Large-panel Buildings Research Articles

Reconstruction of 5-storey large panel buildings, use of atmospheric precipitation water for technical purposes in the building

This article provides basic information on engineering selection and beautification of urban areas where 5-storey residential buildings should be built in response to emergencies in ways to increase the energy efficiency of buildings using atmospheric water for technical purposes.

FULL-SCALE TESTS OF FLOOR SLABS OF LARGE-PANEL RESIDENTIAL BUILDINGS OF THE 97TH SERIES

The authors consider objects of large-panel residential buildings, namely floor slabs, in this study. In view of the fact that the existing design of the slabs was carried out according to the old technical and regulatory documentation to comply with the requirements of modern regulatory documents «StroyPanelKomplekt» proposed new design solutions for the floor slabs of 97 series. The main design features of the slabs after the change in design solutions are: increased cross-sectional area of the working reinforcement (from 6 mm to 8 mm), increased concrete protective layer up to 25 mm. Therefore, before the start of mass production of these slabs, full-scale tests were carried out by «StroyPanelKomplekt» together with the department «Construction production and geotechnics» of PNRPU. The tested slab P3-6-501 is a floor element for large-panel residential buildings of the 97th series. The slab in the building is supported on four sides by internal and external wall panels, concrete design class B15. The design class of the working fittings is A400. During the tests, the indicators necessary for assessing the strength, stiffness and crack resistance, as well as the nature of destruction were controlled, including: the values of the loads causing the controlled limit state; product deflections; crack opening width. To measure the deflections, we used measuring instruments and instruments with a scale division of 0.01 mm, namely, 6PAO deflection meters. To measure the width of the crack opening during the tests, an MPB-2 microscope with a scale of 0.05 mm was used. The test results are presented in this article.

Organization of Training in Construction Technological Processes Based On Digital Resources

The purpose of research is to show the efficiency of the virtual construction site of a large-panel residential building as a digital resource of training on technological processes of construction. As the research methodology appeared the digital paradigm, providing the application of digital resources into construction education, the correlation between the best practice and quality changes based on smart technologies. The principal results of the research are maintenance of the virtual construction site of the residential building; criteria for efficiency of training construction operation processes on the basis of a virtual construction site; levels of student readiness for smart technology applications. The significance of the results is that the content of the virtual construction site allows to develop skills of planning and management of virtual projects The criteria reflect the need of the digital economy for construction engineers who master modern digital technologies. The levels of students’ readiness to apply smart technologies reflect the current situation in construction education.

Redefinition of prefabricated large panel building systems - face lifting or disruptive revolution

The notion of “a large panel system (LPS)” means a building system from prefabricated structural elements, concrete slabs, used for the construction of blocks of flats and other buildings. Despite its simple definition, the name evolved over time into an urban, architectural and sociological phenomenon of massive impact changing the character of many European cities for good. It is estimated that nowadays in Europe (excluding the countries of the former Soviet Union) around 41 million inhabitants live in housing estates built from prefabricated panels. The presented elaboration aims to determine a real scale of this issue and provoke a discussion on the basis of undertaken actions - the discussion about the possibilities of stopping the destructive spatial and social processes affecting such areas. On the basis of the above-discussed architectural, urban planning, sociological and technical aspects of the large panel system housing estates and their juxtaposition with competitive contemporary housing estates, an attempt can be made to compare the negative and positive characteristics of these areas. A division into three groups is proposed: 1. Spatial and functional parameters in urban planning, 2. Spatial and functional parameters in architecture, 3. Technical and aesthetic parameters. However, the above-described terms mainly function on the grounds of the downtown (city-centre) building development. Therefore, only by the reference to the revitalization of housing estates do we understand specific areas in degraded housing complexes. Finally, the undertaking of the revitalization actions in the context of large housing developments made with industrial technologies is called ‘the humanization of housing estates’. This term refers to a whole range of works, beginning from the survey of the technical condition, through consultations with the local community, to the selection of solutions in the field of architecture, economics or ecology. On the contrary to the typical modernization, humanization focuses its activities also on the analysis of the collective addressee, their needs and expectations. Humanization of huge housing complexes is coupled with the strive for sustainable development of cities, which has recently become a strategic term in the economies of all developing European countries.

Calculation on seismic resistance of box-shaped structures of large-panel buildings

The article is devoted to the theoretical calculation of the box-shaped structure of large-panel buildings on dynamic effects, taking into account the spatial work of transverse and longitudinal walls under dynamic effects, set by the base displacement according to a sinusoidal law. The problem is solved using the finite difference method.

Алгоритм расчета полных и удельных энергозатрат на строительной площадке при возведении крупнопанельных зданий

The concepts of total and specific energy consumption in the construction of large-panel buildings are reviewed. Taking into account the volumetric planning, structural, organizational, technological and material and technical aspects of construction, a general algorithm for calculating the total and specific energy consumption at the construction site during the construction of large-panel buildings was formed and the values of the total and specific energy consumption for the representative object were calculated.

The effect of the stress distribution of anchorage and stress in the textured layer on the durability of new anchorages

Abstract The paper estimated the effect of the distribution of edge and shear stresses occurring in the façade texture layer of three-layer walls of large slab panel buildings, as well as the variability of these stresses depending on the anchorage strength of the anchorage. Bonded anchors with seven different diameters M8 ÷ M30, selected based on catalogues, were analysed. The traction stress was determined based on the destructive force, which is determined by the catalogues of manufacturers of bonded anchors. Depending on the choice of the method of repairing the connections between the textured layer and the structural layer, we give the three-layer walls a new character of work. One of the methods of strengthening the textured layer is the popular COPY-ECO system in Poland. It is a system of two anchors (horizontal and diagonal), reflecting the shape of the work of existing hangers. The article also analyses the variants of oblique anchorages for the M12 anchor with inclination angles of 30∘, 45∘ and 60∘. The extent to which the anchorage inclination angle has been assessed influences the higher parameters of the anchor’s bearing capacity due to the shearing of the textured layer.

AUTHOR'S METHOD OF CONTINUUM STATES ON THE EXAMPLE OF IMPERFECTION IN THE CONSTRUCTION OF A LARGE-PANEL BUILDING

The paper presents the results of FEM computer analysis regarding cracking of the wall prefabricated element. The proprietary coating model of the Wk-70 System large-panel building construction was used. For analysis, a construction diaphragm has been separated that is integrally connected to the vertical communication structure. Modeled through the scratch in the attic wall and compared with the wall model without damage. By building the shell model, a real and transparent picture of the static work of the structure was obtained, distinguishing zones: focus, redistribution, compensation and neutralization of stresses, whose genesis results from imperfection - scratches in a reinforced concrete composite. For the first time, the author introduces his own method of assessing the safety status of large-panel buildings - by the States Continuum Method.

Determination of efforts from temperature and humidity exposure in walls

The construction of large-panel buildings has more than half a century of history, during which space-planning and design solutions have been improved, methods of calculation have been developed and the regulatory and technical base has been updated. For this period, accurate and approximate calculation methods, both of individual structural elements and the structural systems of buildings on the whole, have been harmonised and verified, the technologies and techniques of automated calculation methods and software systems for their implementation have been developed. One of the features of the life cycle of the housing stock of large-panel buildings is that over the long period of their operation, the regulatory and technical base on which they were designed periodically underwent changes. In terms of ensuring constructive safety from the effect of power loads on buildings, a system of fixed coefficients of working conditions supports the continuity of development of design standards. The affection of temperature and humidity exposure is determined according to the requirements for the temperature difference between the outer and inner surfaces of the outer walls. Based on the accumulated experimental data for the past years between the design period and the current period of operation, the numerical standard values of the heat transfer coefficients of the inner and outer surfaces of the enclosing structures have changed in relation to the previous standards by which these structures were designed. This necessitates a re-evaluation of efforts caused by temperature and humidity exposure in order to make a decision on the need to strengthen structures.

Technology for repairing and improving energy efficiency of enclosing structures of large-panel buildings of the 1-335 series

The article deals with technological and design solutions for repairs with increasing the thermal properties of wall panels of large-panel buildings of the first series of mass developments. A technology for restoring wall panels using modified structural and heat-insulating concrete is proposed. The technology of repair of gas-concrete panels increases the thermal characteristics of building envelope structures to the level close to the standard, reduces their physical wear. Analysis of repair and restoration works of gas-concrete panels with modified material showed the rationality and financial attractiveness in comparison with the method of shotcrete and subsequent insulation and installation of a ventilated facade.

COMPUTER SECURITY ANALYSIS OF LARGE-PANEL BUILDINGS RESULTING FROM THE COOPERATION OF THE BUILDING WITH THE ELASTIC HALF-SPACE OF THE SOIL CENTER WITH THE POSSIBLE SCRATCHING OF THE REINFORCED CONCRETE COMPOSITE

The work touches on the national security issues of large-panel buildings from the point of view of settlement of the building on the ground. Displacements of the structure in the level of foundation of the building structure cause the secondary distribution of stresses, thus the possibility of structural scratches of internal prefabricated plate elements. The original model FEM of the construction of the large-panel building system Wk-70, which was built for research purposes, allowed the approximation of the phenomenon contained in the title of this work. Awareness of the safety of the construction of buildings implemented in large-panel technology is very important and constitutes a significant overtone, not only structural, but also general social.

Replacing Electrical Wiring in Large-Panel Buildings

The article is devoted to complex solution of repair difficulties facing owners of apartments in old bearing-wall buildings. The example of the series 1-464A presents the experience of repairing apartments with the use of modern materials and technologies. On the basis of theoretical analysis of the range of problems in question the principal stages of repairing an apartment in a bearing-wall building are examined with total electric wiring replacement to improve the performance of the dwelling. The main technological operations are described; the features of the use of electrical components and finishing materials are given.

The Use of Effective Design Solutions and High-Tech Building Materials for Reconstructing Residential Buildings of Mass Development in 1960-1990

In connection with the mass development of large-panel typical buildings, in solving the problem of housing for millions of people in the country, they were supposed to be limited in use for 50-60 years. However, the solution to this problem occurs mainly in Moscow, since significant investments are required to resolve the issue of demolition, relocation of residents and the construction of new buildings on the site of the demolished ones. A method of reconstruction of these objects is proposed with the solution of the issues of thermal modernization of facades and improvement of sanitary and hygienic living conditions, with the involvement of investors without the use of budgetary funds [1].

ЧИСЛЕННОЕ ИССЛЕДОВАНИЕ РАБОТЫ ЗАМКОВОГО СОЕДИНЕНИЯ СТЕНОВЫХ ПАНЕЛЕЙ НА РАСТЯЖЕНИЕ ДО ОБРАЗОВАНИЯ ТРЕЩИН

A large-panel design scheme includes floor elements, wall panel elements, and joints between them. The rigidity and strength characteristics in tension, compression and shearare required to be knownfor correct modeling of large-panel buildings. Due to the lack of universal formulas in the normative and reference literature for determining the strength and rigidity of various types of joints, it is necessary to conduct additional research. In 2014 a new type of vertical monolithic joint for large-panel buildings was developed: the fastener joint of wall panels, which has significant strength and rigidity. The fastener includes acheck clamp, which connects the loop outlets on panel ends and the steel plate, which connects the ends of the clamp. It isnecessary to correctly evaluate the strength and rigidity of the joint for its fully- functional application. The experimental research on the joint in tension discovered its bilinear force-deformation relationship (with great rigidity before cracking, and with marginal one after). To analyze the large-panel buildings under the influence of the main operational loads, it is enough to model the joint’s work on the first stage (before cracking). The aim of the research is to study the fastener joint in tension before cracking. The paper compares the results of numerical modeling with the sample testing results, and determines the rigidity and cracking load for joints with other values of the grouting concrete strength and the diameters of the loop outlets. The research was carried out using flat finite-element model in the Lira-SAPR CAD software package. The results of calculation of the joint model are generally consistent with the results of samples testing. In addition, the rigidity and cracking load were determined for joints with various parameters (concrete strength and loop outlet diameter). The results of the study can be usedfor designing large-panel buildings with this type of joint.

ИССЛЕДОВАНИЕ УСИЛИЙ В ВЕРТИКАЛЬНЫХ ШПОНОЧНЫХ СТЫКАХ КРУПНОПАНЕЛЬНОГО ЗДАНИЯ В ПРОЦЕССЕ ВОЗВЕДЕНИЯ

Recently, the world has seen a tendency of reinforced concrete housing construction industrialization. Russia has gained extensive experience in large-panel housing construction, which helps to find optimal structural solutions, but new solutions lead to the need for additional study. Modern software systems allow you to build volumetric models of a building, taking into account physical non-linearity, which helps to take into account the actual distribution of efforts between the elements. At the same time, to build the correct model of a large-panel building, the flexibility of joints between them is required. The flexibility is calculated by online tests the results of which are used to build the future model of a building in the process of its designing. The calculation model of a building gives an approximate estimate of structural behavior and the degree of its accuracy depends on the correct selection of the initial premises. This article estimates the numerical model of a large-panel building by comparing it with the results of direct observations of shear movements in the vertical joints of the most loaded walls of a building under construction. The observations were carried out on a 26-story large-panel building with a cross structural system with self-supporting external longitudinal walls. Vertical joints are monolithic reinforced concrete with the use of dowels with cable loop transverse reinforcement. In addition, estimation of forces at the joints is also given. In general, we may conclude that the calculation model of a large-panel building is applied correctly using elastic-flexible connections with limiting ultimate forces for vertical joints modeling. The modeling part of the study is performed using a finite element model taking into account the magnitude of the joints flexibility and the actual stiffness of the building structural elements. The results of the study can be used in modeling, calculation and design of large-panel buildings, and they provide new scientific knowledge about the operation of buildings of this type.

Research and production of prototypes of lightweight concrete panel walls with a screen

Introduction. In industrial housing construction in a dry hot climate, the issues of protecting the premises from overheating have not yet been resolved. The purpose of this study is the theoretical and experimental substantiation of the method of calculating the construction of lightweight concrete panel exterior walls with a screen for large-panel residential buildings in hot climates, with improved performance and providing technical and economic efficiency. Materials and methods. Methods have been developed for ensuring the normative amplitude of temperature fluctuations of the inner surface in the wall due to the targeted formation of material properties and design measures, lightweight concrete wall panels with a screen and suggestions for their production technology have been developed, and recommendations have been made for their operation conditions. The methods of a rational constructive solution to the sun wall consisting of a sunscreen and a supporting structure separated by an air gap have been investigated. Results. It was supposed to carry out theoretical and experimental studies of the operational properties of lightweight concrete panels of external walls with a screen in laboratory and in-situ conditions. The work was performed in stages: At the first stage, the design and production technology of panels with a screen on prototype fragments under laboratory conditions was performed. For this, experimental fragments of 1 × 2 m panels will be made in the laboratory. The parameters of the air gap were determined from the condition of ensuring sufficient natural ventilation. At the second stage, a study was made of the rational structure of lightweight concrete for exterior walls in hot climates. To find the optimal structure of lightweight concrete from a thermal point of view, a 3-factor experiment was conducted. At the third stage, a theoretical study of the temperature regime of shielded and single-layer large-panel exterior walls was performed. At the fourth stage there was a generalization of the above studies, the manufacture and installation of experimental-industrial designs of panels with a screen in the amount of 10 pieces. At the Bukhara house-building combine. Conclusions. The described study by the method of experimental design and the experimental production of sample fragments confirmed the possibility of producing panels with a screen and an air gap in a single technological cycle. Analysis of the results of theoretical calculations shows that walls with vertical screens and a ventilated air gap are quite effective means of reducing the exposure of solar radiation to buildings and reducing the cost of cooling premises.

The consideration of compliance of structural joints in the numerical calculation of large-panel buildings

The article considers the determination of compliance of vertical joints of wall panels of large-panel buildings made on embedded parts. The simulation of these joints in the calculation model of the structural system of a large-panel building is shown. The algorithm for determining the compliance of vertical joints of wall panels of large-panel buildings is described using the «New displacement program» developed by the authors of this article. The service opportunities of the program for the presentation of calculation results are shown. The comparative results of determining the compliance of wall panels vertical joints using two types of connecting parts are presented, which demonstrates the capabilities of the program to investigate the operation of vertical joints in large-panel buildings with different structural solutions of joints.

The deformability of shear bonds in the load-bearing systems of panel buildings

Civil buildings, like construction objects, have a certain life cycle; building structures subjected to power influences lose their design bearing capacity and operational suitability over time. The service life of prefabricated buildings was oriented to 50 years. Nevertheless, most of these buildings are still in operation in Russia. The service life of the mass typical series of prefabricated panel buildings is coming to an end, which necessitates a reliable assessment of the stress-strain state of building structures. Analyzes the stress-strain state of the load-bearing systems of mass buildings with linear and nonlinear deformation of shear bond materials. A 9-story large-panel residential building, consisting of one section, was taken as the object of study. Introduction to the algorithm of nonlinear deformation of only one type of shear bond allows us to fix a noticeable difference in the stress-strain state of the vertical load-bearing structures of the building. The discrete-continuous mathematical model creates a methodological basis for researching other basic elements of the spatial bearing system of a multi-storey building and assessing their contribution to the redistribution of efforts.

Techno-Economic and Material Science Expediency of Modernization and the Renaissance of Large-Panel House Building in Armenia

For Armenia, the main criterion of reliability and durability of buildings is the level of their seismic resistance. The experience of the 1988 Spitak devastating earthquake showed that the only type of apartment buildings that did not collapse and did not cause any loss of life or material damage were large paneled houses, which were designed for lower levels of seismic impact. In spite of the undeniable fact of high seismic stability and effective technical and economic indicators given in the article, further, due to low heat-insulating indicators of applied wall protection panels and limited spans up to 6m, the construction of such buildings in the republic was gradually reduced and has already undeservedly reached almost complete cessation. In this regard, it should be noted that at present there are already a lot of highly effective thermal insulation materials and technologies that allow to easily solve this problem of external walls and get large paneled buildings with a high level of energy saving. As for the limitation of spans, it cannot be considered a decisive factor, because spans up to 6m are quite acceptable for the construction of social apartment buildings. 80% of the population has a strong demand for such housing. The country has an acute shortage of affordable, high-seismic safe houses and this is especially acute now in the Spitak earthquake zone, where after more than 30 years, many still live in temporary houses. We believe that the construction of large-panel buildings would have solved this problem long ago. From all given it is possible to conclude that modernization according to achievements of a science and revival of large-panel housing construction for republic has quite reasonable technical-economic and town-planning basis.

Research on problems of panel buildings

The purpose of the study is to identify and reveal the main problems arising from the operation of panel buildings, to determine the location of the leakage of joints in panel buildings and to analyze the economic effect of a thermal imaging survey with subsequent repair. The main results of the research consist in analyzing the types of joints of large-panel buildings and their features as well as in conducting the thermal imaging survey of interpanel joints for heat loss and identifying the most problematic areas, according to the results of which heat loss is formed through the vertical and horizontal joints between the panels, as well as at the junction points of the windows. According to the results, the economic effect of the thermal imaging survey shows that the additional costs of paying for heat before overhaul due to the deterioration of the thermal protection quality are many times greater than the cost of the thermal imaging survey, taking into account the additional costs of eliminating thermal protection defects.