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Journal articles on the topic 'Reinforced concrete monolithic construction'
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1
Nosenko, Viktor, and Oleg Krivenko. "Influence of house bearing construction rigidi-ty of precast reinforced concrete on stress-strain state Continuous Flight Auger (CFA) piles foundations." Bases and Foundations, no. 40 (June 4, 2020): 48–57. http://dx.doi.org/10.32347/0475-1132.40.2020.48-57.
Full textAbstract:
At present, the tendency to build multi-storey residential buildings has become widespread in Ukraine. This is due to a number of reasons: significant increase in land prices in cities, dense urban development and the availability of appropriate equipment for the construction of such structures. One of the most common materials for multi-storey buildings is monolithic reinforced concrete. The main advantage of monolithic structures is the possibility of free spatial planning and the possibility of uniform redistribution of forces in the elements of the frame - the house works as one rigid entire structure. On the other hand, such structures require a long construction time and appropriate highly qualified control of monolithic works. Therefore, as an alternative, prefabricated reinforced concrete structures are used to accelerate the pace of construction.
In this work, the influence of the rigidity of a precast reinforced concrete house on the stress-strain state of CFA piles foundation is investigated. The stress-strain state of a precast reinforced concrete building with two basement options is analyzed: precast and monolithic.
The numerical modeling of the interaction of the system elements is used as a research method: soil base - foundation - aboveground structure.
It was found that the replacement in a prefabricated house only one basement floor of precast concrete on a monolithic one affects the redistribution of forces, so the self-supporting wall is loaded 2.6 times, and the busiest wall, which rests on both sides of the floor slab, is unloaded to 2.1 times.
It was found that in the case of a basement made of precast reinforced concrete with a precast basement the difference efforts in pile heads (under the load-bearing walls) can differ 1.98 times, and in the case of a monolithic one 1.17 times. So it is mean, the monolithic foundation redistributed of efforts between the piles is more uniform.
It is established that the monolithic reinforced concrete basement, in comparison with the prefabricated one, reduces the uneven settlement of the foundation by 2.4 times.
When designing large-panel houses, it is advisable to provide a basement floor monolithic - this will allow to load the fundamental constructions more evenly, which in its reduction reduces the relative deformation of buildings and reduces their cost.
2
Malakhova, Anna. "Estimation of cracking of reinforced concrete load-bearing construction structures at the stage of their technical inspection." MATEC Web of Conferences 251 (2018): 02040. http://dx.doi.org/10.1051/matecconf/201825102040.
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The article describes the process and causes of cracking of bearing reinforced concrete structures, revealed during the inspection of the technical condition of structural elements of buildings at the stage of their erection, at the stage of suspended construction and in the operational stage. The reasons for the appearance of cracks in reinforced concrete structures under force loads and climatic influences are analyzed. Possible reasons for the appearance of cracks in a monolithic reinforced concrete beam ceiling of a multi-storey building of a column structural system and in monolithic walls of an underground cylindrical reservoir, identified by the author of the article when inspecting the technical condition of these structures, are given. The relationship between the appearance of destructive cracks and the design errors of a monolithic reinforced concrete beam ceiling is shown. The complex nature of the causes of the appearance of cracks in the monolithic walls of the underground reservoir is revealed. The article describes the capabilities of the LIRA-CAD software package for determining the pattern and parameters of fracture-formation of reinforced concrete structures for subsequent comparison with the results of an inspection of the technical condition of structural elements of buildings and structures.
3
Bobalo, Taras, Yaroslav Blikharskyy, Rostyslav Vashkevich, and Myhailo Volynets. "Bearing capacity of RC beams reinforced with high strength rebars and steel plate." MATEC Web of Conferences 230 (2018): 02003. http://dx.doi.org/10.1051/matecconf/201823002003.
Full textAbstract:
Nowadays, reducing the material content of not only buildings and structures in general, but also individual constructions is a topical task that can be realized through the use of high-strength concrete and reinforcement, as well as with the use of external reinforcement. The concentrated location of sheet reinforcement on the external the most tense facets of steel and concrete structures increases the operating height of the cross-section, makes it possible to more effectively use the strength properties of steel in comparison with conventional reinforced concrete, and with the same bearing capacity to economize on expenses. Composite and monolithic reinforced concrete structures with external reinforcement are used in various construction sectors around the world. This contributed to the expansion of the use of reinforced concrete for special buildings of power-engineering and hydrotechnical construction. The technical nd econom efficiency, as well as the possibility of using external rebar as formwork for monolithic concrete construction, have been proved. Therefore, there is a need for the study of structures with combined reinforcement, in which high rigidity of steel and concrete structures is combined with an effective use of high-strength reinforcing bars (rebar) without prior tension
4
Shabalin, Viktor, Boris Smishljaev, Aleksandr Zhuravlev, and Jaroslav Sheetz. "Using seismoacoustic sounding technique for the purpose of structural integrity evaluation of the solid reinforced-concrete foundation for the power transmission line supports." MATEC Web of Conferences 265 (2019): 05018. http://dx.doi.org/10.1051/matecconf/201926505018.
Full textAbstract:
During construction of the monolithic reinforced-concrete foundation, it is not easy to monitor both a continuous haulage and technology of concrete placement. For that matter, some breach of the foundation structural integrity may occur. Currently, there is no unanimous integrated practice of monitoring concrete placement for building oversize solid reinforced-concrete foundations. The surveying results of the solid concrete foundation dimensioned 16m by 16m and from 2 to 3.5m thick are set forth in the article. Such geophysical technique as seismoacoustic sounding has proved effective for concrete placement quality control of monolithic reinforced-concrete foundations by means of a non-destructive method.
5
Абакумов, Р. Г., Roman Abakumov, И. Авилова, I. Avilova, М. Абакумова, Marina Abakumova, С. Анисимов, and R. Abakumov. "ONTOLOGY OF RESEARCH EFFICIENCY AND PROSPECTS OF LARGE-PANEL AND MONOLITHIC REINFORCED CONCRETE CONSTRUCTION OF RESIDENTIAL OBJECTS." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 4, no. 10 (November 7, 2019): 40–52. http://dx.doi.org/10.34031/article_5db33b395b0bb8.51040783.
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The article is devoted to the issues of ontology, research of the effectiveness and prospects of large-panel and monolithic reinforced concrete construction of residential objects. Increasing demands on the effectiveness of multi-story housing construction determine the relevance of this study. Methodological foundations of substantiation and a comparative analysis of the effectiveness of monolithic and large-panel reinforced concrete multi-story construction are considered; prospects for the development of these housing technologies are justified. The article presents an analysis of the pros and cons of monolithic and large-panel reinforced concrete multi-storey construction of residential buildings, a comparative analysis of the processes of organization and technology of construction works. The problems of large-panel and monolithic construction are ranked according to the level of their materiality, measures to improve construction technologies are proposed. The comparative analysis of cost indicators of monolithic and panel construction on the basis of the data presented in collections of standards of the price of construction is presented. The need to introduce and update the normative documentation having legal force for regulation of the basic provisions of the modern improved large-panel construction is proved. Attention is paid to the design conditions for the manufacture and installation of the monolithic and large-panel multi-storey construction of residential buildings used in the methodological approach. Cases of expediency of comparison on criterion "duration of construction" are analyzed. The article proposes an original methodological approach for evaluating the effectiveness of monolithic and large-panel construction, taking into account the conditions and nature of the uncertainty of the initial data, which will justify the choice of the most effective options for the construction of multi-storey housing construction.
6
Ruseckaitė, Indrė, and Aušra Černauskienė. "MONOLITH EXPERIMENT IN VILNIUS: BETWEEN IDEA AND PRAGMATISM / MONOLITO EKSPERIMENTAS VILNIUJE: TARP IDĖJOS IR PRAGMATIŠKUMO." JOURNAL OF ARCHITECTURE AND URBANISM 36, no. 3 (October 9, 2012): 194–208. http://dx.doi.org/10.3846/20297955.2012.732490.
Full textAbstract:
In postwar development of modernist architecture, ambiguity of reinforced concrete in the role of a causer of a qualitative leap of the architectural thought is particularly reflected by controversial application directions and scales of the present material: from industrialised mass construction of prefabricated reinforced concrete large-panel houses seen as pure pragmatism to individual examples of monolithic reinforced concrete architecture with exclusive plasticity seen as idea disseminators. This is the relation between the ideological content and pragmatism of the monolithic reinforced concrete technology the present article deals with discussing the issue in the contexts of Vilnius housing construction. Multi-dwelling units of monolithic reinforced concrete constructed in compliance with an innovative and experimental technology of that time have been chosen due to relatively low realisation scale thereof and due to the fact that the experiment under investigation hardly took a couple of the last decades of the Soviet era, the end whereof also denotes breakup of the phenomenon. The paper aims at answering what are the pragmatic and ideological impulses having determined development of the technology, what architectural and urban ideas are displayed by the buildings constructed; why the monolithic experiment with the significant role to be played in the unrealised perspective plans of urban development has finished together with the Soviet period and what are today's manifestations with respect to assessment and architectural interpretations of the phenomenon. Conclusions of the article maintain that the best display of the relation between the ideological content and pragmatism of the monolithic reinforced concrete technology in Vilnius is exposed in the contexts of housing construction. Demand for the rapid and inexpensive housing construction technology and new reinforced concrete technologies were combined in the field of construction industrialisation and projects of multiple apartment houses. Necessity for original non-standard architectural vertical accents in the monotonous environment characteristic of the quarters of standard apartment houses encouraged to search for an appropriate innovative technology. Monolithic reinforced concrete (as an alternative to prefabricated reinforced concrete large-panel or brickwork construction being unfavourable to the present typology) was chosen due to a range of pragmatic reasons such as comparatively short design and realisation time, lower labour expenditures and less metal input required. Having joined together ideological and pragmatic needs, the monolithic reinforced concrete technology was applied for some ninety apartment houses in Vilnius from 1974 to 1990. Initially employed for the ultimate challenges, i.e. tower-blocks, later the monolithic experiment was used in construction of barrier blocks and terraced houses of composite structures, whereas at the end of the Soviet era it was utilised for construction of single-family houses. Greater technological potential of the experiment having lasted just for eighteen years enabled more freedom in interpretation of the plan structure of an apartment house, therefore, innovations in living spaces are an integral part of the monolithic experiment. Sculpturesqueness of monolithic towers, form iconicity, demonstration of functional building segments in the plan and volume point to ideological changes in modernist architecture. Switchover from one form to structural combination of a few ones, display of the present structurality in the volume also suggest reflections of structural ideas of "spatial blocks" in design of apartment houses, wherein a flat or a group of flats turn into a segment or block of the plan and spatial structure. Being able to open a range of opportunities for exposition of monolithic reinforced concrete and texture thereof, thereby ensuring development of the "techno-functional" structuralism trend, the monolithic reinforced concrete technology failed to gain the expected scope in the real life due to limited technological possibilities. Contextual ideas, born in the sixties of the 20th c. and declaring the necessity to reinterpret the principles of historic architecture and the old city forms as well as to adapt them to the newly developed urban areas, are also found in the changes of Lithuanian architectural and urban thought. The notion of architectural mounds of Vilnius generated during this period was both elaborated in the central part of the city and rephrased in residential districts. Monolithic tower-blocks were clustered next to the major (micro)raion centres, thereby forming mounds, or were used as peaks of the mounds shaped of standard apartment houses, often turning into the functional concentration points of microraions themselves. At that time, the idea of a barrier block acting as a protection wall that safeguards the microraion against highway noise was developed, however, it was worked out just on the basis of the monolithic technology. Demand for the morphotype with respect to switchover from free building-up to perimeter one and possibilities thereof are marked by construction of perimeter blocks of apartment complexes, the ideas of "privacy" reborn wherein were eventually transformed in projects of monolithic terraced and individual houses as well as in very few realisations. Monolithic reinforced concrete apartment houses represent the technological heritage of the uncompleted and discontinued monolithic experiment having gone out together with the Soviet era. Non-relevant scopes of apartment house construction with the scale of that time as well as the doubts having arisen at the end of the Soviet period with respect to justification of the monolithic technology in construction of apartment houses testify to the end of the monolithic experiment under discussion. Application field of monolithic reinforced concrete moves to interior building structures "dressing" the exterior with modern materials, therefore, monolithic facades just remain a part of the experiment of the past Soviet era, the reverberations whereof are found in individual buildings of today's architecture solely. Santrauka Gelžbetonio kaip kokybinio architektūrinės minties šuolio kaltininko dviprasmiškumas pokarinėje modernistinės architektūros raidoje ypač matomas iš kontraversiškų šios medžiagos naudojimo krypčių ir mastų: nuo industrializuotos masinės surenkamų gelžbetoninių stambiaplokščių namų statybos kaip grynojo pragmatiškumo iki pavienių išskirtinės plastikos monolitinio gelžbetonio architektūros pavyzdžių kaip idėjos skleidėjų. Būtent monolitinio gelžbetonio technologijos idėjiškumo ir pragmatiškumo santykis straipsnyje ir nagrinėjamas, šį klausimą perkėlus į Vilniaus gyvenamosios statybos kontekstus. Monolitinio gelžbetonio gyvenamieji namai, pastatyti naudojant savo laiku inovatyvią ir eksperimentinę technologiją, pasirinkti dėl palyginti nedidelio jų įgyvendinimo masto ir dėl to, kad šis eksperimentas tetruko ne visus porą paskutinių sovietinės eros, kurios pabaiga žymi ir šio fenomeno nutrūkimą, dešimtmečių. Tekste siekiama atsakyti, kokie pragmatiniai ir idėjiniai postūmiai lėmė šios technologijos plėtojimą, kokios architektūrinės ir urbanistinės idėjos skleidžiasi šiuose objektuose; kodėl monolitinis eksperimentas, kuriam nemenkas vaidmuo numatytas neįvykusiuose miesto plėtros ateities planuose, pasibaigė kartu su sovietmečiu ir kaip reiškiasi šiandieniniai šio reiškinio vertinimai bei architektūrinės interpretacijos.
7
Kazakov, Dmitry, Aleksandr Tkachenko, Arben Arzumanov, Leonid Bolotskikh, and Andrey Mishchenko. "Development of technology for the construction of heat-efficient monolithic vaults from basalt fiber concrete." E3S Web of Conferences 258 (2021): 09041. http://dx.doi.org/10.1051/e3sconf/202125809041.
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The paper considers the issue of erection of structures of buildings and structures from monolithic dispersed-reinforced concrete, capable of performing not only a load-bearing, but also a protective function. The analysis of a number of dispersed-reinforced concretes with both structural and thermal insulation properties has been carried out. An increase in thermal efficiency is expected through the use of industrial porous aggregates. The technical indicators of samples of basalt-fiber-reinforced concrete with fillers: perlite and foam glass have been experimentally investigated. Experimental relationships are obtained that characterize the compressive and bending strength, as well as the thermal conductivity of the materials under study.
8
A.Farzaliyev, S., ., and . "Improving the Efficiency of Construction of High-Rise Monolithic Reinforced Concrete Buildings with the Introduction of Innovative Technologies and Technologies." International Journal of Engineering & Technology 7, no. 3.2 (June 20, 2018): 107. http://dx.doi.org/10.14419/ijet.v7i3.2.14384.
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Innovations' application of techniques and technologies to modern construction production, along with the reduction of manual labor, also boosts its technical and economic performance. Construction production is one of the fields in the country that plays the most important role and reflects the dynamics of the development of the economy in itself. In our country, the issue of organizing a cheap housing market has an importance among a number of socio-economic issues. The programmes adopted in this direction and the initiatives dealing with the improvement of housing conditions for people from a number of categories are evident proof of this. And this, in its turn, requires the solution of a number of organizational and technological problems of construction work carried out by monolithic reinforced concrete structures before both the designers and builders. The article explores the ways of timely commissioning of high-rise monolithic reinforced concrete buildings, improving the organization of work, and increasing the technological efficiency to reduce the cost of construction products. It was determined that during the reinforcement of monolithic reinforced concrete structures, automation of works will reduce labor costs, material consumption, product cost and construction time, while technological efficiency is increasing.
9
Pešata, Michal, Lukáš Procházka, Vlastimil Bilek, and Jana Boháčová. "Construction-Technical Survey of the Interspace of an Industrial Chimney." Solid State Phenomena 322 (August 9, 2021): 209–13. http://dx.doi.org/10.4028/www.scientific.net/ssp.322.209.
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Chimneys are high-rise buildings indispensable for the operation of important plants in industry and in energy. The paper deals with the description and evaluation of defects found on reinforced concrete structures in the chimney interspace. The object of the inspection was a chimney with a reinforced concrete monolithic stem and an offset protective casing. The space between the housing and the stem is ventilated. During the operation of the chimney, aggressive condensate penetrates into the interspace, as a result of which unprotected reinforced concrete structures can degrade.
10
Karpiuk, Іryna, and Vasyl Karpiuk. "Surface Subsidence Ground During Tunnel Construction." Central Ukrainian Scientific Bulletin. Technical Sciences, no. 3(34) (October 2020): 194–200. http://dx.doi.org/10.32515/2664-262x.2020.3(34).194-200.
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The cross-sectional area of the tunnel, fortified with a rim, is always smaller than the excavation area in the ground. Exact methods are still very arbitrary and need to be improved. The article presents the results of calculating the internal force factors of a monolithic reinforced concrete frame of a vaulted tunnel. The data obtained in the calculation of the PC "PLAXIS-8".
11
Deineko, Andrei V., Valentina A. Kurochkina, Irina Yu Yakovleva, and Aleksandr N. Starostin. "Design of reinforced concrete slabs subject to the construction joints." Vestnik MGSU, no. 9 (September 2019): 1106–20. http://dx.doi.org/10.22227/1997-0935.2019.9.1106-1120.
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Introduction. When erecting monolithic reinforced concrete floor slabs, a necessity of construction joints arises. The construction joints are the areas of structural weakening. The construction practice shows that the compliance with the correct technology of the construction joint arrangement is not a sufficient condition to ensure the strength balance of reinforced concrete floor slabs. As a result, the stress-deformation state calculated on the assumption of the concrete slab solidity deviates from the actual state. The relevance of the task is determined by the fact that the conformity of design and actual characteristics of the in-situ reinforced concrete structures as a whole depends on the correct calculations of construction joints.
Materials and methods. The problem of implementing the construction joints in the monolithic floor slabs was considered by way of example of a residential building under construction. In the course of construction, pre-construction land surveys were carried out at the areas of the construction joint arrangement. Calculations of reinforced concrete structures using finite element method (FEM) were also performed.
Results. As a result of the study, the actual deflections of the floor slabs were measured at the areas of the construction joints and FEM calculations were made on the same floor slabs, both those erected at once and those erected in stages subject to the construction joints. The difference between the calculated and actual deflections is conditioned upon the inaccurate conformity between the mathematical model and the real reinforced concrete structure, its erection and maintenance conditions. It should be noted that the deflection of horizontal reinforced concrete structures is only one of the stress-deformation state parameters that can be measured better than the others. It is shown that if the deflection of a real reinforced concrete structure does not correspond with the design estimation, the other stress-deformation state parameters will differ from the design estimation as well.
Conclusions. The influence of joints can be taken into account in the scope of FEM computer-aided calculations with the explicit reproduction of the structure erection by pouring concrete, using engineering approach to the consideration of nonlinearity on the basis of the introducing reduction coefficients to the reinforced concrete effective modulus of elasticity. Solid composition modeling of reinforced concrete provides the best possibilities on taking all sorts of nonlinearity manifestations into consideration.
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Koyankin, Aleksandr Aleksandrovich, and Valeriy Mikhaylovich Mitasov. "CAST-IN-PLACE BUILDING FRAME AND ITS FEATURES AT SEPARATE LIFE CYCLES." Vestnik MGSU, no. 9 (September 2015): 28–35. http://dx.doi.org/10.22227/1997-0935.2015.9.28-35.
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Modern intensive development of precast-cast-in-place construction has led to creation of a wide range of various constructive systems of buildings during the last 100 years. They allow constructing buildings with best account of the requirements of functionality, architectural expressiveness, production possibilities of construction companies, etc. However in spite of this development both precast and cast-in-place housing construction has its peculiarities, positive and negative ones. The constructive systems of precast monolithic buildings existing at the moment are based on the required mutual deformation of prefabricated reinforced and cast iron reinforced concrete at the stage of a building construction and at the stage of its use as well. Having refused from this rule, the authors of this article have introduced a constructive system of a precast monolithic building able to bear loads, developing at the stage of erection (due to completion of a precast frame) and at the stage of use (due to completion of a precast monolithic frame). The offered construction of a precast monolithic building frame allows efficiently using the advantages of precast and cast-in-place construction minimizing their disadvantages and it also fully corresponds to the obligatory requirements to buildings. The corresponding patents are obtained.
13
Ghulyan, Armine B., Garegin L. Tepanyan, and Boris J. Sargsyan. "Problems of Formation of Complex Monolithic Reinforced Concrete Structures." Key Engineering Materials 828 (December 2019): 153–57. http://dx.doi.org/10.4028/www.scientific.net/kem.828.153.
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The features of the structures of complex monolithic reinforced concrete structures are given, the necessity of their organizational and technological design to ensure quality, reduce the duration and safety of construction and installation works is substantiated. A fragment of the formwork for complex curvilinear beams is presented, where the permanent and temporary loads, the permitted steps of the main and secondary beams and remote scaffolds for the PERI and CRAMOS modular formwork systems, which are more common in RA, are calculated in detail.
14
Akimov, Seyran, Olga Balakchina, Elvira Akimova, Vladimir Malahov, and Vasilij Shalenny. "Improving the manufacturability of floor slabs by pre-installing elements that partially replace reinforced concrete and formwork." E3S Web of Conferences 258 (2021): 09019. http://dx.doi.org/10.1051/e3sconf/202125809019.
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The article discusses well-known and perspective constructive and technological systems for the installation of monolithic and precast-monolithic floor slabs of civil and industrial buildings. It shows examples and expediency of using all kinds of inserts made of plastic and other light materials and products for replacing a part of heavy monolithic reinforced concrete. An original resource-saving method for the installation of precast-monolithic floor slabs with a simultaneous increase in the degree of their construction readiness is proposed. This effect is achieved by reducing their own weight and the use of permanent formwork. Reduction in own weight of the precast-monolithic floor slab is ensured by the use of volumetric lightweight trapezoidal or rectangular inserts, preferably made of expanded polystyrene, during its installation. The use of permanent formwork will eliminate the need for the subsequent performance of labor-intensive finishing and insulation works. To confirm the effectiveness of using the proposed method of precast-monolithic floor slab installation, the operation of two floor slabs was modeled in the LIRA SAPR computing complex - the proposed reinforced concrete innovative slab and a solid reinforced concrete slab. Having analyzed the calculated forces, deformations and the corresponding consumption of reinforcement and concrete, comparative indicators were obtained for the proposed innovative slab and for a typical solid floor slab. As a result, significant savings in material and cost have been proven.
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RYAZANOVA, Galina N., and Daria M. POPOVA. "ANALYSIS OF EXISTING METHODS OF CONSTRUCTION FROM MONOLITHIC CONCRETE AND REINFORCED CONCRETE IN WINTER CONDITIONS." Urban construction and architecture 8, no. 1 (March 15, 2018): 16–23. http://dx.doi.org/10.17673/vestnik.2018.01.3.
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The advantages of monolithic concrete and reinforced concrete in comparison with traditional technologies are considered. The evaluation of the structure of construction technology is given. The analysis of the main methods of winter concreting with the development of the structure of heating and non-heating methods is given. The main methods of maintaining concrete and reinforced concrete at negative ambient temperatures are described. An algorithm for estimating the methods of winter concreting for technical and economic indicators is developed: labor costs and electricity consumption. Prospects for the development taking into account the technical and economic eff ectiveness of the option of combining non-heating and heating methods for further investigation are outlined.
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Sokolov, Nikolai S. "Ground Ancher Produced by Electric Discharge Technology, as Monolithic Reinforced Concrete Structure." Key Engineering Materials 771 (June 2018): 75–81. http://dx.doi.org/10.4028/www.scientific.net/kem.771.75.
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The construction of territories with problematic engineering and geological conditions in the presence of unstable, crossed relief is a complex geotechnical task. Therefore, the main purpose of the work is to study the features of the ground anchor, which is made by electric discharge technology, as a monolithic reinforced concrete structure. The questions related to the provision of safe methods of construction and erection works for the erection of any facility in such territories are related to a multifactor problem connected, primarily with the need to develop special geotechnical technologies tied to real engineering and geological conditions, loads from previously erected buildings and structures and, secondly, the actual implementation of them on a particular construction site. The case considered in the article from the geotechnical practice of construction of the facility is confirmed by the fact that due to the availability of modern design and construction and construction works, it is possible to solve any complex problems related to the issues of ensuring the stability of slopes.
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KAPRIELOV, Simon, Andrey SHEYNFELD, Igor ARZUMANOV, and Igor CHILIN. "NEW NATIONAL STANDARD FOR SELF-COMPACTING CONCRETE MIXES." Bulletin of Science and Research Center “Stroitelstvo”, no. 3 (30) (August 30, 2021): 30–40. http://dx.doi.org/10.37538/2224-9494-2021-3(30)-30-40.
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The information about the new national
standard GOST R «Self-compacting concrete
mixtures. Specifications», developed by
the «Research Institute for Concrete and
Reinforced Concrete» named after A.A.
Gvozdev, of JSC «Research Center of
Construction», is presented.
The standard applies to ready-to-use selfcompacting
concrete mixtures of heavyweight,
fine-grained, light-weight and reactive
powder concretes, as well as fiber reinforced
concretes, for the production of monolithic or
precast concrete structures and products, the
shape and reinforcement of which makes it
difficult to place and compaction of an ordinary
concrete mixture.
The standard establishes new terms
and definitions, types and designations,
uniform requirements for new technological
characteristics (slump-flow, segregation,
viscosity and flowability), acceptance
rules and test methods, production and
transportation processes, control and
evaluation procedures conformity of quality
indicators of self-compacting concrete
mixes.
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Novikov, M. V., E. M. Chernyshov, and E. E. Prokshits. "Strain-Stress Distribution of Structural Components from Foam Concrete for Monolithic Construction." Key Engineering Materials 887 (May 2021): 711–17. http://dx.doi.org/10.4028/www.scientific.net/kem.887.711.
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The problem of use of hi-tech macroporous concrete in load-carrying structures of low-rise buildings is designated and the forthcoming research problems of power resistance and deformation of the compressed and bent elements from foam concrete of natural solidification are formulated. Results of pilot researches of intense state of strain of the compressed and bent elements from foam concrete of average density of 1200-1600 kg/m3 of different structural modification in the conditions of short-term and long action of loading are provided. It is established that foam concrete meet for nonrigid indicators regulatory requirements and take the intermediate place between full-strength cellular and light concrete on expanded aggregates that creates premises for their successful application in the bearing concrete and reinforced concrete constructions. Deformation and strength characteristics of foam concrete of different structural modifications taking into account the impact of the long processes caused by solidification of concrete and external power factors, necessary for calculation and structural design are offered. The received results of researches will allow to project rationally bearing and enclosing structures from foam concrete that leads to increase in technological level of monolithic construction.
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Yushchube, S. V., I. I. Podshivalov, and G. I. Tayukin. "HIGH RISE FRAME BUILDING CONSTRUCTION WITH REGARD TO DEFECTS IN MONOLITHIC BASE SLAB." Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel'nogo universiteta. JOURNAL of Construction and Architecture 22, no. 5 (October 31, 2020): 160–72. http://dx.doi.org/10.31675/1607-1859-2020-22-5-160-172.
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The paper analyzes the influence of defects detected in a monolithic base slab on the possibility of its further application in the construction of a 25-storey high-rise frame building. Non destructive testing and vertical core sampling techniques are used for the detailed analysis of the monolithic base slab. It is found that irregularities in the procedure during winter concreting of the base slab decreases the strength properties of concrete and provides the defect formation in the slab structure, namely delamination of the lower protective concrete layer and uncovering of working reinforcement. For the safe use of the 25-storey high-rise building, the base slab is proposed to be strengthened by adding in-situ reinforced concrete layer 100 cm thick.
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Nesvetaev, Grigorii, Yulia Koryanova, Aleksei Kolleganov, and Nikita Kolleganov. "On the Issue of Standardizing Concrete Frost Resistance to Ensure the Reinforced Concrete Structures Durability." Materials Science Forum 1043 (August 18, 2021): 1–7. http://dx.doi.org/10.4028/www.scientific.net/msf.1043.1.
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When erecting monolithic reinforced concrete structures, the structure of concrete can differ significantly from the laboratory standard due to the complexity of providing favorable conditions for hardening, and therefore the compressive strength and especially the frost resistance of concrete may not meet the design requirements, which can negatively affect the reinforced concrete structure durability and require amplification, especially in earthquake-prone areas [1, 2]. Increasing the durability of reinforced concrete structures is possible by creating a rational stress field, for example, by prestressing, incl. variable along the length of the structure [3,4], but this technique is difficult to implement for monolithic reinforced concrete structures. It is possible to use effective materials or methods of manufacturing structures [5, 6]. But this is also mainly problematic for use in the construction of monolithic reinforced concrete structures. Generally accepted methods of calculating the reinforced concrete structures durability subjected to cyclic freezing-thawing during operation, incl. in a water-saturated state, do not exist. At the design stage, ensuring the durability of such reinforced concrete structures is mainly reduced to the reasonable assignment of requirements for concrete quality indicators, depending on the operating conditions, which is the focus of BC 28.13330.2017 (EN 206) and GOST 31384-2017 from the premise of ensuring durability of at least 50 years. In the above-mentioned norms of the Russian Federation, in fact, two approaches are presented to ensure the durability of reinforced concrete structures during cyclic freezing-thawing, incl. in a water-saturated state, namely: designing a concrete structure capable of working under such conditions by standardizing the values of cement consumption, W/C ratio, class of concrete in terms of compressive strength, amount of entrained air, or rationing of concrete grades in terms of frost resistance F1 (first base method GOST 10060-2012 provides for freezing in air, saturation and thawing in water) or F2 (second base method GOST 10060-2012 provides for freezing in air, saturation and thawing in 5% sodium chloride solution). The purpose of this work is to compare various approaches to ensuring the durability of reinforced concrete structures operated during cyclic freezing-thawing and to analyze the provision of durability with standardized indicators when designing the structure of concrete.
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Čajka, Radim, Kamil Burkovič, Pavlina Matečková, David Sekanina, Marie Stara, and Anezka Jurcikova. "Reinforced Concrete Structure of the Puppet Theatre in Ostrava." Applied Mechanics and Materials 744-746 (March 2015): 217–21. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.217.
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The annex building for the alternative scene in the Puppet Theatre of Ostrava was designed and constructed as an interesting structure from raw face concrete. The size of the annex building is not so big. It is, however, distinct in terms of the shape and complexity. The annex building consists of the above-ground and underground parts and the outside amphitheatre. The above-ground part consists of a reinforced concrete monolithic structure with five floors. The façade is made from raw face concrete. The underground part comprises two underground floors and an inside amphitheatre which is connected to the outside amphitheatre. The paper describes the process and bottlenecks in the design and construction of the building which is interesting in terms of architecture and construction.
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Bodnárová, Lenka, Jitka Peterková, Jiri Zach, and Iveta Nováková. "Study of Heat Transport in Structure of Concrete." Advanced Materials Research 1000 (August 2014): 302–5. http://dx.doi.org/10.4028/www.scientific.net/amr.1000.302.
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Current trend of construction of ring roads in large cities going often underground emphasizes safety of implementation and using of such constructions, which is closely connected to possible risks of a fire in these predominantly monolithic structures made from steel reinforced concrete. The paper gives results of the research focused on thermally-technical properties of cement based composite materials resistant to high temperature suitable for application in places with higher risk of fire, like secondary lining of tunnels or underground car parks. The aim was verification of appropriateness of testing mix-designs for application in structures possibly endangered by fire.
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Neighbor, Noel, and David B. South. "An Evaluation of the Monolithic Dome Construction Method for Biological Containment Structures." Journal of the American Biological Safety Association 2, no. 1 (March 1997): 39–46. http://dx.doi.org/10.1177/109135059700200109.
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A monolithic dome was built as a residential structure using a previously developed airform technique. The building consisted of an outer airtight form, polyurethane foam insulation, and reinforced concrete. Except for the airform kit, locally available materials were used for construction using several alternatives and options applicable to this kind of building. The process and options were evaluated relative to their application for the production of biological containment facilities. It was concluded that the monolithic dome building technique is an effective alternative to conventional methods.
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Muir, C. A., D. K. Bull, and S. Pampanin. "Preliminary observations from biaxial testing of a two-storey, two-by-one bay, reinforced concrete slotted beam superassembly." Bulletin of the New Zealand Society for Earthquake Engineering 45, no. 3 (September 30, 2012): 97–104. http://dx.doi.org/10.5459/bnzsee.45.3.97-104.
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Displacement incompatibility between reinforced concrete moment frames and precast flooring systems has been shown experimentally, and in historical earthquakes, to be an area of concern. Plastic hinge formation necessitates beam damage and the resulting elongation of the beam reduces the seating length of the floor, exacerbates the floor damage and induces unanticipated force distributions in the system. In severe cases this can lead to collapse.
The slotted beam is a detail that protects the integrity of the floor diaphragm, respects the hierarchy of strengths intended by the designer and sustains less damage. The detail provides the same ductility and moment resistance as traditional details, whilst exhibiting improved structural performance. This is achieved with only a subtle change in the detailing and no increase in build cost.
This paper briefly presents the development of the slotted beam in reinforced concrete. The design and construction of a large scale reinforced concrete slotted beam superassembly is described. The experimental method used to undertake biaxial quasi-static testing is introduced. Preliminary observations from the experiment are presented. It is shown that the reinforced concrete slotted beam is a viable replacement for the traditional monolithic detail. Extremely promising structural performance and significantly reduced damage compared to monolithic reinforced concrete details is presented.
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Yan, Xi Kang, Kang Ma, Cheng Dong, Lei Wang, and Pei Chen. "Study on Seismic Performance of a Two-Bay Two-Story RCF with Construction Joint under Low-Reversed Cyclic Loading." Advanced Materials Research 753-755 (August 2013): 719–23. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.719.
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Based on experiment of a two-bay two-story reinforced concrete frame with construction joint under low-reversed cyclic loading, hysteretic performance, displacement ductility, bearing capacity degeneration, rigidity degeneration, energy dissipation and displacement restoring capacity are studied systematically. The studies show that the frame with construction joint has not better seismic performance than the monolithic cast frame.
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Catur Endah Yuliati, Ninik, Dewi Sri Murni, Wisnumurti, and Wibowo Ari. "Comparative study of behaviour of reinforced concrete beam-column joints with reference to monolithic and non-monolithic connection." MATEC Web of Conferences 195 (2018): 02021. http://dx.doi.org/10.1051/matecconf/201819502021.
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The implementation method of reinforced concrete construction has progressed very rapidly. This development aims to speed up time and reduce costs. One of the most widely used methods is the precast method, but the less popular precast method is used for simple storey buildings. Therefore, in this study the semi-precast method, which is easy to implement in a simple storey building, was presented. Parts of columns and beams were cast in place with different casting times. Therefore, the connection become non-monolithic. This study presented a comparison between the deflection and the static load capacity that can be received by the connection of reinforced concrete beam-column which is monolithically connected and non- monolithic. 3 sets of specimens were made to represent monolithic and non-monolithic specimens. The nonmonolithic specimens were made with 2 models, i.e. without and with a notch. The beam-column connections were tested experimentally and compared to the monolithic beam-column connection. The results showed that the notch on non-monolithic test specimens can increase the load capacity and reduce deflection compared to the specimen test without notch. The experimental results also showed that the strength and performance of structural non-monolithic beam-column connections were as good as those of monolithic beam-column joints.
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Hryanina, Ol'ga, Elena Saksonova, Dmitry Abaev, and Vladimir Radaev. "ASSESSMENT OF EFFICIENCY OF A WATER PIPE DEVICE DURING THE CONSTRUCTION OF A FEDERAL VEHICLE ROAD." Construction and Architecture 7, no. 4 (December 19, 2019): 63–67. http://dx.doi.org/10.29039/2308-0191-2019-7-4-63-67.
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The geological structure, hydrogeological conditions were evaluated and the main indicators of the engineering and geological properties of the base soils at the construction site of the federal highway were determined. The designed section of the road crosses the existing field roads. To pass field roads, an artificial construction device is required. A feasibility study of three options for the construction of a reinforced concrete culvert, a single-span overpass and a two-span tunnel type overpass has been completed. The advantages and disadvantages of each of the considered options for structures are analyzed. As a recommended option, a monolithic reinforced concrete pipe device is provided. The corresponding conclusions and recommendations are given.
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BRODŇAN, MIROSLAV, and PETER KOTEŠ. "ASSESSMENT OF THE CURRENT STATE OF THE CONCRETE STRUCTURE OF THE TRIBUNE." Structure and Environment 12, no. 2 (June 30, 2020): 72–76. http://dx.doi.org/10.30540/sae-2020-008.
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The paper is focused on diagnostics of reinforced concrete structure of the tribune of Závodisko Bratislava. The structure was realized by a combination of monolithic and prefabricated concrete elements as well as steel load-bearing elements. The complex state of the rough construction was evaluated, including the verification survey of the foundation of the construction. Non-destructive and destructive methods were used. Based on the results of the diagnostics and recalculation, it was decided to further progress the finish of the tribune.
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Žiogas, Vigantas Antanas, Svajūnas Juočiūnas, Violeta Medelienė, and Giedrius Žiogas. "CONCRETING AND EARLY HARDENING PROCESSES IN MONOLITHIC REINFORCED CONCRETE STRUCTURES / PROCESAI, VYKSTANTYS BETONAVIMO IR PRADINIO KIETĖJIMO METU GELŽBETONINĖSE MONOLITINĖSE KONSTRUKCIJOSE." Engineering Structures and Technologies 4, no. 2 (June 26, 2012): 67–75. http://dx.doi.org/10.3846/2029882x.2012.699258.
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The exploitation time and reliability of monolithic reinforced concrete structures largely depend on concreting technology and process influence during concreting and early setting stages. Different types of cracks in monolithic reinforced concrete structures appear due to internal and external effects. Cracks appear when the technology of structure concreting is damaged, when formwork is removed during the further setting and structures loaded period. In order to avoid micro and macro cracks in monolithic structures, it is important to measure the particular setting time moment and technological process moment when stresses that exceed the permissible values appear in concrete. The article analyses the processes that appear when horizontal, sloping and vertical monolithic reinforced concrete structures are concreted. The analysis of concrete mixture pressure on formwork is performed. The pressure which is calculated according to different countries’ methodology is different: the smallest pressure is obtained calculating according to the British recommendations, and the largest pressure is obtained according to French CIB recommendations. In Lithuania, it is recommended to follow the German DIN 18218 standard. The balance conditions of concrete mixture concreting on slope surface are described. The main concreting technology parameters and their interaction are analysed; the speed, intensity and time of continuous concreting technology are presented. When the process of continuous concreting is performed, it is necessary to evaluate the interaction and values of parameters properly. Methodical theoretical calculation is presented. Practical solutions for industrial building construction applying the modern sliding formwork technology are presented. The impact of cement type, superplasticizers and temperature over the concrete mixture mobility, changes, fresh concrete structural strength and concrete setting kinetics are analysed. The main characteristics of the initial setting — the beginning of structure formation, when concrete mixture turns into concrete state — is analysed applying the ultrasonic method. The beginning of structure formation influences the regulated time of concrete mixture laying and compaction. The requirements for structural strength (permissible strength limits) and concreting rate (formwork movement) of freshly formed concrete are set when the construction is performed applying the continuous concreting technology method. The analysis is implemented performing the construction of cylindrical sludge tank with slipping formwork. While performing the analysis during concreting, it was stated that the concrete setting kinetics corresponds to the sludge tank concreting rate. The analysis performed after concreting and in 28 days of hardening revealed that there are no surface defects or cracks, and concrete strength exceeds the required sludge tank design strength. Santrauka Monolitinių gelžbetoninių statinių konstrukcijų eksploatacijos trukmė ir patikimumas daugiausia priklauso nuo betonavimo technologijos ir procesų poveikių betonavimo bei pradinio kietėjimo metu. Straipsnyje nagrinėjami procesai, vykstantys betonuojant horizontaliąsias, nuožulniąsias ir vertikaliąsias monolitines gelžbetonines konstrukcijas. Atlikta betono mišinio slėgio į formas analizė. Tiriami pagrindiniai betonavimo technologijos parametrai, analizuojamas jų ryšys, pateikiamas nepertraukiamo betonavimo technologijos betonavimo greitis, intensyvumas, trukmė. Atlikti teoriniai skaičiavimai ir siūlomi praktiniai sprendimai pramoninių statinių statybai, naudojant šiuolaikinę slankiųjų klojinių technologiją. Ištirta cemento tipo, superplastiklių, temperatūros įtaka šviežiai suformuoto betono struktūriniam stipriui ir betono kietėjimo kinetikai. Nustatyti reikalavimai šviežiai suformuoto betono struktūriniam stipriui, betonavimo greičiui (klojinių kėlimui), vykdant statybą nepertraukiamos betonavimo technologijos metodu. Tyrimai pritaikyti vykdant cilindrinio dumblo pūdytuvo statybą slankiaisiais klojiniais.
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Shang, Dong Fan, Tie Cheng Wang, and Zhi Feng Yang. "A Research on Key Technology in Overturn-Preventing of Longxi Tower’s Monolithic Movement." Applied Mechanics and Materials 548-549 (April 2014): 1810–14. http://dx.doi.org/10.4028/www.scientific.net/amm.548-549.1810.
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Longxi Tower is the first time shift of pagoda relics in China. All the following factors increase the difficulty of the shift: long years’ construction, serious aging of its structure, poor integrity, small base area and great height. In the process, we used steel initiative urging support system and reinforced concrete protective tube for Longxi Tower’s reinforcement protection, so as to form a stable entirety. Compared to no protection measures, overturn-preventing calculations and further reinforce protection measures improved the safety factor 6.0 times, thus greatly improving the overturn-preventing ability of Longxi Tower.
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Sarkisov, David A., Boris V. Zhadanovskii, Sergey A. Sinenko, and Maksim K. Esenov. "Prospects for the use of solar energy to accelerate the hardening of concrete in the construction of monolithic structures in Russia." E3S Web of Conferences 284 (2021): 06001. http://dx.doi.org/10.1051/e3sconf/202128406001.
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This article addresses the issue of solving the problem of using the solar energy, that allows decreasing of the unit costs, or even avoiding using of the traditional energy resources for performance of the concrete in the southern regions of Russian. Researches that were carried out allow developing more contemporary methods of monolithic construction’s concrete curing. Various types of methods of solar energy using in case to produce precast concrete or reinforced concrete items found vast distribution and implementation in construction industry.
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Treschev, Alexander, Victor Telichko, and Nikita Zolotov. "DETERMINATION OF STRAIN-STRESS PARAMETERS OF A MULTI-STOREY REINFORCED CONCRETE BUILDING ON AN ELASTIC FOUNDATION WITH ALLOWANCE FOR DIFFERENT RESISTANTANCE OF MATERIALS AND CRACKING." International Journal for Computational Civil and Structural Engineering 15, no. 4 (December 29, 2019): 150–63. http://dx.doi.org/10.22337/2587-9618-2019-15-4-150-163.
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In this paper, we consider the construction of a finite-element model for determining the stress-strain state of a multi-storey building made of monolithic reinforced concrete on an elastic foundation. This takes into account the dependence of the mechanical characteristics of concrete on the form of the stressed state, the development of plastic deformation in the reinforcement, cracking. Confirmed that the account of the complicated properties of the material is necessary for obtaining correct estimates of the stress-strain state of reinforced concrete structures under conditions of progressive cracking.
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Folic, Radomir, Damir Zenunovic, and Nesib Residbegovic. "Strength of connections in precast concrete structures." Facta universitatis - series: Architecture and Civil Engineering 9, no. 2 (2011): 241–59. http://dx.doi.org/10.2298/fuace1102241f.
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The available experimental and numerical results of many studies of behavior of reinforced concrete connections for different stages of loading, up to fracture loading, are presented and analyzed in this paper. The problem of beam-column connection (or plate-wall connection) in prefabricated monolithic structures is emphasized. Fracture mechanisms of RC structures, the theoretical basis for their analysis, and the use of fracture mechanics in RC structures were also considered, as well as the mathematical models of prefabricated connections. In order to formulate an adequate mathematical model for calculating the connections, the dominant parameters influencing the behaviour of these connections were analyzed. A failure model for the prefabricated wall - monolithic RC plate connection was formulated. In building the model, the results of implemented experimental and numerical research of prefabricated connection in the MMS system from 2007 were used. Experiences with the implementation of the aforementioned construction system in structures in Tuzla, in the 1980's last century, were additionally used. The proposed mathematical models provide a sufficiently accurate failure assessment of prefabricated reinforced concrete connections.
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SHEMBAKOV, V. A. "Innovative Construction Technology with High Factory Readiness from the Chuvash Republic." Zhilishchnoe Stroitel'stvo, no. 10 (2020): 29–35. http://dx.doi.org/10.31659/0044-4472-2020-10-29-35.
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The technology that fully meets the modern requirements of the market in the Russian Federation is presented – stand technology of precast-monolithic frame and large-panel housing construction with the use of floor slabs with pre-stressing up to 8 m, both solid and caisson versions on universal stands. This technology, which combines the best solutions of prefabricated, monolithic, panel, brick and other construction technologies, competes with the latest Western developments. The advantages of the proposed technology are as follows: high factory readiness and quality, versatility and architectural expressiveness of building structures (97% of the frame), precast building; energy savings – consumption is three times less compared to existing technologies for the production of reinforced concrete products; material savings (1.5 times less than for monolithic and panel housing construction); high speed of construction (up to 5 ths. m2 of prefabricated monolithic frame per month for one tower crane; lower weight of bearing structures compared to other structures (0.146 m3 of precast concrete per 1 m2 of the total area of the building) and, as a result, lower costs for foundations and the use of mechanisms with a lower load capacity on construction sites; reliable erection without welding; usable area – more than 80% of the total area; free planning solutions; quick adjustment of equipment for the production of products necessary for the market at a given time. The bench technology of precast-monolithic frame and large-panel housing construction with the use of floor slabs with pre-stressing up to 8 m is an example of the implementation of inter-industry cooperation in the construction materials and mechanical engineering industry based on Russian scientific developments and adapted modern foreign technologies. Keywords: innovations, construction technology with high factory readiness, modernization of large-panel housing construction and construction industry plants, industrial housing construction, prefabricated monolithic frame, energy efficiency, construction speed.
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Kapustin, F. L., and A. F. Kapustin. "Influence of Plasticizers on the Properties of Fine-Grained Polymer Concrete." Solid State Phenomena 299 (January 2020): 72–77. http://dx.doi.org/10.4028/www.scientific.net/ssp.299.72.
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Polymer concretes are used in construction, engineering, electrical and chemical industries. Polymer concrete mixes are characterized by low mobility mixtures, due to their high viscosity. It makes difficult to use them in the production of thin-walled and high-reinforced structures, monolithic floors, application of finishing and protective coatings and repairing of roads. The influence of additives of dibutyl-phthalate, chlorinated paraffin, technical glycerin and engine oil on the mobility of the concrete mix and the physical and mechanical properties of fine-grained concrete, based on polyester resin, was studied. For polymer concretes with different type and quantity of plasticizer the density and bending and compression strength were determined. To improve the workability of the concrete mix and obtain a polymer concrete with a homogeneous structure and high strength, it is recommended to use chlor-paraffin ChP-470A and “Lukoil” engine oil as a plasticizer.
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BUTENKO, Sergey A., and Dinara R. ZALYAKAEVA. "ASSESSMENT OF QUALITY AND STRENGTH OF CONCRETE IN CONDITIONS OF REAL CONSTRUCTION." Urban construction and architecture 9, no. 4 (December 15, 2019): 4–10. http://dx.doi.org/10.17673/vestnik.2019.04.1.
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The determination of the actual class of concrete in monolithic reinforced concrete structures is the most important factor determining the quality and strength of structures. In practice, the actual grade of concrete may differ from the design value. If this difference occurs in the direction of decreasing the actual concrete class, then the normative and design characteristics of concrete, the bearing capacity and rigidity of the structures, respectively, decrease and there is a need to strengthen the structures. Current regulatory documents allow you to determine the actual class of concrete in both continuous and spot inspection of structures. The article discusses specific examples to determine the actual class of concrete and draws conclusions about the rational use of a continuous or selective examination of structures of various types with specific examples.
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G. Tonkacheev and K. Nosach. "Influence of concrete mix properties on technology of arrangement column foundations." Ways to Improve Construction Efficiency, no. 45 (October 16, 2020): 102–11. http://dx.doi.org/10.32347/2707-501x.2020.45.102-111.
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The article analyzes the selection of concrete mix for the device of the columnar foundation under the column of the frame structure. Depending on the technology of the device - monolithic, prefabricated, prefabricated-monolithic - the main factors influencing the choice are determined.Frame structures have been actively erected since the beginning of the 20th century, with the development of industrial construction. The advantages of frame structures are the unification of structural elements, the possibility of using prefabricated elements, universal planning of the structure, its durability. According to the purpose of the building can be warehouse, factory and retail space. At construction of a frame construction there is a question not only in a choice of technology of the device of these or those elements, but also selection of materials, in particular concrete mix.When installing frame structures often use ready-made structural elements of precast concrete or metal. This reduces the duration of construction, and, accordingly, reduce labor costs and operating time of mechanisms. When using prefabricated elements, the weather influence on the course of construction works is practically leveled. Reinforced concrete and metal structures made in the factory, as a rule, meet the required quality characteristics.As for the technology of laying foundations, in particular columnar, the question often arises about their construction in a rational way. The cost of prefabricated foundation structures is higher than monolithic ones due to factory, loading and unloading and transport costs. However, with this technology the foundations are installed in a short time. The technology of installation of monolithic foundations depends on weather conditions, is characterized by high labor costs and the duration of the process loses to the prefabricated method.In the conditions of water-saturated soils monolithic concreting is complicated, as it is necessary to take measures for drainage [1]. There is also a prefabricated monolithic technology of foundations, which allows the rational use of both technologies. For example, to reduce the time and reduce the complexity, you can arrange a monolithic foundation with a prefabricated glass, or, if there is water in the pit, you can use a prefabricated foundation slab and a monolithic glass with a formwork retainer module [1].The construction of columnar foundations differs in the volume of concrete depending on the load and soil conditions. Sometimes the volume of concrete reaches tens of cubic meters per foundation, so the problem of taking into account the properties of the concrete mixture becomes relevant. First of all, there are questions about the selection of the composition of the concrete mixture and the technology of its delivery to the site. The influence of the properties of the concrete mixture is considered by example.For example, the following properties of the concrete mixture were taken into account: ease of laying, which depends on the complexity of laying the concrete mixture; expediency of use of the special chemical additives improving some properties of concrete mix; the maximum allowable size of the fraction; rigidity of concrete mix; compaction.The results are shown in the table, which clearly shows the difference in the required volume.
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Ro, Kyong-Min, Min-Sook Kim, Chang-Geun Cho, and Young-Hak Lee. "An Experimental Study on the Flexural Behavior of Precast Concrete Modular Beam Systems Using Inserted Steel Plates." Applied Sciences 11, no. 9 (April 26, 2021): 3931. http://dx.doi.org/10.3390/app11093931.
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Recently, interest in using precast concrete (PC) modules has increased due to their better seismic performance than steel modules. However, they must be joined by additional elements to ensure structural integration between the modules. The essential aim of the precast concrete module is to ensure structural performance with appropriate connection methods. However, the technical problem of connecting PC modules still needs to be improved. This study proposed a PC modular beam system for improved structural and splicing performance, and simple construction. This modular system consisted of modules with steel plates inserted to improve integrity of modules, ease of construction, and low cost. The structural performance of the proposed PC modular beam system was evaluated by flexural test on one reinforced concrete (RC) beam specimen consisting of a monolithic beam, and two PC specimens with the proposed modular system. The results demonstrated that the proposed PC modular beam system achieved approximately 80% of the structural performance compared to the monolithic specimen, with approximately 1.3-fold greater ductility.
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Pešata, Michal, Lukáš Procházka, Jana Boháčová, and Jana Daňková. "Damage of Industrial Reinforced Concrete Chimneys Caused by High Temperatures." Key Engineering Materials 808 (June 2019): 153–58. http://dx.doi.org/10.4028/www.scientific.net/kem.808.153.
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The paper deals with the resistance of reinforced concrete against fire and the degradation of reinforced concrete due to high temperatures. In the first part the processes of degradation of concrete are solved due to the evaporation of water and its change of state with respect to the different thermal expansion of aggregates and concrete reinforcement members. The main part is focused on the construction of monolithic and prefabricated structures of industrial chimneys. The most common types of protection of the chimney's internal parts from the exhaust gases are discussed here. Also the possibilities of designing individual expansion joints are described. In the experiment, the problem of chimney damage, with the subsequent description of the chimney diagnostics in the premises of Unipetrol in Litvínov, was solved due to an extraordinary event - explosion of the ethylene unit.
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Brauns, Janis, and Guntis Andersons. "ANALYSIS AND OPTIMUM DESIGN OF CONCRETE RESERVOIR WALL." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 8, no. 2 (June 30, 2002): 94–97. http://dx.doi.org/10.3846/13923730.2002.10531258.
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The design problems of reservoirs for collection, safekeeping and utilization of aggressive sewage and liquid manure in agricultural production have been discussed. As economic construction of reservoirs are reinforced concrete cylindrical containers. The stress analysis and optimum design of the wall of open monolithic reservoir has been performed. The optimum parameters of reservoir wall are fixed taking into account strength and serviceability limit state requirements. Based on the results obtained, it is determined that economical solutions can be reached by using combinations of concrete and steel with high strength classes.
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Cherednichenko, Nadezhda, and Pavel Oleinik. "Methods of erection of high-rise buildings." E3S Web of Conferences 33 (2018): 03040. http://dx.doi.org/10.1051/e3sconf/20183303040.
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The article contains the factors determining the choice of methods for organizing the construction and production of construction and installation work for the construction of high-rise buildings. There are also indicated specific features of their underground parts, characterized by powerful slab-pile foundations, large volumes of earthworks, reinforced bases and foundations for assembly cranes. The work cycle is considered when using reinforced concrete, steel and combined skeletons of high-rise buildings; the areas of application of flow, separate and complex methods are being disclosed. The main conditions for the erection of high-rise buildings and their components are singled out: the choice of formwork systems, delivery and lifting of concrete mixes, installation of reinforcement, the formation of lifting and transporting and auxiliary equipment. The article prescribes the reserves of reduction in the duration of construction due to the creation of: complex mechanized technologies for the efficient construction of foundations in various soil conditions, including in the heaving, swelling, hindered, subsidence, bulk, water-saturated forms; complex mechanized technologies for the erection of monolithic reinforced concrete structures, taking into account the winter conditions of production and the use of mobile concrete-laying complexes and new generation machines; modular formwork systems, distinguished by their versatility, ease, simplicity in operation suitable for complex high-rise construction; more perfect methodology and the development of a set of progressive organizational and technological solutions that ensure a rational relationship between the processes of production and their maximum overlap in time and space.
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Zavyalova, O. B., and A. I. Shein. "Application of Grid Approximation Method for the Calculation of Monolithic Reinforced Concrete Frame Taking into Account Construction Sequence and Concrete Creep." Applied Mechanics and Materials 752-753 (April 2015): 617–22. http://dx.doi.org/10.4028/www.scientific.net/amm.752-753.617.
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The algorithm taking into account the concrete creep and changes of its modulus of instantaneous elasticity is defined. Such algorithm was based on formulas obtained by Harutyunyan (Harutyunyan, 1952). The program with the time factor taking into account both the specified events and the sequence of frames erection in a monolithic design was made.
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M.A, Salahov, and . "Calculation of Organizational-Technological Tasks by Ensuring the Stability and Reliability; Erection of Multi-Storey Frame Buildings." International Journal of Engineering & Technology 7, no. 3.2 (June 20, 2018): 367. http://dx.doi.org/10.14419/ijet.v7i3.2.14554.
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In the article fundamentally new problems are considered - the calculation of organizational and technological tasks by ensuring the stability of multi-storey frame buildings. Multi-storey frame construction is a very complex spatial rod systems with inclusion of planar and volumetric elements from prefabricated and monolithic reinforced concrete or metal lattice systems in them and is used in almost all fields of the national economy.
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Azizov, Taliat, Anna Azizova, and Sakr Al Ghadban. "Construction and Calculation of Reinforced Concrete Overlap with A High Spatial Work Effect." International Journal of Engineering & Technology 7, no. 3.2 (June 20, 2018): 567. http://dx.doi.org/10.14419/ijet.v7i3.2.14591.
Full textAbstract:
The article proposes the construction of a prefabricated monolithic reinforced concrete overlap consisting of beams hollow triangular section. It is shown that in such overlap the effect of spatial work is much higher than the analogous effect in traditional overlap that consists of U-shaped or T-beams and slabs. The technique of determining the forces of interaction of individual beams in the composition of the overlap is given. The technique is based on a discrete-continual method developed by the author, which is adapted to the calculation of overlaps that consist of considered beams. The technique of determining the effort between the shelf and the ribs of a beam during its bending is presented. It is based on the theory of compound rods. The algorithm of calculation taking into account the spatial work is presented as well as the principles of constructing overlaps consisting of beams hollow triangular section, taking into account the change in their rigidity as a result of cracks formation. An approach to the determination of the rigidity of beams with normal torsion fractures is given, based on the approximation of numerical experimental data.
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Gnyrya, Aleksei, Sergey Korobkov, and Ivan Gaag. "Numerical solution of the thermal problem for electric heating of concrete structures in winter." E3S Web of Conferences 258 (2021): 09048. http://dx.doi.org/10.1051/e3sconf/202125809048.
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This paper presents the results of a numerical solution of the thermal problem for electrical heating of a monolithic reinforced concrete raft foundation in the ELCUT Pro software and computing system. The purpose of this work was to solve a thermodynamic problem in the case of electric heating of concrete of a monolithic raft foundation with insulated heating wires in the winter. The foundations of an industrial building under construction in Tomsk are taken as a basis. The relevance of these studies in construction is caused by the need to ensure the temperature conditions necessary for the hardening and strength of concrete in the winter. The initial parameters for the concrete structure being built were entered in the Elcut Pro software package with the WinConcret add-in. As a result of the calculation, the optimal step of winding insulated heating wires on the reinforcing cage was determined, which leads to a uniform distribution of temperature fields over the section of the structure. The analysis of the temperature field in the section of the structure was carried out. Technological measures were developed that level this field and at the same time ensure a favorable temperature of concrete hardening, which is the main task of thermal calculation. Based on the simulation results obtained in the Elcut Pro software package, a technology has been developed for electric heating of concrete foundations at negative temperatures, which has been implemented in the conditions of a construction site.
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B.K., DZHAMUEV. "Increasing the Monolithic Nature of Masonry Made of Cellular Concrete Blocks by Using Polyurethane Foam Glue as a Masonry Mortar." Stroitel'nye Materialy 786, no. 11 (2020): 4–9. http://dx.doi.org/10.31659/0585-430x-2020-786-11-4-9.
Full textAbstract:
This study is a continuation of previously published work [1]. The results of experimental determination of the strength of normal adhesion (under axial tension) in masonry made of autoclave–hardened cellular concrete blocks of compressive strength classes B1,5-B3,5 on cement mortars and polyurethane foam adhesives are presented. The tests were carried out in the laboratory of the Department “Reinforced Concrete and Stone Structures” of the Moscow State University of Civil Engineering (National Research University). The experiment was carried out on samples-cubes with a size of 150x150x150 mm, which were cut out of cellular concrete blocks, fastened (glued) together using masonry (binding) compositions. In the course of the study, it was found that when using various polyurethane foam glue compositions in masonry made of cellular concrete blocks of compressive strength classes B1,5–B3,5, the resistance to axial stretching over an unbound section (normal adhesion) of the masonry increases by approximately 9–25%. It was also found that the nature of the destruction of samples made on polyurethane foam adhesives (destruction occurs along the body of concrete), indicates the monolithic nature of the masonry. The analysis of the results obtained makes it possible to conclude that the resistance to axial tension along the unbound section of the masonry depends on the strength of the material from which the block is made, and not on the compressive strength of the masonry (binder) mortar used, as indicated in table 11 of SP 15.13330.2012 “Stone and reinforced masonry structures”. This factor must be taken into account when calculating masonry from autoclave-hardened cellular concrete blocks on polyurethane foam compositions.
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Yan, Xueyuan, Suguo Wang, Canling Huang, Ai Qi, and Chao Hong. "Experimental Study of a New Precast Prestressed Concrete Joint." Applied Sciences 8, no. 10 (October 10, 2018): 1871. http://dx.doi.org/10.3390/app8101871.
Full textAbstract:
Precast monolithic structures are increasingly applied in construction. Such a structure has a performance somewhere between that of a pure precast structure and that of a cast-in-place structure. A precast concrete frame structure is one of the most common prefabricated structural systems. The post-pouring joint is important for controlling the seismic performance of the entire precast monolithic frame structure. This paper investigated the joints of a precast prestressed concrete frame structure. A reversed cyclic loading test was carried out on two precast prestressed concrete beam–column joints that were fabricated with two different concrete strengths in the keyway area. This testing was also performed on a cast-in-place reinforced concrete joint for comparison. The phenomena such as joint crack development, yielding, and ultimate damage were observed, and the seismic performance of the proposed precast prestressed concrete joint was determined. The results showed that the precast prestressed concrete joint and the cast-in-place joint had a similar failure mode. The stiffness, bearing capacity, ductility, and energy dissipation were comparable. The hysteresis curves were full and showed that the joints had good energy dissipation. The presence of prestressing tendons limited the development of cracks in the precast beams. The concrete strength of the keyway area had little effect on the seismic performance of the precast prestressed concrete joints. The precast prestressed concrete joints had a seismic performance that was comparable to the equivalent monolithic system.
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Kvaraia, Irakli, and Liana Giorgobiani. "Construction of Tbilisi Skyscrapers." Works of Georgian Technical University, no. 1(519) (March 29, 2021): 232–44. http://dx.doi.org/10.36073/1512-0996-2021-1-232-244.
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The first tall building was built in 1938 in Tbilisi. This is the famous "11-storey house" on Heroes' Square. Until the end of the XX century, the tallest building in Tbilisi was the 22-storey hotel "Iveria". It was built in 1967, according to the decision by the former Soviet government that there should be at least one tall building in every capital of the Soviet republics. From the beginning of this century, Georgia completely switched to the construction of monolithic reinforced concrete and the number of high-rise buildings immediately increased both in Tbilisi and throughout the country. The first real skyscraper with a height of more than 100 meters was built in 2016 in Tbilisi. It was the 138-foot tower of Hotel Biltmore. After that, six more skyscrapers were built, which should be considered as the beginning of a new phase of Tbilisi urban planning.
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Inozemtcev, Aleksandr, and Thanh Qui Duong. "Technical and economic efficiency of materials using 3D-printing in construction on the example of high-strength lightweight fiber-reinforced concrete." E3S Web of Conferences 97 (2019): 02010. http://dx.doi.org/10.1051/e3sconf/20199702010.
Full textAbstract:
The technology of 3D printing in construction causes great interest by increasing the speed and accuracy of building structures, reducing labor costs, construction waste and risks to human health. Today, the principles of 3D-printing actually are interpretations of the existing monolithic or prefabricated technology. This requires the development of high-performance materials for the extrusion of functional structures. The paper shows the example of the effectiveness application of high-strength lightweight fiber-reinforced concrete with a complex of structural and thermal insulation properties in 3D-printing technology. It has been established that the use of high-strength lightweight fiber-reinforced concrete for 3D-printing provides an increase in the useful space by 1.1...5.4 %, a reduction in the material consumption of wall structures by 6.1...19.1 % and a reduction in the number of machine hours by 29.6...37.4 %. The total technical and economic efficiency of using such a material for a standard or optimized wall section is 30.8...50.4 %.
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Hranilović, Igor, Darko Meštrović, Zsolt Kokrehel, and Dean Čizmar. "Screw Connection in Reinforced Concrete Column Joints of Prefabricated Structures." Solid State Phenomena 259 (May 2017): 249–54. http://dx.doi.org/10.4028/www.scientific.net/ssp.259.249.
Full textAbstract:
Classic connection between prefabricated reinforced concrete columns on a foundation slab using the concrete plinth base can sometimes be very problematic, especially in limited construction conditions and / or foundation on sandy terrain where the groundwater is very close to the ground surface. By applying the screw connection between a prefabricated reinforced concrete column and the foundation structure using anchor bolts and column shoes, the overall height of the foundation is successfully reduced. The established connection between prefabricated reinforced concrete column and the foundation can immediately sustain the design force after assembly and it is considered to be a rigid connection that acts as an equivalent conventional connection with concrete plinth base, without any other additional support and welding. The successful implementation is possible with underground levels of structures where the inverted concrete plinth bases are implemented - the indentation in the foundation slab for the connection of prefabricated columns with base plate is avoided.Application of the screw connection also enables the design of the continuation of the column at higher altitude (column to column) or connection of the upper part the element with the monolithic structure. Screw connection is particularly suitable for use in seismic areas because the performed tests showed very good ductility of the connections under cyclic load.