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Having identified the relationship between the influencing factors of organizational and technical solutions and the effectiveness of the organization of the process of erecting structural elements of multi-storey buildings, it is possible to reasonably predict the probability of achieving the desired result at any stage of the construction process. The effectiveness of the method of assessing the factors of organizational and technical solutions is determined by a large-scale approach to the selection of factors that determine the organization of the process of erecting structural elements of monolithic buildings.

Today’s priority in construction lies in three primary areas: ecology, energy efficiency and cost-effectiveness. It means that the most important task it to construct environmental, energy-efficient and cost-effective buildings and structures. To erect houses having such characteristics, primary elements of a structure (brick block, etc.) must be made subject to the conditions that provide for the above characteristics. The prevailing trend in construction is the production of environmental, energy-efficient and cost-effective construction materials. This research is intended to develop an energy efficient procedure to make heat-insulating materials based on crushed cotton plant stems. To achieve this goal, the authors have addressed the following issues: describing the process of making a heat-insulating material based on crush cotton plant stems; analysis of energy-efficient characteristics of manufacturing materials based on crushed cotton plant stems; and analysis of environmental friendliness of such a material. The research applies the deductive method based on mathematical modelling. The subject of the research is the procedure to make a material based on crushed cotton plant stems. The primary conclusion and outcome of this research is that papercrete based on crushed cotton plant stems has such advantages as cost-effectiveness, environmental friendliness, energy efficiency and low resource demand in manufacturing and operation. The resulting strength of papercrete allows using it as a heat insulating material to erect low-rise buildings.

The formation of conditions for ensuring the established quality of construction objects of various functional purposes is impossible without solving a set of tasks related to the systematic analysis of factors that ensure the organization. Improving the effectiveness of supervisory authorities consists in focusing attention on critical stages of construction and reducing excessive attention to secondary aspects that do not affect the safety of the construction object and do not deviate from the design documentation, in order to reduce the number of inspections and the excessive impact of state supervision in general. The program of inspections of construction supervision is formed on the basis of approved departmental regulations. These rules do not specify quantitative data on the conduct of inspections, nor do they define specific moments of construction of facilities during which it is necessary to conduct a supervisory procedure with a visit to the facility. The current inspection regulations are aimed at identifying deviations from the requirements of project documentation and current regulatory documentation and are not aimed at preventing and preventing the occurrence of critical defects. Necessary to develop a scientifically based methodology for conducting supervisory activities that ensures the formation of high-quality construction products.

Failure to meet the deadlines for the implementation of investment-construction projects is a problem in all countries of the world and leads to unstable activity of construction companies. This article studies the most important destabilizing factors affecting the main indicator of sustainable activity of construction companies, i.e., the duration of the implementation of an investment-construction projects. To determine and assess the impact of destabilizing factors on the duration of implementation of selected investment-construction projects, a survey was conducted in which a number of customers, consultants, and contractors involved in construction projects took part. Questionnaires developed on the basis of a cluster sample were sent to respondents, and 84 responses were received in response to the assessment of destabilizing factors. To analyze the received and grouped information, structural equation modeling using the Smart-PLS program was used. As a result of modeling, a number of results were obtained, the most important of which was the identification of the main reasons that lead to an average (20–50%) increase in the duration of projects in the construction sector. The most significant was the lack of an appropriate procurement program for materials; inefficient scheduling by contractors and instability of construction production, poor-quality processing of incoming information, and untimely decision-making due to changes in projects during their implementation. Destabilizing factors contribute to an increase in the duration of construction sector projects, which leads to time overruns, cost overruns, and an increase in the negative impact on the overall use of resources. As a result of the study, a set of recommendations was formed, the most important of which is the use of possible compensatory measures that can allow construction companies to eliminate the risks of disrupting construction deadlines for sustainable activities. These compensatory measures include: 1. recommendations to customers of the construction project, 2. recommendations to contractors, and 3. recommendations to the consultant. Moreover, the control of destabilizing factors that can cause delays, the improvement of contracts, and the precise and clearer definition of all elements of the project can help to reduce the duration of construction, and will allow companies to maintain sustainable activities in the construction industry. [ABSTRACT FROM AUTHOR]

The risk factors that arise during the implementation of investment and construction projects differ in nature, degree of influence, and other characteristics. Ignoring these factors and measures to manage them often leads to critical consequences in the form of disruptions in the timing of work. The article discusses the risk factors arising at the construction stage, their classification, as well as the measures and strategies necessary to manage these factors. A methodology has been developed that includes conducting a survey in the form of a questionnaire in order to collect information about risk factors that affect the implementation of investment and construction projects. The fuzzy TOPSIS technique was used to compare the sustainable functioning of three construction companies (alternatives) on the basis of its application of measures and strategies necessary to deal with risk factors (criteria). Experts with experience in the construction sector were involved in the survey. The results showed that financial, technical, legal, economic, managerial, and natural factors have the greatest impact on investment and construction projects. It is recommended to pay special attention to the listed factors when developing measures aimed at preventing risks and their consequences. The methodology described in the study can be used by construction companies in strategic planning. The analysis of the stability of construction companies, depending on their use of various ways to counteract risk factors, allowed us to develop a number of practical recommendations to reduce the impact of the studied factors on achieving the goals of investment and construction projects. [ABSTRACT FROM AUTHOR]

Natural disasters and warfare lead to the destruction of city buildings and infrastructure, leaving large numbers of people homeless. The rebuilding of destroyed cities needs to be carried out promptly while maintaining a balance between construction quality and duration. Rework due to defects and the lengthy approval of non-conformances significantly increases the duration of construction. This study aimed to develop a decision support system to fix or negotiate strategies to address construction defects, depending on their level of risk. The paper addresses the following objectives: classifying defects by the quality of construction that they affect; building a tree of construction defect risks; and developing an artificial neural network (ANN) to assess the defect risk. The weights of the links are represented by posterior probabilities of damage calculated using the Bayes' theorem in the pre-training stage. The ANN has been adapted to cast-in-place reinforced concrete structures. When training the resulting ANN on a sample of precedents, the test sample demonstrated convergence and low errors. The resulting model will accelerate construction by automating assessments of defect severity and reducing the time spent on reworking defects with low quality risk. [ABSTRACT FROM AUTHOR]

Today, the professional activities of consulting engineers need new functions based on a research-based approach to the design, construction and operation of sophisticated construction projects. The authors introduce new terms and use the concept of technology platforms to present a research-driven platform for consulting engineers. This platform is a complex system that has three constituent subsystems, including "Processes", the "Database of work items" and "Participants". Formalized interaction between the platform constituents is based on a tree of goals. The implementation of actions, focused on each goal, allowed (1) clustering the requirements applicable to the new type of consulting engineers; (2) developing an algorithm that underlies the database of work items to be performed by new consulting engineers; (3) developing the principle of automated selection of work items; (4) making a graphical representation of activities, performed by consulting engineers in the form of a BPMN diagram. The platform is a concept for a novel approach to the activities of consulting engineers, who will contribute their experience and use the research-driven approach to ensure the reliability and safety of sophisticated construction projects. [ABSTRACT FROM AUTHOR]

A large number of large industrial cities around the world are characterized by the presence of industrial sites in the Central part of the city and areas close to the center. A significant part of these zones have lost their relevance and are not used as production facilities, but function as rental businesses. The relevance of the study considered in this article is due to the need to create an organizational and technological model for the development of project documentation for the redevelopment of industrial facilities in the absence of Federal and regional programs in Russia that affect this area, as well as the lack of a regulatory framework for regulating the activities of project organizations that develop the above projects. The article deals with the General principles of developing an organizational and technological model that allows evaluating and optimizing the designer’s activity when repurposing industrial objects, as well as aimed at improving the design processes of such objects. For scientific, methodological and system-technical bases of designing organizational structures of enterprises and organization of production processes of modeling re-profiling of industrial territories, it was necessary to solve the following tasks: study and generalization of foreign and domestic experiences of redevelopment of industrial zones; identification of actual problems in the design of redevelopment of industrial territories; study of factors that affect the effectiveness of the designer; establishing the degree of influence of the identified factors on the quality of the project documentation produced. The parameters and organizational principles described in the article are taken into account when re-profiling industrial objects in the urban environment of large Russian megalopolises.

Many factors influence what organizational and technological decisions will be made to ensure the safety of buildings and structures. The authors considered factors reflecting their full characteristics. Based on the regulatory documentation used in the design of buildings and structures for the section of design documentation “Structural and space-planning decisions”, the types of safety that are influenced by the design decisions are determined, factors for each type of safety are determined, and safety factors are ranked by importance.

The study is aimed at developing a tool for the formation of a rational set of machines for excavation work in urban areas. The instrument to be developed will affect the main project parameters, such as the project cost and term of implementation. An expert survey was launched among the leading specialists of the construction industry to make a set of significant parameters and identify the weighting ratio, since both are required to select the machines for rational sets designated for excavation work in urban environments. The equation of multiple regression was solved to determine the extent of significance by calculating Fisher's ratio. This equation shows that significant parameters are inter-related and can be used in this method. A method for making a rational set of machines, designated for the performance of excavation work in urban environments, has the following stages: at the first stage, the choice of the necessary excavation work at the construction site is made; at the second stage, limitations, arising at the site, are introduced; at the third stage, the minimum number of major machines is determined; at the fourth stage, a rational set of machines is made step by step. If implemented, this study demonstrates the high economic efficiency of the proposed method of expanding excavation work in urban environments. The study shows that the use of a mathematical model will boost the project's success, as it demonstrates the critical factors of risk at the initial stage of the life cycle of a construction project. [ABSTRACT FROM AUTHOR]

The environment of an underground structure is much more complex than the above-ground environment. Erosion processes are underway in soil and groundwater; groundwater seepage and soil pressure are also typical for underground environments. Alternating layers of dry and wet soil have a strong effect on concrete, and they reduce its durability. Corrosion of cement concretes is caused by the diffusion of free calcium hydroxide, located in the pores of concrete, from the volume of the cement stone to its surface, bordering on an aggressive environment, and the further transition of the substance through the phase boundary solid (concrete)–soil-aggressive environment (liquid). Due to the fact that all minerals in cement stone exist only in saturated or close-to-saturated solutions of calcium hydroxide, a decrease in the content of which in the pores of concrete as a result of mass transfer processes causes a change in the phase and thermodynamic equilibrium in the body of concrete and leads to the decomposition of highly basic compounds of cement stone and, consequently, to the deterioration of the mechanical properties of concrete (reduction in strength, modulus of elasticity, etc.). A mathematical model of mass transfer in a two-layer plate imitating the "reinforced concrete structure—layer of the soil–coastal marine area" system is proposed as a system of nonstationary partial derivative differential equations of the parabolic type with Newmann's boundary conditions inside the building and at the interface between the soil and the marine environment and with conjugating boundary conditions at the interface between the concrete and the soil. When the boundary problem of mass conductivity in the "concrete–soil" system is solved, expressions are obtained to determine the dynamics of the concentration profiles of the target component (calcium ions) in the volumes of the concrete and soil. As a result, one can select the optimum composition of concrete, having high anticorrosion properties, to extend the durability of the concrete constructions of offshore marine structures. [ABSTRACT FROM AUTHOR]

The efficiency potential of organizational and technological solutions using the methods of non-destructive testing of the strength of monolithic structures in the construction of civil buildings and structures has been investigated. In this article scientific and technical hypothesis was compiled. It consists in the assumption of the possibility of developing a system for evaluating the organizational-technological potential of using non-destructive testing methods based on the method of qualimetric analysis. The four most significant groups of parameters were identified on the basis of this method. They can have a significant impact on the organizational and technological potential of using non-destructive testing methods. The orthogonal central compositional plan was chosen as the basis for planning the experiment. This will reduce the number of experiments in the formation of the potential to 25, and to assess the degree of influence of each production and technological module in the implementation of the construction project. The system of variation of groups of parameters consisting of three levels was formed for the purpose of further research based on the tree of goals. The basis for the mathematical apparatus is prepared. This unit characterizes the parameters of the object.

With use of factor matrix, four groups of parameters were identified, and one group was determined as the most significant one, which affects the complex quality index in high-rise apartment buildings constriction. The dependence between the complex quality index and the values of influencing factors was determined. The mathematical model that allows making adjustments to achieve the required levels of quality at all stages of the construction project was considered.

Article justify the need for a systematic approach to the formation of uniform requirements for the volume and level of construction supervision carried out in the conversion of industrial facilities. Author determines the factors that affect the safety, is the quantitative characteristics of various types of control measures carried out by specialists of state construction supervision both at the facility and in the office. As a hypothesis, author considers the possibility of forming a single deterministic system that provides objective supervision during the conversion and does not create an excessive burden for both the state and the developer. As a result, the existing legislation in the field of state construction supervision is incomplete and partly contradictory. In this article the necessity of formation of scientifically grounded hierarchical organizational and technological system of construction supervision is defined.

The article is devoted to the study of the possibility of using SIP-technology in solving the problem of housing shortages in Bujumbura. The author analyzed the design features of houses, foreign experience in the development of low-rise construction, the advantages of using SIP-panels compared to other building materials. Organizational and technological solutions for the construction of low-rise apartment buildings using SIP-panels will help to provide the population with comfortable housing at an affordable price. The SIP-technology enables the construction in places with difficult terrain due to their difficult engineering and geological conditions.

The study focuses on developing a methodology for calculating an integrated quality index of administrative and engineering solutions that affect the safety of multi-storey residential buildings at each stage of their lifecycle. This method can be used to design a tool for assessing the integrated quality of multi-storey residential buildings at each stage of production. Advanced quality assessment methods were analyzed within the framework of this study. The analysis led to the conclusion that the most relevant problem is the lack of an integrated approach to the quality assessment of multi-storey residential buildings. Having studied an extensive number of research works, the authors identified the main parameters that affect the quality of a construction facility. The aims of the study were to (1) develop an integrated quality index for multi-storey residential buildings (this index is to be applicable as early as at the stage of pre-construction arrangements); (2) develop methods for calculating and evaluating the integrated quality index for high-rise residential buildings at the stage of construction arrangements; (3) improve the efficiency of administrative and engineering solutions; and (4) devise a mathematical model that will identify the numerical value of the proposed multi-factor criteria. The research results show the feasibility and expediency of introducing this methodology in residential construction as it allows for a comprehensive measurement and quality assessment of high-rise residential buildings. [ABSTRACT FROM AUTHOR]

The parameters influencing on the use of non-destructive methods of control are considered when building monolithic constructions of civil and industrial buildings and structures. The analysis of the factor influence on the capacity of the method of the non-destructive control with the expert assessment method is made. Based on the qualimetric analysis three the most significant groups of the factors which can influence on the capacity of the use of the non-destructive control method (Pnc) are determined. The mathematical apparatus base is prepared, which characterize the object parameters.

Against the backdrop of the economic crisis and the complicated international situation, the government pays great attention to reforming the construction industry, creating the conditions for adapting construction firms to the existing situation and associated entrepreneurial and production risks. Concurrently, as the ever-increasing competition places higher requirements on potential participants in construction projects under state-financed and municipal contracts, new laws and regulations are being developed and improved, and bidding rules are systemized and optimized to help select the most reliable contractors resistant to various impacts. The purpose of this paper is to describe the term “sustainability of a construction firm” and to set the tasks of research into the ways of increasing sustainability of construction firms based on efficient organization of construction operations and up-to-date production and labor technology. The scientific problem suggested for review lies in ensuring guaranteed sustainability of construction firms amid uncertainties of construction operations. This paper focuses on research into and the methods for determining a correlation between sustainability of a construction firm and its resource potential that depends on a number of diverse factors.

In the publication mobile building life cycle is researched. There is comparison with the stationary construction. The article discusses in detail specialized cycles of the mobile object construction. The interrelation of specialized cycles of the mobile building object, technical, organizational and technological requirements that underlie the effective implementation of mobile building object is detected.

The stages of pre-project preparation and design development are the fundamentals to the further implementation of an investment and construction project. The success of construction and commissioning of facilities depends on the smooth completion of these stages. The duration of stages depends on the competence and coordination of interaction between participants of an investment and construction project, rational decision making by the project manager and a number of other factors. Identifying these factors and finding rational planning options in terms of the stages of pre-project preparation and design development is a highly relevant task. With this in mind, the authors have developed an organizational and management model of a rational procedure to be implemented by the project manager at the stages of pre-project preparation and design development for a facility to be constructed. The model takes into account the influence of negative factors. The authors have also developed a method for selecting rational solutions at the stages in question. The analysis of the research literature and regulatory documents was performed for this purpose. The method of expert evaluations, elements of numerical analysis, mathematical processing of practical results and methods of mathematical modeling were applied. As a result, the authors have developed an organizational and management model for a rational combination of procedures at the stages of pre-project preparation and design development for a facility to be constructed and derived a formula determining the duration of implementation of each stage and a technique designated for selecting rational solutions at the stages in question. The findings of this study can simplify project planning and process management at the stages of pre-project preparation and design development in terms of information modeling. [ABSTRACT FROM AUTHOR]

The article presents the results of the investigation of universal calibration dependences used in testing of the concrete strength by shear, rebound and ultrasound test methods. Many of the instruments currently used do not provide the required measurement accuracy, especially when using universal calibration dependences. The introduction of new more sophisticated instruments for nondestructive testing of concrete strength requires an assessment of their accuracy, taking into account the composition of concrete and other parameters. The shear test method, called “direct”, does not provide the required accuracy of measurements, and the use of this method for the calibration of sclerometers and ultrasonic devices is unacceptable. The aim of the research is to clarify the dependences, taking into account the data on concrete composition, parameters of materials used, and the age of concrete. The studies will allow you to set the values of the coefficients to be used in the generalized calibration curve, with considering the concrete information obtained at a particular construction site (where concrete strength is tested).

Now software developed on the basis of artificial neural networks (ANN) has been actively implemented in construction companies to support decision-making in organization and management of construction processes. ANN learning is the main stage of its development. A key question for supervised learning is how many number of training examples we need to approximate the true relationship between network inputs and output with the desired accuracy. Also designing of ANN architecture is related to learning problem known as “curse of dimensionality”. This problem is important for the study of construction process management because of the difficulty to get training data from construction sites. In previous studies the authors have designed a 4-layer feedforward ANN with a unit model of 12-5-4-1 to approximate estimation and prediction of roofing process. This paper presented the statistical learning side of created ANN with simple-error-minimization algorithm. The sample size to efficient training and the confidence interval of network outputs defined. In conclusion the authors predicted successful ANN learning in a large construction business company within a short space of time.

The modern rhythm of human life leads to well-known problems, which are air, water and soil pollution and climate warming. An increase in the power of industries and vehicles leads not only to atmospheric pollution by-products of incomplete fuel combustion but also to various microscopic particles that form aerosols, which carry an obvious danger to human health and also pollute the buildings' facades. An environmentally friendly building material with a hybrid method "Nano-titania gradient" was developed. This method consists of forming a gradient of n-TiO2 particles concentration in the composite since the physical properties of the composite are always inextricably linked to the geometry. To increase the efficiency of the photocatalytic process, a method of surface sensitization of titanium dioxide with the use of graphene oxide was proposed, which contributed to an increase in the overall photosensitivity. Thus, the decomposition of nitrogen oxide by volume with the modified surface increased by 27% in comparison with the classic titanium dioxide, and the decomposition of volatile organic substances increased by 32%. It was found that for the facade plate made with surface-sensitized TiO2, the process of self-cleaning is completed after 3 h after the irradiation start. The modern rhythm of human life leads to well-known problems, which are air, water and soil pollution and climate warming. Using the theory of percolation, the concentration range of the photocatalyst content was calculated. To facilitate the material, waste cellulose was introduced. To increase the efficiency of the photocatalytic process, a method of surface sensitization of titanium dioxide (SS TiO2) with the use of graphene oxide was proposed. The analysis of the experimental-statistical models of the compressive strength shows that the optimum content of TiO2 was in the range from 0.8 to 1.1%, and cellulose from 0.4 to 0.8%, the optimum content of SS TiO2 was in the range from 0.7 to 1.1%, and cellulose from 0.4 to 0.8%. Analysis of the experimental and statistical model of the bending strength shows that the optimal content of TiO2 and SS TiO2 was in the range of 0.6 to 1.0%, and cellulose from 0.4 to 0.8%. When studying the structure of composites, it was found that titanium dioxide was sorbed on the surface of swollen cellulose fibers and remained there after the process of cement hydration. The effectiveness of the method of surface sensitization of titanium dioxide by combining it with graphene oxide was shown. Thus, the decomposition of nitrogen oxide by volume with the modified surface increased by 27% in comparison with the classic titanium dioxide, and the decomposition of volatile organic substances increased by 32%. It was found that for the facade plate made with surface-sensitized TiO2, the process of self-cleaning was completed after 3 h after the irradiation start. [ABSTRACT FROM AUTHOR]

Recent years have witnessed active construction of multi-storey residential buildings. The scale of construction, its timing and limitations in financing contribute to the emergence of risk factors affecting the key parameters of cost and duration of projects. The purpose of this research is to develop the most effective mathematical model to reveal, study and estimate in a timely manner the influence of risk factors on stable implementation of a construction project during its life cycle. The mathematical model of the study is based on the theory of fuzzy sets, including 25 rules used to estimate the influence of a risk factor. An expert survey of leading specialists in the construction industry was performed and risk factors distributed over the stages of the life cycle were listed. Risk factors affecting the sustainability of the life cycle of a multi-storey residential building were identified and ranked. The result of the study shows that the application of the mathematical model will significantly increase the success of construction projects by identifying the critical risk factors in the phases of their life cycle. Since the proposed model is relatively new in Russia, it should be considered as a starting point for a new assessment of the impact of risk factors on projects. The methodology can be improved, and many aspects are still to be analyzed. [ABSTRACT FROM AUTHOR]

In this article, problems of mathematical modeling and experiment planning of the organization and management of construction. The authors designated the basic restrictions and the difficulties in this field. Concluded that the planning of research experiment is possible in the information sphere with using of heuristic, graphical, mathematical models, as well as neural networks and genetic algorithms. The authors note the need for use of expert information in the case of the formalization of quality parameters. The article presented an overview of the translation methods of qualitative information into mathematical language. Comparison of methods the qualimetry of USSR scientists, the analytic hierarchy process and fuzzy set theory were performed. The benefits of the latter for interpretation of qualitative parameters were identified. The authors have given many examples of application fuzzy sets for formalization of organizational factors of construction processes. Finally, there conclusion was made about progressiveness and effectiveness of fuzzy set theory to describe the qualitative parameters of organization and management of construction.

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