension steel reinforcement of a flexural strengthened beam can be transformed to a less brittle behavior with yielding of tension steel reinforcement and a well-defined enhancement of structural performance in terms of both deformation and strength. The results presented in this paper should enable engineers to counteract shear failure of externally strengthened beams with little or even no internal shear reinforcement.Key words: carbon fibre reinforced polymer, shear behavior, external flexural strengthening, structural performance.

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

2015 ◽  
Vol 10 (3) ◽  
pp. 201-206 ◽  
Author(s):  
Viktor Gribniak ◽  
Aleksandr K. Arnautov ◽  
Gintaris Kaklauskas ◽  
Vytautas Tamulenas ◽  
Edgaras Timinskas ◽  
...  
Keyword(s):  
Deformation Behaviour ◽  
High Strength ◽  
Concrete Bridges ◽  
Polymer Materials ◽  
Structural Stiffness ◽  
New Materials ◽  
Basalt Fibre ◽  
Reinforced Polymer ◽  
Polymer Sheets ◽  
Fibre Reinforced Polymer

Basalt polymers are rather new materials for civil engineering; therefore, identification of peculiarities and limitations of application of such polymers in concrete structures (particularly bridges) is of vital importance. This paper experimentally investigates deformation behaviour and cracking of flexural elements, which are predominant parameters governing serviceability of the bridges. Unlike a common practice, the present study is not limited by the analysis of concrete beams reinforced with the polymer bars; it also considers effectiveness of basalt fibre reinforced polymer sheets for repairing the beams. The analysis has revealed that a combination of the high strength and elasticity polymer materials governs the effective repair of the beams by significantly increasing (up to 40%) the structural stiffness.

scholarly journals Numerical Modeling of GFRP Reinforced Concrete Slabs

2017 ◽  
Vol 1 (4) ◽  
Author(s):  
Omer R EL Zaroug, John P Forth, Jianqiao YE
Keyword(s):  
Finite Element ◽  
Mechanical Load ◽  
Weight Ratio ◽  
High Strength ◽  
Load Range ◽  
Finite Element Program ◽  
Reinforced Concrete Slabs ◽  
Reinforced Polymer ◽  
Element Program ◽  
Fibre Reinforced Polymer

The use of non-metallic fibre reinforced polymer reinforcement as an alternative to steel reinforcement in concrete is gaining acceptance mainly due to its high corrosion resistance. High strength-to-weight ratio, high stiffness-to-weight ratio and ease of handling and fabrication are added advantages. Other benefits are that they do not influence to magnetic fields and radio frequencies and they are thermally non-conductive. However, the stress-strain relationship for Glass fibre reinforced polymer reinforcement (GFRP) is linear up to rupture when the ultimate strength is reached. Unlike steel reinforcing bars, GFRP rebars do not undergo yield deformation or strain hardening before rupture. Also, GFRP reinforcement possesses a relatively low elastic modulus of elasticity compared with that of steel. As a consequence, for GFRP reinforced sections, larger deflections and crack widths are expected than the ones obtained from equivalent steel reinforced sections for the same load. This investigation provides details of the numerical analysis of GFRP reinforced slabs loaded mechanically using the commercial finite element program (DIANA). To prove the validity of the proposed finite element approach, a comparison is made with experimental test results obtained from full-size slabs. The comparisons are made on the basis of first cracking load, load-deflection response at midspan, cracking patterns, mode of failure and loads at failure. Using the DIANA software for the analysis of GFRP reinforced slabs under mechanical load is possible and can produce acceptable predictions throughout the load range in terms of final load and crack patterns. However, DIANA overestimated the first cracking load and tended to over predict the experimental deflections.  

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