DESIGNING AND DETAILING OF BUILDING SYSTEMS. MECHANICS IN CIVIL ENGINEERING

DURABILITY OF THREE-LAYERED WALLS WITH BRICK FACING THAT PROVIDES HIGH THERMAL PROTECTION

Vestnik MGSU 1/2013
  • Umnyakova Nina Pavlovna - Scientific and Research Institute of Building Physics of the Russian Academy of Architecture and Construction Sciences (NIISF RAASN) +7 (495) 482-39-67, Scientific and Research Institute of Building Physics of the Russian Academy of Architecture and Construction Sciences (NIISF RAASN), 21 Lokomotivnyy proezd, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 94-100

The author examines possible reasons for the fracturing of external three – layered walls that have an efficient insulation of the thickness of 120 — 150 mm. The external wall layer is made of bricks. A comparative analysis of the temperature distribution inside the walls has demonstrated that the full-depth frost penetration into the brick facing of the wall that has 120 mm insulation occurs when the outside temperature is below –1 °C. However, the same effect occurs when the outside temperature is below –3 °C in respect of walls that have 50 mm insulation.If the average monthly temperature pattern, particularly the autumn one, is taken into consideration, in the event of the average November temperature of –2.2 °C the chance of full — depth wall freezing is higher if the insulation layer is thicker, and lower, if the insulation layer is 50 mm thick. The analysis of average monthly temperatures and ranges of their fluctuations has revealed that full-depth wall freezing lasts for 6 months, if the insulation layer is 120 mm thick, and if the insulation layer is thinner, the effect lasts only for 4 months. These calculations have proven that the thicker the insulation, the higher the temperature deformations and temperature stresses within the outside brick layer. These effects accelerate the fracturing of three — layered walls.

DOI: 10.22227/1997-0935.2013.1.94-100

References
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  8. Umnyakova N.P. Vozvedenie energoeffektivnykh zdaniy v tselyakh umen’sheniya negativnogo vozdeystviya na okruzhayushchuyu sredu [Erection of Energy Efficient Buildings with a View to Reduction of the Negative Impact onto the Environment]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2011, no. 3, vol. 2, pp. 459—464.
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ANALYSIS OF SUFFICIENCY OF THE BEARING CAPACITY OF BUILDING STRUCTURES OF OPERATING SITES OF MAIN BUILDINGS OF THERMAL POWER PLANTS

Vestnik MGSU 3/2012
  • Alekseeva Ekaterina Leonidovna - Moscow State University of Civil Engineering (MSUCE) postgraduate student, Moscow State University of Civil Engineering (MSUCE), 26 Yaroslavskoe shosse, Moscow, 129337, Russia; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 25 - 29

Upon examination of eleven main buildings of power plants, analysis of defects and damages of building structures was performed. Thereafter, the damageability of principal bearing structures of main buildings of thermal plants was analyzed. It was identified that the fastest growing defects and damages were concentrated in the structures of operating sites. The research of the rate of development of the most frequent damages and defects made it possible to conclude that internal corrosion of the reinforcing steel was the most dangerous defect, as far as the reinforced concrete elements of operating sites were concerned. Methods of mathematical statistics were applied to identify the reinforcing steel development pattern inside reinforced concrete elements of floors of operating sites. It was identified that the probability of corrosion of reinforced concrete elements of operating sites was distributed in accordance with the demonstrative law. Based on these data, calculation of strength of reinforced concrete slabs and metal beams was performed in terms of their regular sections, given the natural loads and the realistic condition of structures. As a result, dependence between the bearing capacity reserve ratio and the corrosion development pattern was identified for reinforced concrete slabs and metal beams of operating sites. In order to analyze the sufficiency of the bearing capacity of building structures of operating sites in relation to their time in commission, equations were derived to identify the nature of dependence between the sufficiency of the bearing capacity of reinforced concrete slabs and metal beams of the operating sites and their time in commission.

DOI: 10.22227/1997-0935.2012.3.25 - 29

References
  1. Dobromyslov A.N. Diagnostika povrezhdeniy zdaniy i inzhenernykh sooruzheniy [Damage Diagnostics of Buildings and Engineering Structures]. Moscow, MSUCE, 2008.
  2. Kuznetsov I.P., Ioffe Y.R. Proektirovanie i stroitel’stvo teplovykh elektrostantsiy [Project Design and Construction of Heat Power Plants]. 3rd revised edition, Moscow, Energoatomizdat Publ., 1985.
  3. Kuznecov I.P., Ioffe Ju.R. Rukovodstvo po ekspluatatsii stroitel’nykh konstruktsiy proizvodstvennykh zdaniy promyshlennykh predpriyatiy [Guidelines for Operation of Building Structures of Production Buildings of Industrial Enterprises]. 4th reprint edition, Moscow, 2004.

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