The analysis of the experimental data is carried out and the works devoted to the account of the influence of the compressive pressure factor with the purpose of optimizing the parameters of the centrifuged products of the annular section at the compaction stage are studied. The number of rotations of the mold at the compaction stage is calculated for different values of the compressive pressure. A statistical analysis of the regression equations obtained is performed using three criteria: homogeneity of variances, significance of coefficients and adequacy, which was tested with the help of Fisher's criterion. The data were statistically processed using the Mathcad program, which allowed obtaining regression equations in the form of polynomials of the second degree with specific values of their coefficients. Graphic interpretation of mathematical dependencies is constructed. The calculated dependencies are obtained that allow to determine the required number of revolutions for any required diameter and wall thickness of annular centrifuged products for a given fixed value of the compressive pressure in concrete.
Keywords: compressive pressure, centrifuged products of annular section, response function, factor of variation, least squares method, regression equation
An actual problem of the lack of green spaces in modern cities is considered. Some ways of applying gardening in the structure of the building are suggested, which can solve the indicated problem. The most detailed consideration is the reception of horizontal external landscaping, examples of domestic and foreign experience are given.
Keywords: Green architecture, green spaces, vertical landscaping, atrium landscaping, horizontal outdoor landscaping, house-garden decoration of building facades, roofs in operation
The article presents calculation of the cost of overlappings from LSTK and wooden ones. The floors of the two-storey house with a span and overlap with a span of 12 m were calculated. Calculation of the cost of materials is presented for each option. In conclusion, conclusions were drawn on the rational use of material types for each of the calculated spans.
Keywords: light steel thin-walled structures, LSTK ceiling, wooden flooring, reduced characteristics, effective cross-section, construction
At present, progress in building materials science and the construction industry is gaining in importance. New technologies provide high quality products, its environmental safety, efficient use of raw materials, saving resources. The creation of high technologies is possible only with the use of the latest achievements in physics, chemistry and other basic sciences. To date, the most promising are nanotechnology.
Keywords: nano-concrete, natural raw materials, additives, macro-reinforcement, fiber, nanostructure, crack resistance
The properties and main characteristics of the large-tonnage waste of industry - hydrolytic lignin, as well as the direction of its rational use are considered. The results of an experiment on the effect of the lignin of the Kosivinsk hydrolysis plant on the main properties of the cement-sand composition are presented. It is shown that the addition of hydrolytic lignin in an amount of 15-20% by mass in exchange for the binder will yield a building material with a mark of average density D1900-D2000 and a class of compressive strength B5-B7.5.
Keywords: hydrolytic lignin, waste, low-rise construction, wall material, secondary raw materials, utilization
The technique of calculating the metal corrugated structures using the finite element method for an axisymmetric load is considered in the article. One-dimensional finite elements in the form of truncated cones are used. Calculations are performed using the program developed by the authors in the Matlab package. An example of calculation of a ground well rigidly clamped in the base under the action of ground pressure is given. The sinusoidal profile of the corrugation is considered. The graphs of changes in bending moments and ring forces are presented. For a smooth shell of the same thickness, the bending moment in the pinch was 30.3% higher compared to the corrugated, and the maximum value of the ring force was 15.7% higher.
Keywords: metal corrugated structures, cylindrical shell, finite element method, axisymmetric problem, soil well, shell theory, edge effect
In this paper, various methods were used to calculate the flexion plate, obtained approximating the function of the deflection plate, numerical values and diagrams of displacements and moments, conclusions are drawn from the results of the methods.
Keywords: plate, approximating function, curvature, energy functionality
The article formulates a number of measures to reduce the negative impact of construction technologies on the environment. Documents establishing "green" standards are considered. Some environmentally friendly technologies used in green building are studied. The experience of construction of eco-facilities in Russia and abroad is considered.
Keywords: green building, green standards, energy efficiency, environmental friendliness
The article presents the analysis of dust pollution of atmospheric air in the vicinity of the enterprise for the production of gypsum products. Given the dynamics of changes in the concentration of fine dust, and also investigated the characteristics of the distribution of concentrations of fine dust РМ0.3, , PM2. 5, РМ5 , PM10 etc.
Keywords: atmospheric air, fine dust, PM0.3, PM0.5, PM1.0, PM2.5, PM5 and PM10, dust concentration, speed, wind direction, air humidity, integral mass distribution function, particle diameter by diameter
dependences of value distribution of hardness of an armature of the class A500C of different diameters are constructed. For determination of the minimum values the method of graphic transition from selective data to set is used. Calculation of the smallest values of hardness using the shift received in the analysis of set is carried out.
Keywords: selection, armature, population of final volume
The safety of technological processes in the performance of loading and unloading, construction and installation works is becoming increasingly important. The desire of manufacturers to increase the power characteristics of load-lifting mechanisms and their number makes their mark on the unsatisfactory OSH management system in general, plus the discipline and unsatisfactory technical condition of the equipment leave much to be desired. The situation is not better with observance of elementary safety standards, which, as a rule, are skeptical not only for the working class, but also for engineers and managers who do not conduct personnel training, are not interested in the application of personal protective equipment (in rare cases), attestation of workplaces, everything is done formally, as a result of which the picture is not formed in the best way.
Keywords: safety engineering, construction, cranes, industrial injuries, construction and installation works, industrial accidents
The article presents the results of studies to determine the energy efficiency of the two options for the mutual placement of the fan and the air heater in the ventilation system. The traditional variant with the installation of the air heater to the fan and the layout solution with the installation of the air heater after the fan are considered. It is shown that thermodynamic processes occur in the systems under consideration, the direction and energy efficiency of which depends on the layout solution of the system. By using the method of analysis of aerodynamic efficiency of ventilation systems, it is proved that the implementation of the objective function of the system with the highest energy efficiency corresponds to the installation of the fan in front of the air heater. This option corresponds to the minimum values of the volumetric capacity of the fan and its power consumption.
Keywords: fan, air heater, ventilation system, heating and ventilation system, energy, power, energy efficiency, energy conversion, mechanical power flow, thermodynamic system
The paper reports that there currently exist various technologies and methods for achieving energy efficiency of reconstructed buildings and facilities. It highlights the fact that practically all mansard construction technologies conform to the up-to-date requirements for energy efficiency and resource conservation. At the same time, the analysis of a number of foreign and national publications shows that the modern trends in ensuring energy efficiency of buildings and facilities are based on the use of solar, thermal and biocincrete panels, which also prove to be environmentally friendly.
Keywords: mezzanine, solar panels, thermal panels, biocincrete panels, efficiency ratio of solar energy generating panels, energy efficiency, environmental safety
The possibility of revealing the main defects that arise when strengthening reinforced concrete structures by external reinforcement systems based on carbon fibers is considered. The efficiency of active and passive methods of thermography is compared, and the possibility of using the passive method at negative ambient temperatures is considered. Under laboratory conditions, ferroconcrete samples with defects in the form of air bubbles and glue were made and a comparison of the mapping of these defects on thermograms was made.
Keywords: composite materials, reinforcement, external reinforcement systems, infrared thermography, defect, work quality assessment, technical condition assessment, span structures, bridge supports
Possible unfavorable changes in roofing bitumen mastics (RBM), such as shrinkage, cracking, aging, insufficient adhesion, etc., which occur under the influence of external factors, are summarized. The limitations of the chemical modification of RBM and the advantages of physical methods, in particular microwave effect, are shown. The possibilities of using microwave energy in the processes of extraction of the bitumen component, during its dehydration and activation, during the synthesis, drying and intensification of the reactions of obtaining modifiers and their combination in bitumen compositions are systematized. The prospects of using microwave in the activation processes of mineral fillers, as well as the application and repair of bituminous coatings, are revealed. It is shown that conformational and intermolecular changes under the influence of microwave can lead to an increase in water resistance, strength, combined with elasticity, thermal and frost resistance, and also the durability of RBM.
Keywords: roofing mastic, bitumen composition, filler, chemical modification, physical methods, microwave, drying, activation, interface, strength, water resistance, elasticity, adhesion
The calculations and assessment of the impact of the built dormitories on the design of the existing building in accordance with the requirements of SP 22.13330.2011 and techniques of the FEM program Plaxis 2012.01 (Build 8962)
Keywords: pile foundations, Plaxis program, Geology
The article analyzes the problems and prospects for the development of green technologies and green construction in Russia and the world as as well. The author provides us the information about the outstanding examples of green buildings in the world. The dynamics of construction of green buildings for the period from 2000 to 2018 has been revealed in the article. It is also presented the advantages of introducing green technologies in the construction of buildings with respect to all participants in the construction process. By opinion of the author the important role in the part of stimulating the development of green construction plays the state, legislative initiatives. Factors restraining the growth of eco-sustainable construction in our country are revealed
Keywords: green technology, ecological construction, sustainable development, green building, resource saving, green standards, energy efficiency
The article presents the results of studies of the surface characteristics of textile materials used for personal protective equipment and in construction projects, taking into account the climatic conditions of their operation. The features of their optical and color properties in the open industrial area in the cold period, which form the elements of General industrial safety, are revealed. The influence of low temperature and humidity on the structure and surface properties of materials of the different fibrous composition is experimentally established. This leads to the correction of optical parameters of various objects on construction and industrial sites, determining the conditions of sufficient or limited visibility. The results are adapted to solving the problems of designing environmental spaces of construction projects and the development of innovations in textile materials science and means of individual safety in the industry.
Keywords: fibrous materials, design and evaluation of construction projects, environmental and industrial safety, design of environmental spaces, innovations in textile materials science
The description of information exchange methods between CAD and CAE systems is presented. The description of the modular system of design and strength analysis of geodesic shells GeoTran is given. Translation of geometric models from ArchiCAD to Patran/Nastran/Patran has drawbacks. It is proposed to implement the translation of geometric models in a neutral SAT format. Developed a translator geometric models of single-contour geodetic shells from ArchiCAD in SAT format. The translator allows you to automate the exchange of information between the CAD system ArchiCAD and various CAE systems designed for strength analysis.
Keywords: data exchange between CAD and CAE systems, neutral file, SAT and OBJ formats, geodesic shells, translation of geometric models
The question of cost management of the construction organization within the economic mechanism of functioning of the enterprises of a construction complex is considered, classical techniques and the options of their use accepted in construction are given. Examines "the system of regulatory cost accounting", regulatory documents on the formation of the cost of construction products.
Keywords: cost management, cost management, costs, construction, construction organization, construction products
in this article we consider the thermophysical and sound-physical properties of window blocks of various designs used in buildings and structures. For practical research, some dependencies are offered that allow us to describe the various properties of window blocks in wooden, metal and plastic bindings
Keywords: thermophysical properties, sound-physical properties, translucent fences, window blocks
The Algorithm and program for calculating for the strength, deformation and fracture toughness of reinforced concrete structures. It has been improved under various regimes of slightly-repeated loads on the basis of the development of scientific ideas about the effect of the own field of stresses of concrete with the EMBALIT and SP, as well as the establishment of low-cycle fatigue strength of such concretes and limits fatigue strength from the main factors. The main regularities of development of own deformations and stresses of concrete during hardening under conditions of restriction of expansion deformations and without restriction are revealed.
Keywords: design features, self-expanding concrete, embalite, calculation of strength of reinforced concrete columns, low-cycle fatigue strength, superplasticizers, embalit additive, calculation of crack resistance of reinforced concrete structures, intrinsic defor
The authors (of the research) suggest choosing the most eco- and energy-efficient engineering system in order to purify the air of the dyrer drums dust. The choice should be made on the basis of the analysis and evaluation of the dust properties and determination of the control methods of the dust aerosol stability, which, eventually will ensure its effective destruction as a dispersed system in the air purification process.
Keywords: inorganic dust, disperse system, characteristics of pollutant properties, manufacturing company in construction industry, labour safety, brick manufacture, dryer drum, energy parameters
The influence of polycarboxylate-based superplasticizers on the water-holding capacity of cements and the properties of highly mobile and self-compacting concretes has been studied. In the course of studies it was found that the water-holding capacity of cement in the presence of a specific additive reflects its potential activity and is a very important characteristic when choosing a pair of "cement-superplasticizer". Rheological activity of superplasticizer with cement concrete were estimated according to the value of the maximum shear stress of cement slurries. To assess the composition of self-compacting concrete should be used cement utilization factor in concrete, reflecting its technical and economic efficiency. Concretes with a rationally selected grain composition and dosage of polycarboxylate-based superplasticizers can achieve high strength with a minimum specific consumption of cement.
Keywords: water-holding capacity of cement, rheological activity of superplasticizer, self-compacting concrete, concrete strength, cement utilization factor