Journal articles on the topic 'Composite reinforced concrete Testing'
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1
Michalek, Peter, Jakub Kralovanec, and Jan Bujnak. "Composite Steel and RPC Testing." Pollack Periodica 15, no. 3 (November 7, 2020): 144–49. http://dx.doi.org/10.1556/606.2020.15.3.14.
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Reactive powder concretes are a set of ultrahigh-strength concrete reinforced with fibers. Their compressive strength is greater than 100 MPa. For assuring connection of steel beams and a concrete slab, steel stud connectors are used. The investigation of that kind of shear connection efficiency, in the case of this higher strength concrete deck using standard push-out test specimens has been executed. The experimental results are presented in the paper.
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Hosseini Mehrab, Alireza, Seyedmahdi Amirfakhrian, and M. Reza Esfahani. "Fracture characteristics of various concrete composites containing polypropylene fibers through five fracture mechanics methods." Materials Testing 65, no. 1 (January 1, 2023): 10–32. http://dx.doi.org/10.1515/mt-2022-0210.
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Abstract This paper investigates and compares the experimental results of fracture characteristics in various polypropylene fiber-reinforced concretes (high strength concrete, lightweight concrete, and engineered cementitious composite) on 90 three-point bend (notched and un-notched) beams. Five widely used fracture mechanics testing methods, such as work of fracture method, stress-displacement curve method, size effect method, J integral method, and ASTM E399, were used to investigate the fracture behavior. Results have demonstrated that fracture energy and fracture toughness improved as the dosage of polypropylene fibers increased in concretes. However, this improvement was different in concretes owing to various results of fracture mechanics testing methods and different properties of each concrete. Aggregates played significant role in the performance of polypropylene fibers on the fracture behavior of concretes. Among testing methods, the ASTM E399 showed the lowest values for the fracture toughness of concretes. Both work of fracture and stress-displacement curve methods exhibited appropriate results for the fracture energy of polypropylene fiber-reinforced concrete composites. The accuracy of size effect method was acceptable for determining size-independent fracture parameters of plain high strength and lightweight concretes. Furthermore, the J integral method showed more relevant results for the fracture toughness of polypropylene fiber-reinforced engineered cementitious composite.
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Wang, Yan Lei, Qing Duo Hao, and Jin Ping Ou. "Experimental Testing of Fiber Reinforced Polymer-Concrete Composite Beam." Advanced Materials Research 168-170 (December 2010): 549–52. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.549.
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A new form of fiber reinforced polymer (FRP)-concrete composite beam is proposed in this study. The proposed composite beam consists of a GFRP box beam combined with a thin layer of concrete in the compression zone. The interaction between the GFRP beam and the concrete was obtained by bonding coarse-sand on the top flange of the GFRP beam. One GFRP box beam and one GFRP-concrete composite beam were investigated in four-point bending test. Load-deflection response, mid-span longitudinal strain distributions and interface slip between GFRP beam and the concrete for the proposed composite beam were studied. Following conclusions are drawn from this study: (1) the stiffness and strength of the composite beam has been significantly increased, and the cost-to-stiffness ratio of the composite beam has been drastically reduced comparing with GFRP-only box beam; (2) a good composite action has been achieved between the GFRP beam and the concrete; (3) crushing of concrete in compression defines flexural collapse of the proposed composite beam..
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Mander, Thomas J., and Zachery I. Smith. "Composite Steel Stud Blast Panel Design and Experimental Testing." Applied Mechanics and Materials 82 (July 2011): 479–84. http://dx.doi.org/10.4028/www.scientific.net/amm.82.479.
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Based on Federal Aviation Authority (FAA) requirements, project specific blast loads are determined for the design of a new airport traffic control tower. These blast loads must be resisted by exterior wall panels on the control tower, protecting building occupants from intentional explosives attack scenarios. Such blast resistant walls are typically constructed of thick reinforced concrete panels or composite steel plate and rolled sections, as conventional building cladding systems have relatively low blast resistance. While these more robust design approaches are valid, the additional cladding mass they represent will significantly increase the base shear and overturning demand in seismic zones. This paper investigates the use of a light structural system comprised of a steel stud wall assembly partially embedded in a thin layer of concrete to obtain composite action. Fiber reinforced polymer (FRP) composites are also included to increase the blast resistance and aid in keeping the panel weight to a minimum. Two full-scale composite steel stud walls are designed, constructed, and tested dynamically in the BakerRisk shock tube. The stud walls consist of back-to-back 150 mm deep, 14 gauge (1.8 mm thick), cold-formed steel studs spaced at 610 mm on center. Both specimens have a 50 mm thick normal weight concrete layer, reinforced with welded wire mesh that is welded to the stud compression flanges to achieve composite action. Two layers of Tyfo® SEH-51A fiber reinforced composites are used on the tension flange of the steel studs. A single layer of Tyfo® SEH-51A composites is used on the tension face of the concrete layer between the studs for one of the specimens. Web stiffeners are used at the bearing support to prevent premature web crippling shear failure of the specimens. The stud walls are analyzed using single-degree-of-freedom (SDOF) models. A non-linear moment-curvature relationship, accounting for actual material constitutive properties, is used for determining the resistance function of the walls. Blast pressure and impulse data from the shock tube tests is used to compare analytical predictions to the measured displacement-time response. Analytical predictions of panel response for both tests are within ten percent of the observed response based on displacement.
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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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Nevskii, A. V. "CARBON FIBER REINFORCED CONCRETE COLUMNS UNDER STATIC AND DYNAMIC LOADS." Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel'nogo universiteta. JOURNAL of Construction and Architecture, no. 4 (August 29, 2018): 111–21. http://dx.doi.org/10.31675/1607-1859-2018-20-4-111-121.
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Many new developments in the field of creating promising building materials relate to polymer fiber composites for reinforcing concrete constructions. The most effective use of such composites is provided by carbon fiber reinforcement. To date, the issues related to design, calculation and use of concrete constructions with carbon composite reinforcement under dynamic compressive loading have not been well studied. Purpose: The purpose of this study is to determine strength of dynamically loaded concrete constructions reinforced with carbon fiber using different methods of modification of deformation properties of concrete. Methodology: Experimental studies include testing two concrete columns with steel rod reinforcement and six concrete columns modified by carbon fiber and carbon composite reinforcement. The columns are tested under axial static and dynamic compressive loads. Research findings: The resulting longitudinal deformations of concrete and carbon-composite reinforcement and the limiting compressive force are determined. Value: New experimental data are obtained for the concrete column strength reinforced with carbon composite rods. The experimental results indicate the effective resistance to compression of carbon composite reinforcement. This phenomenon is observed in the case of carbon fiber and carbon composite reinforcement of compressed concrete constructions under the dynamic load. Practical implications: Resistance of carbon composite reinforcement to the dynamic compression affects the concrete strength, especially when its deformation properties are modified by carbon fiber and carbon composite reinforcement. The obtained results can be used in strength calculations of concrete constructions under the dynamic load.
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Prabakaran, E., D. Vasanth Kumar, A. Jaganathan, P. Ashok Kumar, and M. Veeerapathran. "Analysis on Fiber Reinforced Epoxy Concrete Composite for Industrial Flooring – A Review." Journal of Physics: Conference Series 2272, no. 1 (July 1, 2022): 012026. http://dx.doi.org/10.1088/1742-6596/2272/1/012026.
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Abstract Fiber composites are the having an good scope in construction industry as they are light in weight, durable, economic, and resistant to temperatures. Many researchers concentrate on the composites for the industrial flooring with the fibers. The main objective of this paper is to review the fiber reinforced epoxy for industrial flooring. Epoxy can be used as flooring elements in industries as they deliver good performance. Since, natural and synthetic fibres can be used with filler matrices, which are very much cheaper than the conventional steel fibres reinforced composite concrete flooring and other type of composites here fibre is considered for reinforcing with epoxy or polymer concrete filler matrix. Fibre-polymer and fibre-concrete composite properties has been reviewed for testing procedure for flexural test, bending test, tensile test and based on the results, it is clear that the fibre-polymer concrete composite, which has good mechanical properties and performance than the mentioned composites, can be made for industrial flooring
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Wang, Yan Lei, Qing Duo Hao, and Jin Ping Ou. "Flexural Testing of Fiber Reinforced Polymer-Concrete Composite Bridge Superstructure." Advanced Materials Research 79-82 (August 2009): 1855–58. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.1855.
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The concept of the fiber reinforced polymer (FRP)-concrete composite design was exploited in a new type of bridge superstructure. The proposed FRP-concrete composite bridge superstructure is intended to have durable, structurally sound, and cost effective composite system that will take full advantage of the inherent and complementary properties of FRP material and concrete. As a trial case, a prototype bridge superstructure was designed as a simply supported single-span one-lane bridge with a span length of 10 m. The bridge superstructure consists of two bridge decks and each bridge deck is comprised of four FRP box sections combined with a thin layer of concrete in the compression zone. A test specimen, fabricated as a one-third scale model of the prototype bridge superstructure, was subjected to four-points loading to simulate the two heaviest axles of the Chinese design truck load. The test results indicate that the proposed bridge model meets the stiffness requirement and has significant reserve strength.
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Lindner, Marco, Konrad Vanselow, Sandra Gelbrich, and Lothar Kroll. "Fibre-reinforced polymer stirrup for reinforcing concrete structures." Technologies for Lightweight Structures (TLS) 3, no. 1 (January 24, 2020): 17–24. http://dx.doi.org/10.21935/tls.v3i1.117.
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Fibre-plastic composites offer an interesting alternative to concrete reinforcement. In order to expandthe application spectrum of reinforcing elements in fibre composite construction, a new steel-free bracingsystem with reduced radii of curvature was developed. An improvement in load carrying capacity couldbe proven in extensive investigations based on international testing methods and verified by practicaltests. With the help of newly reinforced precast concrete elements from the area of waterways and trafficroutes, a high potential for lightweight construction and resource efficiency can be impressivelydemonstrated.
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Orlowsky, Jeanette, Markus Beßling, and Vitalii Kryzhanovskyi. "Prospects for the Use of Textile-Reinforced Concrete in Buildings and Structures Maintenance." Buildings 13, no. 1 (January 10, 2023): 189. http://dx.doi.org/10.3390/buildings13010189.
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This paper discusses the state of the art in research on the use of textile-reinforced concretes in structural maintenance. Textile-reinforced concretes can be used in structural maintenance for various purposes, including the sealing and protection of the existing building structures, as well as for the strengthening of structures. The first-mentioned aspects are explained in this paper on the basis of example applications. A special focus is placed on the maintenance of heritage-protected structures. The development, characterization, and testing of a textile-reinforced concrete system for a heritage-protected structure are presented. Examples of the application of textile-reinforced concrete for strengthening highway pavements and masonry are also given. In particular, the possibility of adapting the textile-reinforced concrete repair material to the needs of the individual building is one advantage of this composite material.
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Lumingkewas, Riana Herlina, Akhmad Herman Yuwono, Sigit Pranowo Hadiwardoyo, and Dani Saparudin. "The Compressive Strength of Coconut Fibers Reinforced Nano Concrete Composite." Materials Science Forum 943 (January 2019): 105–10. http://dx.doi.org/10.4028/www.scientific.net/msf.943.105.
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The compressive strength of the concrete reviewed in this study uses nanosilica and coconut fibers. The addition of coconut fibers to concrete contributes to the construction of sustainable and environmentally friendly building materials. The testing method carried out physically and mechanically. Testing the compressive strength of the nanoconcrete composite with variations in the amount of nanosilica which substituted with cement. Using variations of nanosilica composition, namely 0%, 0.5%, 1%, 1.5%, and 2% added with coconut fiber to determine the effect of compressive strength from nanoconcrete composite. The results obtained are the optimal value of concrete compressive strength with nanosilica is the addition of 2% nanosilica, which increases 43% of standard concrete. Moreover, on concrete with the addition of nanosilica and the addition of coconut fibers 1% test results in concrete compressive strength which is optimal in the addition of 0.5% nanosilica, which is 58% increase from normal concrete. The conclusion of this study that the addition of nanosilica and reinforced with coconut fiber will increase the compressive strength of concrete, this is an excellent composite material to get environmentally friendly building materials using.
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Hou, Hetao, Weiqi Fu, Canxing Qiu, Jirun Cheng, Zhe Qu, Wencan Zhu, and Tianxiang Ma. "Effect of axial compression ratio on concrete-filled steel tube composite shear wall." Advances in Structural Engineering 22, no. 3 (August 28, 2018): 656–69. http://dx.doi.org/10.1177/1369433218796407.
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This study proposes a new type of shear wall, namely, the concrete-filled steel tube composite shear wall, for high performance seismic force resisting structures. In order to study the seismic behavior of concrete-filled steel tube composite shear wall, cyclic loading tests were conducted on three full-scale specimens. One conventional reinforced concrete shear wall was included in the testing program for comparison purpose. Regarding the seismic performance of the shear walls, the failure mode, deformation capacity, bearing capacity, ductility, hysteretic characteristics, and energy dissipation are key parameters in the analysis procedure. The testing results indicated that the bearing capacity, the ductility, and the energy dissipation of the concrete-filled steel tube composite shear walls are greater than that of conventional reinforced concrete shear walls. In addition, the influence of axial compression ratio on the seismic behavior of concrete-filled steel tube composite shear wall is also investigated. It was found that higher axial compression ratio leads to an increase in the bearing capacity of concrete-filled steel tube composite shear walls while a reduction in the ductility capacity.
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Nugroho, Bintoro Siswo, Yoga Pebrianto, Irfana Diah Faryuni, and Asifa Asri. "Effects of Silica Nanoparticle Addition on Physical and Mechanical properties of Sugar Palm Fibers Reinforced Cement Composite Concrete." International Journal of Engineering and Applied Science Research 1, no. 1 (July 30, 2020): 24. http://dx.doi.org/10.26418/ijeasr.v1i1.42087.
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This study examines the effect of nanosilica addition to the physical and mechanical properties of sugar palm fibers (SPFs) reinforced cement composite concrete. The composite concrete ingredients are SPFs as the filler, cement and nano-silica as the matrix, CaCl2 as the catalyst, and water. Testing and fabrication of the composite concrete were performed according to the standard of ASTM C 1185 and ASTM C 1186. The results obtained show that, in general, the addition of nanosilica improves the quality of the composite concrete. A positive effect is attained by adding nanosilica to its optimum amount. The excessive addition of nanosilica reduces the quality of the composite. The composite's mechanical property that is negatively affected by the addition of the nanosilica is the elasticity, in which more nanosilica added stiffer the composite.
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Zainurrahman, Eko Darma, and Sri Nuryati. "Carbon Fiber Reinforced Polymer Sebagai Perkuatan Lentur pada Balok Beton." BENTANG : Jurnal Teoritis dan Terapan Bidang Rekayasa Sipil 8, no. 1 (January 15, 2020): 20–28. http://dx.doi.org/10.33558/bentang.v8i1.1947.
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Concrete Beams can experience a sudden collapse when overload because of its brittle characteristic. The use of Carbon Fiber Reinforced Polymer (CFRP) on concrete beams externally as external confinement is predicted to improve concrete mechanics properties, increase the ductility and capacity of concrete, and the flexural strength of concrete beams. An experimental study on the reinforcement of concrete beams with Carbon Fiber Reinforced Polymer (CFRP) was carried out to estimate the effectiveness of CFRP on concrete structures as a concrete beam flexural reinforcement material. Two types of concrete beams are provided in this study to test the flexural strengthening effect of the externally bound CFRP composite. First type of concrete beam used for testing is a normal concrete beams, whereas the second tested beam, the CFRP was laminated by coating the beams with Fiber. The dimensions of both types are 15cm x15cm with a length of 55cm footing range. Testing result obtained the compressive strength was 23,29 MPa, flexural strength of normal and CRFP concretes were 33,41 Kg/cm2 and 48,07 Kg/cm2 respectively. It was concluded that the use of CRFP at the concrete beam increases flexural strength up to 44% with the ratio of 143 %.
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Holberg, A. M., and H. R. Hamilton. "Strengthening URM with GFRP Composites and Ductile Connections." Earthquake Spectra 18, no. 1 (February 2002): 63–84. http://dx.doi.org/10.1193/1.1461376.
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Research on the use of fiber-reinforced polymer (FRP) composites for strengthening of unreinforced or inadequately reinforced hollow concrete masonry is covered in this paper. Quasi-static shear wall tests were conducted on unreinforced concrete masonry specimens that had been strengthened with unidirectional glass fiber strips applied to the surface of the masonry using a two-part epoxy to form a surface-bonded GFRP composite. The strips were strategically placed to improve both flexural and shear strength in the in-plane direction. The GFRP composite system was combined with conventional structural steel and reinforcing steel connections that were designed to yield before the composite ruptured, resulting in a ductile failure mode under cyclic testing. The drift capacities of the tested specimens ranged from 0.6% to 1.7%.
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Nikolaev, Valery, Valentina Stepanova, and Vyacheslav Falikman. "Application of non-metallic composite reinforcement for contact line supports." MATEC Web of Conferences 323 (2020): 01004. http://dx.doi.org/10.1051/matecconf/202032301004.
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The technology for pre-stressing and anchoring of the composite rebar was developed. It makes possible to reinforce concrete products and produce the contact line supports of high quality, which possesses advantages in comparison with the steel reinforced concrete. The prototypes of supporting structures with the use of the composite BFRP reinforcement were developed. They were tested for strength, rigidity and crack resistance. In the course of testing, the value of a pole deflection in the plane of the application of the control load was determined. Poles with composite reinforcement (with vibratory load and after vibratory load) and steel reinforced poles were tested and compared. Results obtained show that the vibratory load had no significant impact on the properties of supports reinforced with pre-stressed composite rebars and confirm the practical possibility to use them. In the future, it is necessary to develop the working drawings for the replacement of the steel reinforcement by a composite polymer rebar and the technical requirements for supports of the contact lines of Russian Railways as well as the technical regulations for their design and manufacturing.
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Schumann, Alexander, Sebastian May, and Manfred Curbach. "Design and Testing of Various Ceiling Elements Made of Carbon Reinforced Concrete." Proceedings 2, no. 8 (July 12, 2018): 543. http://dx.doi.org/10.3390/icem18-05436.
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In this paper the design and recalculation of new type ceiling elements made of carbon reinforced concrete (CRC) is described. With the use of the high-potential composite material carbon reinforced concrete, structures can be, compared to conventional steel reinforced concrete (RC), designed and manufactured slimmer and lighter. Because of this and the increased sustainability of ceiling elements made of CRC a noteworthy amount of concrete can be saved. To show the potential of CRC elements, four different structures for various fields of application are shown. The first ceiling element, which will be introduced, fits perfectly for the use in multi-storey car parks because of the high resistance of the carbon fibers against corrosion. Another CRC structure in this paper was created in a research project as a demonstrator to show the potential of the newly developed concrete mixture for CRC. To prove the ability of this new developed concrete, large-scale CRC I-beams were produced in a precast concrete factory. The third ceiling element was designed and manufactured in form of a shell to combine the high strength composite material with an improved design for ceiling elements. The last introduced CRC element was developed as demonstrator in another research project and was designed in form of a ribbed slab.
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Eryshev, V. A. "Methodology of studying the mechanical properties of composite materials (reinforced concrete)." Industrial laboratory. Diagnostics of materials 84, no. 12 (December 20, 2018): 61–67. http://dx.doi.org/10.26896/1028-6861-2018-84-12-61-67.
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The mechanical properties of a complex composite material formed by steel and hardened concrete, are studied. A technique of operative quality control of new credible concrete and reinforcement, both in laboratory and field conditions is developed for determination of the strength and strain characteristics of materials, as well as cohesion forces determining their joint operation under load. The design of the mobile unit is presented. The unit provides a possibility of changing the direction of loading and testing the reinforced element of the given shape both for tension and compression. Moreover, the nomenclature of testing equipment and the number of molds for manufacturing concrete samples substantially decrease. Using the values of forcing resulting in concrete cracking when the joint work of concrete and reinforcement is disrupted the values of the inherent stresses and strains attributed to the concrete shrinkage are determined. An analytical relationship between the forces and deformations of the reinforced concrete sample with central reinforcement is derived for axial tension and compression, with allowance for strains and stresses in the reinforcement and concrete resulted from concrete shrinkage. The results of experimental studies are presented, including tension diagrams and diagrams of developing axial deformations with an increase in the load under the central loading of the reinforced elements. A methodology of accounting for stresses and deformations resulted from concrete shrinkage is developed. The applicability of the derived analytical relationships between stresses and deformations on the material diagrams to calculations of the reinforced concrete structures in the framework of the deformation model is estimated.
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Jevtic, Dragica, Dimitrije Zakic, and Aleksandar Savic. "Modeling of properties of fiber reinforced cement composites." Facta universitatis - series: Architecture and Civil Engineering 6, no. 2 (2008): 165–72. http://dx.doi.org/10.2298/fuace0802165j.
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This paper presents the results of authors' laboratory testing of the influence of steel fibers as fiber reinforcement on the change of properties of cement composite mortar and concrete type materials. Mixtures adopted - compositions of mortars had identical amounts of components: cement, sand and silica fume. The second type of mortar contained 60 kg/m3 of fiber reinforcement, as well as the addition of the latest generation of superplasticizer. Physical and mechanical properties of fiber reinforced mortars and etalon mixtures (density, flexural strength, compressive strength) were compared. Tests on concrete type cement composites included: density, mechanical strengths and the deformation properties. The tests showed an improvement in the properties of fiber reinforced composites.
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Maaroof, Atyaf Abdul Azeez, Jasim Ali Abdullah, and Suhaib Yahya Kasim. "Performance of Steel Perforated and Partially-Encased Composite Self-Connected Beams." Jurnal Kejuruteraan 34, no. 4 (July 30, 2022): 703–17. http://dx.doi.org/10.17576/jkukm-2022-34(4)-18.
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The self-connected partially encased composite beams may be used rather than the conventional composite beams; those are connected by the concrete passing through the web-openings of the perforated profiles which works as shear connectors. This technique minimizes the construction cost and enhances the load carrying capacity and ductility of this kind of structures better than the perforated steel beams. The presented work investigates the performance of perforated steel and partially-encased composited self-connected simply supported beams applied to three-points of loading. The effect of the openings shape and the presence of concrete on the performance of the beams are investigated by testing eight specimens of perforated steel and composite beams. The openings’ shapes of perforated steel profiles and composite beams were square, rectangular and circular. The solid steel profiles are taken as control beams in both exposed and encased specimens. The composite beam constructed using perforated steel profile with square openings was reinforced with conventional reinforcement, and setting its stirrups passing through the openings to improve the self connection. The failure modes, strain behaviours, and load-deflection curves were extensively discussed. The composite beams reinforced with perforated steel profiles exhibit higher composite performance than that reinforced with solid profiles. The concrete encasement improved the local deformation performance of the perforated steel profiles (50-300%), leading to a more ductile behaviour and a higher dissipation of energy. The square openings provide higher connectivity than other shapes due to the better arrangement of openings and presence of reinforced concrete.
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Kravcov, Alexander N., Pavel Svoboda, Adam Konvalinka, Elena B. Cherepetskaya, Alexsander A. Karabutov, Dmitry V. Morozov, and Ivan A. Shibaev. "Laser-Ultrasonic Testing of the Structure and Properties of Concrete and Carbon Fiber-Reinforced Plastics." Key Engineering Materials 722 (December 2016): 267–72. http://dx.doi.org/10.4028/www.scientific.net/kem.722.267.
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This paper discusses the possibility of studying composite materials by non-destructive laser-ultrasonic testing technique. Concrete samples and carbon-epoxy composites were examined, defects located and elastic wave velocities measured. The internal structure of the samples was visualized in 2D images.
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Ibrahim, Teghreed H., and Abbas A. Allawi. "The Response of Reinforced Concrete Composite Beams Reinforced with Pultruded GFRP to Repeated Loads." Journal of Engineering 29, no. 1 (January 1, 2023): 158–74. http://dx.doi.org/10.31026/j.eng.2023.01.10.
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This paper investigates the experimental response of composite reinforced concrete with GFRP and steel I-sections under limited cycles of repeated load. The practical work included testing four beams. A reference beam, two composite beams with pultruded GFRP I-sections, and a composite beam with a steel I-beam were subjected to repeated loading. The repeated loading test started by loading gradually up to a maximum of 75% of the ultimate static failure load for five loading and unloading cycles. After that, the specimens were reloaded gradually until failure. All test specimens were tested under a three-point load. Experimental results showed that the ductility index increased for the composite beams relative to the reference specimen by 156.2% for a composite beam with GFRP with shear connectors, 148.6% for composite beams with GFRP without connectors, and 96% for the composite beam with a steel I-section.
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Weiler, Lia, and Anya Vollpracht. "Environmental Compatibility of Carbon Reinforced Concrete: Irrigated Construction Elements." Key Engineering Materials 809 (June 2019): 314–19. http://dx.doi.org/10.4028/www.scientific.net/kem.809.314.
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To foster a sustainable deployment of the innovative composite material ‘carbon concrete composite’ in the building sector, it is necessary to ensure its resource efficiency and environmental compatibility. The Institute for Building Materials Research of the RWTH Aachen University is therefore investigating the leaching behavior of this material, especially for the case of irrigated façade elements. Laboratory and outdoor exposure tests are run to determine and assess the heavy metal and trace element emissions by leaching. Feasible interconnections between laboratory and outdoor examinations can be used to develop a faster testing of future composite materials. Current results show no critical release of environmental harmful substances from carbon concrete composite.
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Havlíková, Ivana, Romana Viktória Majtánová, Hana Šimonová, Jaromír Láník, and Zbyněk Keršner. "Evaluation of Three-Point Bending Fracture Tests of Concrete Specimens with Polypropylene Fibres via Double-K Model." Key Engineering Materials 592-593 (November 2013): 185–88. http://dx.doi.org/10.4028/www.scientific.net/kem.592-593.185.
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The fracture-mechanical parameter values of concrete, a quasi-brittle composite material, are determined via evaluation of records of experiments on specimens with stress concentrators. One of the fracture models applicable to concrete is the double-K model. This model combines the concept of cohesive forces acting on the effective crack increment with a criterion based on the stress intensity factor. The outputs of the model are critical crack tip opening displacement and fracture toughness values, including the initiation stress intensity factor value corresponding to the beginning of stable crack propagation. Outputs of three-point bending fracture tests of fibre reinforced concrete obtained using double-K fracture model are presented in this paper. The main aim is the determination and comparison of the above-mentioned parameter values of two types of the composite both without and with polypropylene fibres. Both types of tested composite had the same basic matrix consisting of cement, sand and water. In one case, gravel was used for normal weight concrete, in the other case lightweight aggregates were used for lightweight concrete. Both types of the testing matrix were designed with a similar value of compressive strength. Concretes were reinforced by spread polypropylene fibres of three lengths. There were made eight sets of testing concrete specimens: without fibres, and with fibres of 19 mm, 38 mm and 54 mm length. Dosage of fibres was 9 kg/m3 in all six cases.
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Liu, Ji Ming, Fei Zhou, Jie Zheng, and Xiang Yang Xing. "The Study on Implified Calculation of Cracking Torque of Steel Reinforced Concrete Combined Force." Advanced Materials Research 163-167 (December 2010): 1673–77. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1673.
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Based on a steel reinforced concrete composite post crack under the torque simplified calculation method was studied. Using the simplified formula derived for H steel reinforced concrete structures under the action of compound and cracking torque is calculated. And simplify the calculation compared with the experimental value. The result is calculated with the testing results.
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Gencturk, Bora, and Farshid Hosseini. "Evaluation of reinforced concrete and reinforced engineered cementitious composite (ECC) members and structures using small-scale testing." Canadian Journal of Civil Engineering 42, no. 3 (March 2015): 164–77. http://dx.doi.org/10.1139/cjce-2013-0445.
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The behavior of reinforced concrete (RC) and reinforced engineered cementitious composites (ECC) was comparatively investigated at the component and system levels through a small-scale (1/8 scale factor) experimental program. The logistical and financial advantages of small-scale testing were utilized to investigate a range of parameters, including the effect of reinforcement ratio and material properties, on the response of reinforced concrete and reinforced ECC structures. The procedures pertaining to material preparation, specimen construction, and input motion development that were critical for enhancing the similarity between the scales are provided. Engineered cementitious composite mixtures with different cost and sustainability indices were evaluated. Under cyclic loading, the stiffness, strength, ductility, and energy absorption capacity of columns made of different ECC mixtures were found to be 110, 65, 45, and 100% higher, respectively, than those of the RC columns. The system level investigation through hybrid simulation showed that the ECC structures sustain less deformation under earthquake excitation due to high energy absorption capacity of the material. The differences in cost, sustainability, and structural performance of different ECC mixtures suggest that a careful selection of materials is required for optimal performance.
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Komarkova, Tereza, Pavel Fiala, Miloslav Steinbauer, and Zdenek Roubal. "Testing an Impedance Non-destructive Method to Evaluate Steel-Fiber Concrete Samples." Measurement Science Review 18, no. 1 (February 1, 2018): 35–40. http://dx.doi.org/10.1515/msr-2018-0006.
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Abstract Steel-fiber reinforced concrete is a composite material characterized by outstanding tensile properties and resistance to the development of cracks. The concrete, however, exhibits such characteristics only on the condition that the steel fibers in the final, hardened composite have been distributed evenly. The current methods to evaluate the distribution and concentration of a fiber composite are either destructive or exhibit a limited capability of evaluating the concentration and orientation of the fibers. In this context, the paper discusses tests related to the evaluation of the density and orientation of fibers in a composite material. Compared to the approaches used to date, the proposed technique is based on the evaluation of the electrical impedance Z in the band close to the resonance of the sensor–sample configuration. Using analytically expressed equations, we can evaluate the monitored part of the composite and its density at various depths of the tested sample. The method employs test blocks of composites, utilizing the resonance of the measuring device and the measured sample set; the desired state occurs within the interval of between f=3 kHz and 400 kHz.
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Bedi, Raman, S. P. Singh, and Rakesh Chandra. "Flexural Fatigue-Life Assessment and Strength Prediction of Glass Fibre Reinforced Polymer Concrete Composites." ISRN Materials Science 2014 (March 27, 2014): 1–8. http://dx.doi.org/10.1155/2014/928278.
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The paper presents the results of an investigation conducted to assess the fatigue-life and prediction of flexural fatigue strength of polymer concrete composites based on epoxy resin as binder material. Three point flexural fatigue tests were conducted on polymer concrete specimens using MTS servo controlled actuator, to obtain the fatigue lives of the composites at different stress levels. One hundred and thirty-seven specimens of size 40×40×160 mm were tested in flexural fatigue. Forty-three static flexural tests were also conducted to facilitate fatigue testing. It has been observed that the probabilistic distribution of fatigue-life of polymer concrete composite (PCC) and glass fibre reinforced polymer concrete composite (GFRPCC), at a particular stress level, approximately follows the two-parameter Weibull distribution, with statistical corelation coefficient values exceeding 0.90. The fatigue strength prediction model, representing S-N relationship, has been examined and the material coefficients have been obtained for GFRPCC containing 0.5% and 1.0% glass fibres. Design fatigue lives for GFRPCC containing different contents of glass fibres have been estimated for acceptable probabilities of failure and compared with those of PCC.
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Korolev, Alexander Sergeevich, Anastasia Kopp, Denis Odnoburcev, Vladislav Loskov, Pavel Shimanovsky, Yulia Koroleva, and Nikolai Ivanovich Vatin. "Compressive and Tensile Elastic Properties of Concrete: Empirical Factors in Span Reinforced Structures Design." Materials 14, no. 24 (December 9, 2021): 7578. http://dx.doi.org/10.3390/ma14247578.
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Concretes with the same strength can have various deformability that influences span structures deflection. In addition, a significant factor is the non-linear deformation of concrete dependence on the load. The main deformability parameter of concrete is the instantaneous modulus of elasticity. This research aims to evaluate the relation of concrete compressive and tensile elastic properties testing. The beam samples at 80 × 140 × 1400 cm with one rod Ø8 composite or Ø10 steel reinforcement were experimentally tested. It was shown that instantaneous elastic deformations under compression are much lower than tensile. Prolonged elastic deformations under compression are close to tensile. It results in compressive elasticity modulus exceeding the tensile. The relation between these moduli is proposed. The relation provides operative elasticity modulus testing by the bending tensile method. The elasticity modulus’s evaluation for the reinforced span structures could be based only on the bending testing results. A 10% elasticity modulus increase, which seems not significant, increases at 30–40% the stress of the reinforced span structures under load and 30% increases the cracking point stress.
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Rehacek, Stanislav, Petr Hunka, David Citek, Jiri Kolisko, and Ivo Simunek. "Impact Testing of Concrete Using a Drop-Weight Impact Machine." Advanced Materials Research 1106 (June 2015): 225–28. http://dx.doi.org/10.4028/www.scientific.net/amr.1106.225.
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Fibre-reinforced composite materials are becoming important in many areas of technological application. In addition to the static load, such structures may be stressed with short-term dynamic loads or even dynamic impact loads during their lifespan. Impact loading of structural components produces a complex process, where both the characteristics of the design itself and the material parameters influence the resultant behavior. It is clear that fibre reinforced concrete has a positive impact on increasing of the resistance to impact loads. Results of two different impact load tests carried out on drop-weight test machine are presented in this report.
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Lehmann, Marek, and Wiesława Głodkowska. "Shear Capacity and Behaviour of Bending Reinforced Concrete Beams Made of Steel Fibre-Reinforced Waste Sand Concrete." Materials 14, no. 11 (June 1, 2021): 2996. http://dx.doi.org/10.3390/ma14112996.
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Inthis paper, we report the results of our research on reinforced concrete beams made of fine aggregate fibre composite, with the addition of steel fibres at 1.2% of the composite volume. The fine aggregate fibre composite is a novel construction material, in which the aggregate used is a post-production waste. Twenty reinforced concrete beams with varying degree of shear reinforcement, in the form of stirrups with and without the addition of steel fibres, tested under loading. The shear capacity results of reinforced concrete beams made of the fine aggregate fibre composite being bent by a transversal force, as well as the cracking forces causing the appearance of the first diagonal crack, are discussed. The stages of functioning of such elements are described. Furthermore, the effect of the steel fibres on the reduction of diagonal cracking is analysed. Computation of the shear capacity of the tested elements is performed, based on the Model Code 2010 and RILEM TC-162 TDF standards, for two variants of the compression strut inclination angle θ that measured during testing, and the minimum(in accordance with the Model Code 2010 standard). We found that the SMCFT method part of Model Code 2010 showed the best compatibility with the experimental results. The tests and analyses performed demonstrate that the developed novel fibrecomposite—the properties of which are close to, or better than, those of the ordinary concrete—can be used successfully for the manufacturing of construction elements in the shear capacity aspect. The developed fine aggregate fibrecomposite could serve, in some applications, as an alternative to ordinary concrete.
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Caldová, Eva, František Wald, and Anna Kuklíková. "Fire Test of Timber-fibre Concrete Composite Floor." Journal of Structural Fire Engineering 6, no. 2 (June 1, 2015): 147–54. http://dx.doi.org/10.1260/2040-2317.6.2.147.
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The subject of this paper is a description of experimental programme of timber-fibre concrete floor in fire. Furnace test was performed on one full-size floor specimen at the Fire testing laboratory PAVUS. Floor specimen was 4, 5 m long and 3 m wide, consisting of 60 mm fibre concrete topping on plywood formwork, connected to GL beams. It was subjected the standard fire for over 150 min. The membrane effect of the floor was progressively activated and the fire performance of timber-fibre concrete floor was better comparing to traditional design method. The project is a part of the experimental research that deals with the effect of membrane action of composite timber fibre reinforced floor slabs exposed to fire which is based on previous research on steel fibre reinforced concrete slabs. The main objective of the project is the preparation of the analytical model which can predict the fire resistance of such floors with dispersed reinforcement.
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Polskoy, Petr P., Dmitry Mailyan, Alexey N. Beskopylny, Besarion Meskhi, Aleksandr V. Shilov, and Artur Umarov. "Strength of Compressed Reinforced Concrete Elements Reinforced with CFRP at Different Load Application Eccentricity." Polymers 15, no. 1 (December 21, 2022): 26. http://dx.doi.org/10.3390/polym15010026.
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Currently, many studies are devoted to the use of polymer composite materials to increase the strength and stability of concrete elements. In compressed reinforced concrete elements, the bearing capacity depends on the eccentricity of the external application of the external force and the corresponding stress-strain state, as well as the location and number of composite materials glued to the surface of the structure. The choice of a scheme for placing composite materials depending on the stress state of the structure is an urgent scientific problem. At the same time, the issue of central compression and the compression of columns with large eccentricities has been well studied. However, studies conducted in the range of average eccentricities often have conflicting results, which is the problem area of this study. The primary aim of this study was to increase the strength and stiffness of compressed reinforced concrete elements reinforced with composite materials, as well as a comparative analysis of the bearing capacity of ten different combinations of external longitudinal, transverse, and combined reinforcement. The results of testing 16 compressed columns under the action of various eccentricities of external load application (e0/h = 0; 0.16; 0.32) are presented. It is shown that the use of composite materials in strengthening structures increases the bearing capacity up to 41%, and the stiffness of the sections increases up to 30%. Based on the results of the study, recommendations are proposed for improving the calculation method for inflexible columns reinforced in the transverse direction, which take the work of concrete under the conditions of a three-dimensional stress state into consideration.
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Fedotov, M. Yu, O. N. Budadin, S. O. Kozelskaya, I. G. Ovchinnikov, and I. S. Shelemba. "MONITORING BY FIBER OPTICAL SENSORS OF RELIABILITY OF OPERATION OF BUILDING STRUCTURES WITH EXTERNAL COMPOSITE REINFORCEMENT." Kontrol'. Diagnostika, no. 265 (July 2020): 54–64. http://dx.doi.org/10.14489/td.2020.07.pp.054-064.
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This article describes of the actual state of building structures by the example of structures of reinforced concrete and metal bridges. It is shown that a high degree of wear of artificial structures leads to the need for a reliable assessment of their actual condition using modern methods and means of non-destructive testing and diagnostics, as well as strengthening exploited structures with polymer composite materials. The results of researches on fiber-optic monitoring and strengthening of bridge spans with composite materials based on domestic and foreign carbon reinforcing fillers and epoxy polymer matrices are presented. It has been experimentally shown that for reinforced concrete structures it is advisable to use composite strengthening systems using external reinforcement installed directly on the damaged object by contact molding. For metal structures, this approach is not applicable due to a significant difference in the coefficients of linear thermal expansion of composites and metals. In this case, an amplification system based on prefabricated composite truss systems made by autoclave and unautoclave molding can be applied. The obtained research results also indicate the advisability of joint use of monitoring systems and strengthening of damaged bridge structures by composites.
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Fedotov, M. Yu, O. N. Budadin, S. O. Kozelskaya, I. G. Ovchinnikov, and I. S. Shelemba. "MONITORING BY FIBER OPTICAL SENSORS OF RELIABILITY OF OPERATION OF BUILDING STRUCTURES WITH EXTERNAL COMPOSITE REINFORCEMENT." Kontrol'. Diagnostika, no. 265 (July 2020): 54–64. http://dx.doi.org/10.14489/td.2020.07.pp.054-064.
Full textAbstract:
This article describes of the actual state of building structures by the example of structures of reinforced concrete and metal bridges. It is shown that a high degree of wear of artificial structures leads to the need for a reliable assessment of their actual condition using modern methods and means of non-destructive testing and diagnostics, as well as strengthening exploited structures with polymer composite materials. The results of researches on fiber-optic monitoring and strengthening of bridge spans with composite materials based on domestic and foreign carbon reinforcing fillers and epoxy polymer matrices are presented. It has been experimentally shown that for reinforced concrete structures it is advisable to use composite strengthening systems using external reinforcement installed directly on the damaged object by contact molding. For metal structures, this approach is not applicable due to a significant difference in the coefficients of linear thermal expansion of composites and metals. In this case, an amplification system based on prefabricated composite truss systems made by autoclave and unautoclave molding can be applied. The obtained research results also indicate the advisability of joint use of monitoring systems and strengthening of damaged bridge structures by composites.
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Ali, A., Z. Soomro, S. Iqbal, N. Bhatti, and A. F. Abro. "Prediction of Corner Columns’ Load Capacity Using Composite Material Analogy." Engineering, Technology & Applied Science Research 8, no. 2 (April 19, 2018): 2745–49. http://dx.doi.org/10.48084/etasr.1879.
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There are numerous reasons for which concrete has become the most widely used construction material in buildings, one of them being its availability in different types, such as fiber-reinforced, lightweight, high strength, conventional and self-compacting concrete. This advantage is specially realized in high-rise building construction, where common construction practice is to use concretes of different types or strength classes in slabs and columns. Columns in such structures are generally made from concrete which is higher in compressive strength than the one used in floors or slabs. This raises issue of selection of concrete strength that should be used for estimating column capacity. Current paper tries to address this issue by testing nine (09) sandwich column specimens under axial loading. The floor concrete portion of the sandwich column was made of normal strength concrete, whereas column portions from comparatively higher strength concrete. Test results show that aspect ratio (h/b) influences the effective concrete strength of such columns. A previously adopted methodology of composite material analogy with some modifications has been found to predict well the capacity of columns where variation in floor and concrete strength is significant.
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Hering, Marcus, and Manfred Curbach. "A new testing method for textile reinforced concrete under impact load." MATEC Web of Conferences 199 (2018): 11010. http://dx.doi.org/10.1051/matecconf/201819911010.
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Textile reinforced concrete, especially textile reinforced concrete with carbon fibres, was already been used for strengthening steel reinforced concrete structures under static loads up to now. The question is if the composite can also be used for strengthening structures against impact loads. The main goal of a current research project at the Technische Universität Dresden is the development and characterization of a reinforcement fabric with optimized impact resistance. But there is a challenge. There is the need to find the best combination of fibre material (glass, carbon, steel, basalt, …) and reinforcement structure (short fibres, 2D-fabrics, 3D-fabrics, …), but testing the large number of possible combinations is not possible with the established methods. In general, large-scale tests are necessary which are very expensive and time consuming. Therefore, a new testing method has been developed to deal with this large number of possible combinations of material and structural experiments. The following paper describes this new testing method to find the best fabric reinforcement for strengthening reinforced concrete structures against impact loads. The testing devise, which is located in the drop tower facility at the Otto Mohr Laboratory, and the test set-up are illustrated and described. The measurement equipment and the methods to evaluate the experimental results are explained in detail.
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Saidi, Taufiq, Taufiq Saidi, Muttaqin Hasan, Muttaqin Hasan, Zahra Amalia, Muhammad Iqbal, and Muhammad Iqbal. "Behaviour Analysis of Strengthened-RC Beam with Natural Fiber Reinforced Polymer (NFRP) based on Abaca Fiber by Using Finite Element Method." Aceh International Journal of Science and Technology 11, no. 2 (September 6, 2022): 155–64. http://dx.doi.org/10.13170/aijst.11.2.26520.
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The use of synthetic Fiber Reinforced Polymer (FRP) as a composite material is an alternative material that has been widely used for strengthening and repairing reinforced concrete structures. However, the high price is one of the obstacles in applying synthetic FRP materials in developing countries such as Indonesia. Utilization of natural fiber as a Natural Fiber Reinforced Polymer (NFRP) composite material is an alternative, especially in shear strengthening of reinforced concrete beams. Because it has good tensile strength and also is environmentally friendly. Technological developments in the field of computing make modelling various aspects easier. One of them is modelling reinforced concrete (RC) beams. ATENA V534 is a software that can be used for finite element-based modelling. Therefore, in this study, the ATENA V534 software was used to evaluate the results of research and testing behaviour of reinforced concrete beams from the previous studies about strengthened beam for shear by using NFRP. Behaviour that is evaluated in the form of load and deflection, the pattern of cracks and failure, and stress and strain of reinforcements. The numerical results obtained in ATENA V534 showed in a good agreement with experimental results.
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Meera Sahib, Mohammed Muneer, and Surumi Rasia Salim. "Influence of Fiber Hybridization on Strength and Toughness of RC Beams." Civil Engineering Journal 8, no. 3 (March 1, 2022): 549–66. http://dx.doi.org/10.28991/cej-2022-08-03-010.
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This paper focuses on the experimental investigation designed to study the behavior of hybrid fiber-reinforced concrete (HFRC) beams under flexure and impact loading. The addition of fibers to concrete can improve a number of its properties. For optimal response, different types of fibers may be suitably combined to produce HFRC. Optimized combinations of different fiber types in concrete can produce a composite with better engineering properties than that with only one type. The study compared the mechanical properties of fresh and hardened HFRC, Steel Fiber Reinforced Concrete (SFRC), and conventional concrete to arrive at the optimum fiber content for improved behavior of concrete by testing 135 specimens. Subsequently, the behavior of steel fiber-reinforced concrete beams was investigated with and without fiber hybridization under flexural and impact loading, followed by a comparison of the results. Fiber hybridization was achieved by developing concrete containing a combination of steel and polypropylene fibers. Eighteen beam specimens of size 1650×200×150 mm were tested in the investigation. Test outcomes demonstrated that the inclusion of fibers in a hybrid form could ensure superior composite performance in terms of flexure and impact resistance when compared to the incorporation of a single type of fibers in reinforced concrete. Doi: 10.28991/CEJ-2022-08-03-010 Full Text: PDF
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Santos, Pedro Gil Girão dos, Carlos Eduardo de Jesus Martins, Jonathan Skinner, Richard Harris, Alfredo Manuel Pereira Geraldes Dias, and Luís Manuel Cortesão Godinho. "Modal Frequencies of a Reinforced Timber-Concrete Composite Floor: Testing and Modeling." Journal of Structural Engineering 141, no. 11 (November 2015): 04015029. http://dx.doi.org/10.1061/(asce)st.1943-541x.0001275.
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McRory, Jared W., Fray F. Pozo-Lora, Zachary Benson, Raed Tawadrous, and Marc Maguire. "Behavior of Hybrid Reinforced Concrete Bridge Decks under Static and Fatigue Loading." Polymers 14, no. 23 (November 26, 2022): 5153. http://dx.doi.org/10.3390/polym14235153.
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This paper presents a new bridge deck reinforcement alternative using hybrid reinforced concrete (Hybrid) consisting of Glass Fiber Reinforced Polymer (GFRP) rebar and alkali-resistant fiberglass composite macrofibers added to the concrete mixture. Fiberglass composite macrofibers are a miniaturized GFRP reinforcing bar that is a composite of resin and glass fibers. An experimental testing program and analytical modeling were conducted to evaluate the structural performance at the service and ultimate limit states. Thirteen full-scale bridge deck specimens were constructed and tested under static and fatigue loading. The fatigue loading was applied up to two million cycles at a frequency of 4 Hz. Post-fatigue, the specimens were tested to failure to compare pre-and post-fatigue behavior. Simplified and moment-curvature analytical models were used to predict the specimens’ flexural strength at the ultimate level, and both were found to be accurate for predicting pre- and post-fatigue strength. Deflection and crack width were monitored throughout the fatigue loading, and these values were compared to the recommended AASHTO LRFD serviceability limits. Testing and analytical results showed that the Hybrid deck is a viable alternative to steel-reinforced and GFRP-reinforced bridge decks for flexural behavior. The service and ultimate level behavior of each bridge deck type was adequate as compared to the AASHTO LRFD service limits. The exceptional post-peak energy absorption demonstrated by the Hybrid adds ductility to previously elastic GFRP reinforced sections.
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Fuchs, Alexander, Iurie Curosu, and Michael Kaliske. "Numerical Mesoscale Analysis of Textile Reinforced Concrete." Materials 13, no. 18 (September 6, 2020): 3944. http://dx.doi.org/10.3390/ma13183944.
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This contribution presents a framework for Numerical Material Testing (NMT) of textile reinforced concrete based on the mesomechanical analysis of a Representative Volume Element (RVE). Hence, the focus of this work is on the construction of a proper RVE representing the dominant mechanical characteristics of Textile Reinforced Concrete (TRC). For this purpose, the RVE geometry is derived from the periodic mesostructure. Furthermore, sufficient constitutive models for the individual composite constituents as well as their interfacial interactions are considered, accounting for the particular mechanical properties. The textile yarns are modeled as elastic transversal isotropic unidirectional layers. For the concrete matrix, an advanced gradient enhanced microplane model is utilized considering the complex plasticity and damage behavior at multiaxial loading conditions. The mechanical interactions of the constituents are modeled by an interface formulation considering debonding and friction as well as contact. These individual constitutive models are calibrated by corresponding experimental results. Finally, the damage mechanisms as well as the load bearing behavior of the constructed TRC-RVE are analyzed within an NMT procedure based on a first-order homogenization approach. Moreover, the effective constitutive characteristics of the composite at macroscale are derived. The numerical results are discussed and compared to experimental results.
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Erfan, Abeer M., Hossam H. Ahmed, Bishoy A. Mina, and Taha A. El-Sayed. "Structural Performance of Eccentric Ferrocement Reinforced Concrete Columns." Nanoscience and Nanotechnology Letters 11, no. 9 (September 1, 2019): 1213–25. http://dx.doi.org/10.1166/nnl.2019.3008.
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This research proposed a method for producing reinforced composite concrete columns, reinforced with different types of steel wire meshes. The experimental program included casting and testing of nine square columns with dimensions of 200 mm × 200 mm × 1500 mm under eccentric compression load, with an eccentricity equaling 25 mm from the column center in x direction. The experimental program specimens comprised of four designation series to make comparative study between conventionally reinforced concrete columns. Concrete columns reinforced with steel bars and stirrups as control specimen and other groups were expanded steel mesh and welded steel mesh but the fourth group used modified and galvanized steel wire meshes of expanded and welded type. The main variables were type of reinforcing materials, number of layers and volume fraction of reinforcement. The main objective was to evaluate the effectiveness of employing the new materials in reinforcing the composite concrete columns in enhancing the confinement of concrete column and resistance for eccentric loads. Results indicated that this methodology of concrete columns reinforcement can be developed in high strength, crack resistance, high ductility and energy absorption properties. Moreover, Non-linear finite element analysis (NLFEA) was carried out to simulate the behaviour of the reinforced concrete columns under eccentric loads. The analytical model was agreed with experimental results employing ANSYS-14.5 Software.
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Novak, Josef, and Alena Kohoutkova. "Optimization of Pretensioned Steel Fiber Reinforced Concrete Beam." Advanced Materials Research 1106 (June 2015): 94–97. http://dx.doi.org/10.4028/www.scientific.net/amr.1106.94.
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Pretensioned concrete beams are used as a main load bearing member for composite bridges with a span to 30 m. The advantage of longitudinal prefabrication technology of beams for small span bridges is quick installation, savings of straight supporting scaffolding of centers and formwork. The amount of labour with formwork, reinforcement and concrete including work with scaffolding of centers on site is reduced at a minimum. During searching applications of steel fiber reinforced concrete (SFRC) suitable for this kind of structure a pretensioned concrete beam suitable for a bridge bay with a span from 12 to 15 m has been chosen for an investigation. Three types of beam were manufactured for experimental tests. The beams were supposed to be a part of a bridge bay with a composite slab. These pretensioned beams were made of SFRC. In case of the experimental tests, a cast-in place concrete cover from plain concrete was casted on the top of the beams. The cast-in place concrete cover simulated a top composite slab. The bearing capacity of the beams with the cast-in place concrete cover was tested until their destruction. The tested beams showed higher bearing capacity than it was determined by a theoretical calculation. The beams also demonstrated high safety against collapse during structure overloading. The process of the experimental testing was also simulated on a numerical nonlinear model and then the results were compared. The result comparison of the both types of tests did not show any significant irregularities.
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Machovec, Jan, Filip Vogel, Steven Linforth, and Petr Konvalinka. "Experimental and Numerical Analysis of Tensile Properties of Textile Reinforced Concrete with Steel Fibres." Key Engineering Materials 722 (December 2016): 275–80. http://dx.doi.org/10.4028/www.scientific.net/kem.722.275.
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The topic of this article is the experimental and numerical testing of tensile strength of glass textile reinforced cement-based composites with steel fibres. Cement-based composite is similar to high-performance concrete, with its maximal compressive strength higher than 100 MPa. We used thirty six dogbone-shaped specimens for uniaxial tensile loading with three different kinds of textile reinforcement. The difference between reinforcement was in its weight of 1 m2 of textile. We focused on maximal tensile stress in specimens and the ductile behaviour after first cracking occurred. We will compare results from experimental testing made on different types of reinforcement and results from numerical computer model. Tensile stress was generated by loading with constant increase of displacement.
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Zezulová, Eva, and Tereza Komárková. "Techniques of Non-Destructive Testing of Steel Fiber Reinforced Concrete." Key Engineering Materials 755 (September 2017): 153–58. http://dx.doi.org/10.4028/www.scientific.net/kem.755.153.
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Non-destructive testing (NDT) is seeing increasingly frequent use in civil engineering thanks to the fact that the tests are repeatable and do not cause serious damage to the material. The requirements for the development and modernization of available testing devices and methodologies are ever increasing and the testing of existing structures often requires the use of NDT. Unfortunately, every measurement and methodology has its limits and the measurement devices for the evaluation of steel fiber reinforced concrete (SFRC) are no exception. In recent decades there has been an effort to modernize and develop existing measurement devices for SFRC testing. This building material is commonly used especially in large-scale structures. Nevertheless, the technology of SFRC could seem complicated when compared with ordinary concrete and the very nature of this composite material could lead to SFRC inhomogeneity during construction. This paper describes the assessment of SFRC by more or less available methodologies and measurements utilizing non-destructive principles.
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Wang, Zhi-Hang, Jin-Yu Xu, Er-Lei Bai, and Liang-Xue Nie. "Dielectric Model of Carbon Nanofiber Reinforced Concrete." Materials 13, no. 21 (October 30, 2020): 4869. http://dx.doi.org/10.3390/ma13214869.
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The formula describing the relationship between the dielectric constant of a composite and the dielectric constants or volume rates of its components is called a dielectric model. The establishment of a cement concrete dielectric model is the basic and key technique for applying electromagnetic wave technology to concrete structure quality testing and internal damage detection. To construct the dielectric model of carbon nanofiber reinforced concrete, the carbon nanofiber reinforced concrete was measured by the transmission and reflection method for dielectric constant ε, and ε,, in the frequency range of 1.7~2.6 GHz as the fiber content was 0, 0.1%, 0.2%, 0.3% and 0.5%. Meanwhile, concrete was considered as a composite material composed of three phases, matrix (mortar), coarse aggregate (limestone gravel) and air, and the dielectric constants and volume rates of each component phase were tested. The Brown model, CRIM (Complex Refractive Index Model) model and Looyenga model commonly used in composite materials were modified based on the experimental data, suitable dielectric models of carbon nanofiber reinforced concrete were constructed, and a reliability check and error analysis of the modified models were carried out. The results showed that the goodness of fit between the calculated curves based on the three modified models and the measured curves was very high, the accuracy and applicability were very strong and the variation rule for the dielectric constant of carbon nanofiber concrete with the frequency of electromagnetic wave could be described accurately. For ε, and ε,,, the error between the dielectric constant calculated by the three modified models and the corresponding measured values was very small. For the dielectric constant ε,, the average error was maintained below 1.2%, and the minimum error was only 0.35%; for the dielectric constant ε,,, the average error was maintained below 3.55%.
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Smith-Gillis, Reagan, Roberto Lopez-Anido, Todd S. Rushing, and Eric N. Landis. "Development of Thermoplastic Composite Reinforced Ultra-High-Performance Concrete Panels for Impact Resistance." Materials 14, no. 10 (May 12, 2021): 2490. http://dx.doi.org/10.3390/ma14102490.
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In order to improve flexural and impact performance, thin panels of steel fiber-reinforced ultra-high performance concrete (UHPC) were further reinforced with external layers of continuous fiber-reinforced thermoplastic (CFRTP) composites. CFRTP sheets were bonded to 305 × 305 × 12 mm UHPC panels using two different techniques. First, unidirectional E-glass fiber-reinforced tapes of polyethylene terephthalate glycol-modified (PETG) were arranged in layers and fused to the UHPC panels through thermoforming. Second, E-glass fiber woven fabrics were placed on the panel faces and bonded by vacuum infusion with a methyl methacrylate (MAA) polymer. Specimens were cut into four 150 mm square panels for quasi-static and low-velocity impact testing in which loads were applied at the panel centers. Under quasi-static loading, both types of thermoplastic composite reinforcements led to a 150–180% increase in both peak load capacity and toughness. Impact performance was measured in terms of both residual deformation and change in specimen compliance, and CFRTP additions were reduced both by 80% to 95%, indicating an increase in damage resistance. While both reinforcement fabrication techniques provided added performance, the thermoforming method was preferable due to its simplicity and fewer specialized tool requirements.
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Patel, Priya A., Prachi V. Pandya, Gaurav J. Vyas, and Dhruv Trivedi. "Evaluating Durability Properties of Composite Fibre Reinforced Concrete by Using Mineral Admixtures." ECS Transactions 107, no. 1 (April 24, 2022): 6381–95. http://dx.doi.org/10.1149/10701.6381ecst.
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This study is aimed at investigating durability properties of fibre reinforced concrete. The sorptivity test to assess rate of absorption, and the rapid chloride penetration test was performed to assess the permeability of concrete. The weight loss and strength loss measured after 28 and 56 days immersion in 5% concentrated HCL, H2SO4 solution to check aggressive ions of concrete, such as chlorides and sulphates. Normal concrete is used for the above assessment. The addition of nano silica by fractions such 0%, 1.5%, 3.0%, and 4.5% by weight of cement. For each of above combination 1% steel and 0.25% polypropylenes fibres respectively by volume of binders were added. A constant aggregate binder ratio and water binder ratio were maintained throughout this investigation process. At the end of above testing, the aim is to find out optimum percentage combination of ultra fine fly ash and nanosilica to achieve better durability of concrete.
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Tonkikh, Gennady, and D. Chesnokov. "The influence of the shear connectors ductility on the seismic resistance of composite steel-concrete floors." Earthquake Engineering. Construction Safety, no. 4 (August 25, 2021): 28–35. http://dx.doi.org/10.37153/2618-9283-2021-4-28-35.
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According to the existing practice of composite structure design, shear connectors, which provide an interaction of supporting steel beams and reinforced concrete slabs, can be considered as ductile or non-ductile. Taking into account the ductility of connectors allows designer to create an optimal structure from an economic point of view and increase its earthquake resistance. Within the framework of this study, the results of push-testing composite specimen conducted by the authors earlier are considered. The powder-actuated shear connectors had been used for providing interaction between the steel and reinforced concrete parts. In conclusion, the assessment of the ductility and expediency of using powder-actuated shear connectors for earthquake-resistant construction is given.