Aleksandr Barmotin, Aleksei Kosik
Strength, fracture toughness and deformability of joints of drywall elements under bending
Donbas National Academy of Civil Engineering and Architecture
Abstract. Contrary to GOST 6266-97, European regulatory framework, apart of the requirements and testing methods of drywall boards, regulates the characteristics and methods of testing of joints in which the requirements to puttying and reinforcing materials for sealing joints in standard and reinforced drywall boards are determined. It allows to conduct the analysis of prototype deformation. To study the work of joint, a series of experimental researches has been conducted. The main purpose of these researches is to determine the ultimate strength, fracture toughness and deformability of the most common single-layer and dual-layer drywall elements on the screw and glue joints. For this the universal installation has been designed, allowing to test the three- and four-point bending. Experimental studies have shown that within the elastic behavior the drywall elements work as a homogeneous solid material and in calculations can be presented as an orthotropic material with given (equivalent to) elastic properties, while bond σ−ε mending the Hooke’s law. In samples with a one-way amplification of section (additional reinforcement by glass fleece or adhesive and screw connection of layers) the tensile strength in each case is lightly increasing. The simultaneous presence of two extension factors results in a significant increase of fracture toughness, which reaches the tensile strength in bending with destruction of the sample on joint and in cross section.
Keywords: drywall boards, strength, deformability, orthotropic materials, crack resistance.
Mykola Zaichenko, Olena Yegorova
The rheological properties of cement pastes formulated for self-compacting concretes with multifunctional modifier
Donbas National Academy of Civil Engineering and Architecture
Abstract. The rheological properties of cement pastes formulated for self-compacting concretes (SCC) were used to investigate the efficiency of multifunctional modifier on the properties of fresh and hardened concrete. It was found that the multifunctional modifier in the form of the concentrated suspension of silica fume in the solution of polynaphthalene sulfonate condensate superplasticizer and sodium hydroxide affects the rheological properties of cement paste, decreasing plastic viscosity and slightly decreasing the value of yield stress. The regularities of the influence of the rheological properties of cement pastes with organic-mineral modifier on the properties of fresh self-compacting concrete (flowability; T500 slump flow time; passing ability; resistance to segregation) were determined. An alkaline component of the multifunctional modifier allows to perform a partial replacement (35–45 %) of the Portland cement with ground granulated blast furnace slag.
Keywords: self-compacting concrete, cement paste, rheological properties, multifunctional modifier, plastic viscosity, yield stress, flowability, resistance to segregation.
Nickolay Sholukh, Andrey Anisimov
Social and methodological aspects of the reconstruction of quarterly building of the industrial town in the areas of compact residence of the blind
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article is devoted to the working out of the research program in the reconstruction of the quarterly building of the industrial town in the areas of compact residence of the blind. The history of the formation and the current state of the areas of compact residence of people with visual defects in the cities of Donetsk and Makeyevka are researched. On the basis of detail analysis of this areas and immediately of the zones of influence of the enterprises UTOS of the above towns the conclusion of the enterprises UTOS of the above towns the conclusion about necessity and advisability of the reconstruction of the existing building is drawn. Attention to the importance of talking into account the specific needs of blind people living in these areas is given. The recommendations on the methodology of performing of the researches in the field of reconstruction of urban development in the areas of compact residence of the blind are given.
Keywords: areas of compact residence of the blind, the enterprises UTOS, quarterly development, the specific needs of the blind, the reconstruction, the research methodology.
Valentine Penchuk, Andrey Kralin, Andrey Didenko
Functional remodeling of construction machines under operation conditions
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article examined the relationship building project with a construction technique, performs various processing operations in a wide variety of production volumes of work. It presents a detailed diagram of the implementation process of working construction machine functions in view of its life cycle and diversity of processes, as well as interaction in the process of converting an artificial environment «person – machine – environment». We consider a multi-dimensional space, in which the operation of construction machines equipped with the basic working bodies for the «average» conditions environment interaction, which often do not coincide with the actual conditions. The cost of operating characteristics of various types of construction machinery and the need for their wide nomenclature are taking into account.
Keywords: construction site, production technology, efficiency, functional upgrades, construction machine, operation, functionality, environment, life cycle, technological operations, shift actuator.