Iuliia Kushnir a, Volodumur Pents a, Mukola Ovsiy b
Methodical basis calculating the carrying capacity of the normal rectangular reduced section prestressed reinforced concrete beams based on the estimated deformation model
a Poltava National Technical University named in honor of Yuri Kondratyuk
b PE «Building expertise»
Abstract. Proposed the method of calculating the strength the normal section of continuous of rectangular prestressed steel-concrete beams depending on the stress-strain state at the time of the destruction of composite materials (concrete, structural steel I-sections and prestressed tendon). Methodical basis calculating the carrying capacity of the normal reduced section prestressed reinforced concrete beams were designed based on the estimated deformation model using basic practical scientific propositions, which presented V. Mitrofanov in papers [13–16], as well as leading national scholars E. Babich [6, 7], A. Barashikov [8, 9], V. Dorofeyev [11], A. Bambura [5, 10], A. Pavlikov [13, 16, 17], S. Rogovoy [18] and foreign James J. McGregor and James C. Wight [19], taking into account the requirements of the standards [1]. Mathematical expressions, which are propose in the work, permit tell apart the cases calculating the bearing capacity prestressed reinforced concrete beams, which, in turn will, deliver the opportunity to simplify the process calculation using the deformation model.
Keywords: steel, concrete, prestressed, rebar, beam, normal cross section, deformation, boundary tension, strength.
Victor Levchenko, Dmitry Levchenko, Vladimir Kirichenko, Alekcej Harin
Of the preventive repairs system for buildings and constructions
Donbas National Academy of Civil Engineering and Architecture
Abstract. In order to ensure the reliability of exploiting buildings and constructions when some elements, joints or the whole constructions worsen, preventive maintenance should be fulfilled. The preventive system foresees carrying out a certain amount of work to provide the faultless operation of all the elements and the system as a whole for the next intermaintenance period. The repairs are focused on the prevention of some breakages in the constructions which in their turn lead to the increase of running costs. Indirect expenses connected with failures can be consistent and increase depending on how long they have been out of order and some other factors. This article offers some methods to analyze the involved expenses, which provide construction reliability, depending on frequency of routine repairs.
Keywords: reliability, faultless operation, indirect expenses, efficiency, reparability.
Valentin Osipov
The use of screens against blindness to reduse accidents on the roads in the dark of the night
State higher educational establishment «Luhansk building College»
Abstract. The article suggested to use the screen, which protects from the glare of on the roads of the General using of Ukraine for the protection of drivers of vehicles from far and near light of the headlights of oncoming traffic, a theoretical calculation of the optimum height for example, the national automobile roads of state value of N-21. For the calculation was used the Method of calculation of efficiency of the height of the screen, which was developed by the ANO «Institute of problems of traffic safety» (d. Moscow), which specializes in the development of projects of normative acts in the sphere of road traffic safety in the territory of the Russian Federation. Russian methodology used because of the lack of a regulatory document, which would regulate the establishment of the screen, which protects from the glare of on the territory of Ukraine. As a result of calculations it was determined the optimum height the screen, which protects from the glare of to set them on the road IB category. Defined as a perspective, the continuation of the work on the protection of the drivers from the glare of the headlights on the highway the other technical categories, where the number of lanes is less than two, and there is no dividing line. In addition it is proposed to explore the possibility of using different types of materials for the manufacture of the screen, which protects from the glare of, which have opposed the aggressive environment on the road.
Keywords: accident rate, screen against the glare of, barrier fencing.
Arkadiy Vinitskiy a, Georgiy Ryabov b, Nina Senik a, Alexander Meshkov a, Julia Korostelyova b, Ekaterina Fetyuhina b
Siliceous raw material in manufacturing of granulated insulation materials on the technology of low-temperature foaming
a Scientific and Technological Center «Silicate materials and technologies»
b Industrial Investment Company «Diatomit-Invest» LLC
Abstract. Granulated foam glass is an effective insulation material based on natural raw materials. Its manufacturing on the technology of low temperature foaming, excluding premelting of glass or the use of scrap and waste glass, comprises the steps of drying and grinding of diatomite rock of Inza deposit (Ulyanovsk region), mixing the crushing product with a caustic soda, sodium hydroxide aqueous solution and the poreforming liquid mixture (glycerin) in the intensive-mixer granulator for forming of granulated material, its drying at a temperature of
125 °C and foaming at the temperature of 800 °C. The choice of diatomite as a silica component for insulating filling agents on the technology of low temperature swelling is caused by a high content of silica in the rock, the constancy of the composition and porous nanostructure (average pore size is of 0.1 to 1–2 microns). The quality (density, strength and thermal conductivity characteristics) of the developed heat-insulating crystalline granulated material is comparable to the best foreign models. The work was released within the contract № 13.G.25.31.0092 dated 22.10.2010 between the Ministry of Education of the Russian Federation and Diatomovy Kombinat.
Keywords: diatomaceous earth (diatomite), low-temperature foaming, thermal insulation material, granulated foam glass.
Alexsandr Khaljushev
Exploitation properties of concrete with the modified composite cements
Donbas National Academy of Civil Engineering and Architecture
Abstract. Results of experimental researches of an exploitations ability in the conditions of a short-term and long loading of concrete with composite cement type CEM V/B modified in high-voltage electric field are resulted. It is established, that finegrained concrete mixes with composite cements type CEM V/B activated in high-voltage electric field at corresponding modes, are characterized smaller on 23–27 % by indicators of effective viscosity in comparison with similar structures of concrete mixes that provides reduction of a water demand of concrete mixes by 5–7 % at achievement of necessary indicators of slump. It promotes formation of more dense structure of concrete (increase of average density, decrease in average radius of pores and increase of their uniformity on the sizes α). In turn, more dense structure on the modified composite cement causes its increase deformation and performance properties.
Keywords: composite cement, modified, deformations of creep and shrinkage, frost resistance.