Articoli di riviste: "Reinforced concrete construction Ductility"

1

Mo, Y. L., e S. F. Perng. "Behavior of Framed Shearwalls Made of Corrugated Steel under Lateral Load Reversals". Advances in Structural Engineering 3, n. 3 (luglio 2000): 255–62. http://dx.doi.org/10.1260/1369433001502184.

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Reinforced concrete buildings with shearwalls are very efficient to resist earthquake disturbances. In general, reinforced concrete frames are governed by flexure and low-rise shearwalls are governed by shear. If a structure includes both frames and shearwalls, it is generally governed by shearwalls. However, the ductility of ordinary reinforced concrete framed shearwalls is very limited. The experiments on framed shearwalls made of corrugated steel was recently reported. It was found that the ductility of framed shearwalls can be greatly improved if the thickness of the corrugated steel wall is appropriate to the surrounding reinforced concrete frame. If the thickness of the corrugated steel wall is too large when compared to the surrounding frame, the ductility will be reduced. It is shown in this paper that the fiber-reinforced plastic composites can be used to strengthen the critical regions of the reinforced concrete frames, so that the seismic behavior (including ductility and energy dissipation capability) is greatly improved.

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Hosen, Md Akter, Mahaad Issa Shammas, Sukanta Kumer Shill, Safat Al-Deen, Mohd Zamin Jumaat e Huzaifa Hashim. "Ductility Enhancement of Sustainable Fibrous-Reinforced High-Strength Lightweight Concrete". Polymers 14, n. 4 (14 febbraio 2022): 727. http://dx.doi.org/10.3390/polym14040727.

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To limit the cross-sectional size of concrete structures, high-strength, lightweight concrete is preferred for the design and construction of structural elements. However, the main drawback of high-strength, lightweight concrete is its brittleness over normal-weight concrete. The ductility of concrete is a crucial factor, which plays an important role when the concrete structures are subjected to extreme situations, such as earthquakes and wind. This study aims to improve the ductility of high-strength, lightweight concrete by incorporating steel fibers. The palm oil clinker (POC)-based, high-strength, lightweight concrete specimens reinforced with steel fibers were prepared and their ductility was systematically examined. POC was used as aggregates and supplementary cementitious materials. Steel fibers from 0–1.50% (by volume), with an increment of 0.5%, were used in the concrete mix. Compression ductility, displacement ductility and energy ductility were used as indicators to evaluate the enhancement of ductility. Moreover, the compressive strength, flexural strength, stress-strain behavior, modulus of elasticity, load-displacement characteristics, energy absorption capacity and deformability of the concrete samples were investigated. The compression ductility, displacement ductility and energy ductility indexes were found to be increased by up to 472%, 140% and 568% compared to the control specimens (concrete with 0% steel fibers), respectively. Moreover, the deformability and energy absorption capacity of the concrete were increased by up to 566% and 125%, respectively. Therefore, POC-based, high-strength, fibrous, lightweight concrete could perform better than conventional concrete under extreme loading conditions as it showed significantly higher ductility.

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Bai, Z. Z., e F. T. K. Au. "Ductility of symmetrically reinforced concrete columns". Magazine of Concrete Research 61, n. 5 (giugno 2009): 345–57. http://dx.doi.org/10.1680/macr.2008.00149.

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Du, Chuang, Xiao Ming Yang e Ning Li Li. "Performance Analysis of Concrete-Filled Steel Tube Column and Reinforced Concrete Column under Axial Compression". Advanced Materials Research 446-449 (gennaio 2012): 82–85. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.82.

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In this paper, a comparative investigation into the behavior of concrete-filled steel tube column and reinforced concrete column with the same quantity of material and cross-section sizes under axial load have been undertaken using the finite element method. Both is analyzed to compare the axial compression performance,including bearing capacity, ductility and their mechanism. The results of the analyses clearly exhibit that bearing capacity of concrete-filled steel tube column is higher about 25% than that of reinforced concrete column. Under the same conditions, ductility of concrete-filled steel tube column is better than reinforced concrete column, its application is recommended in construction practice.

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Xiang, Ping, ZH Deng, YS Su, HP Wang e YF Wan. "Experimental investigation on joints between steel-reinforced concrete T-shaped column and reinforced concrete beam under bidirectional low-cyclic reversed loading". Advances in Structural Engineering 20, n. 3 (29 luglio 2016): 446–60. http://dx.doi.org/10.1177/1369433216653841.

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Steel-reinforced concrete T-shaped column-beam structure system has superiorities of both steel-reinforced structure and special-shaped column structure. This research focuses on steel-reinforced concrete T-shaped column-beam joint design and experimentally investigates seismic behaviors of the proposed joints. Pseudo-static tests are carried out on three steel-reinforced concrete T-shaped column-reinforced concrete beam joints and one reinforced concrete T-shaped column-reinforced concrete beam joint. The experiments were conducted under bidirectional low-cyclic reversed loading to simulate realistic loading conditions under earthquake. Hysteresis loops of all the specimens, including load–deflection, moment–rotation, and load–shear deformation loops, are plotted for the evaluation of seismic reaction. The working index, ductility coefficient, and equivalent viscous-damping coefficient are calculated for comparisons. Meanwhile, the ductility, capacity of energy dissipation, stiffness degradation, and the function of steel reinforcement in resisting shear force in the joint core area are intensively studied. Based on experimental results, this research analyzes shear-resistant capacity and the inner force transmission in these joints. It is found that the steel-reinforced concrete T-shaped column-reinforced concrete beam joint performs well under seismic conditions; moreover, shear-resistant capacity, ductility, and reliability are satisfactory. Conclusions derived from this research are useful for engineering practice.

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Renić, Tvrtko, e Tomislav Kišiček. "Ductility of Concrete Beams Reinforced with FRP Rebars". Buildings 11, n. 9 (21 settembre 2021): 424. http://dx.doi.org/10.3390/buildings11090424.

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Concrete beams reinforced with FRP rebars have greater durability than standard steel reinforced elements. The main disadvantage of using FRP rebars is the low ductility of elements which may be unacceptable in certain situations. There are several different ways of increasing the ductility of concrete elements, which are analyzed in this paper. They are compared based on efficiency, influence on durability and ease of construction. Less analyzed and tested methods are given more attention to try and expand the current knowledge and possibilities. For methods that lack experimental data, theoretical analysis is undertaken to assess the possible influence of that method on the increase in ductility. Ductility was obtained by calculating bending moment–curvature diagrams of cross sections for different reinforcement layouts. One method that lacks experimental data is confining the compressive area of beams with tensile FRP reinforcement. Theoretical analysis showed that confining the compressive area of concrete can significantly increase the ductility and bending capacity of beams. Since experimental data of beams reinforced with FRP rebars in tension and confined compressive area is sparse, some suggestions on the possible test setups are given to validate this theoretical analysis. Concrete beams reinforced with FRP can be detailed in such a way that they have sufficient ductility, but additional experimental research is needed.

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Kuang, J. S., e A. I. Atanda. "Enhancing ductility of reinforced concrete frame buildings". Proceedings of the Institution of Civil Engineers - Structures and Buildings 158, n. 4 (agosto 2005): 253–65. http://dx.doi.org/10.1680/stbu.2005.158.4.253.

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8

Alzeebaree, Radhwan, Abdulkadir Çevik, Alaa Mohammedameen, Anıl Niş e Mehmet Eren Gülşan. "Mechanical performance of FRP-confined geopolymer concrete under seawater attack". Advances in Structural Engineering 23, n. 6 (14 novembre 2019): 1055–73. http://dx.doi.org/10.1177/1369433219886964.

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In the study, mechanical properties and durability performance of confined/unconfined geopolymer concrete and ordinary concrete specimens were investigated under ambient and seawater environments. Some of the specimens were confined by carbon fiber and basalt fiber–reinforced polymer fabric materials with one layer and three layers under chloride and ambient environments to observe mechanical strength contribution and durability performances of these hybrid types of materials. These fiber-reinforced polymer fabric materials were also evaluated in terms of retrofit purposes especially in the marine structures. In addition, microstructural evaluation is also conducted using scanning electron microscope on geopolymer concrete and ordinary concrete specimens to observe the amount of deterioration in microscale due to the chloride attacks. Results indicated that confined specimens exhibited enhanced strength, ductility, and durability properties than unconfined specimens, and the degree of the enhancement depended on the fiber-reinforced polymer confinement type and the number of fiber-reinforced polymer layer. Specimens confined by carbon fabrics with three layers showed superior mechanical properties and durability performance against chloride attack, while specimens confined by basalt fabrics with one layer exhibited low performance, and unconfined specimens showed the worst performance. Both fiber-reinforced polymer fabric materials can be utilized as retrofit materials in structural elements against chloride attacks. The results also pointed out that seawater attack reduced the ductility performance of the geopolymer concrete and ordinary concrete specimens. Furthermore, geopolymer concrete specimens were found more durable than the ordinary concrete specimens, and both types of concretes exhibited similar fracture properties, indicating that geopolymer concrete can be utilized for structural elements instead of ordinary concretes.

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Yuan, Huang, Huan-Peng Hong, Huang Deng e Yu Bai. "Displacement ductility of staged construction-steel tube-reinforced concrete columns". Construction and Building Materials 188 (novembre 2018): 1137–48. http://dx.doi.org/10.1016/j.conbuildmat.2018.08.141.

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Kwan, A. K. H., J. C. M. Ho e H. J. Pam. "Flexural strength and ductility of reinforced concrete beams". Proceedings of the Institution of Civil Engineers - Structures and Buildings 152, n. 4 (novembre 2002): 361–69. http://dx.doi.org/10.1680/stbu.2002.152.4.361.

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11

ZOUZOU, A., e D. HALDANE. "DETAILING REINFORCED CONCRETE CLOSING CORNER JOINTS FOR DUCTILITY." Proceedings of the Institution of Civil Engineers - Structures and Buildings 99, n. 1 (febbraio 1993): 43–48. http://dx.doi.org/10.1680/istbu.1993.22508.

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12

Tann, D. B., R. Delpak e P. Davies. "Ductility and deformability of fibre-reinforced polymer-strengthened reinforced concrete beams". Structures Buildings 157, n. 1 (gennaio 2004): 19–30. http://dx.doi.org/10.1680/stbu.157.1.19.36407.

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Tann, D. B., R. Delpak e P. Davies. "Ductility and deformability of fibre-reinforced polymer-strengthened reinforced concrete beams". Proceedings of the Institution of Civil Engineers - Structures and Buildings 157, n. 1 (gennaio 2004): 19–30. http://dx.doi.org/10.1680/stbu.2004.157.1.19.

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14

De Lorenzis, L., D. Galati e A. La Tegola. "Stiffness and ductility of fibre-reinforced polymer-strengthened reinforced concrete members". Proceedings of the Institution of Civil Engineers - Structures and Buildings 157, n. 1 (gennaio 2004): 31–51. http://dx.doi.org/10.1680/stbu.2004.157.1.31.

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15

Pei, Weichang, Daiyu Wang, Xuan Wang e Zhenyu Wang. "Axial monotonic and cyclic compressive behavior of square GFRP tube–confined steel-reinforced concrete composite columns". Advances in Structural Engineering 24, n. 1 (20 luglio 2020): 25–41. http://dx.doi.org/10.1177/1369433220934557.

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Fiber-reinforced polymer tube–confined steel fiber–reinforced concrete column is a novel composite column proposed recently, which consists of a traditional steel-reinforced concrete column and an external glass fiber–reinforced plastic tube for lateral confinement. In order to investigate the axial compression behavior of steel fiber–reinforced concrete columns, a total of 16 square specimens were fabricated and tested under axial monotonic and cyclic compressive loading. Three different configurations of inner shaped steels, including cross-shaped, box-shaped with wielding, and box-shaped without wielding were considered. Two thicknesses of glass fiber–reinforced concrete tubes were also considered as the main experimental parameters. On the basis of test results, a thorough analysis of the failure process based on strain analysis was discussed. The test results showed that steel fiber–reinforced concrete columns exhibited higher ductility and load capacity compared with fiber-reinforced plastic–confined plain concrete columns. Two quantitative indexes were proposed to measure the confinement of steel fiber–reinforced concretes. The axial cyclic mechanical behaviors were discussed through comparative analysis with monotonic behaviors. The remnant strains and modulus of the cyclic behaviors were also discussed.

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Oehlers, Deric J., M. S. Mohamed Ali e Michael C. Griffith. "Concrete Component of the Rotational Ductility of Reinforced Concrete Flexural Members". Advances in Structural Engineering 11, n. 3 (giugno 2008): 281–91. http://dx.doi.org/10.1260/136943308785082571.

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17

Kim, Min Sook, e Young Hak Lee. "Flexural Behavior of Reinforced Concrete Beams Retrofitted with Modularized Steel Plates". Applied Sciences 11, n. 5 (6 marzo 2021): 2348. http://dx.doi.org/10.3390/app11052348.

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Many structural retrofitting methods tend to only focus on how to improve the strength and ductility of structural members. It is necessary for developing retrofitting strategy to consider not only upgrading the capacity but also achieving rapid and economical construction. In this paper, a new retrofitting details and technique is proposed to improve structural capacity and constructability for retrofitting reinforced concrete beams. The components of retrofitting are prefabricated, and the components are quickly assembled using bolts and chemical anchors on site. The details of modularized steel plates for retrofitting have been chosen based on the finite element analysis. To evaluate the structural performance of concrete beams retrofitted with the proposed details, five concrete beams with and without retrofitting were tested. The proposed retrofitting method significantly increased both the maximum load capacity and ductility of reinforced concrete beams. The test results showed that the flexural performance of the existing reinforced concrete beams increased by 3 times, the ductility by 2.5 times, and the energy dissipation capacity by 7 times.

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Xue, Jianyang, Lei Zhai, Yuze Bao, Rui Ren e Xicheng Zhang. "Seismic behavior of steel-reinforced recycled concrete inner-beam–column connection under low cyclic loads". Advances in Structural Engineering 21, n. 5 (16 agosto 2017): 631–42. http://dx.doi.org/10.1177/1369433217723413.

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This article presents the results of low cyclic loading tests on steel-reinforced recycled concrete inner-beam–column connections, including four 1:2.5 scaled specimens with different replacement rates of recycled coarse aggregates. The main objective of this study is to evaluate the seismic behavior of steel-reinforced recycled concrete inner-beam–column connection based on the seismic tests of the four specimens under low cyclic loads with vertical axial force. The main design parameter of the beam–column connections in this research is the recycled coarse aggregate replacement percentage. The crack status, failure modes, hysteresis loops, skeleton curves, energy dissipation, capacity stiffness of degradation, and ductility of steel-reinforced recycled concrete inner-beam–column connections are presented and analyzed. The results indicate that the main failure pattern of the steel-reinforced recycled concrete inner-beam–column connection is the shearing diagonal compression in the beam–column connection zone. As the recycled aggregate replacement percentage increases, both the bearing capacity and ductility of the steel-reinforced recycled concrete beam–column connections decrease to some extent. However, the seismic behavior of the steel-reinforced recycled concrete inner-beam–column connection does not degrade significantly compared with the ordinary steel-reinforced concrete beam–column connection.

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Li, Jun-Tao, Zong-Ping Chen, Jin-Jun Xu, Cheng-Gui Jing e Jian-Yang Xue. "Cyclic behavior of concrete-filled steel tubular column–reinforced concrete beam frames incorporating 100% recycled concrete aggregates". Advances in Structural Engineering 21, n. 12 (7 febbraio 2018): 1802–14. http://dx.doi.org/10.1177/1369433218755521.

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Concrete-filled steel tubular structural members can be recognized as an effective mean to improve the mechanical behavior in terms of strength, stiffness, ductility, and energy dissipation for the initial recycle aggregate concrete deficiencies compared with natural aggregate concrete. A small-scale model of square concrete-filled steel tubular column–reinforced concrete beam frame realized employing 100% recycled coarse aggregates was tested under combined axial loads and cyclic reversed lateral flexure. The failure modes, plastic hinges sequence, hysteresis loop, skeleton curve, stiffness degeneration, energy dissipation capacity, and ductility of the frame were presented and analyzed in detail. The structural behavior of square concrete-filled steel tubular column–reinforced concrete beam frame with 100% recycled coarse aggregates was compared with circular concrete-filled steel tubular column–reinforced concrete beam frame made with 100% recycled coarse aggregates. A fiber-based program model for the nonlinear analysis of concrete-filled steel tubular column–reinforced concrete beam frames incorporating recycled coarse aggregates was developed using SeismoStruct, to highlight the effect of recycled coarse aggregate content on mechanical behavior of recycled aggregate concrete and the confinement effect provided by outer tubes on core concrete. The analysis results show that the numerical model can well simulate and predict the seismic behavior of concrete-filled steel tubular column–reinforced concrete beam frames with 100% recycled coarse aggregate content. Both experimental and numerical results demonstrate that concrete-filled steel tubular column–reinforced concrete beam frames with large content of recycled coarse aggregates have a receivable seismic performance, and it is feasible to apply and popularize recycled aggregate concrete into concrete-filled steel tubular structures in seismic regions.

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More, Florence More Dattu Shanker, e Senthil Selvan Subramanian. "Experimental Investigation on the Axial Compressive Behaviour of Cold-Formed Steel-Concrete Composite Columns Infilled with Various Types of Fibre-Reinforced Concrete". Buildings 13, n. 1 (6 gennaio 2023): 151. http://dx.doi.org/10.3390/buildings13010151.

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The exceptional structural strength and low cost of steel-concrete composite columns make them a popular choice for civil engineering structures. Numerous forms of composite columns, including steel tubes filled with concrete, have been produced recently in response to various construction situations. Cold-formed steel tubular columns with concrete filling have higher strength and ductility due to their capacity to withstand inner buckling and postpone outward buckling. The objective of this research is to determine the ductile and strength performance of composite columns containing various forms of fibre-reinforced concrete when subjected to axial compression. Several different kinds of fibre-reinforced concrete (FRC) are employed as additives in hollow steel columns, including steel FRC, carbon FRC, glass FRC, coir FRC, jute FRC, and sisal FRC. Axial compression tests were performed on 24 columns, including three hollow steel columns and 21 composite columns. Three distinct slenderness ratios were developed and used. Axial bearing capacity, compressive stress-strain curves, ductility, peak strain, axial shortening, and toughness were among the topics covered by the axial compression test. Experimental findings demonstrated that all conventional composite columns experienced failure through overall buckling, Local buckling and crushing of concrete infill, which was transformed into more ductile failure using fibre-reinforced concrete infills. The test results revealed that fibre-reinforced concrete-infilled steel columns outperformed conventional composite columns in terms of strength, ductility, and energy absorption capacity. The percentage increase in load-carrying capacity was observed as 203.88%, 193.48% and 190.03% when compared to hollow cold-formed steel tubular columns in stub, short and medium columns, respectively. Under assessment of stub, short, and medium columns, the load-strain plots demonstrated that the steel fibre-reinforced concrete in-filled columns performed well in terms of ductility. Localized buckling and crushing of the concrete infill caused the composite columns with low slenderness ratios to fail. In contrast, concrete-filled steel tube columns with higher slenderness ratios showed column failure through the overall buckling of the composite column.

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Whitehead, P. A., e T. J. Ibell. "Deformability and ductility in over-reinforced concrete structures". Magazine of Concrete Research 56, n. 3 (aprile 2004): 167–77. http://dx.doi.org/10.1680/macr.2004.56.3.167.

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Hou, Hetao, Weiqi Fu, Canxing Qiu, Jirun Cheng, Zhe Qu, Wencan Zhu e Tianxiang Ma. "Effect of axial compression ratio on concrete-filled steel tube composite shear wall". Advances in Structural Engineering 22, n. 3 (28 agosto 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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Safitri, Endah, Iswandi Imran, Nuroji e Sholihin Asa'ad. "The Effect of Steel Ring Width Variations as the External Confinement on Load-Moment Interaction Behavior of Reinforced Concrete Column". Applied Mechanics and Materials 845 (luglio 2016): 188–92. http://dx.doi.org/10.4028/www.scientific.net/amm.845.188.

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Nowaday, we require higher capacity and ductility of structural member particulary in reinforced concret column in construction world. One way to improve the ductility and carrying capacity of concrete is confining the concrete. To investigate the effects of external confinement on column capacity, an analytical study is carried out. A steel ring external confinement is used in this study. The stress-strain diagrams design for confined concrete are developed by considering different proposed confined models based on width variations of the steel ring. The test results showed that steel ring are effective as external confinement in confining the concrete. Capability of concrete to support load simultaneously is increasing along the width of the ring. Its effect on column capacity is studied in terms of load – moment interaction diagram of column. The presence of external reinforcement expands the interaction diagram of the column particularly when it is in the compression-controlled region.

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Raghuraman, N. "PREDICTION OF HIGH-PERFORMANCE FIBERREINFORCED POLYMER CONCRETE USING FUZZY NEURAL NETWORK PROTOTYPES". YMER Digital 21, n. 01 (13 gennaio 2022): 192–205. http://dx.doi.org/10.37896/ymer21.01/18.

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RC building elements of Reinforcing and upgrading is essential to extend its maintenance time, to overcome first structural limitations, and to control the consequence of building construction or design flaws. The RC constructions are reinforced by using the FRP-fiber reinforced polymer. This study utilizes the FRP in concrete structures for instance a Jute, coir, and Sisal is explored for its reliability in improving ductility and strength related structural performance. FRP structural response of the model parameters is studied by measuring the numerical and experimental terms, for instance, Ductility, Deflection, Tensile-Strength, and Compression-Strength. The quality of the sample specimens is tested by using the Fuzzy Neural Network (FNN) system. At this time, compared with existing jobs, the propounded Fuzzy Neural Network model accomplishes the best presentation regarding all boundaries for the fiberreinforced specimen over different stacked conditions

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El-Kashif, Khaled Farouk Omar, Abdel-Rahman Hazem, Mohamed Ahmed Rozik e Hany Ahmed Abdalla. "Strengthening of deficient reinforced concrete columns subjected to concentric and eccentric loads". Advances in Structural Engineering 23, n. 7 (19 dicembre 2019): 1322–35. http://dx.doi.org/10.1177/1369433219895358.

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In this research, different techniques of repair of deficient reinforced concrete columns are compared. These include carbon fiber–reinforced polymer sheets, steel jackets, and reinforced concrete jackets. The experimental investigation includes testing of 16 deficient columns of dimensions 150 × 150 × 800 mm subjected to concentric and eccentric loading up to failure. Two main variables are considered: the load eccentricity and the strengthening technique. The experimental results showed that the three strengthening techniques used in this research significantly improved the ultimate load carrying capacity in all cases of loading. Also, in the two cases of concentric loading and big eccentricity of 150 mm, carbon fiber–reinforced polymer wrapping achieved the highest ductility and absorbed energy capacity. In addition, strengthening with reinforced concrete jacket improved the initial stiffness and toughness. The cracking load, ultimate load, and ductility of the deficient columns after strengthening were experimentally recorded and compared. The results can help the structural engineer to consider the most efficient method of repair for such columns.

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Hussein, Omar H., Amer M. Ibrahim, Suhad M. Abd, Hadee Mohammed Najm, Saba Shamim e Mohanad Muayad Sabri Sabri. "Hybrid Effect of Steel Bars and PAN Textile Reinforcement on Ductility of One-Way Slab Subjected to Bending". Molecules 27, n. 16 (15 agosto 2022): 5208. http://dx.doi.org/10.3390/molecules27165208.

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Textile reinforced concrete (TRC) has gained attention from the construction industry due to several characteristics such as its lightweight, high tensile strength, design flexibility, corrosion resistance and remarkably long service life. Some structural applications that utilize TRC components include precast panels, structural repairs, waterproofing elements and façades. TRC is produced by incorporating textile fabrics into thin cementitious concrete panels. However, in order to use this strengthening method in construction practice, a design model is required. Investigating the combined effect of conventional steel and textile reinforcement on the ductility behavior of composite TRC/RC one-way slab is vitally important. Therefore, the current study describes the proper methods of calculating the ductility of the composite concrete reinforced by a direct combination of conventional steel and textile reinforcement. Four methods are presented to calculate the ductility of the three considered one-way slab specimens. The three slabs having dimensions 1500 mm × 500 mm × 50 mm were reinforced by steel bars (SRC), by steel with one layer of carbon fabric (SRC + 1T), and by steel with two layers of carbon fabric (SRC + 2T). The three slab specimens were cast by the hand lay-up method, removed from the molds, cured, and then tested in flexure after 28 days using the four-point bending method. The obtained results and calculations revealed the non-reasonability of using the conventional method based on yielding of steel reinforcement as the only criterion in the ductility determination. The results also confirmed the suitability of using the energy-based method over other discussed methods in the calculation of the ductility for the hybrid reinforced members.

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Masood M.M. Irheem, Omar A. El-Nawawy, Hatem H. Gheith e Ayman S. Abo-Beah. "The Flexural Ductility Behavior of Reinforced Concrete Beams with Tension Lap Splices Exposed to Fire". Electronic Journal of Structural Engineering 18, n. 2 (1 giugno 2018): 37–51. http://dx.doi.org/10.56748/ejse.182622.

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Based on a comprehensive review of both previous studies and implemented practices in the field of construction structures, it’s obvious that reinforcing steel bar’s length is limited. Consequently, lap-splices are commonly used in reinforced concrete (RC) structures to solve such problem. Generally, in the design process,safety and serviceability must be satisfied. In essence, in beams with lap splices it’s important to check the ductility, since some variables as fire of RC beams can change the behavior. The present paper aims to validate the effect of fire on the flexural ductility behavior of reinforced concrete beam with lap splice. An experimentaltest Program of thirteen simply supported RC beams with lap-splices were designed, cast and tested in laboratory. The main selected variables are: concrete cover, temperature and fire exposure duration. Results show that; under fire effect with different concrete cover, duration and temperature over the lap-splices zone has major effects on the ductility of RC beams. As, the ductility of beams decreases when the temperature and fire duration increases. Furthermore, ductility of RC beams increases as concrete cover increases under similar conditions. Collectively,this study shows that the fire has a major effect on the bond strength of lap-spliced RC beams and ductility has different behavior when compared with non-fired beam. Consequently, codes have to take fire effects on the lapsplice in design process.

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Skogman, Brian C., Maher K. Tadros e Ronald Grasmick. "Ductility of Reinforced and Prestressed Concrete Flexural Members". PCI Journal 33, n. 6 (1 novembre 1988): 94–107. http://dx.doi.org/10.15554/pcij.11011988.94.107.

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Lv, Yang, Xueqian Wu, Mengran Gao, Jiaxin Chen, Yuhao Zhu, Quanxi Cheng e Yu Chen. "Flexural Behavior of Basalt Fiber Reinforced Polymer Tube Confined Coconut Fiber Reinforced Concrete". Advances in Materials Science and Engineering 2019 (3 febbraio 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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30

Leung, H. Y., e R. V. Balendran. "Flexural behaviour of concrete beams internally reinforced with GFRP rods and steel rebars". Structural Survey 21, n. 4 (1 ottobre 2003): 146–57. http://dx.doi.org/10.1108/02630800310507159.

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Use of fibre‐reinforced polymer (FRP) composite rods, in lieu of steel rebars, as the main flexural reinforcements in reinforced concrete (RC) beams have recently been suggested by many researchers. However, the development of FRP RC beam design is still stagnant in the construction industry and this may be attributed to a number of reasons such as the high cost of FRP rods compared to steel rebars and the reduced member ductility due to the brittleness of FRP rods. To resolve these problems, one of the possible methods is to adopt both FRP rods and steel rebars to internally reinforce the concrete members. The effectiveness of this new reinforcing system remains problematic and continued research in this area is needed. An experimental study on the load‐deflection behaviour of concrete beams internally reinforced with glass fibre‐reinforced polymer (GFRP) rods and steel rebars was therefore conducted and some important findings are summarized in this paper.

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31

Zhu, Zhenyu, Iftekhar Ahmad e Amir Mirmiran. "Effect of Column Parameters on Axial Compression Behavior of Concrete-Filled FRP Tubes". Advances in Structural Engineering 8, n. 4 (agosto 2005): 443–49. http://dx.doi.org/10.1260/136943305774353098.

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Abstract (sommario):

Axial compression tests have shown fiber reinforced polymer (FRP) tubes to significantly enhance both strength and ductility of concrete columns. However, most experiments and associated models typically do not account for the internal reinforcement, size effect of the column, and the end load-bearing conditions of the tube. An experimental program was undertaken to evaluate the effect of these parameters on the performance of CFFT columns. Glass FRP tubes filled with plain, steel-reinforced, and glass FRP-reinforced concrete were tested with and without end grooves, which would prevent the tube from directly bearing of the axial load. The experiments showed the dowel action of the internal reinforcement to improve the ductility of the columns by restraining the lateral dilation of concrete core. Anempirically derived confinement model, augmented with the stress-strain response of the internal reinforcement, showed close agreement with test results.

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32

Elbasha, Nuri Mohamed. "Reinforced HSC Beams". Key Engineering Materials 629-630 (ottobre 2014): 544–50. http://dx.doi.org/10.4028/www.scientific.net/kem.629-630.544.

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Abstract (sommario):

The primary long and short term advantages of high strength concrete are, low creep and shrinkage, higher stiffness, higher elastic modulus, higher tensile strength, higher durability (resistance to chemical attacks) and higher shear resistance. In addition, high strength concrete reduces the size of the member, which in turn reduces the form size, concrete volume, construction time, labor costs and dead load. Reducing the dead load reduces the number and size of the beams, columns and foundations. Thus there is a positive impact on reduction of maintenance and repair costs and an increase in rentable space. Other, yet to be discovered advantages may also exist. High strength concrete has definite advantages over normal strength concrete. The ductility of over reinforced HSC beams is enhanced through the application of helical reinforcement located in the compression region. The pitch of helix is an important parameter controlling the level of strength and ductility enhancement. This paper presents an experimental investigation of the effect of helices on the behavior of over reinforced high strength concrete beams through testing ten helically confined full scale beams. The helix pitches were 25, 50, 75, 100 and 160 mm. Beams’ cross section was 200×300 mm, and with a length of 4 m and a clear span of 3.6 m subjected to four point loading. The main results indicate that helix effectiveness is negligible when the helical pitch is 160 mm (helix diameter). The experimental program in this study proved that the HSC, HSS and helical confinement construct a reinforced concrete beam. This beam has the ability to resist weathering action and chemical attack while maintaining its desired engineering properties. In near future Reinforced High Strength Concrete Beam with Helical Confinement will be considered as a durable and sustainable Reinforced Concrete Beam.

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Sorace, Stefano, e Gloria Terenzi. "Innovative Structural Solutions for Prefab Reinforced Concrete Hall-Type Buildings". Open Construction and Building Technology Journal 13, n. 1 (29 luglio 2019): 149–63. http://dx.doi.org/10.2174/18748368019130149.

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Background:The anti-seismic design of prefab reinforced concrete buildings is usually carried out with a conventional ductility-based approach. This implies a remarkable plastic demand on columns, as well as damages to the connections of structural and non-structural members, for seismic events with comparable intensity to the basic design earthquake normative level.Objective:In view of this, a study was developed and aimed at extending to the field of new prefab reinforced concrete structures the application of advanced seismic protection strategies, capable of guaranteeing undamaged response up to the maximum considered earthquake normative level.Method:A benchmark building was designed as demonstrative case study for this purpose, in the three following hypotheses: (a) according to a traditional ductility-based approach; (b) by incorporating dissipative bracings, equipped with fluid viscous dampers; (c) by placing a seismic isolation system at the base, composed of a set of double curved surface sliders.Results:The results of the verification analyses show that the targeted performance for the design solutions b) and c) is obtained with sizes of columns and plinths notably smaller than those for the conventional design. This allows compensating the additional cost related to the incorporation of the protective devices, for the dissipative bracing system, and limiting additional costs below 25%, for the base isolation solution. At the same time, a supplemental benefit of the latter is represented by greater protection of contents and plants, as they are fully supported by the seismically isolated ground floor.Conclusion:The study highlights the advantages offered by the two advanced seismic protection technologies in an unusual field of application, guaranteeing an enhanced performance of structural and non-structural elements, as well as reduced member sizes, as compared to the traditional ductility-based design.

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Tang, Wei Min, Xiao Bing Li, Lin Zhu Sun, Guo Ping Jin, Zhao Hui Li e Qing Hua Zhang. "Experimental Study on Anti-Seismic Restoration of Rowlock Walls". Advanced Materials Research 163-167 (dicembre 2010): 3787–93. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.3787.

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Based on pseudo-static test of rowlock wall with different constructional measures by MTS loading system, the position of initial crack, distribution of crack, cracking load, failure load, failure state are studied, in order to provide test basis for the determination of economical and effective construction measures for rowlock wall. The test results show that the cracking load and failure load of rowlock wall reinforced with constructional column and tie bar, or with constructional column and horizontal reinforced concrete band,were increased significantly compared with rowlock wall without reinforcement measure. The reinforced rowlock wall has better ductility, whereas rowlock walls without reinforcement measure show obvious brittleness.

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Zhao, Yajun, Yimiao Huang, Haiyang Du e Guowei Ma. "Flexural behaviour of reinforced concrete beams strengthened with pre-stressed and near surface mounted steel–basalt-fibre composite bars". Advances in Structural Engineering 23, n. 6 (2 dicembre 2019): 1154–67. http://dx.doi.org/10.1177/1369433219891595.

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Fibre-reinforced polymer bars have been widely used for strengthening concrete members due to their high strength, light weight and strong corrosion resistance. A near-surface mounted strengthening system has been adopted to protect the fibre-reinforced polymer bars from external hazards. To make up the lower stiffness and ductility of fibre-reinforced polymer bar compared to steel rebar, this study proposed to use a pre-stressed near-surface mounted steel–basalt-fibre-reinforced polymer composite bar. The steel–basalt-fibre-reinforced polymer composite bar is manufactured through wrapping a steel rod by a basalt-fibre-reinforced polymer cover. A total of nine reinforced concrete beams, including one control or calibration and eight others strengthened by pre-stressed near-surface mounted steel–basalt-fibre-reinforced polymer composite bars, are fabricated and tested. Results show that the proposed steel–basalt-fibre-reinforced polymer composite bar strengthening method can improve both the strength and ductility of the reinforced concrete beams. Pre-stressing of the steel–basalt-fibre-reinforced polymer composite bars further increases substantially the beams’ load-carrying capacity by restraining crack propagation in concrete. Standard-based load analysis correctly predicts the cracking load, however, underestimates the ultimate strength of the beams. Finite element method modelling is conducted to provide a more effective load-carrying capacity prediction and a case study is carried out with regard to the amount of the strengthening steel–basalt-fibre-reinforced polymer composite bars.

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Demakos, Constantinos B., Constantinos C. Repapis e Dimitros P. Drivas. "Experimental Investigation of Shear Strength for Steel Fibre Reinforced Concrete Beams". Open Construction & Building Technology Journal 15, n. 1 (19 maggio 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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Cai, Chuan Guo, Zhong Xuan Wei e Xu Pu Yang. "An Experimental Study on Ductility of Fiber-Strengthening Concrete". Advanced Materials Research 535-537 (giugno 2012): 1907–12. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.1907.

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Abstract: In view of the mass brittle failures of reinforced concrete construction in Whenchuan earthquake, the ductility of construction was selected to be the research object. A group of the cyclic-loading experiment was carried out on seven shear-and-pressure concrete columns which mixed with different fiber types and various volume content, but same cross-section and reinforcement. In the process, the load-displacement curves of the columns were attained and the skeleton curves accordingly were drawn, together with the key values in various stages. Based on these, an analysis on various factors which affect the ductility of the columns is conducted. The results show that the ductility of columns is improved significantly and the appearance of plastic hinge is delayed, which are likely to avoid the occurrence of brittle failure in earthquake. The experimental result indicates the steel fiber-strengthening concrete possesses the strongest energy dissipation capacity, the carbon fiber improve ductility of the column, and the synthetic fibers can effectively delay emergence of the plastic hinge, but a lesser extent to improve the shear capacity of the column.

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38

Wang, Tao, Xi Chen, Wen Feng Li e Qi Song Miao. "Seismic Performance of Masonry Buildings Retrofitted by Pre-Cast RC Panels". Applied Mechanics and Materials 166-169 (maggio 2012): 1811–17. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.1811.

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Abstract (sommario):

Proposed in this study is a retrofitting technology that can be applied on exiting masonry buildings. It employs pre-cast reinforced concrete panels to confine existing masonry structure. The pre-cast members constitute a frame which encomprises the existing building. The confinement effectively improves the ductility, strength, and stiffenss of masonry structures. Moreover, the reinforced concrete panels are fabricated in factory, significantly reduces the situ construction and construction period. To demonstrate the design theory, construction organization, and seismic performance of the retrofitted structure, a full-scale structure was tested physically. Pseudo-dynamic testing results indicate the feasibilty and effectiveness of the proposed retrofitting technology.

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39

Tonkikh, Gennady, e D. Chesnokov. "The influence of the shear connectors ductility on the seismic resistance of composite steel-concrete floors". Earthquake Engineering. Construction Safety, n. 4 (25 agosto 2021): 28–35. http://dx.doi.org/10.37153/2618-9283-2021-4-28-35.

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Abstract (sommario):

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.

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40

Yang, Yang, Ze-Yang Sun, Gang Wu, Da-Fu Cao e Zhi-Qin Zhang. "Flexural capacity and design of hybrid FRP-steel-reinforced concrete beams". Advances in Structural Engineering 23, n. 7 (17 dicembre 2019): 1290–304. http://dx.doi.org/10.1177/1369433219894236.

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Abstract (sommario):

This study presents a design method for hybrid fiber-reinforced-polymer-steel-reinforced concrete beams by an optimized analysis of the cross section. First, the relationships among the energy consumption, the bearing capacity, and the reinforcement ratio are analyzed; then, the parameters of the cross section are determined. Comparisons between the available theoretical and experimental results show that the designed hybrid fiber-reinforced-polymer-steel-reinforced concrete beams with a low area ratio between the fiber-reinforced polymer and the steel reinforcement could meet the required carrying capacity and exhibited high ductility.

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41

Whitehead, P. A., T. J. Ibell e N. W. Roberts. "Dicussion: Deformability and ductility in over-reinforced concrete structures". Magazine of Concrete Research 58, n. 7 (settembre 2006): 485–86. http://dx.doi.org/10.1680/macr.2006.58.7.485.

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42

Essawy, Ahmed Sherif, e Moetaz El-Hawary. "Strength and ductility of spirally reinforced rectangular concrete columns". Construction and Building Materials 12, n. 1 (aprile 1998): 31–37. http://dx.doi.org/10.1016/s0950-0618(97)00071-8.

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43

Yan, Xi Kang, Kang Ma, Cheng Dong, Lei Wang e Pei Chen. "Study on Seismic Performance of a Two-Bay Two-Story RCF with Construction Joint under Low-Reversed Cyclic Loading". Advanced Materials Research 753-755 (agosto 2013): 719–23. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.719.

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Abstract (sommario):

Based on experiment of a two-bay two-story reinforced concrete frame with construction joint under low-reversed cyclic loading, hysteretic performance, displacement ductility, bearing capacity degeneration, rigidity degeneration, energy dissipation and displacement restoring capacity are studied systematically. The studies show that the frame with construction joint has not better seismic performance than the monolithic cast frame.

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Chen, Weihong, Kai Feng, Ying Wang, Shuangshuang Cui e Yiwang Lin. "Seismic Performance of a Novel Precast Beam-Column Joint Using Shape Memory Alloy Fibers-Reinforced Engineered Cementitious Composites". Buildings 12, n. 9 (7 settembre 2022): 1404. http://dx.doi.org/10.3390/buildings12091404.

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Abstract (sommario):

A novel precast beam–column joint using shape memory alloy fibers-reinforced engineered cementitious composites (SMA-ECC) was proposed in this study to achieve self-repairing of cracks and internal damage after an earthquake. Three large-scale beam–column joints were tested under displacement reversals, including one monolithically cast conventional concrete joint, one engineered cementitious composites (ECC) reinforced precast concrete joint, and one SMA-ECC reinforced precast concrete joint. Failure mode, crack pattern, hysteretic behavior, stiffness degradation, displacement ductility, and energy dissipation capacity were compared and evaluated through a cyclic loading test. The test results showed that the ECC-based (ECC, SMA-ECC) precast joints have equivalent seismic properties to the monolithically cast concrete joint. ECC-based joints enhanced the ductility and energy dissipation capacity of the joint and, remarkably, reduced crack width. The SMA-ECC reinforced joint also exhibited instant self-healing in terms of the closure of small cracks after unloading. The self-healing performance was further evaluated through ultrasonic pulse tests, with the results showing that the use of SMA-ECC material was efficient in reducing the internal damage of beam–column joints after an earthquake.

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45

Yang, Yong, Xing Du, Yunlong Yu e Yongpu Pan. "Experimental study on the seismic performance of composite columns with an ultra-high-strength concrete-filled steel tube core". Advances in Structural Engineering 23, n. 4 (21 ottobre 2019): 794–809. http://dx.doi.org/10.1177/1369433219879805.

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Abstract (sommario):

The ultra-high-strength concrete-encased concrete-filled steel tube column consists of a concrete-filled steel tube core and a rectangle-shaped reinforced concrete encasement. This article presents the seismic performance analysis of ultra-high-strength concrete-encased concrete-filled steel tube columns subjected to cyclic loading. Based on the measured load-lateral displacement hysteresis curves of six ultra-high-strength concrete-encased concrete-filled steel tube columns and two conventional RC columns, the seismic behaviours, such as the ductility, energy dissipation, stiffness and load-bearing capacity, were analysed. The effects of the arrangement of the stirrups and the layout of the prestressed steel strips on the seismic performance of the composite columns were critically examined. The test results indicated that the ductility and energy dissipation performance of the ultra-high-strength concrete-encased concrete-filled steel tube columns were increased by 74.8% and 162.7%, respectively, compared with the conventional columns. The configuration of the prestressed steel strip increased the ductility of the composite column by 28.9%–63% and increased the energy consumption performance by 160.2%–263.3%. By reducing the stirrup spacing and using prestressed steel strips, the concrete-filled steel tube core columns could be effectively confined, leading to a great enhancement in ductility, energy dissipation, stiffness and load-bearing capacity.

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Song, Jun-Hyeok, e Hee-Chang Eun. "Improvement of Flexural and Shear Strength of RC Beam Reinforced by Glass Fiber-Reinforced Polyurea (GFRPU)". Civil Engineering Journal 7, n. 3 (3 marzo 2021): 407–18. http://dx.doi.org/10.28991/cej-2021-03091662.

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Abstract (sommario):

The Glass Fiber-Reinforced Polyurea (GFRPU) which is the composite by the elastic polyurea and milled glass fiber have the mechanical characteristics to enhance tensile strength as well as ductility. It must be reinforcement materials in repair and retrofit applications for strengthening structural capacity and has a merit of simple construction of spray coating to prevent the debonding from concrete surfaces unlike the existing strengthening methods such as Fiber-reinforced polymer (FRP) or steel plate. This work compares the improvement degree in load-carrying capacity as well as flexural ductility of RC beam reinforced externally by polyurea or GFRPU. Seven specimens of four reinforced concrete (RC) beams for evaluating flexure-resisting capacity and three beams for shear-strengthening capacity are tested. The mechanical behavior and characteristics of the specimens reinforced by local and global reinforcement method classified according to strengthened area are compared. It is shown that the polyurea- or GFRPU- reinforcement leads to the enhancement in the load-resisting capacity up to 8~11% and flexural ductility within the range of 8.41~13.9 times of the non-reinforced beam. And the global reinforcement method has more improvement in the shear- and flexure-resisting capacity than the local method. It is also observed that the GFRPU can be more effectively utilized in enhancing the structural shear-resisting capacity than the flexure-carrying capacity. Doi: 10.28991/cej-2021-03091662 Full Text: PDF

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47

Song, Jun-Hyeok, Eun-Taik Lee e Hee-Chang Eun. "A Study on the Improvement of Structural Performance by Glass Fiber-Reinforced Polyurea (GFRPU) Reinforcement". Advances in Civil Engineering 2019 (19 agosto 2019): 1–8. http://dx.doi.org/10.1155/2019/2818219.

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Abstract (sommario):

Polyurea has a high tensile strength, elongation, and the capability to absorb the energy generated by dynamic and impulsive blast loading. Glass fibers are a reinforcement material for repairing and retrofitting the concrete members. The polyurea provides ductility, and the fibers provide improved stiffness and strength to the composite system. Glass-fiber reinforced polyurea (GFRPU) is a composite of polyurea and fibers and is applied as a reinforcement through a simple spraying method. GFRPU coating has a simple construction, and unlike existing strengthening methods such as fiber-reinforced polymer (FRP) or a steel plate, it prevents a debonding from the concrete surface. Seven beams of one externally nonreinforced concrete beam and six concrete beams with and without a reinforcing bar are tested using the thickness of the spray and the number of coating faces. The applicability of GFRPU was investigated through the experiments, and the test results indicate that the GFRPU strengthening method is feasible for enhancing the load-carrying capacity and flexural ductility.

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Bui, Linh Van Hong, Boonchai Stitmannaithum e Tamon Ueda. "Ductility of Concrete Beams Reinforced with Both Fiber-Reinforced Polymer and Steel Tension Bars". Journal of Advanced Concrete Technology 16, n. 11 (14 novembre 2018): 531–48. http://dx.doi.org/10.3151/jact.16.531.

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49

Wu, Y. F. "New Avenue of Achieving Ductility for Reinforced Concrete Members". Journal of Structural Engineering 132, n. 9 (settembre 2006): 1502–6. http://dx.doi.org/10.1061/(asce)0733-9445(2006)132:9(1502).

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50

Xu, L. H., Q. L. Wang, M. Yu, Y. Chi, B. Yang, M. Liu e J. Q. Ye. "Experimental Study on Seismic Behavior of Cluster-Reinforced Precast Concrete Columns with Grouting-Anchor Connections". Journal of Earthquake and Tsunami 13, n. 03n04 (giugno 2019): 1940007. http://dx.doi.org/10.1142/s1793431119400074.

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Abstract (sommario):

The prefabricated residential buildings have become one of the most dominating construction methods in the modern construction industry. The seismic behavior of prefabricated components is crucial in the limit state design of the precast structure. This paper investigates the seismic behavior of a new type precast concrete column that has clustered steel reinforcement with grouting connection. Quasi-static tests are carried out on three cast-in-situ columns and seven precast columns. Axial compression ratio, lap length and lap space are the main variables considered. The failure process, hysteresis curve, skeleton curve, stiffness degradation, displacement ductility and energy dissipation are elaborated. The experimental results show that the precast columns with cluster reinforcement have similar seismic behavior to the cast-in-situ columns. Reducing the axial pressure can improve the ductility and energy consumption performance of the cluster-reinforced columns and exert its ductility to improve its seismic performance. During the assembly, a moderate increase in lap length can improve the seismic behavior of precast columns, whereas the lap space has an insignificant effect on the seismic behavior which indicates that the lap space is not an important factor during construction. The research outcome can serve as a reference for further development and application of precast structures.

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