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1
Safi, Walid Ahmad, Yo Hibino, Koichi Kusunoki, Yasushi Sanada, and Tomohisa Mukai. "Impact of the Reinforcement Detailing on Seismic Performance of Isolated Non-structural Walls." Buildings 10, no. 5 (May 7, 2020): 89. http://dx.doi.org/10.3390/buildings10050089.
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Following the observation of severe damage to structurally isolated non-structural reinforced concrete walls after major earthquakes, researchers began to reassess the effectiveness and connection detail of non-structural walls to moment-resisting frames. A method to control damages to the non-structural wall, is to cast exterior non-structural concrete wall elements to be monolithic with frame elements, without anchoring the wall longitudinal bar. The non-anchorage of the wall longitudinal bar significantly increases the drift capacity of the wall and decreases damage. Using an experimental approach, this study assesses the influence of reinforcement detailing and quantity of the transverse reinforcements on the strength and drift capacity of the non-structural hanging wall. This study further evaluates the workability mechanism of the transverse reinforcements and reinforcement detailing with concrete. The non-anchorage of hanging walls, having boundary confinements, was found to exhibit a higher drift and strength capacity than similar walls with the anchored detailing without boundary confinements. The strength capacity of the anchored detailing hanging walls with minimum amounts of reinforcements was higher than that of the non-anchored specimen. The boundary confinements were found to be more influential on the capability of the hanging wall when placed along with non-anchored detailing reinforcement.
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Tannert, Thomas, Jorge M. Branco, and Mariapaola Riggio. "RILEM TC "Reinforcement of Timber Elements in Existing Structures"." Advanced Materials Research 778 (September 2013): 1041–48. http://dx.doi.org/10.4028/www.scientific.net/amr.778.1041.
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The paper reports on the activities of the RILEM technical committee Reinforcement of Timber Elements in Existing Structures. The main objective of the committee is to coordinate the efforts to improve the reinforcement practice of timber structural elements. Recent developments related to structural reinforcements can be grouped into three categories: (i) addition of new structural systems to support the existing structure; (ii) configuration of a composite system; and (iii) incorporation of elements to increase strength and stiffness. The paper specifically deals with research carried out at the Bern University of Applied Sciences Switzerland (BFH), the University of Minho Portugal (UniMinho), and the University of Trento Italy (UNITN). Research at BFH was devoted to improve the structural performance of rounded dovetail joints by means of different reinforcement methods: i) self-tapping screws, ii) adhesive layer, and iii) a combination of self-tapping screws and adhesive layer. Research at UNITN targeted the use of dry connections for timber-to-timber composites, specifically reversible reinforcement techniques aimed at increasing the load-bearing capacity and the bending stiffness of existing timber floors. At UniMinho, double span continuous glulam slabs were strengthened with fibre-reinforced-polymers. All three examples demonstrate the improved structural performance of timber elements after reinforcing them.
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Ghavami, Khosrow. "Bamboo as reinforcement in structural concrete elements." Cement and Concrete Composites 27, no. 6 (July 2005): 637–49. http://dx.doi.org/10.1016/j.cemconcomp.2004.06.002.
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Libotean, Dan Alexandru, Alexandru Chira, and Ferdinánd-Zsongor Gobesz. "Textile-Reinforced Concrete Structural Elements." Műszaki Tudományos Közlemények 8, no. 1 (April 1, 2018): 61–66. http://dx.doi.org/10.33894/mtk-2018.08.07.
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Abstract The textile reinforced concrete is a material with increased mechanical properties that can allow the production of lighter structural elements. The alkali-resistant textile reinforcement is not affected by corrosion. A structural facade panel and a light pole were modeled in order to study their behavior in the case of wind pressure. The developed numerical simulations were calibrated according to available data from the literature. These simulations revealed information potentially useful in the planning of further experimental tests.
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Pidun, Kevin, and Thomas Gries. "Shaped Textile Reinforcement Elements for Concrete Components." Advanced Materials Research 747 (August 2013): 415–19. http://dx.doi.org/10.4028/www.scientific.net/amr.747.415.
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By now the application of Textile Reinforced Concrete (TRC) for facade constructions can be considered as state of the art. Especially ventilated curtain walls made of TRC and sandwich elements made in combination of TRC-layers and foam cores recently are realized in pilot projects which are predominantly located in Aachen, Germany. The Life funded Insu-Shell façade of the Institute fuer Textiltechnik (ITA) of RWTH Aachen University gives an example of such a pilot project. Furthermore, a pedestrian bridge has been built in Albstadt, Germany. The enormous potential of TRC-applications is shown in these practical projects. All projects have been completed successfully and present good results in terms of the surface quality, the design freedom, the wall thinness and the ecological performance. A networked process chain was aimed at and approached and finally implemented. Apart from this, all these projects incorporating impregnated textile reinforcements reveal unanswered questions regarding production of shaped reinforcement elements, their ability to bear loads and their durability. Particularly the transformation of a 2D-warp-knit fabric to a reinforcement element (textile reinforcement cage) is a challenge, which needs to be addressed further. Since the beginning of 2012 a new transfer project called Shaped textile reinforcement elements for concrete components (T08) within the framework of the Collaborative Research Center 532 `Textile Reinforced Concrete - Development of a new technology` is funded. That challenge is to be solved in the T08 project in cooperation with Institutes from the RWTH Aachen University and industry partners led by the Institute of Structural Concrete of RWTH Aachen University.
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Döbrich, Oliver, Thomas Gereke, and Chokri Cherif. "Modelling of textile composite reinforcements on the micro-scale." Autex Research Journal 14, no. 1 (March 14, 2014): 28–33. http://dx.doi.org/10.2478/v10304-012-0047-z.
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Abstract Numerical simulation tools are increasingly used for developing novel composites and composite reinforcements. The aim of this paper is the application of digital elements for the simulation of the mechanical behaviour of textile reinforcement structures by means of a finite element analysis. The beneficial computational cost of these elements makes them applicable for the use in large models with a solution on near micro-scale. The representation of multifilament yarn models by a large number of element-chains is highly suitable for the analysis of structural and geometrical effects. In this paper, a unit cell generating method for technical reinforcement textiles, using digital elements for the discretization, is introduced.
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Komarov, Valeriy A., Alexander A. Pavlov, Svetlana A. Pavlova, and Ramaz V. Charkviani. "Reinforcement of Aerospace Structural Elements Made of Layered Composite Materials." Procedia Engineering 185 (2017): 126–30. http://dx.doi.org/10.1016/j.proeng.2017.03.329.
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Knauff, M., B. Grzeszykowski, and A. Golubińska. "Minimum Reinforcement for Crack Width Control in RC Tensile Elements." Archives of Civil Engineering 65, no. 1 (March 1, 2019): 111–28. http://dx.doi.org/10.2478/ace-2019-0008.
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AbstractNew approach using direct crack width calculations of the minimum reinforcement in tensile RC elements is presented. Verification involves checking whether the provided reinforcement ensures that the crack width that may result from the thermal-shrinkage effects does not exceed the limit value. The Eurocode provisions were enriched with addendums derived from the German national annex. Three levels of accuracy of the analysis were defined - the higher the level applied, the more significant reduction in the amount of reinforcement required can be achieved. A methodology of determining the minimum reinforcement for crack width control on the example of a RC retaining wall is presented. In the analysis the influence of residual and restraint stresses caused by hydration heat release and shrinkage was considered.
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Massone, Leonardo M., and Eduardo E. López. "Modeling of reinforcement global buckling in RC elements." Engineering Structures 59 (February 2014): 484–94. http://dx.doi.org/10.1016/j.engstruct.2013.11.015.
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Plyusnin, Mikhail G., and Sergey V. Tsybakin. "The effect of anisotropy of elastic properties of GFRP reinforcement on strength of compressed concrete structural elements." Vestnik MGSU, no. 6 (June 2019): 669–79. http://dx.doi.org/10.22227/1997-0935.2019.6.669-679.
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Introduction. Despite the growing interest to the use of GFRP reinforcement in various concrete structures, its use in the concrete compressed zone is not investigated sufficiently. The use of GFRP reinforcement in compressed concrete elements is limited by a combination of low value of its modulus of elasticity and small ultimate deformation of concrete during compression. A number of researchers suggest solving this problem by means of increase the ultimate concrete deformation due to lateral reinforcement. However, unlike steel reinforcement, the elastic properties of composite reinforcement depend on the stress direction, which is due to the significant difference between the moduli of elasticity of the fibre glass and the binder. Consequently, the stress-deformation state of compressed concrete elements with longitudinal GFRP reinforcement and close-set lateral reinforcement will differ from the stress-deformation state of steel-reinforced concrete elements. Materials and methods. To clarify the effect of the anisotropy of fibre-glass reinforcement elastic properties on its work in the concrete compressed zone, a physical experiment and numerical simulation using the LIRA-SAPR software were carried out. Physical nonlinearity of materials was not taken into account in the model. Results. An assessment of the effect of anisotropy of elastic properties of fibre-glass reinforced plastic (GFRP) reinforcement on the strength of compressed concrete elements was accomplished for longitudinal reinforcement. The experiment showed that the location of the longitudinal GFRP reinforcement in the concrete compressed zone in the absence of lateral reinforcement led to a decrease in the average strength of the tested samples by 9.2 %, while the fracture nature of GFRP-reinforced samples differed from the fracture nature of control samples. As a result of the numerical simulation, it was revealed that the cause of the strength reduction is the anisotropy of the elastic properties of GFRP reinforcement, which affects the stress-deformation state of compressed concrete. Conclusions. The analysis of the results of experiment and numerical simulation showed that the reason for the decrease in strength is the low modulus of elasticity of GFRP when compressed in the lateral direction as compared with the similar characteristic of concrete. The degree of strength reduction will also depend on the relation between the moduli of elasticity of concrete and GFRP when compressed in the longitudinal direction.
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Gowripalan, N., and A. R. Cusens. "Modified polymer bar reinforcement for concrete elements." Construction and Building Materials 2, no. 2 (July 1988): 106–11. http://dx.doi.org/10.1016/0950-0618(88)90024-4.
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Balić, Jure, and Siniša Bizjak. "Installation of stainless metal reinforcements in stone cultural monuments." St open 2 (July 9, 2021): 1–17. http://dx.doi.org/10.48188/so.2.2.
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Objective: To provide examples of the installation of stainless-steel reinforcements in a stone cultural monument as part of conservation and restoration work. Methods: During conservation and restoration works, metal elements in stone monuments are replaced by stainless steel, which shares the same physical properties as, for example, iron, but its chemical properties are much superior. Estimates of appropriate reinforcement, technical drawings and a detailed plan are drafted before the installation of stainless-steel reinforcements in the stonework itself. For more demanding calculations and designs, structural and other engineers and architects were consulted to obtain the optimal dimensions of structural elements. Results: The presented examples of stone monuments (an ancient stone sarcophagus, two ancient sculptures, one medieval portal, two baroque baptismal fonts and a baroque bell gable) were reinforced with stainless steel. A reinforcing mesh was utilized to connect fragments of the sarcophagus and reconstruct the missing parts. The sculptures were found in fragments and required steel reinforcement to be set up in a free-standing position. The baptismal fonts were also found in fragments due to the corrosion of their iron clamps; they were furnished with a detachable, externally invisible steel reinforcement. The medieval portal was at risk of collapse due to the static instability caused by the rupture of its load-bearing lintel. The lintel was reinforced with a steel bar, which absorbs compression forces acting on the stone superstructure. The baroque bell gable was a prime example of a monument damaged by its iron clamps. These were completely removed and the structural stability was secured by embedding a reversible steel structure in the stonework. Conclusion: Good physical and chemical properties make stainless steel the basic material in the reinforcement of stone cultural monuments. Its application in the conservation and restoration of stone monuments is currently the best and most efficient solution for restoring sustainable structural stability, original appearance and optimal positioning of monuments, as well as preventing further deterioration.
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Novak, Josef, and Alena Kohoutkova. "Structural Fiber Reinforced Concrete Elements." Solid State Phenomena 259 (May 2017): 221–26. http://dx.doi.org/10.4028/www.scientific.net/ssp.259.221.
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The building industry offers a wide range of materials which can be used for the production of various structural elements. Fibre reinforced concrete (FRC) is a material which is more frequently utilized for concrete structures. The reason is its physical and mechanical properties which contribute to traditional concrete elements and structures various economical benefits such as structure subtlety, part or full elimination of conventional reinforcement, resistance to mechanical loading and surrounding environment. Therefore, it is necessary to search for appropriate structures where the benefits of FRC could be used. First of all it is necessary to seek for structures which owing to their geometry and intended use seem to be appropriate for FRC application. It can be either new structural elements or existing structural elements made of a different material. During a material optimization there are many parameters to take into account which include production costs, manufacturing technology, structural behaviour, ultimate bearing capacity and durability of proposed member. The efficiency of material optimization is determined by comparing these parameters. While it is relatively easy and cost efficient to determine and evaluate the production costs, structure durability and manufacturing technology, to describe the structural behaviour of innovative elements is a complex task. However there are many sophisticated software which are capable to accurately simulate the behaviour of structural elements by using modern computational methods. At the end of feasibility study, experimental testing is conducted on full-scale pilot elements with the aim to verify their real behaviour as well as to optimize the computational model. As a result, many innovative FRC based structural elements have been developed at Czech Technical University in Prague in cooperation with construction companies.
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Fagone, Mario, and Giovanna Ranocchiai. "An Experimental Analysis of the Mechanical Behaviour of Anchored CFRP-to-Masonry Reinforcements Loaded by Out-of-Plane Actions." Key Engineering Materials 747 (July 2017): 204–11. http://dx.doi.org/10.4028/www.scientific.net/kem.747.204.
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Carbon Fibers Reinforced Composite (CFRP) materials are widely used for structural rehabilitation and retrofitting of both masonry and concrete structures. Recent studies published in the literature are devoted to the analysis of novel methods to increase CFRP-to-substrate bond capacity. Among these, spike anchors demonstrated to be able to effectively increase both strength and ductility of CFRP reinforcement sheets. Since most of the literature in this field refers to CFRP-to-masonry reinforcements loaded by in plane actions, the experimental research described in this paper is devoted to the analysis of the effectiveness of spike anchors in CFRP reinforcements bonded to masonry structural elements loaded by out-of-plane actions.
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Gribniak, Viktor, Pui-Lam Ng, Vytautas Tamulenas, Ieva Misiūnaitė, Arnoldas Norkus, and Antanas Šapalas. "Strengthening of Fibre Reinforced Concrete Elements: Synergy of the Fibres and External Sheet." Sustainability 11, no. 16 (August 17, 2019): 4456. http://dx.doi.org/10.3390/su11164456.
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In structural rehabilitation and strengthening, the structural members are often required to cope with larger design loading due to the upgrading of building services and design standard, while maintaining the member size to preserve the architectural dimensions and headroom. Moreover, durability enhancement by mitigating or eliminating the reinforcement corrosion problem is often desired. Concrete cracking is a major initiating and accelerating factor of the corrosion of steel reinforcement. The application of fibres is a prominent solution to the cracking problem. Furthermore, the fibres can increase the mechanical resistance of the strengthening systems. This study reveals the synergy effect of the combined application of steel fibres and external carbon fibre-reinforced polymer (CFRP) sheets. The investigation encompasses the use of fibre-reinforced polymer (FRP) reinforcing bars, discrete steel fibres, externally bonded and mechanically fastened FRP sheets in different combinations. It is discovered that the steel fibres can help to control concrete cracking and eventually alter the failure mode and enhance the flexural resistance. The FRP reinforcement system, together with the steel fibres, radically resolves the structural safety problem caused by corrosion of the steel bar reinforcement. Finally, the impact of the external sheet on the fire limit state performance needs to be resolved, such as by adopting fire protection rendering for the finishes layer.
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Raczkiewicz, Wioletta, Artur Wójcicki, and Adam Wójcicki. "Using the galvanostatic pulse method to estimate the corrosion of reinforcement in structural elements." South Florida Journal of Development 2, no. 3 (August 9, 2021): 4865–76. http://dx.doi.org/10.46932/sfjdv2n3-080.
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ABSTRACT
Early steel bars corrosion in reinforced concrete elements is difficult to detect because of the lack of visible changes on the concrete surface. To assess reinforcement corrosion risk level without structure damage some non-destructive diagnostic methods are applied. One of them is the galvanostatic pulse method. This semi-non-destructive electrochemical method allows to determine the corrosion areas and estimate the steel bars corrosion activity. Using this method it is possible to measure some electrical parameters (corrosion current density, stationary potential and reinforcement concrete cover resistivity) that allow to indirectly estimate the reinforcement corrosion progress in concrete. So far this method has been generally applied to bridges. The article presents results of studies in which the galvanostatic pulse method was used to determine reinforcement corrosion risk in structures elements different than bridges. Two types of reinforced concrete columns were tested under different environment conditions and two groups of laboratory specimens which were subjected to freezing and thawing cycles in NaCl solution or stayed in natural air–dry conditions. The apparatus GP-5000 GalvaPulseTM was used. Based on the obtained results the conclusions were drawn. The galvanostatic pulse method allows to assess the progress of the reinforcement corrosion process in tested elements. However, it is necessary to measure simultaneously all parameters and make their complex analysis.
RESUMEN
La corrosión temprana de las barras de acero en elementos de hormigón armado es difícil de detectar debido a la falta de cambios visibles en la superficie del hormigón. Para evaluar el nivel de riesgo de corrosión de la armadura sin dañar la estructura se aplican algunos métodos de diagnóstico no destructivos. Uno de ellos es el método del pulso galvanostático. Este método electroquímico semi no destructivo permite determinar las áreas de corrosión y estimar la actividad de corrosión de las barras de acero. Utilizando este método es posible medir algunos parámetros eléctricos (densidad de corriente de corrosión, potencial estacionario y resistividad de la cubierta del hormigón de la armadura) que permiten estimar indirectamente el progreso de la corrosión de la armadura en el hormigón. Hasta ahora este método se ha aplicado generalmente a los puentes. El artículo presenta los resultados de estudios en los que se utilizó el método de impulsos galvanostáticos para determinar el riesgo de corrosión de las armaduras en elementos de estructuras diferentes a los puentes. Se ensayaron dos tipos de columnas de hormigón armado en diferentes condiciones ambientales y dos grupos de probetas de laboratorio que se sometieron a ciclos de congelación y descongelación en solución de NaCl o permanecieron en condiciones naturales de secado al aire. Se utilizó el aparato GP-5000 GalvaPulseTM. A partir de los resultados obtenidos se extrajeron las siguientes conclusiones El método de impulsos galvanostáticos permite evaluar el progreso del proceso de corrosión de la armadura en los elementos ensayados. Sin embargo, es necesario medir simultáneamente todos los parámetros y realizar su complejo análisis.
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Tworzewski, Paweł, Wioletta Raczkiewicz, Wioletta Grzmil, and Przemysław Czapik. "Condition assessment of selected reinforced concrete structural elements of the bus station in Kielce." MATEC Web of Conferences 284 (2019): 06007. http://dx.doi.org/10.1051/matecconf/201928406007.
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The paper presents the results of the research aimed at assessing the condition of reinforcement and concrete cover in selected elements of the structure of the most recognizable structure in Kielce, i.e. PKS station, located at Czarnowska Street. Currently, demolition works are underway resulting from the planned modernization. The assessment of the corrosion risk of the reinforcement in the construction elements was carried out with the use of a semi-non-destructive electrochemical method. The use of this method made it possible to determine the probability of reinforcement corrosion in the selected areas and to estimate its rate. The protective properties of concrete cover were checked by the carbonation test (test using a 1% phenolphthalein solution) and phase composition analysis (X-ray diffraction analysis). In order to determine the position of the reinforcing bars and to estimate the concrete cover thickness distribution in the areas corresponding to the aforementioned measurements, ferromagnetic detection system was used.
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Sysoev, O. E., A. Y. Dobryshkin, and Ye O. Sysoyev. "Effective Elements of Building Structures from Pipe Concrete." Materials Science Forum 945 (February 2019): 80–84. http://dx.doi.org/10.4028/www.scientific.net/msf.945.80.
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The article is devoted to the investigation of pipe-concrete prestressed structural elements with high efficiency. This is due to a more complete use of the strength properties of structural materials in the pipe-concrete beam. The article presents various methods for calculating pipe-concrete elements. The design of a concrete tube with a prestressed element using high-strength concrete is presented. The results of calculations of various designs are shown and the cross-sections of beams for perception of the same bending load are selected. A comparison is made between the consumption of beam materials of various designs. The effectiveness of the use of pipe-concrete elements for receiving bending loads made of high-strength concrete with prestressed reinforcement is shown in comparison with the construction of beams of traditional high-strength concrete, high-strength concrete pipe-concrete with no prestressing of reinforcement and metal beam, mass of the element, consumption of metal and concrete.
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Bratu, P., G. De Marco, and C. Alexandru. "Reinforcement and prestressing systems of concrete at the execution of structural elements." MATEC Web of Conferences 11 (2014): 02007. http://dx.doi.org/10.1051/matecconf/20141102007.
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Sulatani, Haji Akbar, Viktor Gribniak, Arvydas Rimkus, Aleksandr Sokolov, and Lluis Torres. "COMPARATIVE ANALYSIS OF FLEXURAL STIFFNESS OF CONCRETE ELEMENTS WITH DIFFERENT TYPES OF COMPOSITE REINFORCEMENT SYSTEMS." Mokslas - Lietuvos ateitis 13 (January 6, 2021): 1–5. http://dx.doi.org/10.3846/mla.2021.13713.
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Various materials and reinforcement technologies have been created for concrete structures. However, there is no uniform methodology to compare the mechanical characteristics of different reinforcement systems. In structural systems, residual stiffness can estimate the efficiency of the reinforcement. This study introduces a simplified approach for the flexural stiffness analysis. It employs a new testing layout designed with the purpose to form multiple cracks in a small laboratory specimen. The achieved solution requires neither iterative calculations nor a description of the loading history. Several composite reinforcement schemes, including internal glass fibre reinforced polymer (GFRP) bars, carbon fibre reinforced polymer (CFRP) sheets and near-surface mounted (NSM) strips are considered. The analysis of the test results reveals a substantial efficiency of the external CFRP reinforcement systems.
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Barsukov, Vladimir, Alla Volik, and Svetlana Sazon. "Structural Mechanics Aspect of Strength of Composite Reinforcement." E3S Web of Conferences 212 (2020): 02002. http://dx.doi.org/10.1051/e3sconf/202021202002.
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When operating in wet and corrosive conditions, composite reinforcement is in some cases an effective substitute for the suitable steel reinforcement. However, many questions related to its design, production and operation are insufficiently studied. The aim of the work is to create a methodology and carry out a comparative structural and mechanical analysis of strength indexes when working under load of coils and a bar of composite construction reinforcement. A method has been developed for analyzing the loading capacity of composite reinforcement according to the criteria of strength at rupture of a bar, as well as shear strength and bearing strength of its braid coils. Analytical and numerical modeling of conditions of equal strength of structural elements of composite construction reinforcement was carried out. Theoretically substantiated the assumption of a relatively low loading capacity of the braid coils in comparison with the loading capacity of the reinforcement bar. A predictive estimate of the conditions for ensuring the uniform strength of the bar for breaking and braid coils for shear and crushing by the method of lower estimation (for the minimum values of strength) has been carried out using the example of composite reinforcing bars produced by the industry of Republic of Belarus. In conclusion, results of work are formulated and it is noted that the results can be used by manufacturers and consumers of construction composite reinforcement, also in the educational process in the training of engineering personnel for the construction profile.
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Zergua, Abdesselam, and Mohamed Naimi. "ELASTIC-PLASTIC FRACTURE ANALYSIS OF STRUCTURAL COLUMNS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 12, no. 2 (June 30, 2006): 181–86. http://dx.doi.org/10.3846/13923730.2006.9636390.
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This research is achieved in the general frame‐work of the study of the concrete behaviour. It has for objective the development of a numerical tool able to predict the behaviour of reinforced concrete columns with circular and square cross‐sections under an increasing compressive axial load. The concrete behaviour is assumed as elastic‐plastic model with an associated flow rule in compression region and as elastic with tension stiffening behaviour in the tension region. Two yield surfaces have been taken into account according to the Drucker‐Prager and Rankine failure criterions. However, the reinforcing steel is assumed as an elastic strain hardening model. A finite element method using solid cube elements for concrete, and bar elements for the reinforcement have been used. Correlation study between numerical and experimental results is conducted with the objective to establish the validity of the proposed model and identify the significance of the transverse reinforcement volumetric ratio effect on the response of reinforced concrete members. Good agreement has been observed in comparing these results.
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Segura-Castillo, Luis, Nicolás García, Iliana Rodríguez Viacava, and Gemma Rodríguez de Sensale. "Structural Model for Fibre-Reinforced Precast Concrete Sandwich Panels." Advances in Civil Engineering 2018 (November 22, 2018): 1–11. http://dx.doi.org/10.1155/2018/3235012.
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Fibre-reinforced concrete (FRC) has been used in numerous types of precast elements around the world, as has been shown that reductions in production costs and time can be obtained; however, there is little experience of this material in Uruguay. Therefore, our study analysed the feasibility of its utilisation in this country. This paper reports on the development of a simple analysis model that is useful for the design of FRC precast elements. The model efficiency was evaluated through its application to a practical case study—vertical precast concrete sandwich panel systems tested by bending. Three different types of reinforcement were analysed: synthetic fibres, metal fibres, and steel mesh. With the developed model, the cost-efficiency of different panel geometries and amounts of reinforcement were evaluated. The model allowed consideration of the contribution of the fibres to withstand internal tensile forces of the panels and therefore be able to substitute for the steel mesh in the panel wythes. It was found that it was possible to optimise panel reinforcement and geometry, thereby reducing wythe thickness. Besides the reduction in production time, it was possible to achieve cost savings of up to 10% by replacing steel mesh with fibres and of more than 20% if the geometry was also modified.
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Sergei N. Nazarenko and Galina A. Grudcina. "Method of the Finite-Element Model Formation Containing the 3D Elements for Structural Calculations of the Reinforced Concrete Structures Considering the Crack Opening." Communications - Scientific letters of the University of Zilina 23, no. 1 (January 4, 2021): D15—D25. http://dx.doi.org/10.26552/com.c.2021.1.d15-d25.
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This article presents the 3D computational modeling method for reinforced concrete structures. An example of calculation of the reinforced concrete beam, using the Finite Element Method in SCAD++ following proposed algorithm, is given. Results comparison to the analytical calculation of the model with selected reinforcement is presented. For concrete, the 3D solid Finite Elements are used and the 3D beam elements for reinforcement. The model is formed using AutoCAD and AutoLISP, which creates a text data file in SCAD format for the description of model. In addition, computation of the 3D model of the crossbar with a crack is performed. Crack sizes are set in the stretched zone based on data from initial calculation. Graphic results obtained in SCAD++ are presented.
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Wood, Timothy A., William D. Lawson, Priyantha W. Jayawickrama, and James G. Surles. "Pullout Behavior of Steel Mechanically Stabilized Earth Reinforcements." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 52 (May 11, 2018): 238–50. http://dx.doi.org/10.1177/0361198118758314.
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Instrumented pullout tests of unprecedented scope and scale explore the pullout behavior for three steel mechanically stabilized earth reinforcement types: ribbed strips, ladder-like strips, and three-wire bar mat grids. These data quantify the distribution of pullout resistance between longitudinal elements and illustrate the nature of certain reinforcement deformations. Consistent with characteristic inextensible pullout behavior and soil-reinforcement interaction, synthesized strain-gage data illustrate linear stress reduction along the embedment length during pullout for all three reinforcement styles. For ladder-like strips, the axial force divides evenly between the two longitudinal elements. For the three-wire bar mat grid, the center bar carries approximately 40% of the axial force, whereas each outside bar carries approximately 30% of the axial force. Observed pullout-induced deformation in the transverse elements of three-wire bar mat grids having widely spaced longitudinal bars is conceptually different from extensible behavior and suggests the need for refinement in current pullout resistance formulations.
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Leal G., J. M., J. J. Pérez Gavilán, J. H. Castorena G., and J. I. Velázquez D. "Infill walls with confining elements and horizontal reinforcement: An experimental study." Engineering Structures 150 (November 2017): 153–65. http://dx.doi.org/10.1016/j.engstruct.2017.07.042.
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Bidaj, Altin, Enio Deneko, and Mario Hysenlliu. "DIFFERENT REINFORCEMENT TECHNIQUES IN DAMAGED BUILDINGS." Academic Perspective Procedia 2, no. 2 (October 27, 2019): 211–19. http://dx.doi.org/10.33793/acperpro.02.02.28.
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During their lifetime, the capacity of the single elements or of the entire structures is not anymore adequate to the static and dynamic functions requested by the project, mainly caused from deterioration of the masonry structures or the change of the destination and the purpose of the elements. Externally bonded FRP may be used in a repair capacity for structures that have moderate earthquakes damages or to reinforce structures considered to be vulnerable. The FRP strengthening systems are used mainly for flexural and shear strengthening of the structural elements subjected to bending moments and shear forces larger than their flexural and shear capacity, especially the beam-column joints. Many experiences in rehabilitation of damaged masonry buildings have been carried out in Europe in the last decades. Several unsuccessful results have underscored the need for adequate assessment prior to any rehabilitation. In fact, when neither the real state of damage nor the effectiveness of repairs is known, the results of the intervention are also unpredictable. In this article there are described different techniques used for reinforcement of masonry structures, with their advantages or disadvantages.
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Rimshin, V. I., and S. I. Merkulov. "EXTERNAL REINFORCEMENT OF CONCRETE STRUCTURES USING COMPOSITE MATERIALS." Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel'nogo universiteta. JOURNAL of Construction and Architecture, no. 5 (October 30, 2018): 92–100. http://dx.doi.org/10.31675/1607-1859-2018-20-5-92-100.
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The paper describes the main directions of non-metallic composite application in concrete reinforcement. The development routes of the structural analysis with composite reinforcement are formulated. The reinforced concrete structure combines the elastic reinforcement element with an adhesive composition having inelastic properties. It is shown that the structural reliability is ensured by adhesion of composite core reinforcement to the concrete. When performing external reinforcement of composite materials, it is necessary to ensure the joint operation of reinforcing elements and the main structure. Today, design methods of concrete structure reinforcement with composite materials do not take into account shear strains in the contact seam. Adhesion of composite material to concrete is indirectly assessed by introducing the service factor of composite material when its design resistance is assigned. Experimental studies concern concrete structures reinforced by bent elements with external reinforcement made of various composite materials. Reinforced concrete beams with A500 and A600 class reinforcement are considered. Test beams are reinforced with fiberglass, coal and carbonates canvases. Some of test beams have U-shaped anchors at the ends and are made of composite materials. Reinforced beams fracture by different schemes: composite peeling due to the adhesive destruction in the area of formation of normal and inclined cracks, compositepeeling with the destruction of protective layer, composite rupture. A part of reinforced concrete beams before the reinforcement are cracked in the stretched zone. Cracks do not affect the load-bearing capacity of reinforced beams.
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Zhao, Wei Feng, Jing Zhou, and Guo Bin Bu. "Application Technology of Bamboo Reinforced Concrete in Building Structure." Applied Mechanics and Materials 195-196 (August 2012): 297–302. http://dx.doi.org/10.4028/www.scientific.net/amm.195-196.297.
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Bamboo is mainly a tropical and subtropical plant which is found adequate in many countries. The strength of bamboo as concrete reinforcement is much lower than steel bar reinforcement. However, one of the merits is a cheap and replenishable agricultural resource and abundantly available. Due to excellent properties like high strength to weight ratio, high tensile strength and free-cutting and processing, bamboo as a potential reinforcement material in place of steel is widely available in concrete structural elements. The present paper introduces some of the existing studies and application technology of bamboo reinforced concrete elements in building structures, such as bamboo reinforced concrete columns, beams, slabs and walls.
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Kruszka, Leopold. "Reinforcement of brick historic buildings threatened by structural damages or by failure." MATEC Web of Conferences 174 (2018): 03013. http://dx.doi.org/10.1051/matecconf/201817403013.
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The paper presents selected aspects of reinforcing the brick cultural heritage buildings, particularly load-carrying elements of those structures. In some cases the operational phase of many load-bearing elements of the historical buildings is shrinking or has used up. The crucial task while carrying out construction works related to reinforcing or repair of the load-bearing structure is to ensure safety. This safety should be assured regarding both the structure itself and its users. The design concept also needs to include recommendations and instructions of the conservatorinspector. The proposed scope of technical assessment and analysis of the load-bearing structures of buildings is presented on selected examples. The performed diagnostics process allowed to properly determine the occurred hazards and on this basis to properly design and carry out repair of damaged elements of structure [1]. The first of the analysed cases concerns the barracks facility near the Makowiecka Street in Przasnysz. Another example described in this paper is the brick dome of the church building of St. Anne in Wilanów district in Warsaw. The damages and failure identification process, as well as taken measures and proposed methods of reinforcement of the structure are presented with reference to the both above mentioned examples.
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Kostinakis, K. G., A. M. Athanatopoulou, and I. E. Avramidis. "Orientation effects of horizontal seismic components on longitudinal reinforcement in R/C frame elements." Natural Hazards and Earth System Sciences 12, no. 1 (January 2, 2012): 1–10. http://dx.doi.org/10.5194/nhess-12-1-2012.
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Abstract. The present paper investigates the influence of the orientation of recorded horizontal ground motion components on the longitudinal reinforcement of R/C frame elements within the context of linear response history analysis. For this purpose, three single-story buildings are analyzed and designed for 13 recorded bi-directional ground motions applied along the horizontal structural axes. The analysis and design is performed for several orientations of the recording angle of the horizontal seismic components. For each orientation the longitudinal reinforcement at all critical cross sections is calculated using four methods of selecting the set of internal forces needed to compute the required reinforcement. The results show that the reinforcement calculated by three of the applied methods is significantly affected by the orientation of the recording angle of ground motion, while the fourth one leads to results which are independent of the orientation of the recording angle.
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KURNAVINA, S. O., and I. V. TSATSULIN. "THE INFLUENCE OF UNCLOSED CRACKS IN COMPRESSED ZONE OF CONCRETE ON THE BEARING CAPACITY OF BENDING REINFORCED CONCRETE ELEMENTS." Building and reconstruction 94, no. 2 (2021): 28–38. http://dx.doi.org/10.33979/2073-7416-2021-94-2-28-38.
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One of the most important issues when calculating buildings and structures for seismic effects is taking into account the presence of damage in the compressed zone of concrete. It is known that the current norms of the Russian Federation [4] on earthquake-resistant construction assume the development of plastic deformations in structural elements. When determining the loads, the possibility of developing plastic deformations in structural elements is taken into account by introducing a decreasing coefficient K1, while neglecting the effect of plastic deformations on the strength of bearing reinforced concrete elements. The presence of plastic deformations in the reinforcement leads to the appearance of residual cracks in the compressed zone of concrete and, as a consequence, to a decrease in the bearing capacity of bending elements in subsequent loading cycles. The influence of unclosed cracks in compressed zone of concrete of bending elements on their bearing capacity for symmetrical and non-symmetrical reinforcement, for different values of reinforcement coefficient and for different values of coefficient of plasticity is considered. Based on the results of calculations the bearing capacity data for bending reinforced concrete elements with residual cracks in compressed zone of concrete have been obtained. The approximate method of determination of residual cracks depth in compressed zone of concrete in terms of coefficient of plasticity in the first semi cycle of loading is proposed.
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Barzegar, Fariborz. "Analysis of RC Membrane Elements With Anisotropic Reinforcement." Journal of Structural Engineering 115, no. 3 (March 1989): 647–65. http://dx.doi.org/10.1061/(asce)0733-9445(1989)115:3(647).
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Włodarczyk, Maria. "The strength capacity of compression members reinforced with FRP bars. The results of structural testing." AUTOBUSY – Technika, Eksploatacja, Systemy Transportowe 19, no. 12 (December 31, 2018): 715–19. http://dx.doi.org/10.24136/atest.2018.484.
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The paper describes experimental testing on compression members reinforced with FRP and steel bars. The main objective of the work was to investigate the effect of reinforcement type on the strength capacity of elements. It was observed that in most of the cases the failure of the elements happened due to concrete crushing..
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Gudonis, Eugenijus, Edgaras Timinskas, Viktor Gribniak, Gintaris Kaklauskas, Aleksandr K. Arnautov, and Vytautas Tamulėnas. "FRP REINFORCEMENT FOR CONCRETE STRUCTURES: STATE-OF-THE-ART REVIEW OF APPLICATION AND DESIGN." Engineering Structures and Technologies 5, no. 4 (May 8, 2014): 147–58. http://dx.doi.org/10.3846/2029882x.2014.889274.
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Fiber reinforced polymers (FRPs) are considered to be a promising alternative to steel reinforcement, especially in concrete structures subjected to an aggressive environment or to the effects of electromagnetic fields. Although attempts to develop effective reinforcement have been followed, the application of FRPs remains limited by the solution to simple structural problems that mainly appear due to the absence of design codes, significant variation in the material properties of FRP composites and limited knowledge gained by engineers as regards the application aspects of FRP composites and structural mechanics of concrete elements reinforced with FRPs. To fill the latter gap, the current state-of-the-art report is dedicated to present recent achievements in FRPs applying practice to a broad engineers’ community. The report also revises the manufacturing process, material properties, the application area and design peculiarities of concrete elements reinforced with FRP composites. Along the focus on internal reinforcement, the paper overviews recent practices of applying FRP reinforced concrete (RC) elements in structural engineering. The review highlights the main problems restricting the application of FRPs in building industry and reveals the problematic issues (related to the material properties of the FRP) important for designing RC following the formulation of targets for further research.
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Ehizemhen Igibah, Christopher, Lucia Omolayo Agashua, and Adavudi Abubakar Sadiq. "Dispersion degree data and chemical properties of Nigerian steel bars used as structural element." International Journal of Engineering & Technology 8, no. 4 (November 10, 2019): 547. http://dx.doi.org/10.14419/ijet.v8i4.29868.
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The study was aimed at assessing degree of uncertainty, effect of water and other chemicals on both locally made and imported reinforcement used for structural elements via Optical Emission Spectrometry technique. Reinforcement from various locations in Lagos state, Nigeria was soaked with chemicals (NaOH, Na2SO4, H2SO4, HCl and H2O) to detect chemicals impact. The results indicated that Carbon, phosphorus and sulphur of Pulkit reinforcement was within ASTM limit. The severity of aqueous solutions on steel rebars was in the order H2SO4 > HCl > Na2SO4 > H2O for both local and imported local bars, while steel rebars were not affected by NaOH solution. Degree of dispersion (COV) of local steel was the highest. This was in terms of elongation of 23.69%, H2SO4 of 0.39% and 1.24% for one and six weeks respectively.
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Barabash, Maria S., Anatol V. Pikul, and Olga Bashynska. "THE MODELING OF STRUCTURAL ENFORCEMENT BY COMPOSITE MATERIALS ON “LIRA-SAPR”." International Journal for Computational Civil and Structural Engineering 13, no. 1 (March 22, 2017): 34–41. http://dx.doi.org/10.22337/2587-9618-2017-13-1-34-41.
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This paper provides detailed suggestions for process of modeling the structural reinforcement by composite materials on the software package "LIRA-SAPR". It provides the implementation of bearing capacity checks for reinforced elements on the program called "ESPRI". The article offers an algorithm for calculation the construction objects in case of the changing of design situation, taking into account the modeling of the composite structure reinforcement. It considers the modeling process of reinforcement of structures using classical methods, such as using of metal casing. In the article you can also find a numerical modeling example of the frame structure reinforcement, with the selection and verification of the composite material. It considered the process of modeling the bearing capacity increasing with using the classical methods, namely the increase of the metal hooping. The article investigates the example of a numerical simulation of the frame bearing capacity increasing with the selection and verification of the composite material. Using the finite element method a mathematical model of the frame structure was constructed. In the frame work it was taken into account the occurrence of the bearing capacity increasing by composite materials in some elements. It compared the kinematic characteristics and effort that have arisen within the frame design model with static analysis, also taking into account physical nonlinearity in the calculation and enhancing certain elements reinforced with composite material. Also in this paper we describe a method of modeling the bearing capacity increasing with using the metal hooping.The calculation of reinforced element is made on the program called ESPRI, followed by an analysis of the overall calculation model work on the software package "LIRA-SAPR". The result of the article is a comparison and analysis of the stress-strain state of the considered computational model for various problem formulations. The results could be used for wider application in the study of methods for increasing the bearing capacity of buildings and structures.
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Choi, S. H., J. Y. Park, I. S. Shin, and Seok Young Han. "Topology Optimization of a Vehicle’s Hood Using Evolutionary Structural Optimization." Key Engineering Materials 326-328 (December 2006): 1217–20. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.1217.
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Topology optimization of the inner reinforcement for a vehicle’s hood has been performed by evolutionary structural optimization (ESO) method. The purpose of this study is to obtain optimal topology of the inner reinforcement for a vehicle’s hood considering static stiffness and natural frequency simultaneously. To do this, the multiobjective design optimization technique was implemented. From several combinations of weighting factors, a Pareto-optimal solution was obtained. Optimal topologies were obtained by the ESO method, i.e., by eliminating the elements having the lowest efficiency from the structural domain. As the weighting factor of the elastic strain efficiency goes from 1 to zero, it is found that the optimal topologies transmits from the optimal topology of static stiffness problem to that of natural frequency problem. Therefore, it was concluded that ESO method is effectively applied to topology optimization of the inner reinforcement of a vehicle’s hood.
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Kim, Jang Hoon, and John B. Mander. "Influence of transverse reinforcement on elastic shear stiffness of cracked concrete elements." Engineering Structures 29, no. 8 (August 2007): 1798–807. http://dx.doi.org/10.1016/j.engstruct.2006.10.001.
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MUNHOZ, F. S., and J. S. GIONGO. "Variation analysis effects of square and rectangular columns section with different longitudinal reinforcement rates in the main reinforcement two pile caps analysis." Revista IBRACON de Estruturas e Materiais 10, no. 3 (June 2017): 760–87. http://dx.doi.org/10.1590/s1983-41952017000300011.
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ABSTRACT The transition between the columns of building and foundation had been used the pile-cap structural elements. The most appropriate method for the pile caps design is the Strut and Tie model. In most cases in the structural project is not considered the influence of certain parameters: the columns cross section and the amount of longitudinal reinforcement columns. This paper studies the effect of the variability of the geometric section of square and rectangular columns, with different longitudinal reinforcement rates, in the main reinforcement traction two pile caps. The basis for study was development experimental program in the Structures Laboratory of EESC-USP . The traction reinforcement bars strains are reduced the pile-caps central section to pile-caps sections that approximate cutting axis shows the experimental results. In models with columns of elongated rectangular section and with great reinforcement rates this reduction is smaller.
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Savin, Sergey Yu. "Stability of eccentrically compressed reinforced concrete elements under special impacts with account taken of shear deformations." Vestnik MGSU, no. 1 (January 2021): 49–58. http://dx.doi.org/10.22227/1997-0935.2021.1.49-58.
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Introduction. When structural models of reinforced concrete frameworks of buildings and structures are designed, bars and plates simulate structural elements. As rule, such an approach entails rigid cohesion between reinforcement bars and concrete; thus, it fails to simulate the true nature of their joint action in the areas having high stress gradients, for example, beam-column junctions. In this regard, it’s necessary to plot analytical dependencies and develop a methodology for the stability analysis of the strain state of bar elements of reinforced concrete frameworks of buildings and structures with account taken of shear deformations at the interface between a reinforcement bar and concrete.
Materials and methods. The Rzhanitsyn composite bar theory was applied to design a stress-strain model of an eccentrically compressed reinforced concrete bar. The Kelvin-Voigt model is proposed as a rheological stress-strain model of static and dynamic resistance of concrete.
Results. Analytical dependencies needed to analyze the stress-strain state and stability of an eccentrically compressed reinforced concrete bar exposed to dynamic loading, were plotted. These dependencies take account of shear deformations at the interface between reinforcement bars and concrete. A nonlinear calculation algorithm was developed; it took account of the elastoplastic behavior of concrete and steel bars, when the stability problem of an eccentrically compressed dynamically loaded reinforced concrete bar was solved.
Conclusions. Analytical dependencies, obtained by the author, allow to take account of shear deformations at the interface between reinforcement bars and concrete in eccentrically compressed reinforced concrete elements of frameworks of buildings and structures for the purpose of analyzing the stability of such elements exposed to special impacts caused by the unexpected failure of one bearing element of a structural system.
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Vybranets, Yu, S. Vikhot, S. Burchenya, and I. Babyak. "ASSESSMENT OF CARRYING CAPACITY OF THE ROUND IN PLAN REINFORCED CONCRETE FOUNDATION FOR THE SILO." Bulletin of Odessa State Academy of Civil Engineering and Architecture, no. 83 (June 4, 2021): 28–37. http://dx.doi.org/10.31650/2415-377x-2021-83-28-37.
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During the design, installation and operation of silos, they have defects and damage of various kinds, which affect the stress-strain state and durability of structural elements. Timely inspections and determination of technical conditions of structural elements of the structure and the site as a whole, will establish the possibility of its further safe operation or the need to restore operational properties by ensuring structural safety and reliability of structures. Therefore, the development of design schemes, methods of calculating the stress-strain state, life expectancy and further reinforcement for round reinforced concrete elements of silos with local damage, is quite relevant. Improper maintenance and operation of structural elements, as well as errors in the design and installation in the future lead to unusable for normal operation and sometimes an emergency. The development of projects to strengthen existing structures is a very responsible matter. The most common solution for strengthening existing foundations is to increase the area of support of the foundation cushion, which is not always possible in a compact building. The purpose of the work is to determine the technical condition of the building structures of the silo and the results of calculations performed in the PC Lira, to offer options for strengthening the foundation on a specific example. Structural solutions of the reinforced concrete monolithic foundation of the silo, the main defects and damages determined by the technical condition of the structure are given. For further safe operation of the structure, it is recommended to reinforce the wall foundations by gluing composite tapes and perform reinforcement of the foundations by controlling the growth of piles in accordance with the additional working design of the structure reinforcement. If the latest recommendations on strengthening and adhering to the safe and reliable operation of construction and structures are followed, further operation of building structures will be safe.
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Barabash, M. S., I. V. Genzerskyi, А. V. Pikul А.V., and О. Yu Bashynska. "METHODS OF MODELING OF COMPOSITE MATERIALS AND COMPOSITE STRUCTURES ON «LIRA-SAPR»." ACADEMIC JOURNAL Series: Industrial Machine Building, Civil Engineering 1, no. 48 (March 27, 2017): 129–37. http://dx.doi.org/10.26906/znp.2017.48.786.
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This paper provides detailed suggestions for the process of structural reinforcement modeling by composite materials on the software package «LIRA-SAPR». It also provides the implementation of bearing capacity checks for reinforced elements on the program called «ESPRI». The article offers an algorithm for calculation of the construction objects in case of design situation changing, considering the modeling of the composite structure reinforcement. It considered the modeling process of reinforcement of structures using classical methods, such as using of metal casing. It also investigated a numerical modeling example of the frame structure reinforcement, with the selection and verification of the composite material.
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Sobhy, Asmaa, Louay Aboul Nour, Hilal Hassan, and Alaaeldin Elsisi. "Behavior of Structural Concrete Frames with Hybrid Reinforcement under Cyclic Loading." Frattura ed Integrità Strutturale 15, no. 57 (June 22, 2021): 70–81. http://dx.doi.org/10.3221/igf-esis.57.07.
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A substantial amount of work was carried out on the use of fiber-reinforced polymer (FRP) in reinforcing concrete structural elements, which demonstrated considerable inelasticity or deformity through monotonous and fatigue loads. Even so, the action of FRP bars in FRP-RC columns and frame structures has not yet been studied during reversed cyclic loading. In this research, reversed cyclic loading was conducted on three beam-column joint models using the finite element method with ANSYS software. The first model was for a joint designed with steel rebar for both the longitudinal reinforcement and stirrups. Glass fiber reinforced polymer (GFRP) rebar was used to reinforced the second joint model for both longitudinal reinforcement and steel stirrups, and the third joint model was designed with hybrid steel/GFRP reinforcement for the longitudinal reinforcement and steel stirrups. The performance of the three models under reversed cyclic loading, such as load vs. story drift and energy dissipation capacity, were compared. The GFRP-reinforced model displayed a predominantly elastic activity up to failure. Although its energy dissipation was weak, its performance in terms of total storey drift demand was satisfactory.
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Duvnjak, Ivan, Ivan Klepo, Marijana Serdar, and Domagoj Damjanović. "Damage Assessment of Reinforced Concrete Elements Due to Corrosion Effect Using Dynamic Parameters: A Review." Buildings 11, no. 10 (September 22, 2021): 425. http://dx.doi.org/10.3390/buildings11100425.
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Corrosion of reinforcement is one of the main problems related to the durability of reinforced concrete structures. This can cause cracks and a separation of the protective layer, as well as reducing strength and structural stiffness, which can result in numerous human casualties. Visual inspection is a standard method of assessing the condition of reinforced concrete structures whose limitations, such as time, interpretability, accessibility, etc., may affect its effectiveness. Therefore, damage determination methods based on dynamic parameters are becoming more and more prominent in the assessment of damage to reinforced concrete structures. The aim of this paper is to review the literature regarding the determination of corrosion of reinforcement by methods based on dynamic parameters, and to identify future research to develop a method that would detect corrosion problems in time through a continuous system of structural health monitoring.
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Błaszczyński, Tomasz, and Przemysław Wielentejczyk. "Renovation of Shaft Mining Building No. 2 in Kłodawa Salt Mine/ Renowacja Budynku Nadszybia Nr 2 Na Terenie Kopalni Soli “Kłodawa” S.A." Civil And Environmental Engineering Reports 17, no. 2 (June 1, 2015): 15–23. http://dx.doi.org/10.1515/ceer-2015-0017.
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Abstract The paper presents the renovation process of the shaft mining building No. 2 situated in the Kłodawa Salt Mine. A technical state of the facility required immediate reinforcement of structural elements, which was confirmed by expertise carried out by the authors. A lack of repairs could be the cause of building damage. The progress of corrosion in some steel profiles of columns or floors was very advanced. The state of the building was rapidly worsening due to the very high salinity of the indoor environment, moisture (building not insulated) and vibrating engines of machinery operating on different floors felt throughout the facility. After carrying out the technical expertise, working plans and specifications, and relevant numerical analysis, the modernization process was realized by the reinforcement or rebuilding of structural elements.
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Pacheco, João, Jorge de Brito, Carlos Chastre, and Luís Evangelista. "Eurocode Shear Design of Coarse Recycled Aggregate Concrete: Reliability Analysis and Partial Factor Calibration." Materials 14, no. 15 (July 22, 2021): 4081. http://dx.doi.org/10.3390/ma14154081.
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This paper contributes to the definition of design clauses for coarse recycled aggregate concrete. One of the main reasons for scepticism towards recycled aggregate concrete is the perceived notion that the heterogeneity of recycled aggregates may increase the uncertainty of the behaviour of concrete. Therefore, the paper uses structural reliability concepts to propose partial factors for recycled aggregate concrete’s design for shear failure. The paper builds upon a previous publication by the authors, in which the model uncertainty of recycled aggregate concrete elements designed for shear, with and without shear reinforcement, was compared with that of natural aggregate concrete elements. In that paper, the statistics of the model uncertainty for recycled aggregate concrete shear design were indeed found to be less favourable than those of natural aggregate concrete. Therefore, a partial factor for recycled aggregate concrete design is needed to ensure safety. This paper presents partial factors calibrated with explicit reliability analyses for different cases of design concerning beams (in the case of shear design of elements with shear reinforcement) and slabs (for the design of elements without shear reinforcement). For full incorporation of coarse recycled concrete aggregates and the design of elements without shear reinforcement, the calibrated partial factor reduces the design value of shear resistance by 10% (design with EN1992) or 15% (design with prEN1992) in comparison to natural aggregate concrete’s design. For the shear design of elements with shear reinforcement, the partial factor decreases resistance by 5% but a sensitivity analysis showed that the reduction might be, under pessimistic expectations, of up to 20%.
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Nour, Ali, Bruno Massicotte, Emre Yildiz, and Viacheslav Koval. "Finite element modeling of concrete structures reinforced with internal and external fibre-reinforced polymers." Canadian Journal of Civil Engineering 34, no. 3 (March 1, 2007): 340–54. http://dx.doi.org/10.1139/l06-140.
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Externally bonded fibre-reinforced-polymer (FRP) laminates and fabrics have been successfully used for strengthening damaged or deficient concrete members, whereas internal FRP reinforcements are becoming an efficient alternative to steel reinforcement, particularly in corrosive environments. Despite the enormous progress that has been observed in the last decade, further research is still required to consolidate recent developments and expand the scope of application of FRPs for structural uses. Nonlinear finite element analysis combined with laboratory testing constitutes an efficient approach for pursuing this objective. The scope of this paper is to illustrate, through a selection of a wide variety of typical applications, the contribution of a refined three-dimensional (3-D) constitutive model for investigating the nonlinear response of concrete structures reinforced with internal and external FRPs. The analyses are carried out using a general and portable constitutive concrete model implemented as a user-defined subroutine at Gauss integration point level in commercial finite element software. The constitutive law follows a 3-D hypoelastic approach that models the nonlinear behaviour of concrete using a scalar damage parameter that accounts for the anisotropic behaviour of partially confined concrete and the inelastic volume expansion upon reaching the peak strength. In tension, the model adopts a macroscopic approach that is directly integrated into the concrete law. It simulates implicitly the reinforcing bar – concrete interaction using tension-stiffening factors modified according to the nature of reinforcement that vary as a function of the member strain. The applications include results of well-known test series published in the literature on beams with external and internal FRP reinforcement, slabs with internal reinforcements, bond failure analysis of external FRP, and the effect of confinement on the behaviour in compression of circular and square elements. The paper demonstrates the ability of the concrete model to correctly simulate the behaviour of structural elements reinforced with FRPs at service load level and reproduce failure mechanisms and loads that are consistent with the experimental observations.Key words: constitutive model, nonlinear analysis, finite element, reinforced concrete, glass-fibre-reinforced polymer (GFRP), carbon-fibre-reinforced polymer (CFRP), strengthening, steel.
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Elmenshawi, Abdelsamie, Tom Brown, and Nigel Shrive. "A fuzzy logic approach to predict seismic ductility and shear strength of reinforced concrete elements." Canadian Journal of Civil Engineering 37, no. 9 (September 2010): 1232–46. http://dx.doi.org/10.1139/l10-052.
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Structures require ductility to withstand severe earthquake-induced loads and remain standing. A new method for modelling seismic displacement ductility is proposed here, in which a fuzzy inference system is utilized to include the uncertainty in the parameters that influence this behaviour. The proposed model is also used to determine the lateral shear strength, a vital parameter in seismic design. Experimental data are presented for beams subjected to cyclic loading. Numerous input design parameters were considered including the beam width/depth ratio, the longitudinal reinforcement ratio, the bottom/top reinforcement ratio, the concrete compressive strength, the transverse reinforcement strength, and the shear span-to-depth ratio. Output parameters included the displacement ductility and lateral shear strength. The proposed model can predict the outputs successfully with an error of ±20%, but is more effective in predicting shear strength than displacement ductility.
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Rahardianto, Suhariyanto, Trias. "INVESTIGASI KERUNTUHAN SEBAGIAN STRUKTUR BETON LANTAI 2 PADA PROYEK PEMBANGUNAN DAN REHABILITASI PASAR X." PROKONS Jurusan Teknik Sipil 8, no. 1 (February 28, 2014): 33. http://dx.doi.org/10.33795/prokons.v8i1.56.
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Partial collapse of Concrete Structure at 2nd Floor of the Development and Rehabilitation Project Market X, occurred during heavy rain and strong winds conditions. Reconstructively, the collapse of second floor area confined by D, G, 5 and 9 lines, are indicated as the result of domino effect of the collapse preceded by the collapse of the beam midspan along the line of F7-F8. Some factors suspected as the cause of the collapse; the weakness of the composite action of concrete and its reinforcement, and the lack of reinforcement detailing implemented at most structural elements. Action plan that needed be done is temporer retrofitting, demolitioning and cleaning up the wastes. reworking on collapsed structure, repairing and reinforcing some poor structural elements. In addition, the adequacy of concrete cover depth is also need attention, due to the location of the X market which is in the corrosive environment, therefore a guarantee of preventing steel reinforcement from corrosion is required for it will greatly affect to the strength of concrete structures.Keywords: concrete structure, Reconstructive, domino effect, composite action, detailing