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1
Li, Jing, Lin Fu Wang, Juan Li, Xian Feng Qu, and Lin Jang. "Research on Flexural Behavior of Coarse Recycled Aggregate-Filled Plain Concrete Beam." Advanced Materials Research 250-253 (May 2011): 379–82. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.379.
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In order to study the flexural behavior of coarse recycled aggregate-filled plain concrete beams, two beams were made. The experiment of simply supported beam under concentrated loads is performed, which makes us get the ultimate flexural capacity, midspan deflection and the development of cracks of each beam, and the numerical simulation of the damage process of beams is also carried out using finite element software. The results indicated that the tension property of coarse recycled aggregate-filled plain concrete beam is better than ordinary concrete beam, and some failure forms of bending is similar; the strength of recycled aggregates greatly influences flexural behavior of coarse recycled aggregate-filled plain concrete beam.
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Qu, Hong Chang, Hong Yuan Li, and Xuan Zhang. "Flexural Tests of Fiber-Reinforced-Concrete Beams Reinforced with FRP Rebars." Applied Mechanics and Materials 166-169 (May 2012): 1797–800. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.1797.
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This paper investigates the flexural performance of FRP/FRC hybrid reinforcement system as well as FRP/plain concrete beams. Test results showed that the crack widths of FRP/FRC beams were smaller than those of FRP/plain concrete beams at the different corresponding load. With the increase of load, the crack spacing slightly decreased. The plain concrete beams failed in a more brittle mode than the FRC beams. Once they reached their ultimate moments, the load dropped fleetly. Compared to the companion beam, the addition of fibers improved the flexural behavior.
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Srinivas, K. "A Study on the Flexural Behavior of Plain Cement Concrete with Self Compaction Concrete." International Journal for Research in Applied Science and Engineering Technology 9, no. 12 (December 31, 2021): 441–47. http://dx.doi.org/10.22214/ijraset.2021.39330.
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Abstract: To study the flexural behaviour of plain cement concrete with self-compaction concrete using three point loading. We are using two different types of concrete (Plain Cement Concrete and Self Compaction Concrete). For this we are using M20 grade concrete. We cast cubes and beams of sizes 150x150x150mm and 150x150x700mm respectively.Based on the test results it is concluded that the flexural strength of the self-compaction concrete beams is more than the plain cement concrete beams. And in the combination also the flexural strength is more when the plain cement concrete layer is at the bottom while the selfcompaction concrete layer is at top.
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Qeshta, Ismail M. I., Payam Shafigh, Mohd Zamin Jumaat, Aziz Ibrahim Abdulla, Ubagaram Johnson Alengaram, and Zainah Ibrahim. "Flexural Behaviour of Concrete Beams Bonded with Wire Mesh-Epoxy Composite." Applied Mechanics and Materials 567 (June 2014): 411–16. http://dx.doi.org/10.4028/www.scientific.net/amm.567.411.
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This paper investigates the flexural performance of plain concrete beams bonded with wire mesh-epoxy composite. A total of four beam specimens were prepared and tested. Three specimens were bonded with same amount of wire mesh-epoxy composite with varying composite width and one plain concrete specimen was used as a control. The effect of wire mesh-epoxy composite on enhancing the flexural behaviour of concrete beams as well as the effect of different configurations of composite was studied. Test results showedthat the wire mesh-epoxy composite increased the flexural strength of concrete beams. The increase in energy absorption of bonded beams was remarkable. In addition, specimen with large composite width showed better behaviour with respect to energy absorption capability.
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Isa, MN. "FLEXURAL IMPROVEMENT OF PLAIN CONCRETE BEAMS STRENGTHENED WITH HIGH PERFORMANCE FIBRE REINFORCED CONCRETE." Nigerian Journal of Technology 36, no. 3 (June 30, 2017): 697–704. http://dx.doi.org/10.4314/njt.v36i3.6.
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Strengthening of concrete structures have become inevitable due to unavoidable factors such as fatigue and aggressive environmental conditions causing deterioration of concrete structures. Many researchers have turned in the direction of using various high strength and high performance concretes due to their high structural and durability properties, for the purpose of repair and strengthening of concrete structures against these aggressive conditions. As a result, this study carryout experimental, numerical and analytical investigation to study the behaviour of plain concrete (PC) beams strengthened with High Performance Fibre Reinforced Concrete (HPFRC) layer using three different jacketing configurations and tested in flexure. Results show significant improvement in both stiffness and load bearing capacity of plain concrete beams. http://dx.doi.org/10.4314/njt.v36i3.6
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Słowik, Marta. "Influence of tensile softening of concrete on crack development and failure in concrete and reinforced concrete beams." Bulletin of the Military University of Technology 68, no. 1 (March 29, 2019): 213–23. http://dx.doi.org/10.5604/01.3001.0013.1481.
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In the paper, the own test results were presented. The experimental investigation was focused at determining the cracking and load capacity of beams made of concrete. The beams were characterized by different longitudinal reinforcement ratio from zero — plain concrete beams, through low ratio 0.12% — slightly reinforced concrete beams, middle ratio 0.9% — typical reinforced concrete beams, up to the ratios 1.3% and 1.8% — higher reinforced concrete beams. On the basis of the performed experiments and the results of numerical calculations, the process of crack’s formation and crack’s development in plain concrete, slightly reinforced concrete and reinforced concrete beams with different reinforcement ratio was described. When discussing cracking process in the beams, the contribution of strain softening of tensile concrete in the microcracked zone on the character of beams’ failure was analysed as well. Keywords: civil engineering, concrete and reinforced concrete members, cracking and load capacity.
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Taj, Ali I., and Alaa H. Al-Zuhairi. "Behavior of Plain Concrete Beam Analyzed Using Extended Finite Element Method." Association of Arab Universities Journal of Engineering Sciences 26, no. 1 (March 31, 2019): 121–28. http://dx.doi.org/10.33261/jaaru.2019.26.1.016.
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In this study, plain concrete simply supported beams subjected to two points loading were analyzed for the flexure. The numerical model of the beam was constructed in the meso-scale representation of concrete as a two phasic material (aggregate, and mortar). The fracture process of the concrete beams under loading was investigated in the laboratory as well as by the numerical models. The Extended Finite Element Method (XFEM) was employed for the treatment of the discontinuities that appeared during the fracture process in concrete. Finite element method with the feature standard/explicitlywas utilized for the numerical analysis. Aggregate particles were assumedof elliptic shape. Other properties such as grading and sizes of the aggregate particles were taken from standard laboratory tests that conducted on aggregate samples.Two different concrete beamswere experimentally and numerically investigated. The difference between beams was concentrated in the maximum size of aggregate particles. The comparison between experimental and numerical results showed that themeso-scale model gives a good interface for the representing the concrete models in numerical approach. It was concluded that the XFEM is a powerful technique to use for the analysis of the fracture process and crack propagation in concrete.
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Alavizadeh-Farhang, Ali, and Johan Silfwerbrand. "Responses of Plain and Steel Fiber-Reinforced Concrete Beams to Temperature and Mechanical Loads: Experimental Study." Transportation Research Record: Journal of the Transportation Research Board 1740, no. 1 (January 2000): 25–32. http://dx.doi.org/10.3141/1740-04.
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To study the structural responses of plain and steel fiber-reinforced concrete pavements under combined mechanical and thermal loads, two test series have been conducted with plain and steel fiber-reinforced concrete beams. The magnitude and duration of the differences in the induced stresses caused by traffic load and a positive nonlinear temperature gradient (the top surface was warmer than the bottom surface during the day) may lead to some relaxation of thermal stresses and subsequently increase the load-carrying capacity. Considering the loss of support contact in the interior part of the concrete pavement, the experimental study of combined loading with restrained concrete beams may provide some insight and an indication of whether the superposition of stresses is a proper approach. The beams were subjected to solely thermal, solely mechanical, and combined thermal and mechanical loads while the rotation of the beam at supports was prevented. The results of tests conducted with both plain and steel fiber-reinforced beams showed that the superposition of stresses under combined loading before cracking gave a satisfactory estimation of the load-carrying capacities. The results also showed that the effect of relaxation of stresses due to short-term thermal loads was not noticeable in the load-carrying capacity achieved in tests with combined thermal and mechanical loads. On the contrary, a tendency for reduction of the load-carrying capacity was observed at higher thermal gradients. In addition, the overall structural responses of steel fiber-reinforced concrete beams under mechanical load and a nonlinear temperature gradient combined were similar to the responses of plain concrete beams up to the cracking stage. However, the release of thermal stresses due to cracking and the considerable residual load-carrying capacity after cracking were the most important observations for steel fiber-reinforced concrete beams.
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Kim, Chul-Goo, Hong-Gun Park, Geon-Ho Hong, and Su-Min Kang. "Shear Strength of Steel Fiber Concrete - Plain Concrete Composite Beams." Journal of the Korea Concrete Institute 27, no. 5 (October 30, 2015): 501–10. http://dx.doi.org/10.4334/jkci.2015.27.5.501.
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Al-Saidy, A. H. "Performance of Cement-Based Patch Repair Materials in Plain and Reinforced Concrete Members." Journal of Engineering Research [TJER] 13, no. 2 (December 1, 2016): 160. http://dx.doi.org/10.24200/tjer.vol13iss2pp160-171.
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Structural elements such as beams, slabs, and columns may require strengthening or repair during their service life. Different repair materials (RMs) are available and it is usually difficult to choose the best ones, especially when considering the cost of such materials. This paper presents the results of an experimental investigation of patch RMs on plain concrete prisms as well as on reinforced concrete beams. Three cement-based RMs available in the market with different mechanical properties and an ordinary Portland cement (OPC) mix produced in the lab were used in the study. Damage was induced in prisms/beams and then repaired using different materials. The experimental work included assessment of the flexural strength of damaged/repaired plain concrete prisms; slant shear (bond) strength between the concrete and the RM; axial strength of damaged/repaired plain concrete prisms and bond of the repair materials in damaged/repaired reinforced concrete beams loaded to failure. The test results showed that all RMs performed well in restoring the strength of damaged plain concrete. Compatibility of the RMs with substrate concrete was found to be more important in the behavior than superior mechanical properties of the RMs. No difference was noted in the behavior between the RMs in repairing reinforced concrete beams at the tension side.
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Tang, Yuxiang, and Hongniao Chen. "CHARACTERIZATIONS ON FRACTURE PROCESS ZONE OF PLAIN CONCRETE." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 25, no. 8 (October 1, 2019): 819–30. http://dx.doi.org/10.3846/jcem.2019.10799.
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The fracture property of concrete is essential for the safety and durability analysis of concrete structures. Investigating the characteristics of the fracture process zone (FPZ) is of great significance to clarify the nonlinear fracture behaviour of concrete. Experimental and numerical investigations on the FPZ of plain concrete in pre-notched beams subjected to three-point bending were carried out. Electronic speckle pattern interferometry (ESPI) technique was used to observe crack evolution and measure the full-field deformation of the beams. The development of the FPZ were evaluated qualitatively and quantitatively based on the in-plane strain contours and displacement field measured by ESPI, respectively. By integrating the cohesive crack model and finite element (FE) model, various tension softening curves (TSCs) were employed to simulate the fracture response of concrete beams. By comparing the deformation obtained by FE simulation and experiments, the TSCs of plain concrete were evaluated and most suitable TSCs of concrete were recommended.
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Zhao, Shun Bo, Peng Bing Hou, and Fu Lai Qu. "Laboratory Fast Corrosion Test of Plain Steel Bars in Concrete Beams." Advanced Materials Research 535-537 (June 2012): 1803–6. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.1803.
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An experimental study was carried out to examine the non-uniform corrosion of plain steel bars in reinforced concrete beams partially placed in 5% sodium chloride solution under conditions of accelerated corrosion. 4 reinforced concrete beams with different concrete strength were made. The crack distributions of the beams due to pre-loads and expansion of corrosion product, and the sectional corrosion characteristics of plain steel bars are described in detail. The sectional area loss relating to mass loss and change along pure bending length of the beams are discussed. These can be used as the basis of test for further studies to build the numerical models of serviceability of corroded reinforced concrete beams.
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Qin, Yi. "The Influence of Reinforced Concrete Beams Crack on Size Effect." Advanced Materials Research 463-464 (February 2012): 254–58. http://dx.doi.org/10.4028/www.scientific.net/amr.463-464.254.
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We research the influence of reinforced concrete beams crack on size effect by using the fracture Mechanics analysis method and Fracture toughness. First, the weight of three spot curved beam ,the load ,the steel bar, and the cohesive strength of breaking-down process area were superimposed of the stress intensity factor which has in the crack tip, in order to examine whether it has surpassed the fracture toughness, and judge the crack whether will be to expand. Then we went to iterative computation through increasing the load and the crack length which obtained the carrying capacity of corresponding size component, we used the Matlab programming in the entire computational process. The result shows that although the steel bar limited crack expansion of concretes beams and caused “the plasticity” characteristic, the reinforced concrete beams had the size effect phenomenon still, it did not obvious compare with the plain concrete.
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Bernardo, Luís F. A., and Sérgio M. R. Lopes. "Behaviour of concrete beams under torsion: NSC plain and hollow beams." Materials and Structures 41, no. 6 (October 19, 2007): 1143–67. http://dx.doi.org/10.1617/s11527-007-9315-0.
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Koppoju, Manasa, and Muralidhara Rao T. "Fracture Parameters of Plain Concrete Beams Using ANSYS." CVR Journal of Science & Technology 11, no. 1 (December 1, 2016): 18–28. http://dx.doi.org/10.32377/cvrjst1104.
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Gao, Ri, Zhi Min Liu, Li Qian Zhang, and Piet Stroeven. "Static Properties of Plain Reactive Powder Concrete Beams." Key Engineering Materials 302-303 (January 2006): 521–27. http://dx.doi.org/10.4028/www.scientific.net/kem.302-303.521.
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Reactive powder concrete (RPC) is a new kind of ultra-high strength and upper ductility concrete first developed in 1990’s in France. In this paper, the RPC mixture proportion is optimized and its mechanical properties, such as compressive strength, flexural strength, elastic modulus, and its durability, are tested and discussed. Based on the optimal mixture proportion, four simply supported plain RPC beams (without reinforcement bars) are made and tested. The mechanical properties of plain RPC beams, including section deformation, load-displacement relationship, failure forms, crack distribution, crack extension, and ultimate flexural capacity, are discussed. It is concluded that RPC is an excellent material with high strength and durability. Steel fiber is important both to control the crack extension and to enhance the ductility of RPC beams.
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Hao, Yi Fei, Hong Hao, and Gang Chen. "Experimental Tests of Steel Fibre Reinforced Concrete Beams under Drop-Weight Impacts." Key Engineering Materials 626 (August 2014): 311–16. http://dx.doi.org/10.4028/www.scientific.net/kem.626.311.
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Concrete is a brittle material, especially under tension. Intensive researches have been reported to add various types of fibres into concrete mix to increase its ductility. Recently, the authors proposed a new type of steel fibre with spiral shape to reinforce concrete material. Laboratory tests on concrete cylinder specimens demonstrated that compared to other fibre types such as the hooked-end, deformed and corrugated fibres the new fibres have larger displacement capacity and provide better bonding with the concrete. This study performs drop-weight impact tests to investigate the behaviour of concrete beams reinforced by different types of steel fibres. The quasi-static compressive and split tensile tests were also conducted to obtain the static properties of plain concrete and steel fibre reinforced concrete (FRC) materials. The quasi-static tests were carried out using hydraulic testing machine and the impact tests were conducted using an instrumented drop-weight testing system. Plain concrete and concrete reinforced by the commonly used hooked-end steel fibres and the proposed spiral-shaped steel fibres were tested in this study. The volume dosage of 1% fibre was used to prepare all FRC specimens. Repeated drop-weight impacts were applied to the beam specimens until total collapse. A 15.2 kg hard steel was used as the drop-weight impactor. A drop height of 0.5 m was considered in performing the impact tests. The force-displacement relations and the energy absorption capabilities of plain concrete and FRC beams were obtained, compared and discussed. The advantage and effectiveness of the newly proposed spiral-shaped steel fibres in increasing the performance of FRC beam elements under impact loads were examined.
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Al-Sherrawi, Mohannad Husain, Abbas A. Allawi, Basim H. AL-Bayati, Mohanned Al Gharawi, and Ayman El-Zohairy. "Behavior of Precast Prestressed Concrete Segmental Beams." Civil Engineering Journal 4, no. 3 (April 7, 2018): 488. http://dx.doi.org/10.28991/cej-0309109.
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The structural behavior of Segmental Precast Post-tensioned Reinforced Concrete (SPPRC) beams largely depends on the behavior of the joints that connect between the segments. In this research, series of static tests were carried out to investigate the behavior of full-scale SPPRC beams with different types of epoxy-glued joint configurations; multi-key joint, single key, and plain key joint. The reference specimen was monolithically casted beam and the other specimens were segmental beams with five segments for each one. The general theme from the experimental results reflects an approximate similarity in the behavior of the four beams with slight differences. Due to the high tensile strength of the used epoxy in comparison to concrete, cracks at joints occurred in the concrete cover which was attached to the epoxy mortar.
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Abraham, Er Nimmy, Er Gopika Moorthy, and Er Prashanth Krishnan. "Seismic Analysis of Concrete Filled Steel Tubular Column and H Steel Beam of Normal and Reduced Beam Sections." International Journal of Engineering Research in Mechanical and Civil Engineering (IJERMCE) 9, no. 6 (June 24, 2022): 37–40. http://dx.doi.org/10.36647/ijermce/09.06.a007.
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A beam-column junction is a structural member that is subjected to transverse bending and axial compression at the same time. H Steel beams are beams that are composed of an H-steel core within a precast concrete beam. Advantage of H steel beam is its high bearing capacity compared to RC columns. Concrete Filled Steel Tubular (CFST) structure consists of hollow steel tube filled with plain or reinforced concrete. They are lighter than RC columns and are safer and dependable in seismic regions. The study is to find the seismic analysis of developed joints between H steel beam and CFST column under cyclic loading and to compare the behavior of those joints of CFST tubes with normal and Reduced Beam Section beams (RBS). The result aims to show a significant seismic behavior in RBS section than the normal beam section in terms of load- displacement hysteresis curve.
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Słowik, Marta. "The analysis of load carrying capacity and cracking of slightly reinforced concrete members in bending." Budownictwo i Architektura 2, no. 1 (June 11, 2008): 065–78. http://dx.doi.org/10.35784/bud-arch.2312.
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Slightly reinforced concrete members are the members made by concrete with reinforcement less than minimum given in codes for reinforced concrete ones. Plain concrete and slightly reinforced concrete members in bending are treated in the same way during the dimensioning and the influence of longitudinal reinforcement on the load carrying capacity is not taken into account. The mechanism of work and crack formation in slightly reinforced concrete members is not completely recognized. The author’s own research program was made. The experiment was aimed at the determination of cracking moment and load carrying capacity of slightly reinforced concrete beams with different reinforcement ratio. Also plain concrete beams and the typical reinforced concrete beam were tested. The analysis of the obtained values of maximum bending moment and crack’s widths was made according to the reinforcement ratio. The analysis of test results shows how the presence of longitudinal steel bars in concrete members, even when reinforcement ratio is low, changes cracking process and influences the value of cracking moment in flexural members. On the basis of test results, the method how to calculate the load carrying capacity of slightly reinforced concrete elements in bending has been proposed.
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Hameed, Ali Ammar, and Mohannad Husain Al-Sherrawi. "Influence of Steel Fiber on the Shear Strength of a Concrete Beam." Civil Engineering Journal 4, no. 7 (July 10, 2018): 1501. http://dx.doi.org/10.28991/cej-0309190.
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The shear failure in a concrete beam is a brittle type of failure. The addition of steel fibers in a plain concrete mix helps to bridge and restrict the cracks formed in the brittle concrete under applied loads, and enhances the ductility of the concrete. In this research an attempt was made to investigate the behavior and the ultimate shear strength of hooked end steel fiber reinforced concrete beams without traditional shear reinforcement. Four simply-supported reinforced concrete beams with a shear span-to-depth ratio of about 3.0 were tested under two-point loading up to failure. Steel fibers volumetric fractions that used were 0.0, 0.5, 0.75 and 1.0%. Test results indicated that using 1.0% volume fraction of hooked steel fiber led to exclude shear failure and enhanced the use of steel fibers as shear reinforcement in concrete beams. The results also showed that a concrete beam with hooked steel fiber provided higher post-flexural-cracking stiffness, an increase in the shear capacity and energy absorption and an increase in the maximum concrete and steel reinforcement strains.
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Ali, Ashti Sedeeq, Serwan Khorsheed Rafiq, and Dr Ferhad Rahim Karim. "Flexural Strengthening of Normal Strength Plain Concrete Beams using Ultra-High Performance Fiber Reinforced Concrete Strips." CONSTRUCTION 2, no. 1 (July 1, 2022): 136–43. http://dx.doi.org/10.15282/construction.v2i1.7712.
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In recent years, the strengthening of reinforced concrete elements in existing structures has become a very important interest topic because of the demand for development structures and extending their service life. Since the ultra-high-performance fiber-reinforced concrete properties in terms of durability and strength are fully exploited, it became early in the rehabilitation and strengthening field. This paper highlights the flexural behavior of small-scale plain normal strength concrete beam strengthened in flexure by ultra-high performance fiber reinforced concrete strips at the tensile surface by adhesive epoxy material to evaluate and quantify the effect on strength in flexure. Experimental results indicated that the ultra-high performance fiber reinforced concrete strengthening strips enhanced the flexural capacity and stiffness of the normal strength concrete substrate by 369%, 364%, and 168% at crack load and 364%, 232%, and 127% at ultimate load for concrete grades 20.8, 32.6 and 43.3 MPa respectively, delayed the crack development corresponding to apply load more than 0.37, 0.97 and 1.25 kN for strips thickness 10, 15 and 20 mm respectively in all grades of concrete beam and improved beams' ductility behavior. The main important point that affects the performance of flexural strengthening concrete beams using adhesive material is the quality of the interfacial transition bonded zone of the composite system produced between the strengthening material and the existing concrete substrate.
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Al-Zuhairi, Alaa H., and Ali I. Taj. "Effectiveness of Meso-Scale Approach in Modeling of Plain Concrete Beam." Journal of Engineering 24, no. 8 (July 28, 2018): 71. http://dx.doi.org/10.31026/j.eng.2018.08.06.
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The main aim of this research paper is investigating the effectiveness and validity of Meso-Scale Approach (MSA) as a modern technique for the modeling of plain concrete beams. Simply supported plain concrete beam was subjected to two-point loading to detect the response in flexural. Experimentally, a concrete mix was designed and prepared to produce three similar standard concrete prisms for flexural testing. The coarse aggregate used in this mix was crushed aggregate. Numerical Finite Element Analysis (FEA) was conducted on the same concrete beam using the meso-scale modeling. The numerical model was constructed to be a bi-phasic material consisting of cement mortar and coarse aggregate. The interface between the two consisting materials was assumed fully bonded interface. In the ABAQUS program, the Extended Finite Element Method (XFEM) was employed for the treatment of the discontinuity problems, which is accompanied by cracking during the fracture process of plain concrete. The behavior and response of the beam in both meso-scale numerical analysis and experimental test were found in a good agreement. Another check was added by comparing the results using thin-beam theory assuming the concrete as a homogenous linear-elastic material. The result of this comparison showed that the meso-scale model analysis lies between theoretical and experimental models.
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Chandra, Nurman, Ridwan Ridwan, and Muhammad Ikhsan. "Finite Element Modelling of Reinforced Concrete Beam Strengthened with Embedded Steel Reinforcement Bars." Journal of Applied Materials and Technology 1, no. 1 (August 25, 2019): 38–45. http://dx.doi.org/10.31258/jamt.1.1.38-45.
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The increased of loads on existing reinforced concrete infrastructure and the lack of initial design and construction will induce flexural and shear failure. Several methods have been introduced to increase the shear capacity of existing reinforced concrete elements with FRP, involving the use of plates or fabric externally bonded (EB) to the webs of the bridge beams, prestressed straps wrapped around the beams or bars mounted within grooves prepared in the near-surface mounted (NSM) technique. Typical Indonesian concrete bridges consisted main girders connected with diaphragm beams where the distance between those girders are very close. In particular case, where the webs of the beams are difficult to access, a novel approach is introduced, namely deep embedment (DE) method. Three reinforced concrete beam models are prepared for this study. One specimen is the control specimen and identified, as Beam-CS and the other two are the strengthened specimens and identified as Beam-SS-3EB and Beam-SS-5EB. All specimens have the same dimensions and reinforcement configuration. Specimen Beam-SS-3EB was strengthened with three rows of 6 mm embedded plain steel bars while specimen Beam-SS-5EB was strengthened with five rows of 6 mm plain steel bars. The results showed that element size significantly affects the load-displacement curve behaviour. The similarity of the hysteresis curve in the FE analysis using the 25 mm element size suggested a reasonably good agreement between the analytical calculation and the prediction result from the FE analysis. Furthermore, maximum reaction force for Beam-SS-3EB and Beam-SS-5EB were 30.30 kN and 31.77 kN, respectively, represents an increase of 17.67% and 23.29% compared to that of the Beam-CS.
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Abdulhameed, Ali Adel, and AbdulMuttalib Issa Said. "Behaviour of Segmental Concrete Beams Reinforced by Pultruded CFRP Plates: An Experimental Study." Journal of Engineering 25, no. 8 (July 31, 2019): 62–79. http://dx.doi.org/10.31026/j.eng.2019.08.05.
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The research aims to develop an innovative technique for segmental beam fabrication using plain concrete blocks and externally bonded Carbon Fiber Reinforced Polymers Laminates (CFRP) as a main flexural reinforcement. Six beams designed and tested under two-point loadings. Several parameters included in the fabrication of segmental beam were studied such as; bonding length of carbon fiber reinforced polymers, the surface-to-surface condition of concrete segments, interface condition of the bonding surface and thickness of epoxy resin layers. Test results of the segmental beams specimens compared with that gained from testing reinforced concrete beam have similar dimensions for validations. The results display the effectiveness of the developed fabrication method of segmental beams. The modified design procedure for externally bonded carbon fiber reinforced polymers ACI 440.2R-17 was developed for designing segmental beams. The experimental test values also compared with design values, and it was 93.3% and 105.8% of the design values, which indicates the effectiveness of the developed procedure.
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Abdulhameed, Ali A., and AbdulMuttalib Issa Said. "Behaviour of Segmental Concrete Beams Reinforced by Pultruded CFRP Plates: an Experimental Study." Journal of Engineering 25, no. 8 (August 5, 2019): 62–79. http://dx.doi.org/10.31026/j.eng.2019.08.11.
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Research aims to develop a novel technique for segmental beam fabrication using plain concrete blocks and externally bonded Carbon Fiber Reinforced Polymers Laminates (CFRP) as a main flexural reinforcement. Six beams designed an experimentally tested under two-point loadings. Several parameters included in the fabrication of segmental beam studied such as; bonding length of carbon fiber reinforced polymers, the surface-to-surface condition of concrete segments, interface condition of the bonding surface, and thickness of epoxy resin layers. Test results of the segmental beams specimens compared with that gained from testing reinforced concrete beam have similar dimensions for validations. The results show the effectiveness of the developed fabrication method of segmental beams. The modified design procedure for externally bonded carbon fiber reinforced polymers ACI 440.2R-17 developed for designing segmental beams. The experimental test values also compared with design values and it was 93.3% and 105.8% of the design values which indicates the effectiveness of the developed procedure.
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Marefat, Mohammad S., Seyed Masood Hassanzadeh Shirazi, Rasool Rostamshirazi, and Mohammad Khanmohammadi. "Cyclic Response of Concrete Beams Reinforced by Plain Bars." Journal of Earthquake Engineering 13, no. 4 (May 4, 2009): 463–81. http://dx.doi.org/10.1080/13632460902837769.
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Zhang, Hai-Long, and Chang-Chun Pei. "Flexural properties of steel fiber types and reinforcement ratio for high-strength recycled concrete beams." Advances in Structural Engineering 20, no. 10 (January 8, 2017): 1512–22. http://dx.doi.org/10.1177/1369433216683196.
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This article took fly ash and silica fume as cementing materials to replace part of cement and took recycled coarse aggregate to replace part of gravel to mix plain concrete and studied the flexural properties of the beams with high-strength steel fiber–recycled concrete by changing the types of steel fiber and reinforcement ratio. The results showed that fly ash and silica fume could improve strength and flexural capacity of the recycled concrete beam by filling micro-cracks of recycled coarse aggregate and reduce the development speed of deflection and crack width of the test beam. Steel fibers could significantly slow the development of deflection and crack width of the beams with high-strength recycled concrete, and the difference in end-structure could increase the flexural capacity of the beams in varying degrees. The article put forward theory of improving the bearing capacity of the beam with three kinds of steel fibers by introducing the influence factor of steel fiber end-structure.
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Jing, Hang, and Yong Quan Li. "Nonlinear Finite Element Analysis of Layered Steel Fiber Reinforced Concrete Beam." Applied Mechanics and Materials 166-169 (May 2012): 616–19. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.616.
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A simplified finite element model for analysis of the Layered steel fiber beams with the concrete damaged plasticity model has been presented. The numerical simulation of load-deflection curve of layered steel fiber reinforced concrete beam under three-point loads is performed using ABAQUS. The results of simulation are generally in conformance with the experiment. The results of numerical simulation show that layered steel fiber has little contribution to the elastic capacity of concrete beam. But it can improve the ultimate bearing capacity of concrete beam obviously. The bending collapse style of layered steel fiber reinforced concrete beam is different from plain concrete beam evidently with obvious ductile characteristic.
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Mohammed, Ihtesham Hussain, Ahmed Majid Salim Al Aamri, Shakila Javed, and Yahya Ubaid Al Shamsi. "A Comparative Investigation on Normal and High Strength Concrete Beams under Torsion." Materials Science Forum 1048 (January 4, 2022): 359–65. http://dx.doi.org/10.4028/www.scientific.net/msf.1048.359.
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In this study, an experimental investigation was done to study the behaviour of Normal Strength Concrete (NSC) and High Strength Concrete (HSC) Plain beams under torsion with the concrete mix of M40 and M100. No mineral admixtures are used to obtain the required strength of concrete. Eight NSC beams and eight HSC beams whose width was varying with 75 mm, 100 mm, and 150 mm; depth varying as 75 mm, 100 mm, 150 mm and 200 mm; and span of the beams varying 600 mm, 800 mm and 1200 mm were casted and cured to stud the effect of torsion. The principle aim of this study was to understand the torsional behaviour of the NSC and HSC beams for rotation, cracking, size effect and torsional strength. A standard torsional loading method was used for conducting the testing of beams. The results obtained were compared with different theories and code equations. It was observed that the torsional strength of the beam increases with the increase in strength of concrete. HSC beams have higher torsional strength than the NSC beams which has the same amount of reinforcement.
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Deng, Zong Cai, Hong Liang Deng, Jian Hui Li, and Guo Dong Liu. "Flexural Fatigue Behavior and Performance Characteristics of Polyacrylonitrile Fiber Reinforced Concrete." Key Engineering Materials 302-303 (January 2006): 572–83. http://dx.doi.org/10.4028/www.scientific.net/kem.302-303.572.
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This paper presents the results of an experimental investigation to determine the flexural fatigue strength and fatigue life of concrete beams reinforced with monofilament polyacrylonitrile fibers (PAN fiber for short). The performance of fresh concrete and the elastic and mechanical properties of hardened concrete are compared by samples with and without fibers. The toughness calculated according to both ASTM and JCI methods increased with the addition of fibers. The toughness indexes I5 was 3.8-4.2 times，I10 was 5.8—6.8 times that of the plain concrete. The equivalent strength was 0.63-0.87 MPa for PAN fiber reinforced concrete. When compared to plain concrete, the endurance limit of concrete beams only reinforced with PAN fiber is increased by 12 percent.
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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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Kaushar, Aajma. "Experimental Study of Foam Concrete by Using Different Mixes." International Journal for Research in Applied Science and Engineering Technology 10, no. 1 (January 31, 2022): 1357–64. http://dx.doi.org/10.22214/ijraset.2022.40038.
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Abstract: Foamed concrete can also be termed as lightweight or cellular concrete. It consist of is a cementitious paste, fines, water and has coarse aggregate without voids. Voids are created by using foam. It creates more strength than plain foam concrete (PFC) by using admixtures like fly ash, silica and fibers in it . Under this research program, three different mixes were made: plain foamed concrete (PFC), polypropylene fiber reinforced foamed concrete (PPFC) and basalt fiber reinforced foamed concrete (BFC). Specimens were tested for compressive strength, splitting tensile strength, young’s modulus and poisson’s ratio, flexural strength and RFC (Reinforced foamed concrete) strength. This study showed that the use of optimum foam volume i.e. 20% gives a specific density of foam concrete 70 – 100 PFC and compressive strength of 3000 – 5500 psi. As the study of flexural and compression application eight different steel reinforced sandwich beams, sixteen compression column of witch eight are tested with and without reinforcement separately respectively. These sandwich beams of steel reinforcement were divided in four different sets as two of each, normal concrete - Styrofoam R-13 rating combination, normal concrete - PFC combination, normal concrete - PPFC combination and normal concrete – BFC combination. Likewise, for study of structural behavior of compression column the specimens were divided same as sandwich beams into different groups. The flexural strength of BFC specimen was 10 times more than PFC specimen. Among the RFC beam specimens, BFC has shown maximum load carrying capacity. Keywords: Foam concrete, light weight concrete, strength, PFC, BFC and PPFC
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Sagi, Murali Sagar Varma, Chandrashekhar Lakavath, S. Suriya Prakash, and Akanshu Sharma. "Experimental Study on Evaluation of Replacing Minimum Web Reinforcement with Discrete Fibers in RC Deep Beams." Fibers 9, no. 11 (November 11, 2021): 73. http://dx.doi.org/10.3390/fib9110073.
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This study investigates the possibility of replacing the minimum web reinforcement in deep beams with discrete fibers. Additionally, the equivalent dosage of fibers required to obtain similar performance of the deep beam with minimum web reinforcement is investigated. Deep beams made of plain concrete with no fibers, beams with minimum web reinforcement as per AASHTO LFRD recommendations (0.3% in both horizontal and vertical), and with a 0.5% volume fraction of steel, macro-synthetic and hybrid fibers are tested at a shear span to height ratio (a/h) of one. Test results show that the presence of 0.3% web reinforcement in horizontal and vertical directions increased the peak load by 25% compared to the plain concrete beams. However, it did not significantly change the first diagonal crack load. With the addition of 0.5% of steel, macro-synthetic and hybrid fibers, the peak load increased by 49%, 42%, and 63%, respectively, compared to the plain concrete specimen. The addition of steel fibers significantly improved the first cracking load. In contrast, macro-synthetic fibers did not affect the first cracking load but improved the ductility with higher deflections at peak. Hybridization of steel and macro synthetic fibers showed improved performance compared to the individual fibers of the same volume in peak load and ductility. Test results showed that a 0.5% volume fraction of discrete macro steel or synthetic or hybrid fibers can be used to completely replace the minimum web reinforcement (0.3% in both directions).
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Cui, Yifei, Shihao Qu, Jiuwen Bao, and Peng Zhang. "Bond Performance of Steel Bar and Fly Ash-Based Geopolymer Concrete in Beam End Tests." Polymers 14, no. 10 (May 14, 2022): 2012. http://dx.doi.org/10.3390/polym14102012.
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This paper presents a comprehensive investigation of the bond characteristics of steel bar reinforced geopolymer concrete (GPC). The ASTM A944 beam end tests were conducted on GPC beams reinforced with plain or ribbed bars. The bond–slip curves and the bond strength of GPC beams were obtained. The relationship between the bond stress and relative slip in plain and ribbed bar reinforced GPC has been represented by empirical formulae. The bond testing results were compared with those of corresponding ordinary Portland cement concrete (OPC) using statistical hypothesis tests. The results of hypothesis testing showed that GPC was significantly superior to OPC in terms of bond capability with plain bars and bond stiffness with ribbed bars. The statistical analysis indicated that the bond–slip relations derived for OPC are inapplicable to GPC; thus, new bond–slip relations are suggested to estimate the development of bond stress and relative slip between GPC and steel bars.
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Tawfik, Ahmed Bahgat, Sameh Youssef Mahfouz, and Salah El-Din Fahmy Taher. "Nonlinear ABAQUS Simulations for Notched Concrete Beams." Materials 14, no. 23 (November 30, 2021): 7349. http://dx.doi.org/10.3390/ma14237349.
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The numerical simulation of concrete fracture is difficult because of the brittle, inelastic-nonlinear nature of concrete. In this study, notched plain and reinforced concrete beams were investigated numerically to study their flexural response using different crack simulation techniques in ABAQUS. The flexural response was expressed by hardening and softening regime, flexural capacity, failure ductility, damage initiation and propagation, fracture energy, crack path, and crack mouth opening displacement. The employed techniques were the contour integral technique (CIT), the extended finite element method (XFEM), and the virtual crack closure technique (VCCT). A parametric study regarding the initial notch-to-depth ratio (ao/D), the shear span-to-depth ratio (S.S/D), and external post-tensioning (EPT) were investigated. It was found that both XFEM and VCCT produced better results, but XFEM had better flexural simulation. Contrarily, the CIT models failed to express the softening behavior and to capture the crack path. Furthermore, the flexural capacity was increased after reducing the (ao/D) and after decreasing the S.S/D. Additionally, using EPT increased the flexural capacity, showed the ductile flexural response, and reduced the flexural softening. Moreover, using reinforcement led to more ductile behavior, controlled damage propagation, and a dramatic increase in the flexural capacity. Furthermore, CIT showed reliable results for reinforced concrete beams, unlike plain concrete beams.
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Lakusic, Stjepan. "Mechanical flexural properties of concrete with melt-extract stainless steel fibres." Journal of the Croatian Association of Civil Engineers 72, no. 12 (January 2021): 1155–64. http://dx.doi.org/10.14256/jce.2992.2020.
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An experimental study is performed to evaluate the effect of melt-extract stainless steel fibres on mechanical and flexural properties of concrete. A total of seventy-two specimens are used to determine an optimum fibre dosage and mechanical properties of plain and steel fibre reinforced concrete. Twelve full-scale beam specimens are then exposed to four-point bending tests. The effect of melt-extract stainless steel fibres on flexural behaviour of beams is quantified in this testing. A beam specimen is exposed to four-point bending, after being subjected to 15000 cycles of fatigue load. Pre- and post-fatigue flexural properties of beams with melt-extract steel fibres are compared and discussed.
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Lakusic, Stjepan. "Mechanical flexural properties of concrete with melt-extract stainless steel fibres." Journal of the Croatian Association of Civil Engineers 72, no. 12 (January 2021): 1155–64. http://dx.doi.org/10.14256/jce.2992.2020.
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An experimental study is performed to evaluate the effect of melt-extract stainless steel fibres on mechanical and flexural properties of concrete. A total of seventy-two specimens are used to determine an optimum fibre dosage and mechanical properties of plain and steel fibre reinforced concrete. Twelve full-scale beam specimens are then exposed to four-point bending tests. The effect of melt-extract stainless steel fibres on flexural behaviour of beams is quantified in this testing. A beam specimen is exposed to four-point bending, after being subjected to 15000 cycles of fatigue load. Pre- and post-fatigue flexural properties of beams with melt-extract steel fibres are compared and discussed.
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Hieu, Nguyen Trung, and Nguyen Van Tuan. "Effect of loading rate on flexural behavior of concrete and reinforced concrete beams." Journal of Science and Technology in Civil Engineering (STCE) - NUCE 15, no. 3 (August 16, 2021): 136–43. http://dx.doi.org/10.31814/stce.nuce2021-15(3)-11.
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The elasto-plastic characteristics of plain concrete are inevitably affected by the loading rate. This paper presents an experimental investigation on the effect of loading rate on flexural behavior of concrete and reinforced concrete (RC) beams, which was carried out with Walter+bai electro-hydraulic servo system. Three-point bending tests on 100 × 100 × 400 mm prismatic concrete samples and 80 × 120 × 1100 mm RC beams with different displacement controlled loading rates of 0.01 mm/min, 0.1 mm/min, and 3 mm/min were imposed. Based on the test results, the effects of loading rates on the load-displacement curve, cracking, and ultimate load-carrying capacities of RC beams were evaluated.
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Li, Chun Xia, and Shi Lin Yan. "Minimum Reinforcement Ratio of Concrete Beams Reinforced with FRP Bars." Advanced Materials Research 282-283 (July 2011): 553–56. http://dx.doi.org/10.4028/www.scientific.net/amr.282-283.553.
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Based on the non-linearity stress strain relation of concrete, the cracking moment of plain flexural concrete member is established, and the flexural capacity of concrete beams reinforced with FRP bars is also obtained under FRP rupture-controlled failure. To prevent FRP rupture failure upon concrete cracking, the minimum reinforcement ration should be derived from simplified calculation, which may provide some theoretic guidance on design and construction for concrete structure reinforced with FRP bars.
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Ding, Jun, Xia Huang, Gang Zhu, Song Chen, and Guochao Wang. "Mechanical Performance Evaluation of Concrete Beams Strengthened with Carbon Fiber Materials." Advances in Materials Science and Engineering 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/572151.
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As a kind of novel material of high strength and light weight, carbon fiber materials have been widely used in construction industry to repair the damaged bridges improving its mechanical performance. In this work, the reinforced plates made of carbon fiber materials (for short CFRP) are externally bonded to the bottom of concrete beams to enhance load capacity of beams. The strain energy release rates are calculated at the interest crack in concrete beams based on virtual crack closure technology using FEM and are chosen as the criterion to determine whether the mechanical properties of beams are strengthened by being externally bonded with CFRP. The effects of main crack propagation on plain concrete beam, on concrete beam strengthened with CFRP, and on inclined crack are also discussed. The comparison between the beams with and without CFRP shows that the CFRP significantly increases the loading capacity and crack resistance. It also shows that the main crack propagation can reduce loading capacity and crack resistance regardless of strengthening. The experiment observation also supports this. It proves the validity of the method, and it is concluded that in order to increase the loading capacity and crack resistance effectively, controlling over the crack propagation is necessary.
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Tang, Xiaochao, Isaac Higgins, and Mohamad Jlilati. "Behavior of Geogrid-Reinforced Portland Cement Concrete under Static Flexural Loading." Infrastructures 3, no. 4 (September 26, 2018): 41. http://dx.doi.org/10.3390/infrastructures3040041.
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Geogrids have been investigated by a limited number of studies as a potential alternative to steel reinforcement for Portland cement concrete (PCC), especially in situations where using steel reinforcement may not be suitable due to constructability and durability limitations. This study aims to investigate the flexural behavior of simply-supported concrete beams reinforced by geogrids, which would aid in assessing the potential use of geogrids for concrete structures such as overlays and other thin sections. Another objective of this study is to examine the potential benefits of embedding geogrids in PCC, and to investigate the mechanism and effectiveness of geogrid reinforcement in PCC. Plain and geogrid-reinforced concrete beams were fabricated and tested under a static four-point flexural bending load. The midspan deflection and crack mouth opening displacement (CMOD) of the beams were recorded during loading. Additionally, for geogrid-reinforced beams, strain gages were attached on the geogrids to monitor the strains that developed in geogrids. Results reveal that the geogrid primarily contributes to improving the ductility of the post-peak behavior of plain concrete and to delaying the collapse failure of concrete beams. Strain measurements of the geogrids indicate that the geogrids were activated and mobilized instantly upon the application of the flexural load. Both the strain measurements and observations of the geogrids post failure suggest that there was no slippage between the geogrids and the concrete.
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Brake, Nicholas A., Karim Chatti, and Ali Albanna. "Fatigue crack resistance characterisation of fully supported plain concrete beams." Road Materials and Pavement Design 19, no. 3 (January 31, 2018): 511–24. http://dx.doi.org/10.1080/14680629.2018.1418676.
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Demakos, Constantinos B., Constantinos C. Repapis, and Dimitros P. Drivas. "Experimental Investigation of Shear Strength for Steel Fibre Reinforced Concrete Beams." Open Construction & Building Technology Journal 15, no. 1 (May 19, 2021): 81–92. http://dx.doi.org/10.2174/1874836802115010081.
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Aims: The aim of this paper is to investigate the influence of the volume fraction of fibres, the depth of the beam and the shear span-to-depth ratio on the shear strength of steel fibre reinforced concrete beams. Background: Concrete is a material widely used in structures, as it has high compressive strength and stiffness with low cost manufacturing. However, it presents low tensile strength and ductility. Therefore, through years various materials have been embedded inside it to improve its properties, one of which is steel fibres. Steel fibre reinforced concrete presents improved flexural, tensile, shear and torsional strength and post-cracking ductility. Objective: A better understanding of the shear performance of SFRC could lead to improved behaviour and higher safety of structures subject to high shear forces. Therefore, the influence of steel fibres on shear strength of reinforced concrete beams without transverse reinforcement is experimentally investigated. Methods: Eighteen concrete beams were constructed for this purpose and tested under monotonic four-point bending, six of which were made of plain concrete and twelve of SFRC. Two different aspect ratios of beams, steel fibres volume fractions and shear span-to-depth ratios were selected. Results: During the experimental tests, the ultimate loading, deformation at the mid-span, propagation of cracks and failure mode were detected. From the tests, it was shown that SFRC beams with high volume fractions of fibres exhibited an increased shear capacity. Conclusion: The addition of steel fibres resulted in a slight increase of the compressive strength and a significant increase in the tensile strength of concrete and shear resistance capacity of the beam. Moreover, these beams exhibit a more ductile behaviour. Empirical relations predicting the shear strength capacity of fibre reinforced concrete beams were revised and applied successfully to verify the experimental results obtained in this study.
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Krassowska, Julita, and Marta Kosior-Kazberuk. "Failure mode in shear of steel fiber reinforced concrete beams." MATEC Web of Conferences 163 (2018): 02003. http://dx.doi.org/10.1051/matecconf/201816302003.
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Experimental tests were carried out to assess the failure model of steel fiber reinforced concrete beams. Experimental research was focused on observing changes in the behavior of the tested elements depending on the amount of shear reinforcement and the fiber. Model two-span beams with a cross-section of 80x180 mm and a length of 2000 mm were tested. The beams had varied stirrup spacing. The following amounts of steel fibres in concrete were used: 78.5 kg/m3 (1.0%) i 118 kg/m3 (1.5%). Concrete beams without fibres were examined at the same time. The beams were loaded in a five-point bending test until they were destroyed. Shear or bending capacity of the element was observed. Fibre reinforced concrete beams were not destroyed rapidly, but they kept their shape consistent under load. Larger number of diagonal cracks with a smaller width were observed in fibre reinforced concrete beams. Failure of concrete beams without fibres was rapid, with a characteristic brittle cracking. Steel fibres revealed the ability to transfer significant shear stress after cracking in comparison to plain concrete.
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Li, Chang Yong, Hui Yang, Yang Liu, and Ke Ke Gao. "Flexural Behavior of Reinforced Concrete Beams Superposing with Partial Steel Fiber Reinforced Full-Lightweight Concrete." Applied Mechanics and Materials 438-439 (October 2013): 800–803. http://dx.doi.org/10.4028/www.scientific.net/amm.438-439.800.
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To improve the flexural properties and lighten the weight of ordinary reinforced concrete beam (RCB), this paper develops a new type of superposed RCB in which the tensile zone was partially cast with the steel fiber reinforced full-lightweight concrete (SFRFLC). 10 beams with different height of SFRFLC were designed. Their flexural behaviors were measured including the concrete strain at mid-span cross section, the load vs deflection curve, the cracking load and the ultimate load. It may be concluded that the test beams damage in ductile, the concrete strains at mid-span cross section basically fit the assumption of plain cross section, the variations of load vs deflection curves are similar with obvious changes at the points of the cracking of concrete and the yield of tensile reinforcements, the cracking loads are almost equal, and the ultimate loads tends to decrease with the increasing height of SFRFLC. The SFRFLC and ordinary concrete work well together, the suitable height of SFRFLC is there should be further studied.
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Lv, Yang, Xueqian Wu, Mengran Gao, Jiaxin Chen, Yuhao Zhu, Quanxi Cheng, and Yu Chen. "Flexural Behavior of Basalt Fiber Reinforced Polymer Tube Confined Coconut Fiber Reinforced Concrete." Advances in Materials Science and Engineering 2019 (February 3, 2019): 1–7. http://dx.doi.org/10.1155/2019/1670478.
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Basalt fiber has arisen new perspectives due to the potential low cost and excellent mechanical performance, together with the use of environmental friendly coir can be beneficial to the development of sustainable construction. In this study, a new composite structure called basalt fiber reinforced polymer (BFRP) tube encased coconut fiber reinforced concrete (CFRC) is developed. The 28-day compression strength of the plain concrete is about 15 MPa, which represents the low-strength poor-quality concrete widely existing in many old buildings and developing countries. Three types of BFRP tubes, i.e., 2-layer, 4-layer, and 6-layer, with the inner diameter of 100 mm and a length of 520 mm, were prepared. The plain concrete (PC) and CFRC were poured and cured in these tubes to fabricated BFRP tube confined long cylindrical beams. Three PC cylindrical beams and 3 CFRC cylindrical beams were prepared to be the control group. The four-point bending tests of these specimens were carried out to investigate the enhancement due to the BFRP tube and coir reinforcement. The load-carrying capacity, force-displacement relationship, failure mode, and the cracking moment were analyzed. Results show that both BFRP tube confined plain concrete (PC) and BFRP tube confined CFRC have excellent flexural strength and ductility, and the inclusion of the coir can further enhance the ductility of the concrete.
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Rymeš, Jiří, Petr Štemberk, and Alena Kohoutkova. "Experimental Analysis of Strengthening of Dapped-End Beams." Key Engineering Materials 722 (December 2016): 241–46. http://dx.doi.org/10.4028/www.scientific.net/kem.722.241.
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Technology of precast reinforced concrete finds its application in construction of buildings as well as transport infrastructure. Placement of a dapped-end beam on a corbel is one of the typical details for this construction technology. Designing of a dapped-end is crucial for the whole beam because any potential crack decreases the overall stiffness of the beam and can cause a collapse of the whole structure in the worst case. This paper presents results of an experimental research which was performed on a set of 6 small-scale dapped-end beams. Two different ways of prestressing were applied to experimental specimens and their ultimate-load bearing capacity were compared with plain concrete samples and with reinforced concrete samples. The results of this work suggest that horizontal prestressing technique is more efficient than vertical prestressing technique if the same prestressing force is applied.
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Chalioris, Kosmidou, and Karayannis. "Cyclic Response of Steel Fiber Reinforced Concrete Slender Beams; an Experimental Study." Materials 12, no. 9 (April 29, 2019): 1398. http://dx.doi.org/10.3390/ma12091398.
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Reinforced concrete (RC) beams under cyclic loading usually suffer from reduced aggregate interlock and eventually weakened concrete compression zone due to severe cracking and the brittle nature of compressive failure. On the other hand, the addition of steel fibers can reduce and delay cracking and increase the flexural/shear capacity and the ductility of RC beams. The influence of steel fibers on the response of RC beams with conventional steel reinforcements subjected to reversal loading by a four-point bending scheme was experimentally investigated. Three slender beams, each 2.5 m long with a rectangular cross-section, were constructed and tested for the purposes of this investigation; two beams using steel fibrous reinforced concrete and one with plain reinforced concrete as the reference specimen. Hook-ended steel fibers, each with a length-to-diameter ratio equal to 44 and two different volumetric proportions (1% and 3%), were added to the steel fiber reinforced concrete (SFRC) beams. Accompanying, compression, and splitting tests were also carried out to evaluate the compressive and tensile splitting strength of the used fibrous concrete mixtures. Test results concerning the hysteretic response based on the energy dissipation capabilities (also in terms of equivalent viscous damping), the damage indices, the cracking performance, and the failure of the examined beams were presented and discussed. Test results indicated that the SFRC beam demonstrated improved overall hysteretic response, increased absorbed energy capacities, enhanced cracking patterns, and altered failure character from concrete crushing to a ductile flexural one compared to the RC beam. The non-fibrous reference specimen demonstrated shear diagonal cracking failing in a brittle manner, whereas the SFRC beam with 1% steel fibers failed after concrete spalling with satisfactory ductility. The SFRC beam with 3% steel fibers exhibited an improved cyclic response, achieving a pronounced flexural behavior with significant ductility due to the ability of the fibers to transfer the developed tensile stresses across crack surfaces, preventing inclined shear cracks or concrete spalling. A report of an experimental database consisting of 39 beam specimens tested under cyclic loading was also presented in order to establish the effectiveness of steel fibers, examine the fiber content efficiency and clarify their role on the hysteretic response and the failure mode of RC structural members.
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Kashyap, AddepalliMallinadh, TanimkiChandraSekhar Rao, and NaraparajuVenkataRamana Rao. "Behaviour of Hybrid Fiber Reinforced Geopolymer Concrete Beams under Flexural Loading." Proceedings of the 12th Structural Engineering Convention, SEC 2022: Themes 1-2 1, no. 1 (December 19, 2022): 195–200. http://dx.doi.org/10.38208/acp.v1.495.
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This paper presents the behaviour of GPC beams with and without fiber under flexural loading. The work is presented in two parts. In the first part tests were conducted for mechanical properties of plain and hybrid fiber reinforced Geopolymer concrete to determine maximum strength characteristics of concrete. In the second part of the program two types of under-reinforced beams were cast with plain GPC and hybrid fiber reinforced GPC (HFRGPC) and tested under two points loading. The percentage of tensile rebar ratio is kept constant for two types of beams. The hybrid fiber reinforced GPC is prepared with 1.5%(1%Steel+0.5% Polypropylene) of fibers and used to cast the under reinforced beams .The cast specimens are tested after a specified curing period to determine first crack load, ultimate load, load-deflection behaviour and crack patterns. The results are compared with the theoretical values. From the test results, the fiber volume fraction has a compelling effect on the cracking load, ultimate load, crack pattern and failure mode. The flexural behaviour of the beams including the induced cracks, failure pattern, load deflection capacity and ductility index were compared. The ductility index of hybrid fiber reinforced beams is greater than that of GPC beams. The HFRGPC beams showed superior performance than that of GPC beams for parameters considered in this experimental study.