INCREASING OPERATIONAL RELIABITY OF RESIDENTIAL BUILDINGS’ COVERINGS

ABSTRACT

Reconstruction and capital repair of residential buildings are one of the main solutions of housing problem. They allow you not only to extend the life cycle the building but also significantly improve the quality of housing conditions to provide houses with modern engineering equipment improve the architectural expressiveness of buildings, increase their energy efficiency, operational reliability and durability. Every year the necessity of reconstruction and major repairs of the housing stock increases in the central part of Russia, since the physical wear of structural elements is added to the moral wear of buildings and engineering systems, that accelerates the overall aging process. The reliability of residential buildings and their coverage is continuously formed at all stages of their existence. At the design stage impact toads are determined, materials are selected and constructive solution that takes into account the main factors of operating conditions of the object are worked out. Thus, the initial level of durability of the building and its elements is formed. The connections of individual elements adopted in the constructive solution, form the maintainability of structures and engineering equipment.  

АННОТАЦИЯ

Реконструкция и капитальный ремонт жилых зданий позволяют не только продлить жизненный цикл здания, но и существенно улучшить качество жилищных условий. С каждым годом возрастает потребность в реконструкции и капитальном ремонте жилищного фонда центральной части России, поскольку к моральному износу зданий добавляется физический износ конструктивных элементов и инженерных систем, что ускоряет общий процесс старения. Надежность жилых зданий и их покрытия непрерывно формируются на всех этапах их существования. На стадии проектирования определяются нагрузки и воздействия, осуществляется выбор материалов и разрабатывается конструктивное решение, учитывающее основные факторы условий эксплуатации объекта. Тем самым формируется первоначальный уровень долговечности и безотказности здания и его элементов. Принятые в конструктивном решении соединения отдельных элементов формируют ремонтопригодность конструкций и инженерного оборудования.

Keywords:  covering of buildings, reliability, durability, capital repair, exploitation, technical condition, monitoring, repair, wear.

Ключевые слова: покрытие зданий, надежность, долговечность, капитальный ремонт, эксплуатация, техническое состояние, мониторинг, ремонт, износ.

INTRODUKTION

According to the statistical data of the state information system of housing and communal services in Tambov region there are 6335 apartment buildings in Tambov region 5005 from them are included into the program of capital repair. The regional repair program determines the frequency of work on repair of engineering networks and structural elements.

Major repairs include a set of works and measures aimed at replacing or restoring separate structures of the building. The reconstruction is connected with restoration of operational indicators and reinforcement of load – bearing elements of buildings. The works require individual approaches other than constructive solutions at new construction. As a rule reconstruction and capital repair of apartment houses in carried out in the conditions of increased tightness that doesn’t allow to use optimal complexes of construction machines and mechanisms. This circumstance requires the development of new methods of work, organizational and technological solutions, the involvement of special equipment and technology. An essential factor increasing the efficiency of reconstruction and capital repair is a timely monitoring of technical condition of constructive elements of apartment houses. During the technical monitoring we envisage comprehensive consideration of external and internal factors’ impact on the building during its exploitation as a consequence for a systematic approach search and adoption of appropriate method on the choice of more rational measures and technologies, aimed at increasing operational reliability of apartment buildings. The reliability of apartment building, its exploitation is ensured objects’ state consists in holding measures aimed at warning and depicting causes of failures and damages of residential buildings’ coverings and also eliminating them by means of repair and maintenance.

Materials and methods: white the research of the problem of increasing operational reliability of coverings of apartment buildings the following methods were used: static analysis based on a theoretical and practical approach, generalizations and comparisons. The methods of research are used from the perspective of various coating materials’ application for residential buildings and methods of their exploitation.

The subject of research are the coverings of apartment buildings in Tambov region.

The aim of research is in a comprehensive solution and the development of scientific and practical problem of increasing operational reliability of apartment houses.

The tasks of research: to define the main criteria of reliability and durability of coverings of residential buildings, to describe the factors, influencing the tern of exploitation of residential buildings’ coverings, to give a comprehensive assessment of technical state of coverings of buildings in Tambov region.

Scientific novelty is in the solution of the matters of improving operational reliability of coverings of residential buildings in the central part of Russia

BASIC RELIABILITY CRITERIA AND DURABILITY OF COVERINGS OF RESIDENTIAL BUILDINGS

The  result of unsatisfactory state of coverings of residential buildings, is the destruction of the main structural elements. In relation to enclosing and load – bearing structures of residential buildings, reliability – is a property, providing a standard temperature – wet and comfortable mode of rooms, while maintaining operational indicators (thermal protection, moisture protection, air protection and sound protection within the specified regulatory limits, but for architectural – constructive element of the building and decorating functions within the specified period of exploitation, strength reliability is also added. Reliability of the covering of the building is defined by the reliability of  its constituent elements which in accordance with the state standard P 27.102-2021 are characterized by there main properties:

faultlessness, that is preserving its efficiency without forced breaks within the given period of time till the occurrence of the first fault  (overhaul period);

by its durability, that is maintaining working capacity before the onset of the limit state with intervals for repair and adjustment work and trouble shooting the problems that have arisen;

maintainability of building elements to prevent and eliminate failures and damages by carrying out maintenance and fulfilling planned and unplanned repairs;

coverings of buildings – the upper structure of the building which perform the function protecting structural elements of the building from atmospheric precipitation and other natural factors;

the reliability of building constructions must be guaranteed by the calculation of the structure as a whole and its individual structural elements for all considered limit states;

selection and control of execution of optimal design solutions, materials;

technological processes of manufacturing and installation of building structures;

creating conditions than secure the normal operation of construction objects;

monitoring of the technical state of the structure as a whole and its separate structural elements;

the conduction of organizational events aimed at reducing the possibility of emergency situations and progressive collapse of residential buildings.

Durability – is a property of an object to maintain working capacity till the onset limit state at the installed system of maintenance and repairs that is with possible intervals in the work. The indicators of durability are the average service life; service life until the first overhaul inter-repair service life. To ensure the required durability of the construction object when designing it, it’s necessary to take into account:

operating conditions for the intended purpose;

calculated environmental impact;

properties of the materials used, possible means of their protection from negative environmental influences and also the possibility of degradation of their properties.

When designing construction projects it is necessary to take into account the possible impact of aggressive environment and other negative conditions influencing on them (alternative freezing and thawing, the presence of anti-icing reagents, sea-water impact, industrial emissions).

Thus the ensuring the required level of reliability of residential buildings coverings in the course of their operation can be performed by technical and organizational methods and should be justified by comprehensive assessments: social, technical, economic, ecological and soon.

FACTORS THAT INFLUENSE THE TERM OF USAGE OF COVERINGS OF RESIDENTIAL BUILDINGS

The factors influencing operational reliability of coverings of residential buildings can be divided in two groups: inner and outer influence. The first group includes physical processes, going in the material of constructions’ coverings, loads and processes occurring at exploitation; constructional factors; the quality of manufacturing materials of the covering. The second group of reasons includes: climatic factors (temperature, humidity, sun radiation alternate freezing and thawing) aggressive factors of the environment (the presence of aggressive components in the atmosphere biological factors, winds, dust and soon and the quality of exploitation. The last factor is more important in a number of cases as by the intensity of covering wear it can exceed all the rest.

Bitumen contained in the soft roof and other substances are unstable to the temperature gradients which are often in winter. It means that to increase the service life of bitumen material the repair and measures caring for it should be carried out at the very beginning of spring. Thus often the term of service of soft roofs can be shortened due to the mechanical influences which include:

solid precipitation;

static loadings;

seismic vibrations;

pressure of evaporations.

The coverings of asbestos and wavy sheets under the influence of low – temperatures, ice and mechanical influence can have cracks and breach and at the strong blows of wind, displacements and their break downs are possible. The influence of natural factors on coverings of sheet steel often lead to corrosion damage.

Also one of the factors is the lack of theoretical and practical knowledge and abilities of the employees of the organizations servicing the housing and repairing the roofs.

Thus, the choice of roofing material depends on the climatic conditions in which it will be operated, on the purpose of the building, on natural and natural factors that will affect it, on the qualifications of the working staff.

COMPREHENSIVE ASSESSMENT OF THE TECHNICAL CONDITION OF COATINGS OF RESIDENTIAL BUILDINGS IN THE TAMBOV REGION

To assess the technical condition of the coatings of residential buildings in the Tambov region, a number of field surveys of apartment buildings were conducted.

The most common coverings of apartment buildings in the Tambov region are:

soft rolled materials based on bitumen (uniflex,steloisol, technoelast, linocrom, bipol, elastisol, etc.);

asbestos cement sheets;

sheet steel coating (profiled sheet, seam roofs).

The soft rolled roof for the most part due to long operation has reached a high degree of wear. Cracks and holes in the waterproofing layer, destruction of the protective layer, aging of the rolled material and mastic, violation of roof slopes and the formation of water stagnation zones are observed.

The cause of these faults is the  faults is the mechanical impact on the rolled carpet during its construction and operation not density in the places of contiquity of the rolled carpet to the walls, parapet, risers, ventilation shafts deformation of load – bearing structures and basis, faults of the leveling screet and water intake funnels (set up on the high places), ultraviolet impact and other natural factors.

Besides that, in Tambov, the facts of application of cooled mastic on a number of rolled roofs, and the use of contaminated graves and coarse sand, application of rolled material on the basis of cardboard with a short service life, application of cement - sand solution of low grade for the device leveling the screeds, free access to the roofing by unauthorized persons, who are not employees of the organization, serving the housing stock, non compliance with the norm of snow and ice.

The inspection of asbestos sheets in Morshansk allowed to find out the following faults: not density at the junction of the sheets in razzhelobki and in the skate as well as in places adjacent to the parapet, walls, tube and skylight, chips and absence of parts of sheets; poor fastening of sheets to the crate.

The factors that caused these defects and reduced operational reliability of the coating from asbestos sheets are:

the breakdown of sheets by strong wind the impact of the tool removal;

of ice and snow;

the deformation of roof coverings;

the impact of strong wind;

the impact ice;

fault at carrying out the works.

The examination of steel sheet coverings of apartment buildings in Kotovsk, in Pervomaisk and Zherdevskyi regions showed that the most wide – spread defects and damages are not density in folds, displacement of water pipes, destruction of the tray and inlet funnels, humidification of the roof truss system.

The main factors influencing the durability of this roof are: unsufficient compression of bends in folds, corrosion destruction under the influence of natural factors, the impact of strong wind and also sliding blocks of snow and ice.

Based on the above – mentioned, in the cause of monitoring the reasons of improper state of roofs of apartment buildings in the Tambov region territory, we can define the main:

cracks, holes and other mechanical damage of roll coatings and asbestos sheets;

humidified state of the insulation and roof truss system;

violation of slopes and formation of slopes and formation of stagnant water zones on the roof coverings;

destruction of the protective layer and aging of the coating material malfunction of the intake funnels and stormwater drainage system.

The result of this process under the long impact can be the destruction and loss of bearing capacity of  structural elements of a department house. Organizational assurance of reliability of residential buildings is help by maintenances services, which fulfil main tasks:

Identification of the first signs of the destruction of structures and materials, and prevention of further development of defects; reduction by preventive measures (scheduled repairs and maintenance) the probability of occurrence of coating damage and structural elements.

To find acceptable ratio between the required level of coating reliability and material costs, connected with its maintenance can be achieved by developing an optimal strategy of performing repairs.

Prompt elimination of defects arising during operation, and the planned sequence of major repairs of roofs allows to provide the required level of reliability of a residential building. As the result of the conducted research, the fact of the need for an integrated approach to increase durability and operational reliability of the coatings of residential buildings was established.

Besides that it is necessary to conduct a systematic monitoring of the state of the roofs of residential buildings. Timely detection of defects and damage to the coating increases its maintainability as a consequence of the increase in its service life.

Forecasting the influence of natural factors allows you to more accurately select the desired coating material of residential building.

To carry out timely repairs of residential buildings, it is necessary to develop a work schedule plan depending on the roof structure, the material of its covering, and also on duration of service life.

References:

1. Dorkin, V.V. Coverings of residential buildings: Uch. / V.V. Dorkin, M.P. Ryabtseva. - M.: Infra-M, 2021. - 576 – 580 pp.
2. Dukarsky, Yu.M. Engineering structures. Coatings of residential buildings: Textbook / Yu.M. Dukarsky, F.V. Russ, O.V. Mareeva. - M.: Infra-M, 2020. - 156 p.
3. Eremeev, P.G. Spatial thin-sheet coatings of residential buildings coatings / P.G. Eremeev. - M.: DIA, 2020. - 560 p.
4. Karpanina, E.N. Coverings of residential buildings / E.N. Karpanina. - M.: Rusains, 2021 - 160 p.
5. Kudishin, Yu.I. Coatings of residential buildings: Textbook for students. institutions of higher Prof. education / Yu.I. Kudishin, E.I. Belenya, V.S. Ignatieva. - M.: IC Academy, 2021. - 688 p.
6. Moskalev, N.S. Coatings of residential buildings: Textbook / N.S. Moskalev, Ya.A. Pronozin. - M.: DIA, 2022. - 344 p.
7. Nekhaev, G.A. Coverings of residential buildings in examples and tasks: A textbook / G.A. Nekhaev, I.A. Zakharova. - M.: DIA, 2020. - 128 p.
8. Monastyrev P.V. Housing stock and energy saving / Housing construction. 2000. No. 5. 14-15 pp.
9. Technical and economic bases of operation, reconstruction and renovation of buildings. Domozhilov Yu.N., Monastyrev P.V., Nikitina N.S., Kauppila V., Kayvonen Yu.A., Aro T. (textbook) / Moscow, 2007. – 35 p.