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1
Šimek, Ondřej, Miloš Zich, Miloslav Janda, Petr Daněk, and Radim Nečas. "Testing of the Prefabricated Reinforced Concrete Pillars." Solid State Phenomena 309 (August 2020): 234–39. http://dx.doi.org/10.4028/www.scientific.net/ssp.309.234.
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The subject of the article is the introduction of the results of the first series of tests of precast reinforced concrete pillars. These are the pillars simulating parts of walls that can, for example, form in the precast wall of residential buildings after an opening has been carved. The pillars are variously reinforced: from the simple reinforcement with wire mesh, to the reinforcement with standard reinforcement bars. Depending on the type of reinforcement and the type of loading, the deformation and tension of the individual pillars are studied. All of the pillars failed due to local compression of the concrete, a transversal tensile failure occurred in all cases.
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Čech, Jindřich, Jiří Kolísko, Petr Tej, Petr Pokorný, and Alena Kohoutkova. "Experimental and Theoretical Analysis of I-Pillars of Noise Barriers Made of Prestressed Steel Fiber Concrete, Prestressed Concrete and Reinforced Concrete with Footings Length of 600 mm." Key Engineering Materials 709 (September 2016): 105–8. http://dx.doi.org/10.4028/www.scientific.net/kem.709.105.
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This paper deals with the experimental testing and theoretical analysis of the flexural load-bearing capacity of I-shaped pillars in noise barriers made of reinforced concrete, prestressed concrete and prestressed steel fiber reinforced concrete. The pillars were loaded as a cantilever under a flexural load, which corresponds to their actual loading when the effect of wind on the panels of the noise barrier is taken into account. For the purpose of the present research, three specimens of I-pillars were tested. The results of the experimental loading tests, as well as the calculated results and the comparison between them, are herein presented.
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Šimek, Ondřej, Miloš Zich, Miloslav Janda, and Radim Nečas. "The Influence of Various Types of Reinforcement of the Concrete Pillars of Precast Walls with an Opening." Solid State Phenomena 322 (August 9, 2021): 94–99. http://dx.doi.org/10.4028/www.scientific.net/ssp.322.94.
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The subject of the article is a comparison of the precast reinforced concrete pillars with different types of reinforcement. These are the pillars simulating parts of walls that can, for example, form in the precast wall of residential buildings after an opening has been carved. The pillars are variously reinforced: from the simple reinforcement with wire mesh to the reinforcement with standard reinforcement bars. Behavior of the pillars, that have been subjected to two types of experiments in the past, is verified by software for non-linear analysis for concrete structures. Depending on the types of loading, the ultimate limit state, deformation and stress state of the individual pillars are studied.
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Trapko, Tomasz, Michał Musiał, and Andrzej Ubysz. "Failure of pillar of sports and entertainment hall structure." MATEC Web of Conferences 146 (2018): 02008. http://dx.doi.org/10.1051/matecconf/201814602008.
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This paper deals with the failure of one of the sports and entertainment halls in Poland. The facility was built in the years 1977-85. Its main load-bearing members were three-hinged double-sloped frames with a total span of 45 m. The main girders of the frames were made of glued-laminated timber. The girders rest on reinforced concrete pillars. Because of the considerable expansion forces the facility was founded on concrete padstones. In the summer of 2016 one of the reinforced concrete pillars was found to have failed. It was established that the failure condition was mainly due to construction errors. A way of strengthening all the pillars with additional RC members was proposed.
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Polskoy, Petr, Sergey Georgiev, Viktor Muradyan, and Aleksandr Shilov. "The deformability of short pillars in various loading options and external composite reinforcement." MATEC Web of Conferences 196 (2018): 02026. http://dx.doi.org/10.1051/matecconf/201819602026.
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The test results on deformation and rigidity of short compressed reinforced concrete pillars with various types of external transverse and longitudinal composite reinforcement are given. The samples from heavy concrete with design strength class B30-35 were tested, having the same cross-section 250x125 (h) mm and length 1200mm with flexibility λh = 10. The pillars were reinforced with 4Ø12A500 in the longitudinal direction and with tied clamps Ø6B500, installed with the step of 180 mm - in the transverse direction. The purpose of the experiment was to determine the effect of the rigidity of reinforced elements on the deformability of short experimental samples. It was necessary to determine how the eccentricity of the load application influences on the variation in the rigidity of the reinforced elements. The purpose was also to obtain data on the deformability of pillars loaded with small eccentricities, i.e. when e0 = 0.16h. It was found that the most effective type for short pillars reinforcement is a three-layer holder, which has maximum rigidity and minimal deformability. However, its efficiency gradually decreases when the eccentricity of the load application increases.
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Phulara, Nav Raj, and Jagadish Bhattarai. "Assessment on Corrosion Damage of Steel Reinforced Concrete Structures of Kathmandu Valley Using Corrosion Potential Mapping Method." Journal of the Institute of Engineering 15, no. 2 (July 31, 2019): 45–54. http://dx.doi.org/10.3126/jie.v15i2.27640.
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Present study is focused to investigate the corrosion damage conditions of steel reinforced twenty eight different types of the concrete structure samples from Kathmandu valley using a non-destructive technique of the corrosion potential mapping (CPM) method in accordance with ASTM C876-91 Standards. It is found from the present assessment that the building roof of public owners house, hume pipes and building pillars used in Kathmandu valley are generally under the low risk of reinforced steel corrosion in these concrete structures, that is, less than 10 % probability of the corrosion damage, although the fencing pillars and the roof slabs of different office buildings are found to be high risk of reinforced steel corrosion damage, that is, more than 90 % probability of corrosion damage among twenty eight concrete structures.
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Mailyan, Dmitry, and Darya Bogomazyuk. "Innovative methods of strengthening reinforced concrete structures." MATEC Web of Conferences 196 (2018): 04068. http://dx.doi.org/10.1051/matecconf/201819604068.
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The article considers some of the most innovative methods of reinforced concrete compressed elements: strengthening of elements with the help of pre-compressed longitudinal reinforcing elements, strengthening by means of concrete padding device, of low strength concrete, to strengthen the elements by biaxial transverse compression of concrete and method is to strengthen the elements with a pre-stretched diagonal reinforcement. The test results on deformation and rigidity of compressed reinforced concrete pillars are given. For each variant of rack reinforcement, depending on their flexibility and the relative eccentricity of the external force, the most technologically and economically feasible method of amplification is proposed.
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Lazarevska, Marijana, Milos Knezevic, and Meri Cvetkovska. "Application of Artificial Neural Networks for Prognostic Modeling of Fire Resistance of Reinforced Concrete Pillars." Applied Mechanics and Materials 148-149 (December 2011): 856–61. http://dx.doi.org/10.4028/www.scientific.net/amm.148-149.856.
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Artificial neural networks can be used for building prognostic models of various engineering problems. This paper presents an example of how we can predict the time of fire resistance based on the given experimental and numerical results. The analyses concerning the behavior of the reinforced-concrete construction elements during the standard fire, together with the basic theoretical information and detailed problem description, as well as the graphical curves for the fire resistance of the reinforced-concrete pillars, are given in the doctoral theses of Prof. Cvetkovska [3]. Using the concepts of artificial neural networks and the results of the performed numerical analyses as input parameters we made the prediction model for determination of the time of fire resistance of reinforced-concrete pillars. The neural network generated excellent results which will be presented further below in this paper.
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Holčapek, Ondřej, Jan Machovec, and Pavel Reiterman. "Strengthening of Masonry Pillars by Textile Reinforced Concrete Wrapping of Different Thickness." Materials Structures Technology 1, no. 2 (January 8, 2019): 42–49. http://dx.doi.org/10.31448/mstj.01.02.2018.42-49.
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Chmielewski, R., A. Baryłka, and J. Obolewicz. "Analysis of design solutions for strengthening the load-bearing structure of a building for further safe use." Journal of Achievements in Materials and Manufacturing Engineering 1, no. 104 (January 1, 2021): 5–10. http://dx.doi.org/10.5604/01.3001.0014.8481.
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Purpose: The article present issues related to strengthening the supporting structure of swimming pool in a primary school building paying special attention to the damaged reinforced concrete pillars of supports. Design/methodology/approach: Analysis of design solutions strengthening the supporting structure of the building for further safe use. Findings: Engineers noticed multiple cracks and deformations in rebar while performing on-site verification. Three posts (pillars) were damaged in the basement rooms and needed repair. Research limitations/implications: Structural elements of building structures wear out over time and cause damage that requires repair. The scope of repair works should be designed and carried out in accordance with applicable law. Practical implications: The solution, which has been designed in great detail, allows the building to continue working without the risk of damaging the structure. Originality/value: Due to the scale of damage to the reinforced concrete columns in the basement of the building, it was necessary to protect the facility against a construction failure.
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Krasnoshchekov, Y. V. "SAFETY OF REINFORCED CONCRETE BRIDGES WITH SPANS STRUCTURES." Russian Automobile and Highway Industry Journal 15, no. 6 (January 11, 2019): 922–32. http://dx.doi.org/10.26518/2071-7296-2018-6-922-932.
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Introduction. The author presents the results of the reliability analysis of the structural systems in spans of bridges.Materials and methods. The analysis of published materials for the purpose of using them in the design of reinforced concrete bridges, in connection with changes in design standards and tightening of regulatory requirements for safety is made by the author.Results. The results of surveys of slab superstructures indicate the reliability and durability of typical structures operated under normal conditions, but in emergency situations there is a danger of progressive collapse. Therefore, in such conditions, split schemes of multi-span structures are unacceptable. The research tasks to ensure the durability of slab superstructures are formulated. In particular, the task of developing the method of durability calculation in case of one of the pillars failure in the continuous span structure, taking into account the dynamic effect is illustrated.Discussion and conclusion. Changes in design of slab structures of bridge cause the necessity to study the reliability and failure in emergency situations.
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Purwanto, Purwanto. "Peningkatan Kestabilan Pilar Tambang Bawah Tanah Marmer di PT Gunung Marmer Raya." JURNAL TEPAT : Applied Technology Journal for Community Engagement and Services 3, no. 1 (June 30, 2020): 27–38. http://dx.doi.org/10.25042/jurnal_tepat.v3i1.79.
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PT Gunung Marmer Raya (PT GMR), a room and pillar underground marble mining is located about 73 km to the north from Makassar, in Desa Tabo-Tabo, Kecamatan Bungoro, Kabupaten Pangkep. In the mining location, discontinuities are found as joint structure across the production area. The purpose of this service is to make pillar redesign that can improve the stability of underground mine. These activities start with field observation, determining the rock characteristic through sample testing in the laboratory, classifying the rock mass using Q-system method, up to redesigning a form of implementation to increase the stability of the marble underground mine. According to calculation of rock mass classification using Q-System, the recommended buffering is systematic bolting and fiber reinforced sprayed concrete as thick as 5-6 cm with spacing between bolts of 2.2 meters, or systematic bolting without concrete layering with spacing between-bolt 1.8 meter. Joint monitoring, especially on pillars, need to be done routinely so joint movement could be anticipated for progressive movement. The existing dimensions of pillar 5 m x 5 m in length and width is not recommended due to the safety factor is under 1,0 (unstable condition). Based on observation and analytic calculation, for each pillar height of up to 11 meters the pillar is recommended to redesign with length and width 5 m x 9 m for the chain pillar (safety factor around 1.35-1.49); and 5 m x 12 m for barrier pillars (safety factor around 1.58-1.74).
Key Words: Underground mining; room and pillar method; Q-system classification system; pillar stability; marble mining.
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Berkowski, Piotr, and Grzegorz Dmochowski. "Structural condition assessment of a reinforced concrete driveway." MATEC Web of Conferences 289 (2019): 10002. http://dx.doi.org/10.1051/matecconf/201928910002.
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The reinforced concrete structure of a driveway built in the eighties of the 20th century is under consideration. It is a single-storey structure with a length of approx. 66.00 m, made in the form of a reinforced concrete skeletal structure, consisting of 7 frames with cantilevers, spaced at 9.00 m: 3 frames in the horizontal part of the driveway are three-span ones, and 4 in the sloping part are single-span frames. The driveway frame main beams have a rectangular cross-section and are based on pillars that have been placed on the spread footing these elements form a monolithic structure. Prefabricated reinforced concrete hollow floor plates were laid on them in the central part of the driveway, and in the outer parts the driveway floor was made of hollow clay slab blocks (Ackerman type). At the time of investigation, the upper layers of the driveway consisted of a surface waterproofing layer, a concrete slab of approx. 10 cm thickness made on a 1 cm sand layer. However, no internal waterproofing layer was found as was in the original design. The paper describes the process of determining the current technical condition of the reinforced concrete driveway structure, paying attention to the design and construction of the object, its operation (including the issues of durability of concrete under the conditions of possible impacts of the marine environment). Static and strength calculations were also performed (supported by concrete and reinforcement tests) and the conditions for further operation of the driveway were analyzed as well as concepts of rehabilitation.
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Lenticchia, Erica, Amedeo Manuello Bertetto, and Rosario Ceravolo. "AE propagation velocity calculation for stiffness estimation in Pier Luigi Nervi’s concrete structures." Curved and Layered Structures 8, no. 1 (January 1, 2021): 109–18. http://dx.doi.org/10.1515/cls-2021-0010.
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Abstract In the present paper, the acoustic emission (AE) device is used with an innovative approach, based on the calculation of P-wave propagation velocity (vp ), to detect the stiffness characteristics and the diffused damage of in-service old concrete structures. The paper presents the result of a recent testing campaign carried out on the slant pillars composing the vertical bearing structures designed by Pier Luigi Nervi in one of his most iconic buildings: the Hall B of Torino Esposizioni. In order to investigate the properties of these inclined pillars, localizations of artificial sources (hammer impacts), by the triangulation procedure, were performed on three different inclined elements characterized by stiffness discrepancies due to different causes: the casting procedures, executed in different stages, and the enlargement of the hall happened a few years later the beginning of the construction. In the present work, the relationship between the velocity of AE signals and the elastic characteristics (principally elastic modulus, E) is evaluated in order to discriminate the stiffness level of the slanted pillars. The procedure presented made it possible to develop an innovative investigation method able to estimate, by means of AE, the state of conservation and the elastic properties and the damage level of the monitored concrete and reinforced concrete structures.
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Močnik, Robert, Božo Koler, Dejan Zupan, and Tomaž Ambrožič. "Investigation of the Precision in Geodetic Reference-Point Positioning Because of Temperature-Induced Pillar Deflections." Sensors 19, no. 16 (August 9, 2019): 3489. http://dx.doi.org/10.3390/s19163489.
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To perform geodetic measurements of displacements of the ground and manmade constructions, stabilised reference points are needed from which control points on the object or its surroundings could be measured. Reference points are most commonly stabilised with reinforced concrete pillars; however, they are not always constructed in an appropriate manner. The influence of temperature variation within a pillar on the position of the fixed screw for forced centring is not negligible and should be considered when performing precise measurements. In this research paper, the displacement of a pillar was calculated as a result of the temperature changes in the pillar, and then an experiment was performed in which the pillar was heated from one side, and the horizontal displacement of the fixed screw for forced centring was measured. Both, calculations and measurements, show that at a temperature difference of 16.2 °C, the fixed screw on a 1.5 m high pillar moves by approximately 1 mm, which is a displacement that should be taken into account in precise measurements.
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N. Hanoon, Ammar, Salah R. Al Zaidee, Qais Sahib Banyhussan, and Ali A. Abdulhameed. "Modified Strut Effectiveness Factor for FRP-Reinforced Concrete Deep Beams." International Journal of Engineering & Technology 7, no. 4.20 (November 28, 2018): 485. http://dx.doi.org/10.14419/ijet.v7i4.20.26248.
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A few examinations have endeavored to assess a definitive shear quality of a fiber fortified polymer (FRP)- strengthened solid shallow shafts. Be that as it may, need data announced for examining the solid profound pillars strengthened with FRP bars. The majority of these investigations don't think about the blend of the rigidity of both FRP support and cement. This examination builds up a basic swagger adequacy factor model to evaluate the referenced issue. Two sorts of disappointment modes; concrete part and pulverizing disappointment modes were examined. Protection from corner to corner part is chiefly given by the longitudinal FRP support, steel shear fortification, and cement rigidity. The proposed model has been confirmed utilizing an aggregate of 45 databases gathered from writing. Results show that the proposed model can evaluate a definitive shear quality. Structure of trial (DOE) programming was used to examine the impact of different parameter esteems on a definitive shear quality limit. The outcomes demonstrate that the shear range to powerful profundity proportion has the most astounding impact contrasted and alternate parameters.
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Andreini, Marco, Anna de Falco, Linda Giresini, and Mauro Sassu. "Seismic Consolidation of ’60s Pilotis R.C. Building for Social Housings with SCC-Steel Shear Walls." Applied Mechanics and Materials 638-640 (September 2014): 1937–42. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.1937.
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The reinforcement of a r.c. building for social housing has been achieved by using Steel-Concrete Composite (SCC) walls at the ground floor, preceded by temporary brick pillars for structural deficiency to vertical loads, due to the poor load capacity of the r.c. columns. The SCC walls have been realized first by placing steel columns on both sides of the existing pillars and, after removal of the temporary brick piers, by merging the steel columns in the cast of the new walls. The top of the walls has been connected to the upper floor in order to ensure the diffusion of the seismic forces. Foundations have been reinforced to support the seismic base shear.
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Biosca, Juan, Gabriel Fabra, Jose Vercher, Maria Soriano, Gracia Lopez, and Santiago Tormo. "Influence of High Temperatures on Concrete Pillars Confined with CFRP." Applied Mechanics and Materials 887 (January 2019): 64–71. http://dx.doi.org/10.4028/www.scientific.net/amm.887.64.
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Concrete is a quite recent material in the history of architecture. However, there are a large number of buildings whose structure consists on this material nowadays. Despite its excellent performance, concrete has a useful lifetime. When this time comes to its end, the structural element needs to be treated, repaired or replaced. We are getting to the point at which many of the concrete constructions are reaching, or already surpassing, the useful lifetime of the material. At this point, the Carbon Fiber Reinforced Polymer (CFRP) takes on importance, appearing on the market as a modern and high performance tool, in terms of structural reinforcement of the concrete. Nevertheless, this relatively new system presents yet some aspects to study and research, such as its long-term behaviour under extreme conditions. This is the departure point of our research, focused on the response of the CFRP system, both fiber and matrix, to adverse temperature conditions. This high and maintained temperature can be reached in places such as structures undergone to large periods of solar radiation around Equator latitudes, machinery installations enclosures which generate high temperatures focused on specific points, and brief small fires, among other situations, which surpass the maximum service temperature recommended by the manufacturers. In order to study this influence, a comparison of the compressive strengths of three groups of standard concrete test specimens has been carried out. Each group consisted of three cylindrical specimens, all manufactured on the same date. The first two groups were tested after their 28 day curing in chamber: one of them without any confinement and the other with CFRP sheet applied according to the manufacturer's specifications. The third group of specimens spent 90 days on a climatic chamber subjected to a temperature of 75°C, above the maximum temperature recommended by the manufacturer, 50°C. This third group was tested 388 days after their manufacture. In order to obtain a reliable basis on which to compare the effective strength provided by the deteriorated CFRP, it was needed to calculate the acquisition of theoretical strength that the concrete would have reached after the mentioned period of time without any added reinforcement. With all the results, it is possible to conclude that, after this period of heat attack, despite having produced an aesthetic degradation of the CFRP sheets, most of the compressive strength of the specimens remains.
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Mañero-Sanz, Hugo, Eva M. García del Toro, Vicente Alcaraz-Carrillo de Albornoz, and Alfredo Luizaga Patiño. "Method for the Improvement of the Elasticity Module of Concrete Specimens by Active Confinement." Sustainability 11, no. 12 (June 14, 2019): 3289. http://dx.doi.org/10.3390/su11123289.
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The purpose of this work is to improve the modulus of elasticity of reinforced concrete pillars in the area where it is known with certainty that the concrete is elastic. To achieve this, an innovative method was devised to introduce an initial tension ( σ i ) resulting in an 11% increase in the working compression. Three concrete batches of five specimens each were prepared for this study. The first batch was used as a control without applying any reinforcement, the second was reinforced with a carbon fiber fabric (CF) layer in the usual way, and in the third batch, an initial tension was introduced to the CF fabric by a technique devised for this purpose. After measuring the modulus of elasticity of each of the specimens that made up each batch, it was observed that the modulus of elasticity obtained for the specimens in the third batch was 8% higher than the specimens in the first and second batches. The compression–deformation behaviour of the specimens observed throughout the study allows us to propose a stress–strain model with three different behaviours: linear elastic, parabolic elasto-plastic and linear elastic.
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Sader Mohammed, Ahlam, and Laith Nasser Hussain. "Finite Element Modeling for Self-Compacting Reinforced Concrete Deep Beams Containing Web Openings." International Journal of Engineering & Technology 7, no. 4.20 (November 28, 2018): 546. http://dx.doi.org/10.14419/ijet.v7i4.20.26416.
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A nonlinear limited component display is utilized to approve the consequences of limited component investigation with that of test work got from written works with the end goal to foresee execution of self-compacted strengthened solid; profound pillars incorporate roundabout web openings. Six indistinguishable profound bars were considered for this reason; one of them was strong that considered as a control bar. ANSYS PC program was utilized to accomplish the investigation of these bars. Examination between the test and limited component strategy results shows a satisfactory understanding with the goal that the proposed model can be embraced in future for further investigations. The diagnostic tests which were improved the situation different cases considered showed that the heap redirection conduct and a definitive burdens are in great concurrence with the distributed libratory results. The outcomes demonstrate that most extreme contrast between the anticipated numerical extreme burdens to the trial extreme load for all cases was under (14%); while the greatest rate distinction for redirection esteems was about 11%. Likewise, the extent of the openings and its area influence the heap conveying limit of the shafts.
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Semerak, M., D. Kharyshyn, N. Ferents, and T. Berezhanskyi. "INVESTIGATION OF THE EFFICIENCY OF THE STEEL TUBE CONFINEMENT CONCRETE PILLARS PROTECTION BY FIRE-RETARDANT MATERIALS." Fire Safety, no. 33 (December 31, 2018): 95–100. http://dx.doi.org/10.32447/20786662.33.2018.13.
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Currently, in Ukraine and abroad for the construction of high-rise buildings and structures using pipe-like structures. Wide application of pipe concrete columns is due to their high carrying capacity at relatively smaller overall dimensions due to the blocking of cracking in concrete by a steel clasp. The advantages of concrete columns should include more simplified conditions of technology of manufacturing and installation on their basis of bearing structures of floor covering.
Piping constructions consist of steel shells and concrete core. Since the steel pipe mainly provides the bearing capacity of the concrete column, its failure or reduction of stiffness, which is characteristic of the fire under the influence of its thermal factors, leads to destruction. Investigation of fire resistance of concrete structures, which are not protected by flame retardant coatings, showed that a steel clasp during a fire after 15 minutes is heated to a critical temperature of 500 ° C.The use of flame retardant coatings is an effective method of fire protection of concrete constructions, which prevents the rapid heating of steel welds and provides a normalized fire resistance limit for such structures. In this work, studies were carried out on the effectiveness of fire protection of concrete columns with different types of fire-retardant materials - mineral wool slabs, special flame retardants and flame-retardant coatings. For fire protection mineral wool materials were used ROCKWOOL plates of the series "Conlit SL150". Mineral wool plates "Conlit SL 150" consist of fibers of rocks of a basalt group, they can withstand, without melting, temperature more than 1000 ° С. The silica-based adhesive "Conlit Glue" can withstand temperatures above 900 ° C, has good adhesion when bonding Conlit SL 150 mineral wool slabs with protective structures. From the second type of fire-retardant materials, the fire-proof composition "Naktresk" was chosen on the basis of gypsum. The coating is formed in the process due to hardening of the mixture on protected surfaces. The third type of flame retardant materials is the flame-retardant intumessent coating "Pyro-Safe Flammoplast SP-A2".It has been established that with the use of fire protection systems on the basis of mineral wool plates "Conlit SL150" and fire retardant "Nutresc", the fire resistance class of reinforced concrete columns increases from R 15 to R 180. The fire protection system on the basis of the painted paint "Pyro-Safe Flammoplast SP-A2" »Increases fire resistance from R 15 to R 75
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Novikov, M. V., O. A. Sotnikova, and A. N. Goikalov. "BEARING CAPACITY OF COMPLEX STRUCTURES OF CELLULAR CONCRETE." Engineering and Construction Bulletin of the Caspian Region 112 (2021): 05–10. http://dx.doi.org/10.52684/2312-3702-2021-36-2-5-10.
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Results of tests of compressed masonry elements from small cellular blocks with foam concrete cores with short-term action of axial load are presented. The nature of the destruction of experimental elements with various reinforcement schemes and the degree of joint work of monolithic foam concrete with gas silicate masonry in a complex structure is established. The strength of these complex structural elements was evaluated and the effectiveness of their application was shown to increase the load-bearing capacity of masonry of walls and pillars in the construction of buildings of small and medium storeys. The strength gain of the compressed elements, due to the reinforcement of the cores with spatial frames, ranged from 10,5 to 12,5 %, the deviation of the theoretical strength values of the centrally compressed complex sections from the experimental ones did not exceed 10 %. One and a half-two-fold reserve of strength of solid and reinforced by foam concrete cores of masonry in case of its application in bearing walls of five-storey building was revealed.
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Botis, Marius Florin, and Camelia Cerbu. "A Method for Reducing of the Overall Torsion for Reinforced Concrete Multi-Storey Irregular Structures." Applied Sciences 10, no. 16 (August 11, 2020): 5555. http://dx.doi.org/10.3390/app10165555.
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The uneven distributions of mass and stiffness in the case of multi-storey concrete buildings lead to a torsion sensitivity of those civil structures under dynamical loadings like earthquakes or wind and gusts. In order to minimize the overall torsion, it is imperatively necessary to reduce the distance between the centre of mass (CM) and centre of stiffness (CS) in the design stage. In this context, the main purpose of this paper is to present a theoretical method of reducing torsion by minimizing the distance between CM and CS at the level of each floor of the structure. Principal stiffness axes are also changed in convenient directions so that the movement of the structure leads to a favourable plastic mechanism in the fundamental mode of vibration. To achieve the goal, the main objective is to change the dimensions and orientations of the pillars located on the perimeter of the structures. The described method was used to study: irregular shaped structures in plan; structures with stairs or with central concrete core; structures with elevation retractions. The overall torsion reducing was achieved with Matlab programs, and the verification of the results was carried out by using the software ETABS 2016.
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Bertolini, Luca, Elena Redaelli, Daniela Lattanzi, and Mariassunta Mapelli. "Conservation techniques on the reinforced concrete pillars of the church of the San Carlo Borromeo hospital in Milan." European Journal of Environmental and Civil Engineering 14, no. 4 (April 2010): 411–25. http://dx.doi.org/10.1080/19648189.2010.9693234.
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Nitto, Kazuhiko, Yasufumi Uekita, Benyan Jiang, Shigeo Oodaira, and Koji Sato. "Conservation and Restoration Guidelines for the Omo Sebua in Bawömataluo Village, South Nias, Indonesia." Asian Culture and History 8, no. 1 (February 29, 2016): 167. http://dx.doi.org/10.5539/ach.v8n1p167.
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<p class="1Body">In recent years, wooden structures have been being gradually replaced by reinforced concrete and brick buildings. Although a conservation system has been established in Indonesia, specific conservation and repair guidelines for traditional wooden buildings have not been well-regulated. This paper takes the <em>omo sebua</em> as a research subject, aims to clarify the deterioration, deformation and their causes, and to propose guidelines for its conservation.</p><p class="1Body">The results of the deterioration and deformation investigation are as following: the maximum inclination of the short pillars is 5/100, and the most common inclination is 2/100. The significant sinkage of the foundation stones reaches 56 cm and the average sinkage is 20~30 cm. The maximum inclination of side pillars is 4/100, and the most common inclination is 2/100. Besides, the corruptions of the roof frame concentrate on the gable wall and termite damages can be seen in the whole building.</p><p class="1Body">Basing on the investigation result, our proposals are as following: 1) conduct a dismantling restoration; 2) recycle the used materials as much as possible to maintain the authenticity of the building; 3) use new materials that are the same as the original ones; 4) rethatch the roofing by sago palm leaf; 5) conduct a structural diagnose, reinforce the structure against an earthquake; 6) include electrical equipment and disaster management in a restoration.</p>
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Fedorov, Evgeny, Dosanbay Bekbergenov, and Gulnar Jangulova. "Modeling and methodology for calculating the strength of a man-made bottom in a system with self-destruction of ore for ecologically safe mining." E3S Web of Conferences 192 (2020): 03018. http://dx.doi.org/10.1051/e3sconf/202019203018.
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The article discusses the features of technological solutions in the development of chromite deposits at great depths in difficult mining and geological conditions. For a system with self-destruction of ore, as well as for other similar systems, the weakest point in mining is the design of the block bottom, especially for the lower horizons, where the geomechanical situation deteriorates significantly, it becomes necessary to use more powerful supports or to erect artificial bottoms that can withstand acting loads exceeding the bearing capacity of metal supports of various modifications. The most promising solution in the conditions of development of fractured massifs is the geotechnology of creating an man-made bottom at the zone of extraction and delivery of ore mass, in the areas of conjugation overstrett and interstrett pillars, reinforced with multi-support reinforced concrete platforms, as a bearing structural element of the mining system with self-destruction of ore, which can withstand extremely high rock pressure. The article presents the results of calculating the strength of an artificial bottom in a system with selfdestruction of ore using numerical 3D modeling.
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Polskoy, Petr, Dmitry Mailyan, Sergey Georgiev, and Viktor Muradyan. "The strength of compressed structures with CFRP materials reinforcement when exceeding the cross-section size." E3S Web of Conferences 33 (2018): 02060. http://dx.doi.org/10.1051/e3sconf/20183302060.
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The increase of high-rise construction volume or «High-Rise Construction» requires the use of high-strength concrete and that leads to the reduction in section size of structures and to the decrease in material consumption. First of all, it refers to the compressed elements for which, when the transverse dimensions are reduced, their flexibility and deformation increase but the load bearing capacity decreases. Growth in construction also leads to the increase of repair and restoration works or to the strengthening of structures. The most effective method of their strengthening in buildings of «High-Rise Construction» is the use of composite materials which reduces the weight of reinforcement elements and labour costs on execution of works. In this article the results of experimental research on strength and deformation of short compressed reinforced concrete structures, reinforced with external carbon fiber reinforcement, are presented. Their flexibility is λh=10, and the cross-section dimensions ratio b/h is 2, that is 1,5 times more, than recommended by standards in Russia. The following research was being done for three kinds of strained and deformed conditions with different variants of composite reinforcement. The results of the experiment proved the real efficiency of composite reinforcement of the compressed elements with sides ratio equal to 2, increasing the bearing capacity of pillars till 1,5 times. These results can be used for designing the buildings of different number of storeys.
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Silva, Lucas Ramon Roque da, Josimara Aparecida da Silva, Matheus Brendon Francisco, Vander Alkmin Ribeiro, Michel Henry Bacelar de Souza, Patricia Capellato, Marcelo Anderson Souza, Valquíria Claret dos Santos, Paulo Cesar Gonçalves, and Mirian de Lourdes Noronha Motta Melo. "Polymeric Waste from Recycling Refrigerators as an Aggregate for Self-Compacting Concrete." Sustainability 12, no. 20 (October 21, 2020): 8731. http://dx.doi.org/10.3390/su12208731.
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The inadequate disposal of household appliances by consumers and industries have annually been generating enormous amounts of polymeric waste (PW). So, the interest in reuse of PW in civil construction has increased. The production of new cementitious materials, such as concrete with PW, proves to be a promising solution to inappropriate disposal of this waste. In this study, self-compacting concrete (SCC) was developed with partial replacement of the coarse aggregates by polymeric waste (PW) from the recycling of refrigerators. In the SCC reference mixture, Portland cement, silica fume, sand, gravel and superplasticizer were used. The study also grouped the gravel as replaced by 5%, 10%, 15% and 20% of PW. In order to analyze the samples, the following tests were used: spreading, viscosity, passing ability, compressive strength, tensile strength, microstructure, modulus of elasticity, specific gravity, absorption, voids index and electrical resistivity. The SCC found showed adequate homogeneity and viscosity, staying within the normative parameters. The mechanical resistance was above 20 MPa; specific mass between 1870 to 2260 kg/m3; modulus of elasticity ranged from 34 to 14 GPa; and electrical resistivity between 319 to 420 ohm.m. Due to the mechanical resistance, the SCC with PW can be used for structural purposes and densely reinforced structures such as pillars, beams and foundation elements.
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Fernandes, Samuel Cameli, Rodrigo Paz Barros, Hilderson da Silva Freitas, Laerte Melo Barros, and David Barbosa de Alencar. "Comparative Study of Steel Economy on fck-25 MPa and fck-50 MPa Reinforced Concrete Pillars in a 4-Story Building." International Journal of Advanced Engineering Research and Science 6, no. 12 (2019): 407–14. http://dx.doi.org/10.22161/ijaers.612.45.
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Ma’ruf, Muhammad Afief, Ulfa Fitriati, and Lailan Ni’mah. "The Behavior of Alternative Kacapuri Foundation on Alluvial Land of Central Borneo." MATEC Web of Conferences 280 (2019): 04009. http://dx.doi.org/10.1051/matecconf/201928004009.
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One of the traditional substructure forms of Borneo is the kacapuri foundation. Previous research conducted a study on this kacapuri foundation by making an alternative kacapuri foundation model by combining a raft of gelam wood with reinforced concrete pillars. The study was originally applied to peat soil, but in reality, the kacapuri foundation was applied to alluvial soils around riverbanks rather than on peatlands. Therefore, this study looks at how the behavior of bearing capacity of the foundation when it is applied on alluvial soil. The location of the study where is located in the traditional Dayak Ngaju tribe in Mandomai village, Central Kalimantan. As a reference the application of the form of foundation using the model of Dayak house Huma Hai in the form of a house on stage with the main material of ironwood. The burden of each column of the house is 9,93 kN in the middle pole position. From the research, it is found that the ultimate bearing capacity is 298 kN /m2, with its own weight is 4,816 kN.
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Medeiros, M. H. F., D. E. Giordano, E. Pereira, A. Vignolo, R. Galeano, and P. Helene. "Inspeção no palacio de la luz – Montevideo: uma visão de durabilidade." Revista ALCONPAT 2, no. 2 (May 30, 2012): 89–103. http://dx.doi.org/10.21041/ra.v2i2.30.
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RESUMOO “Palacio de La Luz” é um edifício projetado pelo arquiteto Fresnedo Siri e que foi inaugurado em 1948, em Montevideu, Uruguai. Após mais de 6 décadas em serviço, esta estrutura necessitou de uma intervenção corretiva por conta de fissuras e problemas de infiltração de água pelas fachadas, que exigiram uma inspeção e diagnóstico para obter-se subsídios adequados para a correta elaboração do projeto de reabilitação. Este trabalho de inspeção e diagnóstico foi realizado em duas etapas da sua vida útil, sendo a primeira em outubro de 2004 e a segunda em janeiro de 2009. O objetivo deste trabalho é apresentar uma comparação de resultados obtidos nas duas inspeções, possibilitando avaliar a evolução dos fenômenos de degradação ocorrida durante esses 5 anos de intervalo. As conclusões deste trabalho são que os pilares estruturais não estão comprometidos, os pilares decorativos necessitam de recuperação imediata e a velocidade de carbonatação do concreto do Palacio de La Luz sofreu uma aceleração nos últimos anos.Palavra-Chave: inspeção; diagnóstico; concreto armado; corrosão.ABSTRACTThe "Palacio de La Luz" is a building designed by architect Fresnedo Siri and was inaugurated in 1948 in Montevideo, Uruguay. After more than six decades in service, this structure required a corrective action due to cracks and water infiltration problems in the facades, which required an inspection and diagnosis to obtain adequate subsidies for the correct preparation of the rehabilitation project. This work of inspection and diagnosis was made in two stages of its service life, the first being in October 2004 and the second in January 2009. The aim of this paper is to present a comparison of results obtained in the two inspections, allowing to evaluate the evolution of the phenomena of degradation that occurred during those five years apart. The conclusions are that the structural columns are not compromised, decorative pillars need immediate recovery and the rate of carbonation of the concrete of the Palacio de La Luz has accelerated in recent years.Key words: inspection; diagnosis; reinforced concrete; corrosion.
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Queiroz Junior, Ailton, and Antonio Ribeiro Santos Junior. "ANÁLISE DE SEGUNDA ORDEM DE ESTRUTURAS EM CONCRETO ARMADO." Revista Científica Semana Acadêmica 9, no. 206 (September 16, 2021): 1–23. http://dx.doi.org/10.35265/2236-6717-206-9100.
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With the expressive increase in the demand for increasingly tall and robust constructions, plus more and more complex structural details that end up becoming a key element for the projects of the structures of the undertakings, it is important to consider the efforts made by the reinforced concrete structures are subjected. In this sense, the present work has as objective the approach of the parameters of global stability a and Yz followed by the verification of the efforts on the pavements and the displacements of the building caused by the loads acting on the structure. In this work, the use of the global stability parameter a and Yz, which is of fundamental relevance and also prescribed in NBR 6118 (ABNT, 2014), was evaluated. The use of the parameter a considered for the evaluation of the overall stability of the structure, but which is not capable of estimating second order efforts, allows us to classify a structure as being of fixed or mobile nodes. The Yz parameter, on the other hand, can be used to obtain second order efforts. To carry out this work, a case study was launched in the structural analysis software Ftool. The present analysis carried out showed that it is possible to conceive a bracing system for a building with up to 30 floors, using the pillar-wall solution having as a substitute resource for the aforementioned solution the solution of frames formed by beams and columns addressed continuously by tall building literature. Therefore, it is worth mentioning that the solution with wall pillars tends to be more expensive than the solution with frames, a system adopted in the development of this work due to the economic viability of the construction, in view of a higher consumption of materials in the superstructure and also higher costs in the construction. execution of foundations, due to the efforts that will be generated in the building (horizontal forces and bending moments).
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Laszlo, Robert, Cristian Radeanu, Stefan Ilici, Mircea Grecea, and Miklos Levente. "Technical and safety aspects at the demolition by blasting works of a cooling tower with a high of 72.00 m." MATEC Web of Conferences 305 (2020): 00072. http://dx.doi.org/10.1051/matecconf/202030500072.
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From the point of view of demolition, one of the most interesting construction categories is the hyperboloid shape cooling towers. These seemingly fragile structures support at the base on a reinforced concrete belt and pillars. An important element to be taken into account when choosing the demolition solution is the slope of the tower. As this ratio between tower height and base diameter is greater (4-5), the easier is the demolition of the tower by overturning, respectively by moving the centre of gravity of the construction away from its base. In the case of the cooling tower described in this article, its height was 72.00 m and the base diameter of 52.00 m - the slope ratio index being less than 2, which was why the chosen solution of demolition was that of partial lateral collapse followed by a total crash of the tower on its position. The article describes how to perform the demolition of the cooling tower, the technical and safety solutions adopted for its successful collapse in the intended direction, in very sensitive location conditions regarding the constructions and installations in its immediate vicinity.
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Marian, Dacian Paul, Ilie Onica, Ramona-Rafila Marian, and Dacian-Andrei Floarea. "Finite Element Analysis of the State of Stresses on the Structures of Buildings Influenced by Underground Mining of Hard Coal Seams in the Jiu Valley Basin (Romania)." Sustainability 12, no. 4 (February 20, 2020): 1598. http://dx.doi.org/10.3390/su12041598.
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The hard coal seams in the Jiu Valley mining basin have been mined with different mining methods and technologies, including with the complete caving of the surrounding rocks and with top coal caving. These mining systems have led to the degradation of the ground surface by producing subsidence of the land, ranging from a few meters up to tens of meters, in the areas with thick coal seams with high dips. When the limits of the main safety pillars are accidentally exceeded whilst mining, buildings situated either below the ground or on the surface are affected. In the future, the possibility exists of mining some of the very large reserves that are immobilized in the main safety pillars, where the gentle dip seams are stored. In consideration of the above, in order to study the behaviour of typical buildings that are under the influence of underground mining and to develop a model of the stress state in the structural elements of the structures, finite element modelling is used. As such, several modelled buildings with one, two, and three levels were generated, as well as buildings with two levels and with different lengths. These buildings were built of reinforced concrete panels or brick masonry and were subjected to the mining influence of a panel specific to the mines in the Jiu Valley basin, sequentially extracted with a longwall coal face method at different operating heights, with the use of roof control by caving of rocks and with top coal caving methods. Following the analysis of the major principal (tensile) stresses and minor principal (compressive) stresses, a series of conclusions regarding the behaviour of these buildings that are under the influence of the underground mining is revealed. In this context, it was concluded that the value and location of the stresses developed in the structure of the buildings depend mainly on the extension of the panel and the volume of the goaf, the relative position of the building in respect to the coal face line, and the length of the building.
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Xu, Quan Jun, Nan Jiang, Yuan Long, Yu Liao, Tao Yang, Ran Ji, and Di Liu. "Investigation of the Large Scale Borehole Soundless Cracking Experiment on the Concrete Members." Applied Mechanics and Materials 782 (August 2015): 219–26. http://dx.doi.org/10.4028/www.scientific.net/amm.782.219.
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In this paper, by the large scale borehole soundless cracking method, the fracture experiments were performed on the plain concrete and reinforced concrete. For plain concrete experiment, the open borehole was prefabricated in the concrete pillar at first. Secondly, two non-woven fabric bags contained soundless cracking agent were prepared, one for the main expanding and the other for blocking. Thirdly, the main expanding bag was plugged, and then the blocking bag. At last, the cracks in the concrete pillar were developed within 3 hours. For reinforced concrete experiment, the closed boreholes were prefabricated in the concrete beam. First the strain gauges were pasted on the designed locations of the stirrups. Secondly, the boreholes were filled with expanding grout and closed by the flange. The beam was cracked afterwards, and the strain was measured by the test system. It is proved that the large scale borehole soundless cracking method on the concrete members is practicable.
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Ou, Man Li, Wei Jun Cao, and Fang Cheng Liu. "An Analysis of the Calculation of the Temperature Field of the Reinforced Concrete Beam under the High Temperature of Fire." Applied Mechanics and Materials 405-408 (September 2013): 2299–304. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.2299.
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Under the high temperature of fire, the temperature change of the reinforced concrete beam is very important to the structure study. This paper, with heat transfer theory as its theoretical basis, explores the analytical method, the common method for analysis, calculation method of numerical value and finite element analysis by analyzing the temperature field of the concrete component cross sections under high temperature. With the help of MATLAB, it calculates and analyzes the temperature field of the reinforced concrete beam under the high temperature of fire, determines the temperature rise curve of the reinforced concrete beam in case of fire, and calculates the cross section temperature fields of the beam or pillar under the circumstances of different cross section sizes and different timings of fire on three sides.
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Witzany, Jiří, Tomáš Čejka, Jiří Karas, Aleš Polák, and Radek Zigler. "Experimental Research into Demountable Joints of a Precast System." Solid State Phenomena 249 (April 2016): 325–30. http://dx.doi.org/10.4028/www.scientific.net/ssp.249.325.
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The TA02010837 project "Multipurpose dismantleable prefabricated reinforced concrete building system with controlled joint properties and the possibility of repeated use " includes the development of a multi-purpose reinforced concrete precast system with demountable joints. The novel concept of the reinforced concrete precast structure brings numerous innovative, not yet verified solutions, construction and structural problems, functional requirements and user qualities. Apart from theoretical and numerical analyses, a component part of the research is demanding and extensive experimental research into the load-bearing system’s structural members and nodes, including the verification of the hybrid prototype implementation system in which the basic versions of the presumed system alternatives are applied – a column, pillar, wall, integrated system and a system composed of open spatial wall units.
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Semko, Oleksandr, Viktor Dariienko, and Vitaliy Sirobaba. "Deformability of Short Steel Reinforced Concrete Structures on Light Concrete." International Journal of Engineering & Technology 7, no. 3.2 (June 20, 2018): 370. http://dx.doi.org/10.14419/ijet.v7i3.2.14555.
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The calculation, modeling and experimental research of steel-concrete tubular elements made of thin-walled galvanized sheet metal and lightweight concrete have been carried out. The proposed type of structures can be used as a separate structure in the form of a column or a pillar, and one of the types of the reinforcement of a certain light structure. The basic technological and constructive requirements for manufacturing and further exploitation of structures are given. For determination of actual work’s indexes of constructions experimental research of standards are undertaken, and recommendations on adjustment of well-known calculation formulas of close constructions as for structural parameters are given. The design (modeling) was performed in MSC / Nastran software. An analysis of the proposed structures use is carried out with the corresponding conclusions.
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Ji, Fei-Yu, Chun-Hui He, Jing-Jing Zhang, and Ji-Huan He. "A fractal Boussinesq equation for nonlinear transverse vibration of a nanofiber-reinforced concrete pillar." Applied Mathematical Modelling 82 (June 2020): 437–48. http://dx.doi.org/10.1016/j.apm.2020.01.027.
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Tvrdá, Katarína. "Solution of a high bridge pillar under wind effects taking into account the real properties of reinforced concrete." MATEC Web of Conferences 313 (2020): 00008. http://dx.doi.org/10.1051/matecconf/202031300008.
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The current standard is that the calculation of a reinforced concrete structure is carried out using the theory of elasticity and its design is based on the requirements of EC2. In this paper, a computational method based on direct numerical integration and Gaussian or Newton-Cotes cubicles that directly reflect the material properties determined by EC2 is presented. The deviations in the internal forces and deformations achieved compared to the classical theory of elasticity are demonstrated in the calculation of the high bridge pillar.
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Figuli, Lucia, and Zuzana Zvaková. "Different Approaches to Determine of the Explosion Effect, of a Homemade Explosive, on the Structure." Applied Mechanics and Materials 796 (October 2015): 77–84. http://dx.doi.org/10.4028/www.scientific.net/amm.796.77.
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With the increase in acts of terrorism, the effects of the explosion on structures has become highly topical. The aim of the paper is an analysis of various approaches to determine the response of blast loaded reinforced concrete pillar. Homemade ANFO (Ammonium nitrate + fuel oil) explosive will be a reference explosive. Such type of explosives is the most used one in terroristic attacks. The paper will be focused on the analysis of the blast wave, based on the experimental tests, and dynamic analysis of a structure under such load.
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Somma, Giuliana, Alessandro Pieretto, and Alberto Dassie'. "Steel to Concrete Bond Transferring in CFST Columns Connected to Beams through the Concrete." Applied Mechanics and Materials 847 (July 2016): 513–20. http://dx.doi.org/10.4028/www.scientific.net/amm.847.513.
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An important innovation in structural design in the last thirty years has been the use of steel-concrete composite columns, with particular diffusion of tubular profiles. These elements are known in the technical Literature as concrete filled steel tube (CFST) and the metal profiles that characterize the external jacket are usually circular, square or rectangular.A relevant issue that must be considered is the transfer of shear stresses by adhesion between steel and concrete in composite columns. The problem of adhesion, and thus its formulation, depends primarily on the type of technology used to connect beams to columns. In particular, two different models can be produced: the first case where the beams are connected only to the metal external jacket of the pillar (i.e. steel beams connected with bolted flanges to the column), and the second where beams and columns are connected also in the concrete matrix (i.e. the case of beams in steel-concrete technology, or traditional reinforced concrete beams).International Standards, regarding the problem of adhesion in jacketed columns, only referee to the first connection type, giving a constant value for adhesion coefficient along the transferring length, with no dependence to the size of the section, and indicate transferring lengths independently from the type of beam-to-column connection and the shape of the section. In the Paper are hence proposed expressions that quantify the fundamental values that govern the action transfer mechanism by adhesion in CFST, such as the transfer length, the perimeter of the active transfer and the shear stress distribution, as a function of the slenderness ratio and of the type of connection adopted. All this has been carried in order to produce a model for the estimation of bond stresses for the second of the two construction system mentioned above.
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Kuznetsov, Yu N., and A. V. Chernyshov. "On the Improvement of Non-pillar Methods of Securing Reused Excavation Workings." Occupational Safety in Industry, no. 10 (October 2020): 16–23. http://dx.doi.org/10.24000/0409-2961-2020-10-16-23.
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The key problem of underground mining of mineral deposits is to ensure the stable condition of the rock mass that contains the mine workings when conducting second working and preparatory works. To do this, it is necessary to create conditions that dictate strict requirements for maintaining the working section of workings. Active and often uncontrolled displacement of rocks in the interface zones leads not only to changes, but also to a significant deterioration in the operational condition of the workings, reducing the efficiency and safety of production processes. Known methods and means of securing workings have a limited scope of application due to the high cost, labor intensity of work or insufficient efficiency. Given the current state of the coal industry and the lack of financial support from the state, the main feasible ways to solve the problem of reducing production costs in the conditions of deep mines in the Eastern Donbass should include increasing the level of spatial concentration of work, as well as the use of less material-intensive and cheaper types of support for excavation workings. To solve the issue of maintaining the development workings of the extraction area and the possibility of non-pillar coal seam mining, a method of securing is proposed. It involves the placement of a rigid cast strip in a transport working and a rigid reusable security structure (multiplier) at the interface between the second and development workings. The structure is installed behind the sections of the mechanized and individual lining or in combination with other security structures (wood chocks and organ timbering, bollards of reinforced concrete blocks), with or without them, but with a mandatory combination of a multiplier with individual support stands.
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Chmielewski, R., L. Kruszka, and L. Muzolf. "LOAD-BEARING CAPACITY ANALYSIS OF BUILDING PARTITIONS OF THE COLD STORAGE CHAMBERS." Problems of strenght and plasticity 81, no. 2 (2019): 240–48. http://dx.doi.org/10.32326/1814-9146-2019-81-2-240-248.
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The paper presents problems related to the load-bearing capacity analysis of the building partitions of the cold storage facility. The subject of the case study are two different buildings built in the early fifties of the last century. Despite the similar cubature and the construction period, the structures of these buildings are different. The analysed cold store in Warsaw (Poland) is a steel and brick structure, while the second example concerns a reinforced concrete slab-pillar structure located in Wloclawek (Poland). In both cases, the issue related to the assessment of the current technical condition of the structural elements, including the safety of the load-bearing structure and the safety of its use was considered. Moreover, the permissible load for inter-storey slabs in both cases was determined. In order to properly determine the current load-bearing capacity of inter-story slabs, the archival technical and operational documentation of buildings was firstly analysed. Their technical condition was also taken into account in the assessment process. In-situ inspections of both buildings had been carried out. This allowed the determination of the scope of necessary tests and the selection of test and check points for each structural element. Such actions allowed to identify cross-sections of the structural elements and the parameters of built-in materials. The performed diagnostics also allowed to properly determine the technical condition of each structural element, the degree of degradation of the structure and to correctly determine its current load-bearing capacity while simultaneously satisfying both limit states - the Ultimate Limit State (ULS) and the Serviceability Limit State (SLS).
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"Trial Think About on Flexural Quality of Fortified Solid Pillars Remotely Reinforced with CFRP Sheets." International Journal of Innovative Technology and Exploring Engineering 8, no. 9S3 (August 23, 2019): 911–14. http://dx.doi.org/10.35940/ijitee.i3193.0789s319.
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Fiber Reinforced polymer are ordinarily utilized for the Strengthening of Reinforced Concrete Structures. In that CFRP assumes a crucial job in giving the quality, solidness and malleability of the Reinforced solid Structures when contrasted and different filaments like GFRP, steel and aramid strands. Concentrate on Flexural Strengthening of RC Beams with CFRP (Multiple Layers) is completed. The component of the pillar examples are 100mmx200mmx1500mm. Fortified solid pillars remotely reinforced with CFRP sheets were tried utilizing a symmetrical two point concentrated static stacking framework. Two pillars were tried for Control Beam for Flexural (FB) and two bars tried for it is preloading of 70% for FB. Furthermore, after that it is tried by CFRP base just various layers for preloading of 70% for FB. The outcome appear in expanding quality when contrasted with preloading of 70% for FB. Test information on burden, diversion and extreme heap of every one of the pillar were acquired. The heap versus avoidance bends were contrasted and Control Beam for Flexural (FB), Preloading 70%FB and tried CFRP base numerous layer for preloading of 70% for FB. In this examination (CFRP) Carbon Fiber Reinforced Polymer gives apparent quality, solidness and malleability in flexure
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Umebayashi, Ryota, Hidehiro Koyamada, Koji Takasu, and Hiroki Suyama. "A STUDY ON INTENSITY DISTRIBUTION OF CONCRETE IN STRUCTURE WITH DIFFERENT BUILDING AGES." Proceedings of International Structural Engineering and Construction 5, no. 2 (December 2018). http://dx.doi.org/10.14455/isec.res.2018.66.
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Recently, seismic diagnosis and earthquake resistant reinforcement works of buildings built before the new earthquake resistant standards are conducted in various places. However, there is no uniformity in sampling methods, and it seems that there are occasional extreme variations in the determination of representative intensity of the building. In addition, the physical properties of structure concrete which factor of the above-mentioned variations are considered to reflect the horizontal and vertical distribution at the time of concrete placing. Therefore, this study, the core of the existing buildings to be disassembled was collected, and the distribution of physical properties of structure concrete was examined. All target buildings were reinforced concrete constructions, and cores were collected from pillars and waist walls. In addition, there are parts that were built at the time without the ready-mixed concrete plant (from 1960) and pump truck (from 1964). Experimental results of horizontal and vertical distributions of compressive intensity at the pillars and waist walls revealed that there was no greatest decrease in strength and there was not much difference between the maximum strength of the pillar and 300 mm from the vicinity of the pillar and about 300 mm from F. L. Therefore, from this study, it seems that the position of 300 mm from the pillar and F. L. is suitable for the measurement position which develops the representative intensity of the building.
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Alves, Elcio Cassimiro, and João Fernando Martins Paixão. "ANÁLISE DE ESTABILIDADE GLOBAL EM EDIFÍCIOS ALTOS." REEC - Revista Eletrônica de Engenharia Civil 13, no. 1 (August 31, 2016). http://dx.doi.org/10.5216/reec.v13i1.39552.
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RESUMO: O projeto de edifícios esbeltos em concreto armado normalmente tem como principal desafio a busca por uma solução estrutural que viabilize sua estabilização horizontal, sem comprometer a segurança, nem os aspectos arquitetônicos ou a economia. Para formar o sistema de contraventamento desses edifícios, normalmente têm-se disponíveis a associação de vigas e pilares formando pórticos, ou a adoção de núcleos rígidos quando a estrutura de tais edifícios exige grande rigidez frente a ações horizontais. Neste trabalho é apresentado o estudo da estabilidade de uma edificação em concreto armado composta por laje nervurada, com ordem de esbeltez de um para quatro para três tipologias de sistemas de contraventamento: pórticos, núcleos rígidos em formato (“U” e pilar-parede). Em cada sistema, foram considerados dois diferentes tipos de ligações (rígidas e semi-rígidas) para avaliar não só a participação das vigas no contraventamento da estrutura como também, a influência de tais modelos e critérios nos deslocamentos laterais e na estabilidade global da edificação, a partir do parâmetro de instabilidade z previsto na norma brasileira NBR 6118 (ABNT, 2014). Para as modelagens foi utilizado o programa comercial Altoqi Eberick V9, que considera as premissas e as prescrições de dimensionamento de estruturas de concreto previstas nas normas brasileiras. Os valores encontrados pelo Software foram analisados e reforçam a importância da utilização de Pilar -Parede ou núcleos rígidos em formato “U” para edifícios altos em concreto armado. ABSTRACT: The Project of slender buildings in reinforced concret, normally has as main challenge the search for a lasting solution that allow its horizontal stabilization, without compromising the safety, neither the architectural aspects or the economy. To form the bracing system of these buildings, normally has been available the association of beams and pillars forming the frameworks, or the adoption of rigid cores when the structure of these buildings requires great rigidity against horizontal actions. In this research aimed to study the overall stability of a building in reinforced concrete consisting of waffle slab, with slenderness approximately one to four, for three types of bracing systems, frameworks and rigid core into two types of format ("U" and pillars in which the lengths are signifi cantly larger than their widths). In each system were considered two different types of connections ( rigid and semi-rigid ) to evaluate not only the participation of the beams in the bracing structure, even as the influence of such models and criteria in the lateral displacement and the overall stability of the building, using instability parameter z fixed on Brazilian standard NBR 6118 (ABNT, 2014). For the modeling, was used the commercial software Altoqi Eberick V9, which considers the assumptions and the sizing requirements of concrete structures described in Brazilian standards. The values that were found by the software, they were analysed, and reinforce the importance of using pillars in which the lengths are signifi cantly larger than their widths or rigid core "U" for tall buildings in reinforced concrete.
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Ovchinnikov, Ilya, Rafail Garibov, and Igor Ovchinnikov. "Comparative assessment of the safety of lighting pillars installed near the road under the action of a car driving over them." Russian journal of transport engineering 5, no. 4 (2018). http://dx.doi.org/10.15862/16sats418.
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The task of the comparative evaluation of the safety lighting poles installed around the road under the action hit them the car. Notes that studies on the calculation and modeling lighting poles when exposed to shock loads due to vehicle collisions is very small. The situation of a conditional vehicle exit (LADAPRIORASEDAN) from the carriageway to the roadside is followed up, followed by a collision with a metal or reinforced concrete support for external electric lighting. Vehicle speed is 60 km/h and the calculation is performed by finite element method. Diagram shows the compressive forces, bending moments, shear forces, displacements. The analysis found that by hitting the conditioned car to support the outer electrical lighting in a bearing of reinforced concrete arise effort close to being admitted that for small deviations from design parameters (e.g., speed limit is exceeded, possible defects and injuries of lighting columns) can lead to the collapse construction, including the possible fall of its vehicle. Consequently, the support of the metal outer lighting when hit by the vehicle conditional security parameters and external lighting strength of reinforced concrete is preferred support.
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Torres, Ariela Silva, and Vivian Michele Bandeira Da Silva. "ANÁLISE DAS MANIFESTAÇÕES PATOLÓGICAS EM RESERVATÓRIOS ELEVADOS NA CIDADE DE PELOTAS/RS." REEC - Revista Eletrônica de Engenharia Civil 12, no. 1 (June 15, 2016). http://dx.doi.org/10.5216/reec.v12i1.37740.
Full textAbstract:
RESUMO: Reservatórios elevados são construções destinadas a receber água das estações de tratamento através das adutoras ou de reservatórios de maior volume apoiados ou enterrados e distribuí-la até os pontos de consumo. Esta estrutura tem como função principal condicionar e equalizar as pressões nas áreas de cotas topográficas mais altas que não podem ser abastecidas pelo reservatório principal. Este trabalho relata um estudo sobre as manifestações patológicas de reservatórios elevados executados em concreto armado na zona urbana da cidade de Pelotas, RS. A etapa de diagnóstico foi feita através de análise visual com registro fotográfico e após comparação com projeto estrutural cedido pelo órgão responsável pelo projeto. Por meio do estudo foi possível identificar manifestações patológicas do tipo: fissuras, sujidade, desplacamentos, corrosão de armaduras e lixiviação. Os resultados das análises das manifestações patológicas demonstraram que, além da falta de manutenção, as especificações de projeto, referentes aos estribos de pilares e vigas, foram decisivas na propagação da corrosão de armaduras, que estão expostas devido à ocorrência de cobrimentos em desacordo com os critérios atuais da norma NBR-6118 (ABNT, 2014) (Projeto de estruturas de concreto armado). O trabalho concluiu que o descaso do poder público com o estabelecimento de processos adequados de manutenção acelerou a degradação da estrutura e ocasionando assim a falha no funcionamento de abastecimento nos bairros que utilizam estes reservatórios. Desta maneira, este trabalho colaborou para o poder público iniciar o processo de estudo da etapa de manutenção destas edificações, com fim de favorecer a comunidade. ABSTRACT: Elevated tanks are buildings designed to receive water treatment plants through pipelines or supported bulk tanks or buried and distribute it to the points of consumption. This structure has the main function condition and equalize the pressures in the areas of highest topographic dimensions that can not be supplied by the main reservoir. This paper reports a study of the pathological manifestations of elevated tanks executed in reinforced concrete in the urban area of Pelotas, Brazil. The diagnostic stage was made by visual analysis with photographic record and after comparison with structural design given by the agency responsible for the project. Through the study it was possible to identify pathological manifestations like: cracks, dirt, spalling, corrosion of armor and leaching. The results of the analysis of pathological manifestations have shown that in addition to lack of maintenance, design specifications, referring to the stirrups of pillars and beams, were instrumental in the spread of corrosion of armor, which are exposed due to the occurrence coatings at odds with the current criteria of ISO-6118 standard (design of reinforced concrete structures). The study concluded that the indifference of the government to establish appropriate maintenance processes accelerated the degradation of the structure and thus causing a failure in supply operation in the districts using these reservoirs. Thus, this work contributed to the government to start the study process of maintaining these buildings stage in order to promote the community.
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Souza, Diego Jesus de, and Marcelo Henrique Farias de Medeiros. "ANÁLISE DA EFICIÊNCIA DE LOCALIZADORES DE ARMADURA ELETROMAGNÉTICOS: UM ESTUDO COMPARATIVO." REEC - Revista Eletrônica de Engenharia Civil 14, no. 1 (September 19, 2017). http://dx.doi.org/10.5216/reec.v14i1.45786.
Full textAbstract:
RESUMO: Na inexistência dos projetos executivos é possível determinar a armadura da estrutura e o seu respectivo cobrimento a partir de aparelhos denominados pacômetros. O presente trabalho tem como objetivo analisar as leituras de equipamentos de dois modelos, o Profometer 5+ e o Wallscanner D-Tect 150, utilizados na detecção das armaduras e cobrimento de um dos pilares do viaduto em Curitiba. A metodologia desenvolvida foi dividida em três etapas, a primeira, para calibração dos equipamentos, realizada em pilares pré-moldados de concreto armado. Na segunda fase, foram executadas leituras em um pilar de um edifício comercial e finalmente, na terceira etapa foram realizadas medições em um pilar com armação desconhecida localizado no viaduto. As leituras realizadas mostraram a eficiência dos equipamentos na localização das armaduras, porém, apresentaram pouca precisão na determinação dos diâmetros das barras. Não foram detectadas armaduras localizadas em camadas mais profundas. Os dois aparelhos permitiram a estimativa do cobrimento das barras detectadas, contudo, a leitura foi bastante afetada em zonas de alta concentração de armadura. Os resultados obtidos, aliados à leveza e facilidade de uso dos equipamentos, permitiram concluir que é recomendável a utilização de pacômetros em inspeções preliminares de pilares de estruturas de concreto armado.ABSTRACT: In the absence of the executive projects it is possible to determine the armature of the structure and its respective covering from devices called pacemakers. The present work has the objective of analyzing the equipment readings of two models, Profometer 5+ and Wallscanner D-Tect 150, used in the detection of the reinforcement and covering of one of the columns of the bridge in Curitiba. The methodology developed was divided into three stages, the first one, for equipment calibration, performed on precast concrete columns. In the second phase, readings were performed on a column of a commercial building and finally, in the third stage measurements were made on a column with unknown frame located on the viaduct. The readings showed the efficiency of the equipment in the location of the reinforcement, but presented little precision in the determination of the bar diameters. No reinforcement was found located in deeper layers. The two devices allowed the estimation of the covering of the detected bars, however, the reading was very affected in zones of high concentration of reinforcement. The results obtained, combined with the lightness and ease of use of the equipment, allowed us to conclude that the use of pacometers in preliminary inspections of pillars of reinforced concrete structures is recommended.