Valery Bratchun, Mixail Pakter, Aleksandr Stukalov, Vitaly Bespalov, Denis Gulyak, Evgeny Romasyuk
Aging of bituminous concrete mixes, bituminous concretes and the ways of their thermo-oxidative firmness increase
Donbas National Academy of Civil Engineering and Architecture
Abstract. This work is devoted to the theoretical and experimental establishment of conformities to law of Physical-chemical processes of thermo-oxidative aging of petroleum road bitumen, bituminous concrete mixes, bituminous concretes in the process of manufacturing, thermostatting in thermos-bunkers, transporting to the site of placement into the layers of non-rigid road surfacing, under maintenance conditions, and in the process of developing ways of decreasing intensity of thermo-oxidative aging of bituminous mixes and bituminous concretes. By means of mass changing, penetration, the temperature of softening, group of chemical compositions it has been set that thermo-oxidation is the dominative external factor of the thin-film bitumen aging. It leads to the accumulation of pyrobitumen, to the formation of a rigid spatial coagulative net and its destruction due to setting tension and mechanical action of transport loadings. The less is the layer bitumen thickness, the quicker is the thermal oxidation on the surface of mineral materials. The activation energy of thermal oxidation processes decreases.
Keywords: petroleum road bitumen, bituminous concrete mixes and bituminous concrete, technological and maintenance aging, thermo-oxidative aging, ways of deceleration of thermo-oxidative aging of bituminous concrete mixes and bituminous concrete.
Igor Garanzha, Serhii Lakhtaryna, Mykola Zaichenko, Anton Tanasoglo, Sergii Bakayev, Sofiia Garanzha
Selection of the of self-compacting concrete composition without mineral additives for use in pipe-concrete structures
Donbas National Academy of Civil Engineering and Architecture
Abstract. In the paper the history of the SCC emergence and the main directions of its research has been considered. It has been presented the main features of the composition and the structure of SCC as a generalized recipe, fundamental differences between its components by geographic attributes, positive qualities and shortcomings taking into account their impact on the quality of the resulting mixture. The prospective application area of SCC jointly with polyhedral metal pipes as part of the composite bearing structures for the urban conditions has been stipulated. The process of mechanical testing of concrete cube-shaped samples under axial compression, performed in two steps, with the purpose to select the composition for the with the purpose to select the composition for the SCC of low classes (marks) of the SCC, without using of mineral binders and with the required degree of motion of the concrete mixture, is described. As a result, the compositions of SCC with strength class B20…B40, has been found out. The cost of the resulting compositions has been determined, which in comparison with the cost of classic heavy concrete was lower.
Keywords: self-compacting concrete, dosages of components, motion of mixture, dispersed filler, super plasticizer, mechanical tests.
Andrey Kralin, Roman Rybalko
Methods for the plastic deformation of the surface layer machine parts
Donbas National Academy of Civil Engineering and Architecture
Abstract. A classification of methods of surface plastic deformation (SPD) has been given. An assessment of experience in the application of surface plastic deformation, as a way of improving the quality of the surface and increase of the longevity of the product, has been done. It has been considered the features methods of SPD, which are realized without chip removal by the deformation of asperities and deep adjacent to the surface layers of the material. The result is a significant reduction in roughness of the surface hardening layer. The surface layer having residual compressive stresses. The results of the latest research in the use of SPD and assessed the prospects for the introduction of data processing techniques in manufacturing, has been given.
Keywords: technology, engineering, performance, reliability, durability, plastic deformation of the surface layer, item, hardening, roughness.
Aleksandr Barmotin, Aleksei Kosik
Experimental and theoretical research of strength and deformability of drywall constructions
Donbas National Academy of Civil Engineering and Architecture
Abstract. Absence of acknowledgment about the experimental data on the deformation parameters of drywall boards of various thickness does not allow to model the stress-strain state of the diverse and complex drywall constructions with guaranteed accuracy. The tests were conducted on three-point bending with a variable span drywall models of thickness 9.5 and
12.5 mm. The tests were executed in the laboratory using the certified equipment of Zwick Roell company. Analysis of the deformation shows that drywall samples of thickness 9.5 and 12.5 mm have both common and distinct characteristics, while samples of t = 9.5 mm have modulus of elasticity higher on 20–30 % and apparent durability compared to samples of t = 12.5 mm. For a complete analysis of the elastic characteristics also the tests on the uniaxial tensile of axial and transverse samples of t= 12.5 mm were carried out. Load-indicating resistors were used for the whole range of deformation measurement, they were also duplicated by dial indicators. For measuring and recording rapidly changing linear deformations in real time, ОВЕН mobile measuring strain gauge system and Veda load-indicating resistors were used. Numerical modeling of the stress-strain state of lowered drywall ceiling on the D 112 system was executed. Drywall facing has been regarded as integral orthotropic plate with equal transverse and axial joints. The calculation was performed using the «SCAD Office» software complex according to I, III, IV strength theory.
Keywords: drywall boards, strength, deformability, orthotropic materials, load-indicating resistors.
Yevgeniy Gayvoronskiy, Anatoliy Yugov
Special features of typology and architecture of objects of slagheaps development, ways of their use in construction and their role in architecture and town-planning of Donetsk region
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article contains the results of complex study of special features of typology and architecture of objects of coal mines slagheaps development. Socio-cultural value of slagheaps, modern trends of their use in construction, their role in architecture and town-planning of Donetsk region, where the coal-mining industry historically is one of the basic town-forming industries, are examined. Slagheaps are one of the main symbols of the region that is regularly used in heraldry, mass media, advertising and commerce, literature and poetry, art. They аre the object of study for such branches as ecology, energy conservation, waste processing, production of construction materials. Demolition and reclamation of slagheaps are the ways to get the reserved urban areas for their subsequent development. The article considers the possibility to construct civil and industrial facilities on the slagheaps; there is the experience of using slagheaps as extreme sports ranges, as objects of art and for the construction of garage cooperatives on them. The complex study of all these issues has a significant importance for training of architects for Donetsk region, as well as for the development of principles and methods of forming the regional architectural style of coal-mining industry buildings and structures and objects of urban construction, in architecture of which the leading town-forming and socio-cultural role of coal-mining industry in Donetsk region is reflected.
Keywords: architecture and town-planning of Donetsk region, town-forming industry, industrial symbols, regional style of architecture, socio-cultural value, slagheaps, coal-mining industry.