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1
Anandan, Sivakumar, and Majed Alsubih. "Mechanical Strength Characterization of Plastic Fiber Reinforced Cement Concrete Composites." Applied Sciences 11, no. 2 (January 18, 2021): 852. http://dx.doi.org/10.3390/app11020852.
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The reinforcing efficiency of plastic fibers obtained from shredded plastic waste was tested in plain concrete mixes and experimentally verified in this study. Plastic fibers up to 0.15% Vf were added to the design concrete mix to assess the fiber effectiveness in terms of improved load carrying capability of various plastic fiber incorporated concrete composites. The effects of plastic fibers distributed homogenously in the entire depth of concrete and confined in the tension zone were evaluated in flexural bending properties. Mechanical strength properties were evaluated for two different types of concrete containing (i) plastic fibers added homogenously throughout the entire depth of concrete and (ii) the plastic fibers confined in the tension zone only. Flexural bending parameters such as toughness, residual strength, crack width, post-peak drop load resistance, and fiber performance index of various plastic fiber substituted concrete mixes were tested in compressive and flexural bending to assess the fiber reinforcing efficiency. Test results indicated that the plastic fibers added in tension zone confinement exhibited higher flexural strength (5.26 N/mm2) improvements compared to homogeneously distributed concrete systems. Flexural bending characteristics in terms of absolute toughness and post peak strain softening were found to be appreciably higher (132%) in tension zone confined plastic fiber concretes compared to homogeneous fiber concrete systems.
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Trivedi, V., N. Vadher, V. Panera, K. K. R. Iyer, and M. Mungle. "Effect of plastic strips on elastic properties of concrete under cyclic loading." Proceedings of the 12th Structural Engineering Convention, SEC 2022: Themes 1-2 1, no. 1 (December 19, 2022): 159–64. http://dx.doi.org/10.38208/acp.v1.489.
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Heterogeneous characteristics of concrete with variation in strength of matrix, aggregate and interface causes non-uniform distribution in stress. Reinforcing concrete alters this distribution and can be designed to reduce non-uniformity. Present study investigates applicability of plastic strips as reinforcement to improve performance of concrete. Since plastic strips are strong in tension, they are oriented to control tensile stress generated in concrete. The approach adopted contributed to increment in compressive strength of fibre reinforced concrete. In comparison with conventional concrete, fibre reinforced concrete has higher but delayed compressive strength, lower initial stiffness and higher energy absorption capacity. In order to assess impact of plastic strips on fundamental properties like Young’s modulus and poisons ratio, cylindrical samples with radially oriented plastic strips are subjected to cyclic loading. Poisson’s ratio is computed by measuring axial and lateral deformation in the sample. To compute Young’s modulus, axial deformation is measured along the gauge length. Response of conventional and fibre reinforced concrete is measured for both loading and unloading cycles considered. In comparison with conventional concrete, fibre reinforced concrete reflects higher axial deformation but the lateral deformation is restrained. This contributes to lower Poisson’s ratio for fibre reinforced concrete. Reduction in lateral deformation of fibre reinforced concrete is an effect of confinement generated by plastic strips. The presence of confinement effect reduces net stress acting at a material point thus increasing compression capacity of concrete. Further, Young’s modulus of fibre reinforced concrete decreases in comparison with conventional concrete. This is due to softening effect of plastic strips in axial direction. However, progressive increment in loading causes substantial degradation in young’s modulus of conventional concrete whereas for fibre reinforced concrete it remains largely stable. Similar stability in also response is reported for poisons ratio. The present study thus establishes role of plastic strips in developing confinement effect contributing to improved performance and predictability in response of strength and material parameters namely Young’s modulus and poisons ratio.
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Xing, Feng, Fa Guang Leng, and Wei Wen Li. "Properties of Cracking Resistance of Cemfiber Reinforced Concrete." Key Engineering Materials 280-283 (February 2007): 1765–70. http://dx.doi.org/10.4028/www.scientific.net/kem.280-283.1765.
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Polypropylene fiber is a new measure to prevent plastic cracks of concrete. Effects of the parameters, such as dosage and types of fibers, on the plastic cracks were studied systematically. The properties of cracking resistance of mortar, ordinary concrete and high performance concrete were investigated by using samples of two types in shape. The results show that: (1) polypropylene fibers may increase the cracking resistance of concrete further; (2) as smaller quantity of cement and higher quantity of aggregate as possible should be used to prevent concrete form cracking; (3) the main reason why polypropylene fibers increase cracking resistance of concrete is that they increase strain capacity of concrete at early age, decrease shrinkage strain, improve plastic tensile strength and decrease tensile stress of the capillary.
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Niu, Jian Gang, Bin Wu, and Jian Bao. "Experimental Study on the Flexural Impact Properties of Fiber Reinforced Lightweight Aggregate Concrete." Applied Mechanics and Materials 488-489 (January 2014): 696–99. http://dx.doi.org/10.4028/www.scientific.net/amm.488-489.696.
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Through experimental study on the flexural impact properties of different dosage of plastic-steel fiber and steel fiber reinforced lightweight aggregate concrete, the results show that energy dissipation of cracking and damaging of steel fiber reinforced lightweight aggregate concrete increase with the increase of fiber ratio. However, energy dissipation of cracking and damaging of plastic-steel fiber concrete increases in early stage and decreases later with the increase of plastic-steel fibers. Enhancement effect of energy dissipation of damaging of plastic-steel fiber is higher than steel fibers.
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K. Askar, Mand. "Mechanical Properties of Concrete Reinforced with Alternative Fibers." Journal of Duhok University 23, no. 1 (September 14, 2020): 149–58. http://dx.doi.org/10.26682/csjuod.2020.23.1.16.
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The aim of this study is to investigate the capability to use alternative fibers and their effectiveness in improving the mechanical properties of concrete. Alternative fibers made of cut stainless steel rebar tie wire (RTW) and shredded west plastic bottles, polyethylene terephthalate (PET) has been used. The reason behind choosing these materials is the low cost and availability of them, as well as because nowadays the whole world is facing environment pollution problems, where many things which are invented for our life are responsible for polluting the environment due to improper waste management. In total, 135 concrete specimens were produced in two stages and subsequently tested; in the first stage of specimen production, steel (RTW) fibers with volume fractions of 1% and 2% were added to M40 concrete mixture, and in the second stage, plastic (PET) fibers with volume fractions of 0.5% and 0.75% were added to M40 concrete mixture. The results indicate that both alternative fibers used have considerable effects on the mechanical properties of concrete, where the mechanical properties were improved at the different percentages used. In general, the use of alternative steel (RTW) fibers and plastic (PET) fibers show a significant enhancement of concrete mechanical properties.
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Hadj Mostefa, Adda, and Merdaci Slimane. "Study of Concretes Reinforced by Plastic Fibers Based on Local Materials." International Journal of Engineering Research in Africa 42 (April 2019): 100–108. http://dx.doi.org/10.4028/www.scientific.net/jera.42.100.
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This work is carried out to investigate the performance of concrete reinforced with plastic fibers obtained locally (bottle waste as fiber). Bottle waste plastic was chosen because it is being thrown after single use and cause environmental problem. One way to recycle wasted bottles plastic is grinded into irregular fiber. Then, it was incorporate with the concrete and tests the performance of the concrete. The study was conducted using cylindrical and rectangular (cube) mold of concrete to investigate the performance of the concrete in term of mechanical properties. In this research, the mechanical properties that were measured are compressive strength, splitting tensile strength and flexural strength. The results revealed that the presence of plastic fiber in concrete will increase the concrete performance, as well as the concrete bond strength is improved and the cracks in the concrete decrease the use of fibers and reduce plastic waste.
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Zhou, Jian, Hai Ning Liu, Su Ma, Jing Jing Li, and He Tao Hou. "Bond Properties of Ceramic Concrete Reinforced by Bamboo Bar." Applied Mechanics and Materials 477-478 (December 2013): 920–25. http://dx.doi.org/10.4028/www.scientific.net/amm.477-478.920.
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Bond properties of ceramic concrete reinforced by bamboo bar were investigated based on pull-out tests. The influences of strength grade of ceramic concrete, material type, bond length, side length and notch spacing of bamboo bar on the bond strength between the bamboo bars and ceramic concrete were studied. The results show that the bond failure mode of ceramic concrete reinforced by bamboo bar without notch is majorly pulling-out failure, however, ceramic concrete reinforced by restructured bamboo (RB) bar with notch appears shear failure mode. The ultimate bond strength of ceramic concrete reinforced by RB bars is higher than that of ceramic concrete reinforced by laminated bamboo (LB) bar, which is close to that of ceramic concrete reinforced by plastic bars,but lower than that of ceramic concrete reinforced by steel bars under the same condition. When the notch spacing is 15 mm, the bond strength of ceramic concrete reinforced by RB bars is the highest. The conclusions can be usable for the the constitutive relationship of ceramic bamboo-reinforced concrete.
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Scarpitti, Nicholas, Nicholas Gavio, Alexander Pol, and Seyed Hamid Reza Sanei. "Recycling Unrecycled Plastic and Composite Wastes as Concrete Reinforcement." Journal of Composites Science 7, no. 1 (January 5, 2023): 11. http://dx.doi.org/10.3390/jcs7010011.
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The land disposal of waste material is a major environmental threat, and recycling efforts must be exponentially improved to mitigate it. In this paper, a feasibility study was conducted to reinforce concrete with waste materials that are not typically recycled. Compression testing was performed to evaluate the mechanical properties of the concrete specimens. The results were compared with a conventional wire mesh reinforcement used in concrete. Alternative reinforcements that are typically disposed of in landfill were used, namely, plastic regrind, carbon fiber scraps, tempered glass, coarse aggregates, and wire mesh. For each reinforcement type, four specimens were manufactured to evaluate the consistency of the results. Cylindrical specimens with ASME standard dimensions of 10.16 cm × 20.32 cm were tested using a Tinius-Olsen compression testing machine after seven days of curing. A constant strain rate of 0.25 MPa/s was applied until a load drop of 30% was detected. The results show that, while the recycled reinforcements had lower compressive strengths than the wire mesh, they maintained a load-carrying capacity of more than 80%. A major improvement was observed in terms of the ductility and toughness of the reinforced concretes. The recycled-carbon-fiber-reinforced specimens showed 12% strain at failure, a major improvement in concrete ductility. The findings of this research indicate that such recycled particles and fibers without any post-processing can be used in the reinforcement of concrete, with a significant improvement in ductility.
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Lu, Chenxuan, Yongcheng Ji, Yunfei Zou, Jieying Zhou, Yuqian Tian, and Zhiqiang Xing. "Mechanical Properties on Various FRP-Reinforced Concrete in Cold Regions." Buildings 13, no. 1 (January 5, 2023): 138. http://dx.doi.org/10.3390/buildings13010138.
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The evaluation of frost resistance varies with different reinforcement methods, but it is a hot research topic for concrete reinforced with Fiber-Reinforced plastic (FRP). Freezing and thawing tests of FRP-reinforced concrete prisms and cylinders are presented to simulate beams and piers of buildings in cold climates. To evaluate the specimens’ frost resistance, tests with various reinforcement techniques, morphological analysis, weight tests, and relative dynamic modulus of elasticity tests were used. Examined also were the variations in stress–strain curves for axial compression tests and load–displacement curves for bending tests following various freeze–thaw cycles. The findings indicated that after 100 freeze–thaw cycles, the weight of unreinforced concrete cylinders decreased by 9.7%, and its compressive strength decreased by 27.6%. On the other hand, CFRP-reinforced concrete cylinders (Carbon-Fiber-Reinforced Plastics) and GFRP (Glass-Fiber-Reinforced Plastics) gained 1.1% and 1.58% in weight, respectively, while the compressive strength decreased by 7.4% and 8%. After 100 freeze–thaw cycles, the weights of concrete prisms with reinforcement, without reinforcement, and with CFRP reinforcement decreased by 12.13%, 8.7%, and 9.6%, respectively, and their bending strength was reduced by 20%, 42%, and 53%, respectively. The frost resistance of the two FRP-reinforced concrete types had significant differences under freeze–thaw cycles because the prismatic specimens were not fully wrapped with FRP materials. Finally, finite element software ABAQUS was used to simulate the freeze–thaw cycle test of the two specimens. Calculated values were compared to experimental results for the load–displacement curve and the axial stress–strain curve under bending load. The comparison of peak displacement produced a maximum error of 8.6%, and the FRP-reinforced concrete model validity was verified.
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Yang, In-Hwan. "The Mechanical Properties of Recycled Plastic Fiber-Reinforced Concrete." Journal of the Korean Recycled Construction Resources Institute 2, no. 3 (September 30, 2014): 225–32. http://dx.doi.org/10.14190/jrcr.2014.2.3.225.
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Miralimov, Mirzakhid Khamitovich. "Nonliear Analysis of Reinforced Concrete Structures Considering Plastic Deformation." Applied Mechanics and Materials 802 (October 2015): 231–36. http://dx.doi.org/10.4028/www.scientific.net/amm.802.231.
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Analytical models and the basic preconditions for analysis of concrete and reinforced concrete structures should be established based on actual plastic properties of concrete and reinforcement, as well as consideration of presence of cracks in the concrete. It is known that the relationship between stress and strain in reinforced concrete is significantly different in the stage of work with cracks and without them. Development of computational method opens wide prospects in this direction. In this work the calculation of strength and definition of forces in constructive elements of structure from operational loadings are made on the basis of the finite element method. Analysis is carried out with the use of quadrangular isoparametric and beam elements by the method of level-by-level plasticization. Analytical model contains the nonlinear properties of concrete and reinforcement. Method and algorithm of calculation have been developed taking into account of real stress-strain diagrams from experiment. Method and algorithm of calculation of reinforced concrete designs include the limiting condition of deformation on the basis of known stress-strain diagram both for reinforcement and concrete. An example of analysis involving a tunnel structure for an underground station to determine internal forces using the proposed method was shown.
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Zanotto, Federica, Alice Sirico, Sebastiano Merchiori, Francesca Vecchi, Andrea Balbo, Patrizia Bernardi, Beatrice Belletti, Alessio Malcevschi, Vincenzo Grassi, and Cecilia Monticelli. "Durability of Reinforced Concrete Containing Biochar and Recycled Polymers." Key Engineering Materials 919 (May 11, 2022): 188–96. http://dx.doi.org/10.4028/p-mwn300.
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In the field of sustainable construction materials, the production of eco-friendly concretes, obtained by the addition of waste products such as biochar and recycled polymer particles, offers interesting alternatives to traditional materials. Biochar is a carbonaceous solid by-product obtained from the thermo-chemical conversion of biomass and its addition into concrete admixtures can offer an eco-friendly carbon sequestration solution, capable to slightly improve concrete properties. Recycled polymer materials can be used to partially replace conventional aggregates with the aim of obtaining lighter concretes that help to face the disposal challenge presented by this non-degradable plastic waste. However, the influence of these waste additions on the corrosion behavior of steel rebars embedded in these “eco-concretes” is still unexplored. Within this context, this work presents some results of an extensive study dealing with the concrete mechanical and physical properties and the rebar corrosion resistance during cyclic exposures to chloride-containing solutions.
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Abousnina, Rajab, Sachindra Premasiri, Vilive Anise, Weena Lokuge, Vanissorn Vimonsatit, Wahid Ferdous, and Omar Alajarmeh. "Mechanical Properties of Macro Polypropylene Fibre-Reinforced Concrete." Polymers 13, no. 23 (November 25, 2021): 4112. http://dx.doi.org/10.3390/polym13234112.
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Adding fibers to concrete helps enhance its tensile strength and ductility. Synthetic fibres are preferable to steel ones which suffer from corrosion that reduces their functionality with time. More consideration is given to synthetic fibres as they can be sourced from waste plastics and their incorporation in concrete is considered a new recycling pathway. Thus, this work investigates the potential engineering benefits of a pioneering application using extruded macro polyfibres in concrete. Two different fiber dosages, 4 kg/m3 and 6 kg/m3, were used to investigate their influence based on several physical, mechanical and microstructural tests, including workability, compressive strength, modulus of elasticity, splitting-tensile strength, flexural test, CMOD, pull-out test and porosity. The test results revealed a slight decrease in the workability of the fibre-reinforced concrete, while all the mechanical and microstructural properties were enhanced significantly. It was observed that the compressive, splitting tensile and bonding strength of the concrete with 6 kg/m3 fibre dosage increased by 19.4%, 41.9% and 17.8% compared to the plain concrete specimens, respectively. Although there was no impact of the fibres on the modulus of rupture, they significantly increased the toughness, resulting in a progressive type of failure instead of the sudden and brittle type. Moreover, the macroporosity was reduced by the fibre addition, thus increasing the concrete compressive strength. Finally, simplified empirical formulas were developed to predict the mechanical properties of the concrete with fibre addition. The outcome of this study will help to increase the implementation of the recycled plastic waste in concrete mix design and promote a circular economy in the waste industry.
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Kwon, Ji Eun, See Hyeon Chae, Sun Min Kwon, Ye Dam Jeong, Euigyung Jeong, and Jongwon Kim. "Effect of slitting of carbon fiber-reinforced plastic strip on flexural properties of reinforced concrete." Materials Research Express 9, no. 4 (April 1, 2022): 045602. http://dx.doi.org/10.1088/2053-1591/ac6a4a.
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Abstract In this study, reinforced concrete was manufactured by attaching a carbon fiber reinforced plastic (CFRP) strips to the surface of the concrete. Strips with the same total area were slitted into one, two, three, four, and six pieces and attached to the upper, lower, and side parts of the concrete. The flexural strength and fracture toughness of the reinforced concrete were investigated. As the number of slits in the strip increased, for the upper reinforcement, the flexural strength gradually increased from 7.88 MPa to 11.21 MPa; for the lower reinforcement, the flexural strength increased significantly from 7.88 MPa to 26.48 MPa and then gradually increased to 33.90 MPa; and for the side reinforcement, the flexural strength increased from 7.12 MPa to 13.96 MPa and then gradually decreased. In the adhesive fracture toughness test, the fracture toughness energy significantly increased from 142.38 J m−2 to 516.63 J m−2 as the contact area between the adhesive and the strip increased. Therefore, in reinforcing concrete using a CFRP strip, it was confirmed that the reinforcement effect was enhanced when the strip was slit and then attached.
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Pešić, Ninoslav, Stana Živanović, Reyes Garcia, and Panos Papastergiou. "Mechanical properties of concrete reinforced with recycled HDPE plastic fibres." Construction and Building Materials 115 (July 2016): 362–70. http://dx.doi.org/10.1016/j.conbuildmat.2016.04.050.
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Wu, Er Jun, and Xing Chen. "Calculation on Plastic Internal Force of Reinforced Concrete Member under Axial Force." Applied Mechanics and Materials 578-579 (July 2014): 31–36. http://dx.doi.org/10.4028/www.scientific.net/amm.578-579.31.
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The design of reinforced concrete structure often used the elastic internal force as the design basis, but the nonlinear behavior of reinforced concrete structures brings about errors in calculation of statically indeterminate structure. By considering the nonlinear properties, the mechanical responses of reinforced concrete structure were investigated, on which an axial force loaded at their middle span section. In a series of analysis on internal force of the reinforced concrete member at all loading stages, through the deformation compatibility equation and the balance equation, the formulas for calculating elastic-plastic internal forces and strains were derived. Comparative examples are provided and the results show a large error between internal forces calculated by the structural mechanics method and those by the elastic-plastic method proposed in this paper, and the maximum error is about 8 times.
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Baciu, A. M., I. Kiss, E. Desnica, and J. Sárosi. "Reinforcing concrete with recycled plastic wastes." Journal of Physics: Conference Series 2212, no. 1 (February 1, 2022): 012031. http://dx.doi.org/10.1088/1742-6596/2212/1/012031.
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Abstract Solid waste is one of the many factors that negatively affect the environment. The plastic is an important type of solid waste with a strong environmental impact, all types of plastic used in daily life becoming, sooner or later, waste. Therefore, increasing consumption of various types of plastic products is one of the most important challenges in environmental protection. From different perspectives, waste reuse is important because it helps to recycle in the production process, reduces environmental pollution, and helps sustain and conserve non–renewable natural resources. On another hand, many constructions require precise techniques and technologies that can utilize a number of new materials. Also, the lightweight building material industry is considered useful in promoting reused materials. In this context, the use of simple concrete and reinforced concrete is somewhat restricted by specific phenomena such as: cracking, fire resistance, shrinkage, shock resistance, wear resistance, durability, etc. For this reason, an improvement in the performance of the concrete can be obtained by adding in their mass of reinforcements dispersed in the form of fibres from different materials. The dispersed reinforced concrete results in the inclusion of a variable amount of discontinuous fibres in the concrete mass. These fibres can be of different types and sizes and have different properties. This type of reinforcements has become a major research subject in recent years. Therefore, using plastic waste in the materials industry is an environmental solution to minimize the proportion of landfills used in waste incineration. Reusing plastics as concrete additives could also redirect old water and soda bottles, the bulk of which would otherwise end up in a landfill. Research has focused on the impact of adding plastic material to fresh and hardened concrete. This study aims to investigate the use of polyethylene terephthalate (PET) wastes in concrete.
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Yuan, Fang, Liping Chen, Mengcheng Chen, and Kaicheng Xu. "Behaviour of Hybrid Steel and FRP-Reinforced Concrete—ECC Composite Columns under Reversed Cyclic Loading." Sensors 18, no. 12 (December 2, 2018): 4231. http://dx.doi.org/10.3390/s18124231.
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Fibre-reinforced polymer (FRP) is used widely in concrete structures owing to its noncorrosive, light-weight, nonmagnetic, and high tensile-strength properties. However, the FRP-reinforced concrete flexural member exhibits low ductility owing to the linear–elastic property of FRP reinforcement. Hybrid steel—FRP-reinforced concrete members exhibit good strength and ductility under flexure owing to the inelastic deformation of steel reinforcement. The existing investigations have focused on the mechanical behaviours of the hybrid steel—FRP-reinforced flexural members. Only few studies have been reported on the members under combined flexural and compression loads, such as columns, owing to the poor compressive behaviour of FRP bars. We herein propose a new type of hybrid steel—FRP-reinforced concrete—engineered cementitious composite (ECC) composite column with ECC applied to the plastic hinge region and tested it under reversed cyclic loading. The hybrid steel—FRP-reinforced concrete column was also tested for comparison. The influence of matrix type in the plastic hinge region on the failure mode, crack pattern, ultimate strength, ductility, and energy dissipation capacity, of the columns were evaluated systematically. We found that the substitution of concrete with ECC in the plastic hinge zone can prevent the local buckling of FRP bars efficiently, and subsequently improve the strength and ductility of the column substantially.
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Suchorab, Zbigniew, Małgorzata Franus, and Danuta Barnat-Hunek. "Properties of Fibrous Concrete Made with Plastic Optical Fibers from E-Waste." Materials 13, no. 10 (May 25, 2020): 2414. http://dx.doi.org/10.3390/ma13102414.
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This article presents research results relating to the potential for waste utilization in the form of polymer optical fiber (POF) scraps. This material is difficult to recycle due to its diverse construction. Three different volumes of POF were used in concrete in these tests: 1%, 2%, and 3%. The experimental studies investigated the basic properties of the concrete, the elastic and dynamic moduli, as well as deformation and deflection of reinforced beams. The microstructures, including the interfacial transition zones (ITZs), were recorded and analyzed using a scanning electron microscope. It was observed that 180 freezing–thawing cycles reduced the concrete frost resistance containing 3% POFs by half compared to the control concrete. The resistance to salt crystallization of this concrete decreased by about 55%. POFs have significant effects on the splitting tensile and flexural strengths compared to the compressive strength. The control beams were destroyed during the four-point static bending tests at half the force applied to the beams that were reinforced with POFs.
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Evdokimov, A. A., E. Sh Imametdinov, and S. S. Malakhovskiy. "STRENGTHENING CONCRETE BUILDING STRUCTURE VIA REINFORCEMENT EXTERNAL SYSTEM FROM CARBON PLASTIC." Proceedings of VIAM, no. 10 (2020): 73–80. http://dx.doi.org/10.18577/2307-6046-2020-0-10-73-80.
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The article describes the results of research work on the reinforcement of concrete structures via carbon reinforcing filler with a cold curing resin. As an object of research were selected: brand of concrete M-350 and experimental cold curing carbon fiber based on an epoxy matrix. The physico-mechanical characteristics of carbon fiber are investigated. The properties of concrete samples externally reinforced with carbon fiber after conducting full-scale exposure in various conditions and without it are investigated. It was established, that strength gain of reinforced samples compared to purely concrete samples is up to 550%.
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Al-Taan, Saad A., and Ayad A. Abdul-Razzak. "Nonlinear Finite Element Analysis of Fiber Reinforced Concrete Slabs." Engineering and Technology Journal 39, no. 3A (March 25, 2021): 426–39. http://dx.doi.org/10.30684/etj.v39i3a.1641.
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This paper presents a study on the behavior of fiber reinforced concrete slabsusing finite element analysis. A previously published finite element program is used for the nonlinear analysis by including the steel fiber concrete properties. Concrete is represented by degenerated quadratic thick shell element, which is the general shear deformable eight node serendipity element, and the thickness is divided into layers. An elastic perfectly plastic and strain hardening plasticity approach are used to model the compression behavior of concrete.The reinforcing bars were smeared within the concrete layers and assumed as either an elastic perfectly plastic material or as an elastic-plastic material with linear strain hardening. Cracks initiation is predicted using a tensile strength criterion. The tension stiffening effect of the steel fibers is simulated using a descending parabolic stress degradation function, which is based on the fracture energy concept. The effect of cracking in reducing the shear modulus and the compressive strength of concrete parallel to the crack direction is considered. The numerical results showedgood agreement with published experimental results for two fibrous reinforced concrete slabs.
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ABDUL RASOOL, Dr Zainab M. R., and Laith MOHAMMED RIDHA MAHMMOD. "EFFECT OF THE WIRE MESH REINFORCEMENT ON SOME PROPERTIES OF THE PRECAST CONCRETE TILES." Al-Qadisiyah Journal for Engineering Sciences 11, no. 2 (January 29, 2019): 256–69. http://dx.doi.org/10.30772/qjes.v11i2.558.
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The possibility of improving some properties of precast concrete tiles under static load has been studied in this research. The experimental approach was adopted in this research to investigate the effect of two types of wire mesh reinforcements on some properties of precast concrete tiles especially flexural failure load. The experimental program is divided into three groups with two ages of the test, the result of each age is an average of three specimens; the first group consists of six specimens which refer to reference tiles, the second group consists of eighteen specimens reinforced with different shapes of a metal wire mesh. The third group consists of eighteen specimens reinforced with different shapes of the plastic wire mesh. Three tests were conducted in this research, flexural failure load, density, and absorption. The main conclusion from this research is; the increasing in flexural failure load of specimens tiles according to reference tiles was 10%, 17% and 25% for tiles reinforced with square plastic wire mesh, stripe plastic wire mesh and specific plastic wire mesh, and 33%, 35% and 21% for square metal wire mesh, stripe metal wire mesh, and specific metal wire mesh respectively.
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Trykoz, L. V., S. M. Kamchatnaya, O. M. Pustovoitova, and A. O. Atynian. "The Investigation of Prestressed Pressure Pipes, Reinforced with Fiberglass Plastic." International Journal of Engineering Research in Africa 36 (June 2018): 1–11. http://dx.doi.org/10.4028/www.scientific.net/jera.36.1.
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The problem of a combined action of reinforced concrete pipe and fiberglass safety cage. The prestressed cage not only decreases deformability of a pipe under load but protects the material of a pipe from agressive external factors. The process of force transfer from concrete pipe and fiberglass has been analyzed and the equation of stress and deformation for pipes and fiberglass has been deduced. It is shown that stress in fiberglass does not remain constant varying wall thickness, reducing towards the concrete core. Hoop stresses in the concrete core increase towards the centre of a pipe. Unlike known solutions the performed calculations take into account the performance of both layers – concrete and fiberglass. The total stresses in a concrete pipe in the most dangerous section from internal pressure and the reduction by fiberglass winding have been determined. The results obtained in the given work provide with the possibility of modelling long-term properties of composite reinforced concrete constructions and optimization of winding angle of fiberglass casing depending on the diameter of a pipe, tension force and the quantity of reinforcing filler.
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Ahmed, Sofyan Younis, Oday Asal Salih, and Orass Najeebabba. "Effect of Plastic Hinge Properties in Pushover Analysis of Reinforced Concrete Plane Frames." International Research Journal of Innovations in Engineering and Technology 06, no. 09 (2022): 42–48. http://dx.doi.org/10.47001/irjiet/2022.609006.
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The four-bay, five-story Reinforced Concrete (RC) frame with two-dimensional beams and a column moment frame system that is vulnerable to Mosul, Iraq's seismic activity is examined. A plastic hinge symbolizes the member yielding failure mode in columns and beams. Utilizing SAP2000 software (V.16), the pushover study was carried out to confirm the code's fundamental goal of life safety performance under seismic events. By combining the seismic hazard with the inelastic structural analysis, one may determine the anticipated seismic performance of a structure. An essential outcome of pushover analysis for both brittle (force-controlled) and ductile (deformationcontrolled) actions of the plastic hinge behavior is the base shear vs structure's tip displacement curve. The pushover analysis, using a variety of alternatives for the plastic hinge behavior, showed that the plastic hinge formed because of its brittle nature placed it in the more severe category. All of the plastic hinges created in the beams as a result of brittle behavior are placed in the risky branch ("Collapse Prevention CP") of the plastic hinge acceptance criterion. This necessitates increasing the shear strength of the beams.
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Khezhev, T. A., G. N. Khadzhishalapov, F. M. Shogenova, A. Kh Artabaev, and M. Kh Mashukova. "Properties of fire-retardant vermiculite-concrete composite and fine-grained concrete for two-layer reinforced cement structures." Herald of Dagestan State Technical University. Technical Sciences 49, no. 2 (August 17, 2022): 165–76. http://dx.doi.org/10.21822/2073-6185-2022-49-2-165-176.
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Objective. Development of compositions of fire-retardant vermiculite-concrete composites for reinforced cement structures. Investigation of the properties of fire-retardant vermiculite-concrete composite and fine-grained concrete for two-layer reinforced cement structures.Method. Methods for increasing the fire resistance of reinforced concrete structures are considered. Research is focused on the development of fire-retardant composites using expanded vermiculite and volcanic ash. To improve the physical and mechanical properties of the fire-retardant composite, a mixture of Portland cement, gypsum, lime, basalt fiber, saponified wood resin, volcanic ash and expanded vermiculite has been developed. For the study of vermiculite concretes reinforced with basalt fiber, a second-order rotatable plan of the regular hexagon type was used.Result. Fiber-vermiculite concretes are proposed, which have improved fire-retardant properties compared to known compositions. This is due to the better preservation of the fiber-vermiculite-concrete layer when heated as a result of fiber reinforcement. Also, thanks to the addition of SDO, the fire-retardant properties of the composite increase due to the additional porosity of the fiber-vermiculite-concrete. The parameters of the "stress-strain" diagram of a vermiculite-concrete composite and fine-grained concrete have been obtained.Conclusion. Vermiculite concretes with an average density of 480-560 kg/m3 have the best fire-retardant properties. The developed two-layer reinforced cement structures have high fire resistance.
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Balaguru, P. "Fiber-reinforced-plastic (FRP) Reinforcement for concrete structures: Properties and applications." Cement and Concrete Composites 16, no. 1 (January 1994): 65–66. http://dx.doi.org/10.1016/0958-9465(94)90032-9.
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Annamaneni, Krishna Kiran, Bhumika Vallabhbhai Dobariya, and Krasnikovs Andrejs. "CONCRETE, REINFORCED BY CARBON FIBRE COMPOSITE STRUCTURE, LOAD BEARING CAPACITY DURING CRACKING." ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 2 (June 17, 2021): 232–37. http://dx.doi.org/10.17770/etr2021vol2.6655.
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Different authors conducted studies on fiber reinforced concretes (FRC) with carbon fibres of different lengths and some results showed that concrete mix with homogeneously distributed short fibres in their volume have good strength and ultra-strain compared to normal plain concrete mix. However, this study is focused more on 3-dimensional (3D) carbon fibre reinforced plastic (epoxy) CFRP composite thin rods frame used as a reinforcement in concrete which shows good increase in loadbearing and ductility. Were investigated concrete mixes with superplasticizer, nano-silica, quartz sand, fine natural sand and gravels. Diagonal cross bracing carbon fibre epoxy frames were used as a reinforcement giving better ductility results. Proposed study approach is to show that the reinforced concrete with provided materials have an increased performance in terms of ductility, sustainability, and load bearing in cracked statement. Total, four groups of concrete and each group with three beams were casted and tested in this experiment, three groups with three different shapes of carbon frames and three beams without frames to compare the mechanical properties after 28 days. Failure mechanisms in any particular case were analysed.
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Statsenko, Nataliya, and Valery Mitasov. "Control of stress-strain state in double-span reinforced concrete beams." MATEC Web of Conferences 143 (2018): 01007. http://dx.doi.org/10.1051/matecconf/201814301007.
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Considering the tendency of reinforced concrete to redistribute load depending on the amount and location of effective reinforcement a series of experiments were performed using a non-traditional approach with set strain behavior of reinforced concrete beams during crack formation. The influence of location and number of cracks on load redistribution in double-span reinforced concrete beams was assessed. During the experiments comparative analysis of moments at support and at span was performed using uniform method of experiment. The paper presents mechanisms of load redistribution caused by non-linear deformations of a cracked element and plastic properties of compressed concrete.
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Grujić, Bojana, Igor Jokanović, Žarko Grujić, and Dragana Zeljić. "Numerical modelling of the reinforced concrete influence on a combined system of tunnel support." Selected Scientific Papers - Journal of Civil Engineering 12, no. 2 (December 1, 2017): 63–70. http://dx.doi.org/10.1515/sspjce-2017-0020.
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Abstract The paper presents the experimental, laboratory determined rheological-dynamic analysis of the properties of fiber reinforced concrete, which was then utilized to show nonlinear analysis of combined system of tunnel support structure. According to the performed experiments and calculations, different processes of destructive behavior of tunnel lining were simulated in combination with elastic and elastic-plastic behavior of materials taking into account the tunnel loading, the interaction between the fiber reinforced concrete and soil, as well as the interaction between the fiber reinforced concrete and the inner lining of the tunnel.
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FOROUGHİ, Saeid, and Bahadır YÜKSEL. "Non-linear displacement and deformation damage limits of reinforced concrete circular columns by analytical observations according to TBSC 2018." International Advanced Researches and Engineering Journal 6, no. 2 (under construction) (August 15, 2022): 68–79. http://dx.doi.org/10.35860/iarej.1058369.
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In the study, based on the non-linear calculation methods used to determine the seismic performance of structures in TBSC 2018, the stress-strain, moment-curvature, displacement capacity, plastic rotation limits, and deformation-based damage limit values of the reinforced concrete circular cross-section columns were calculated and compared according to different design parameters. The studied effects of the design parameters on the non-linear relation of reinforced concrete columns were also evaluated in terms of strength, curvature, and displacement ductility of the sections. All design parameters affecting the non-linear behavior and deformation limits of the reinforced concrete circular cross-section columns were taken into account. Deformation demands for reinforced concrete structural members are essential for detecting element damage. Based on TBSC (2018), non-linear relationships of reinforced concrete columns were obtained in order to calculate plastic hinge properties and deformation limits. For the Limited Damage, Controlled Damage, and Collapse Prevention performance levels defined for the structural elements in TBSC 2018, plastic rotation and deformation limit values were obtained according to the characteristic values calculated from the non-linear analyzes of reinforced concrete circular columns. For column models, damage limits and damage zones calculated based on TBSC 2018 were shown on the visually obtained moment-curvature relationships. Depending on the upper deformation limit values derived, cross-sectional deformation damage levels were determined and evaluated using the moment-curvature relationships. The variation of the non-linear behavior of column models by design parameters and deformation-based damage limits were examined both analytically and visually. The deformation limits remain in a safer direction as a result of increasing longitudinal and spiral reinforcement ratios for the reinforced concrete circular columns.
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Khalil, Wasan, Hisham Ahmed, and Zainab Hussein. "Behavior of high performance artificial lightweight aggregate concrete reinforced with hybrid fibers." MATEC Web of Conferences 162 (2018): 02001. http://dx.doi.org/10.1051/matecconf/201816202001.
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In this investigation, sustainable High Performance Lightweight Aggregate Concrete (HPLWAC) containing artificial aggregate as coarse lightweight aggregate (LWA) and reinforced with mono fiber, double and triple hybrid fibers in different types and aspect ratios were produced. High performance artificial lightweight aggregate concrete mix with compressive strength of 47 MPa, oven dry density of 1828 kg/m3 at 28 days was prepared. The Fibers used included, macro hooked steel fiber with aspect ratio of 60 (type S1), macro crimped plastic fiber (P) with aspect ratio of 63, micro steel fiber with aspect ratio of 65 (type S), and micro polypropylene fiber (PP) with aspect ratio of 667. Four HPLWAC mixes were prepared including, one plain concrete mix (without fiber), one mono fiber reinforced concrete mixes (reinforced with plastic fiber with 0.75% volume fraction), one double hybrid fiber reinforced concrete mixes (0.5% plastic fiber + 0.25% steel fiber type S), and a mix with triple hybrid fiber (0.25% steel fiber type S1+ 0.25% polypropylene fiber + 0.25% steel fiber type S). Fresh (workability and fresh density) and hardened concrete properties (oven dry density, compressive strength, ultrasonic pulse velocity, splitting tensile strength, flexural strength, static modules of elasticity, thermal conductively, and water absorption) were studied. Generally, mono and hybrid (double and triple) fiber reinforced HPLWAC specimens give a significant increase in splitting tensile strength and flexural strength compared with plain HPLWAC specimens. The percentage increases in splitting tensile strength for specimens with mono plastic fiber are, 20.8%, 31.9%, 36.4% and 41%, while the percentage increases in flexure strength are 19.5%, 37%, 33.9% and 34.2% at 7, 28, 60, 90 days age respectively relative to the plain concrete. The maximum splitting tensile and flexure strengths were recorded for triple hybrid fiber reinforced HPLWAC specimens. The percentage increases in splitting tensile strength for triple hybrid fiber reinforced specimens are 19.5%, 37%, 33.9% and 34.2%, while the percentage increases in flexure strength are 50.5%, 62.4. %, 66.8% and 62.2% at 7, 28, 60 and 90 days age respectively relative to the plain concrete specimens.
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Gerland, Florian, Alexander Wetzel, Thomas Schomberg, Olaf Wünsch, and Bernhard Middendorf. "A simulation-based approach to evaluate objective material parameters from concrete rheometer measurements." Applied Rheology 29, no. 1 (January 1, 2019): 130–40. http://dx.doi.org/10.1515/arh-2019-0012.
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Abstract Modern concretes such as ultra-high performance concrete (UHPC) show excellent strength properties combined with favorable flow properties. However, the flow properties depend strongly on process parameters during production (temperature, humidity etc.), but also change sensitively even with slight variations in the mixture. In order to ensure desired processing of the fluidlike material and consistent process quality, the flow properties of the concrete must be evaluated quantitatively and objectively. The usual evaluation of measurements from concrete rheometers, for example of the ball probe system type, does not allow the direct determination of the objective material parameters yield stress and plastic viscosity of the sample. We developed a simulation-based method for the evaluation of rheometric measurements of fine grained high performance concretes like self-compacting concrete (SCC) and UHPC. The method is based on a dimensional analysis for ball measuring systems. Through numerical parameter studies we were able to describe the identified relationship between measuring quantities and material parameters quantitatively for two devices of this type. The evaluation method is based on the Bingham model. With this method it is possible to measure both the yield stress and the plastic viscosity of the fresh sample simultaneously. Device independence of the evaluation process is proven and an application to fiber-reinforced UHPC is presented.
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Borisyuk, Evgenij. "The effect of the type of fixators reinforcement on strength and deformation characteristics of reinforced concrete." E3S Web of Conferences 97 (2019): 02034. http://dx.doi.org/10.1051/e3sconf/20199702034.
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Rebar fixators of various types (plastic and concrete) became widespread with manufacturing of building structures of precast and monolithic reinforced concrete in order to fix steel reinforcement cage in strictly design position and to exclude the probability of its displacement during concreting. Such sufficiently rigid fixing is necessary for the following reliable operation of the structure in the building, as well as for the preservation of steel reinforcement which protected by a necessary layer of concrete from corrosion. Information available in the literature does not allow us to judge about the effects that different types of fixators apply to exploitative properties (such as strength and crack resistance) of reinforced concrete. The experiments, according to the accepted method, showed that these characteristics are slightly worse for the samples with plastic fixators and fixators made of low grade concrete than for the samples without fixators or fixators made of high grade concrete. On the base on the research results it becomes possible to substantiate the distinction between the areas of application of plastic and concrete fixatives
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Zhuang, Ning, Hao Dong Sun, and Song Ge. "Numerical Analysis on Mechanical Properties of Beams Reinforced by CFRP Laminates." Applied Mechanics and Materials 744-746 (March 2015): 196–200. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.196.
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Carbon Fiber Reinforced Plastic (CFRP) has been widely used in large-scale concrete infrastructure’s reinforcement and renovation because of its low weight and high strength, which promotes CFRP application in the field of civil engineering. This paper two aged beams reinforced by CFRP sheet was loaded to failure in four-point bending by laboratory experiment. Then the numerical model was built to simulate the destruction process and compared with test results. Based on the studying of this paper, the changing law of beam’s stress, ultimate bearing capacity growth, failure mode and cracking propagation was investigated during the loading process. The research has guiding significance for the design and construction of concrete structures reinforced by CFRP laminates.
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Kochkarev, Dmitriy, Taliat Azizov, and Tatyana Galinska. "Bending deflection reinforced concrete elements determination." MATEC Web of Conferences 230 (2018): 02012. http://dx.doi.org/10.1051/matecconf/201823002012.
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Longitudinal reinforced concrete elements stiffness exhaustion, often used in building practice, precedes obtaining bearing capacity, and therefore deflections determination becomes a determining factor in their design. In connection with it precise methods for determining such reinforced concrete elements deflections become especially relevant. The elastic-plastic properties of concrete and cracks in the stretched zone of reinforced concrete elements lead to a significant change in their bending stiffness. That is why the deflections determined by the materials classical resistance formulas differ significantly from the real ones. A large quantity of methods for determining deflections is based on the elastic characteristics correction of reinforced concrete elements consolidated section. Such methods, although providing calculation satisfactory results, are rather approximate and have empirical nature, due to it they have limited application. More precise calculation methods consist of curvature usage to determine deflections. The curvature of reinforced concrete elements cross sections is determined directly from the equilibrium equations, which are written taking into account nonlinear materials deformation diagrams. Calculation examples for bending reinforced concrete elements deflection are given.
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Prusiel, Jolanta Anna, Robert Grygo, and Kevin Bujnarowski. "USE OF ECOLOGICAL LIGHTWEIGHT AGGREGATES IN REINFORCED CONCRETE STRUCTURES." Ekonomia i Środowisko - Economics and Environment 79, no. 4 (December 21, 2021): 112–32. http://dx.doi.org/10.34659/2021/4/31.
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The article discusses the possibility of utilization of both waste from CHP plants (Combined heat and power plants), i.e. fly ash, and PET plastic waste (polyethylene terephthalate), through processing into lightweight aggregate used to construct reinforced concrete beam elements to protect the natural environment. Properties of the utilized lightweight artificial aggregates are presented. Selected results of experimental tests in the area of load-bearing capacity and deformability of reinforced concrete beams made in the model scale are presented. An analysis of tests showed that beam elements made with artificial aggregate, despite its lower resistance to crushing, do not differ in terms of their load-bearing capacity compared to reinforced concrete beams made with recycled aggregate, with better flexural strength properties in certain cases.
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Li, Xue Ying, Jing Zhao, Wei Zhe Wang, and Alan Jiang. "Effects of Polypropylene Fiber on Plastic Shrinkage Crack and Mechanical Properties of Concrete." Key Engineering Materials 324-325 (November 2006): 487–90. http://dx.doi.org/10.4028/www.scientific.net/kem.324-325.487.
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This paper reports on the mechanical properties and plastic shrinkage crack of concrete containing modified polypropylene fibera kind of new porous polypropylene fiber. Results of crack properties tests show that after adding modified polypropylene fiber, crack area, maximum crack width and average crack width of concrete decreased markedly. Results of mechanical properties show that flexural and splitting tensile strength of concrete with 1.0‰ modified polypropylene fiber volume fraction at 28 days increased 24% and 28% respectively compared to the reference concrete; Reticulate polypropylene fiber has less effects than modified polypropylene fiber on flexural and splitting tensile strength. Compressive strength of fiber reinforced concrete changed slightly, but flexural strength and splitting tensile strength increased, and the ratio of splitting tensile strength to compressive strength decreased.
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Zhang, Guo Xue, Chang Wei Wang, and Jia Wei Huang. "Nonlinear Analysis on Stainless Steel Reinforced Concrete Columns under Low-Cyclic Load." Applied Mechanics and Materials 256-259 (December 2012): 588–91. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.588.
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In order to study the elastic-plastic mechanics properties of the stainless steel reinforced concrete columns under low-cyclic load, the engineering open-source earthquake simulation system OpenSees is used to carry out the numerical simulation. The comparison between the computed results and the pseudo-static test results shows that the OpenSees may stimulate the mechanical properties of the stainless steel reinforced concrete columns by using the fiber element model, both of the skeleton curves and hysteretic curves are well agreement with the tests results.
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Suksiripattanapong, Cherdsak, Khanet Uraikhot, Sermsak Tiyasangthong, Nattiya Wonglakorn, Wisitsak Tabyang, Sajjakaj Jomnonkwao, and Chayakrit Phetchuay. "Performance of Asphalt Concrete Pavement Reinforced with High-Density Polyethylene Plastic Waste." Infrastructures 7, no. 5 (May 17, 2022): 72. http://dx.doi.org/10.3390/infrastructures7050072.
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This research investigates the possibility of using high-density polyethylene (HDPE) plastic waste to improve the properties of asphalt concrete pavement. HDPE plastic waste contents of 1, 3, 5, and 7% by aggregate weight were used. HDPE plastic waste=stabilized asphalt concrete pavement (HDPE-ACP) was evaluated by performance testing for stability, indirect tensile strength, resilient modulus (MR), and indirect tensile fatigue (ITF). In addition, microstructure, pavement age, and CO2 emissions savings analyses were conducted. The performance test results of the HDPE-ACP were better than those without HDPE plastic waste. The optimum HDPE plastic waste content was 5%, offering the maximum MR, ITF, and pavement age. Scanning electron microscope images showed that the excessive HDPE plastic waste content of 7% caused a surface rupture of the sample. Improvements in the pavement age of the HDPE-ACP samples were observed compared with the samples with no HDPE plastic waste. The highest pavement age of the HDPE-ACP sample was found at an HDPE plastic waste content of 5% by aggregate weight. The CO2 emissions savings of the sample was 67.85 kg CO2-e/m3 at the optimum HDPE plastic waste content.
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Castillo-Lara, Joaquin F., Emmanuel A. Flores-Johnson, Alex Valadez-Gonzalez, Pedro J. Herrera-Franco, Jose G. Carrillo, P. I. Gonzalez-Chi, and Q. M. Li. "Mechanical Properties of Natural Fiber Reinforced Foamed Concrete." Materials 13, no. 14 (July 8, 2020): 3060. http://dx.doi.org/10.3390/ma13143060.
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The mechanical characterization of plain foamed concrete (PFC) and fiber-reinforced foamed concrete (FRFC) with a density of 700 kg/m3 was performed with compression and tension tests. FRFC was reinforced with the natural fiber henequen (untreated or alkaline-treated) at volume fractions of 0.5%, 1% and 1.5%. Polypropylene fiber reinforcement was also used as a reference. For all FRFCs, the inclusion of the fibers enhanced the compressive and tensile strengths and plastic behavior, which was attributed to the increase of specimen integrity. Under compressive loading, after the peak strength, there was no considerable loss in strength and a plateau-like regime was observed. Under tensile loading, the fibers significantly increased the tensile strength of the FRFCs and prevented a sudden failure of the specimens, which was in contrast to the brittle behavior of the PFC. The tensile behavior enhancement was higher when treated henequen fibers were used, which was attributed to the increase in the fiber–matrix bond produced by the alkaline treatment. The microscopic characterization showed that the inclusion of fibers did not modify the air-void size and its distribution. Higher energy absorption was observed for FRFCs when compared to the PFC, which was attributed to the enhanced toughness and ductility by the fibers. The results presented herein warrant further research of FRFC with natural henequen fibers for engineering applications.
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Sivanantham, Pradeep, Beulah Gnana Ananthi Gurupatham, Krishanu Roy, Karthikeyan Rajendiran, and Deepak Pugazhlendi. "Plastic Hinge Length Mechanism of Steel-Fiber-Reinforced Concrete Slab under Repeated Loading." Journal of Composites Science 6, no. 6 (June 2, 2022): 164. http://dx.doi.org/10.3390/jcs6060164.
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The plastic hinge is the most critical damaging part of a structural element, where the highest inelastic rotation would occur. In particular, flexural members develop maximum bending abilities at that point. The current paper experimentally investigates the influence of steel fiber reinforcement at the plastic hinge length of the concrete slab under repeated loading, something which has not been reported by any researcher. Mechanical properties such as compressive strength and tensile strength of M20-grade concrete that are used for casting specimens are tested through the compressive strength test and the split tensile strength test. Six different parameters are considered in the slab while carrying out this study. First, the conventional concrete slab and then the steel-fiber-reinforced slab were cast. The plastic hinge length of the slab was calculated through different empirical expressions taken from methods by Baker, Sawyer, Corley, Mattock, Paulay, Priestley and Park. Finally, the steel fiber was added as per methods detailed by Paulay, Priestley and Park in the plastic hinge length mechanism in the concrete slab at 70 mm and 150 mm separately. The results arrived through experimental investigation by applying repeated loads to the slab, indicating that steel fibers used at critical sections of plastic hinge length provide similar strength, displacement, and performance as that of the conventional RCC slab and fully steel-fiber-reinforced concrete slabs. Steel fiber at a plastic hinge length of slab has a better advantage over a conventional slab.
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Sucharda, Oldrich, and Jan Kubosek. "Modelling and Analysis of Reinforced Concrete Beams." Key Engineering Materials 662 (September 2015): 81–84. http://dx.doi.org/10.4028/www.scientific.net/kem.662.81.
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The goal of the paper is to model and evaluate the total load capacity of the reinforced concrete beams. A non-linear analysis and finite element method were used for that purpose. The model consists of 3D finite elements. The constitutive model of concrete for the non-linear analysis is based on a fracture-plastic theory. The input parameters are the data obtained in previous tests which included both standard tests and additional tests of the testing bodies. There is no shear reinforcement in the beams. The non-linear calculations were carried out for several variants. The study takes into considerations the influence of concrete properties as well as the size of the finite elements.
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Boschmann Käthler, Carolina, Ueli M. Angst, and Bernhard Elsener. "Towards understanding corrosion initiation in concrete – influence of local concrete properties in the steel-concrete interfacial zone." MATEC Web of Conferences 199 (2018): 04002. http://dx.doi.org/10.1051/matecconf/201819904002.
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Chloride-induced corrosion is the most common deterioration process for reinforced infrastructure objects. Improving the understanding of the conditions for initiation of localized corrosion is urgently needed. Research is focused on the influence of “defects” at the steel-concrete interface (SCI), as these weak points might be responsible for corrosion initiation. In contrast to numerous studies with “lab concrete”, this study reports results from reinforced concrete cores drilled from old infrastructure objects containing a non-corroding rebar. In contrast to laboratory studies, this guarantees real conditions at the SCI comprising also irregularities such as air voids, plastic settlement voids, cracks, etc. This allows to study chloride-induced corrosion in real conditions and to determine the so-called “critical chloride content” Ccrit. Visual inspection of the SCI enables to establish (or not) influences of the local conditions at the SCI and Ccrit. It was found that Ccrit strongly decreased with the carbonation depth, even if the carbonation front had not reached the steel. Moreover, coarse air voids and cracks were in this study not particularly susceptible sites for corrosion initiation.
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Kabantsev, Oleg V., Kirill O. Pesin, and Alexey V. Karlin. "ANALYSIS OF STRESS-STRAIN STATE OF REINFORCED CONCRETE PLATE AROUND SUPPORT ZONES." International Journal for Computational Civil and Structural Engineering 13, no. 1 (March 22, 2017): 55–62. http://dx.doi.org/10.22337/2587-9618-2017-13-1-55-62.
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Structural analysis of the formation and evolution processes of structural microdestruction with the tran-sition to macrorestriction occurring during plastic deformation of masonry under biaxial stresses. The dependencies that determine the amount of the plastic phase of the deformation of masonry. Identified processes and their corre-sponding strength criteria, which play a key role in the implementation phase of plastic deformation. It is shown that plastic deformation of masonry under biaxial stresses occurs when the physical line operation of the basic ma-terials of masonry (brick and mortar). Found that the plastic properties of masonry under biaxial stresses are deter-mined by the processes occurring at the nodes of contact interaction of brick and mortar in horizontal and vertical joints. According to the results of numerical studies the values of the coefficients of ductility of masonry at different variants of mechanical characteristics of brick, mortar and adhesive strength of their interaction.
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Shatarat, Nasim, Mutasem Shehadeh, and Mohammad Naser. "Impact of Plastic Hinge Properties on Capacity Curve of Reinforced Concrete Bridges." Advances in Materials Science and Engineering 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/6310321.
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Pushover analysis is becoming recently the most practical tool for nonlinear analysis of regular and irregular highway bridges. The nonlinear behaviour of structural elements in this type of analysis can be modeled through automated-hinge or user-defined hinge models. The nonlinear properties of the user-defined hinge model for existing highway bridges can be determined in accordance with the recommendations of the Seismic Retrofit Manual by the Federal Highway Administration (FHWA-SRM). Finite element software such as the software SAP2000 offers a simpler and easier approach to determine the nonlinear hinge properties through the automated-hinge model which are determined automatically from the member material and cross section properties. However, the uncertainties in using the automated-hinge model in place of user-defined hinge model have never been addressed, especially for existing and widened bridges. In response to this need, pushover analysis was carried out for four old highway bridges, of which two were widened using the same superstructure but with more attention to seismic detailing requirements. The results of the analyses showed noticeable differences in the capacity curves obtained utilizing the user-defined and automated-hinge models. The study recommends that bridge design manuals clearly ask bridge designers to evaluate the deformation capacities of existing bridges and widened bridges using user-defined hinge model that is determined in accordance with the provisions of the FHWA-SRM.
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Inel, Mehmet, and Hayri Baytan Ozmen. "Effects of plastic hinge properties in nonlinear analysis of reinforced concrete buildings." Engineering Structures 28, no. 11 (September 2006): 1494–502. http://dx.doi.org/10.1016/j.engstruct.2006.01.017.
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Bhogayata, Ankur C., and Narendra K. Arora. "Fresh and strength properties of concrete reinforced with metalized plastic waste fibers." Construction and Building Materials 146 (August 2017): 455–63. http://dx.doi.org/10.1016/j.conbuildmat.2017.04.095.
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Tang, Cao Ming, and Qi Nie. "Elasto-Plastic History Analysis of Reinforced Concrete Frame Structure Based on Fiber Beam-Column Model." Advanced Materials Research 250-253 (May 2011): 3517–20. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.3517.
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The three parameters of the earthquake ground motions(peak amplitude, spectrum and duration) and dynamic elasto-plastic properties of the building structure can be considered in elasto-plastic history analysis method, therefore it is significant for seismic performance assessment, nonlinear development progress and failure mechanic analysis of building structures under different level earthquake. The accuracy and availability for constitutive model of concrete and reinforcement subjected to cyclic loading have an important influence on reliability of the elasto-plastic history analysis of building structure based on material model. However, due to the complexity of concrete material, there is no unified constitutive model can be used to analyze nonlinear mechanical behavior of concrete until now. In this paper, a practical uniaxial hysteretic constitutive model of concrete and reinforcement is proposed, a computer program of material model is developed and the model is inserted into ABAQUS software with the user subroutine, using fiber beam element model and explicit time integration method, a elasto-plastic history analysis for shaking table test model of 12-story reinforced concrete frame is carried out. The comparison between computation analysis and experimental results shows that the model has a higher accuracy, efficiency and better availability, it is suitable for the constitutive model of concrete and reinforcement used in elasto-plastic history analysis of building structure.
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Kan, Abdulkadir. "Investigation of some engineering properties of waste polytetrafluoroethylene (PTFE) fiber reinforced concrete." Challenge Journal of Concrete Research Letters 10, no. 3 (September 6, 2019): 56. http://dx.doi.org/10.20528/cjcrl.2019.03.002.
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In this study, a comparison was made between concrete with waste PTFE fiber and standard concrete. Both elastomeric and thermoplastic fluoropolymer find a wide use especially in automotive applications such as seals, pulley etc. A large amount of PTFE occurs during this applications production. PTFE fiber is not a conventional concrete additive. It is a waste material and it can be used as a concrete filler material. In order to investigate the behaviour of this waste material in the concrete, mixtures containing waste PTFE fiber in amounts of 25%, 50%, 75%, and 100% (by weight) in order to replace to the same amount of fine sand (0-1 mm) were prepared. The compressive strength, tensile strength, workability and unit weight of the waste PTFE fiber concrete investigated. It was observed that waste PTFE fiber concretes have sufficient strength to be used as semi structural concrete. The mechanical behaviours of waste PTFE fiber concrete and control concrete were very similar. Moreover, it was observed that the unit weight and workability of the waste PTFE fiber concretes were decreased. This study provides that reusing waste PTFE fiber as an artificial filler material in concrete gives a new approach to solve some of the solid waste problems by plastics.
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Khaleel Ibrahim, Sarah, and Majid Movahedi Rad. "Limited Optimal Plastic Behavior of RC Beams Strengthened by Carbon Fiber Polymers Using Reliability-Based Design." Polymers 15, no. 3 (January 22, 2023): 569. http://dx.doi.org/10.3390/polym15030569.
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The plastic behavior of strengthened haunched beams utilizing carbon fiber-reinforced polymers (CFRP) was investigated using a probabilistic design that took into account random concrete properties, CFRP properties, and complementary strain energy values, with the reliability index serving as a limiting index, as the proposed method considers a novel method that deals with probabilistic parameters for models with limited plastic behavior designed based on the reliability index. The data used in this research were gathered and evaluated in a recent study on simply supported haunched beams reinforced with carbon fiber-reinforced polymers. The purpose of this research was to use the reliability limitation index for simulated strengthened haunched beams by taking into account randomness in concrete and CFRP properties and the complementary strain energy value, which is considered a plastic behavior controller that provides an illustration of the damage amount within the reinforcement steel bars. The results indicate how randomness affects the behavior of the presented models, which are chosen to have different numbers of CFRP strips. The variable randomness affects load and deflection values where the reliability index value increases as the corresponding load value decrease, reflecting the increased probability of failure in models subjected to higher loading conditions, while tension concrete damage percentages are reflected in the damage pattern presented in the results, showing that as the produced load increases, so does the damage intensity. It is also obvious that the reliability index served as a limitation index while taking concrete characteristics and complementary strain energy as random variables.