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
  1. SNiP II-3—79*. Stroitel’naya teplotekhnika [Construction Norms and Rules II-3—79*. Heat Engineering in Construction]. Moscow, Gosstroy SSSR Publ., 1985.
  2. SNiP 23-02—2003. Teplovaya zashchita zdaniy [Construction Norms and Rules 23-02—2003. Thermal Protection of Buildings]. Moscow, Gosstroy SSSR Publ., 2004, 26 p.
  3. Shubin I.L., Umnyakova N.P. Aktualizirovannye stroitel’nye normy po zashchite ot shuma, estestvennomu i iskusstvennomu osveshcheniyu i teplovoy zashchite zdaniy, razrabotannye NIISF RAASN [Revised Construction Norms Applicable to Noise Protection, Natural and Artificial Illumination and Thermal Protection of Buildings Developed by Scientific and Research Institute of Building Physics of RAACS]. Materialy mezhdunarodnoy konferentsii «Sovremennye innovatsionnye tekhnologii izyskaniy, proektirovaniya i stroitel’stva v usloviyakh Kraynego Severa [Works of International Conference on Advanced Innovative Technologies of Surveying, Design and Construction in the Far North]. Yakutsk, 8—10 August, 2012, pp. 40—54.
  4. Fokin K.F. Stroitel’naya teplotekhnika ograzhdayushchikh chastey zdaniy [Heat Engineering of Envelope Elements of Buildings]. Moscow, 2006, 256 p.
  5. SNiP 23-01—99. Stroitel’naya klimatologiya [Construction Norms and Rules 23-01—99. Construction Climatology]. Moscow, 2011, 94 p.
  6. SNiP 2.01.01—82. Stroitel’naya klimatologiya i geofi zika. [Construction Norms and Rules 2.01.01—82. Construction Climatology and Geophysics]. Moscow, Gosstroy SSSR Publ., 1983, 136 p.
  7. Umnyakova N.P. Vliyanie temperaturnykh kolebaniy naruzhnogo vozdukha na obrazovanie kondensata v vozdushnoy prosloyke ventiliruemykh fasadov [Infl uence of Temperature Fluctuations of the Outside Air onto Formation of Condensate within the Air Space of Ventilated Facades]. Stroitel’nye materialy, oborudovanie i tekhnologii XXI veka [Construction Materials, Machinery and Technologies of the 21st Century]. 2004, no. 7, pp. 65—67.
  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.
  9. Umnyakova N.P., Egorova T.S., Belogurov P.B., Andreytseva K.S. Povyshenie energoeffektivnosti zdaniy za schet povysheniya teplotekhnicheskoy odnorodnosti naruzhnykh sten v zone sopryazheniya s balkonnymi plitami [Improvement of the Energy Efficiency of Buildings through Improvement of Thermal Engineering Homogeneity of External Walls in the Zone of Interface with Balcony Slabs]. Stroitel’nye materialy [Construction Materials]. 2012, no. 6, pp. 19—21.
  10. Umnyakova N.P. Osobennosti proektirovaniya energoeffektivnykh zdaniy, umen’shayushchikh negativnoe vliyanie na okruzhayushchuyu sredu [Design of Energy Efficient Buildings Capable of Mitigating the Negative Impact onto the Environment]. Izvestiya Yugo-Zapadnogo gosudarstvennogo universiteta [Proceedings of South-Western State University]. 2011, no. 5, part 2, pp. 33—38.

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Featuresof the stress-and-strain state of outer walls under the influence of variable temperatures

Vestnik MGSU 10/2013
  • Kremnev Vasiliy Anatol'evich - LLC "InformAviaKoM" Director General, LLC "InformAviaKoM", 2 Pionerskaya str., Korolev, Moscow Region, 141074, Russian Federation; +7 (495) 645-20-62; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Kuznetsov Vitaliy Sergeevich - Mytishchi Branch, Moscow State University of Civil Engineering (MGSU) Candidate of Technical Sciences, Professor, Department of Architectural and Construction Design, Mytishchi Branch, Moscow State University of Civil Engineering (MGSU), 50 Olimpiyskiy prospect, Mytishchi, Moscow Region, 141006, Russian Federation; +7 (495) 583-07-65; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Talyzova Yuliya Aleksandrovna - Moscow State University of Civil Engineering (MGSU) Assistant, Department of Architectural and Structural Design, Mytishchi Branch, Moscow State University of Civil Engineering (MGSU), 50 Olimpiyskiy prospect, Mytishchi, Moscow Region, 141006, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 52-59

The authors draw attention to possible problems in the process of construction and operation of monolithic frame buildings, construction of which is now widespread. It is known that cracks can often appear in the facade and side walls. The size of the cracks can exceed the allowable limits and repair does not lead to their complete elimination. Also cracks significantly mar the appearance of a building. Thus, the relevance of this study lies not only in fuller understanding of the operation of walls, but also in the ability to prevent undesirable effects.The authors calculated temperature effects for boundary walls of the building blocks made of heavy concrete. The original dimensions of the walls conformed to a grid of columns for the majority of residential and public buildings.The stress-and-strain state of the walls in case of temperature changes is observed in detail, including the transition from sub-zero to above-zero temperatures within the same section (wall). It was revealed that the temperature variations within the established limits may cause stress-and-strain state in the walls, in which the temperature tensile stresses can exceed the tensile strength of materials. The article contains effective means of reducing thermal strains, which can prevent temperature and shrinkage cracking.

DOI: 10.22227/1997-0935.2013.10.52-59

References
  1. Krivoshein A.D., Fedorov S.V. K voprosu o raschete privedennogo soprotivleniya teploperedache ograzhdayushchikh konstruktsiy [On the Problem of Calculating the Reduced Thermal Resistance of Building Envelopes]. Inzhenerno-stroitel'nyy zhurnal [Magazine of Civil Engineering]. 2010, no. 8. Available at: http://www.engstroy.spb.ru Date of access: 5.12.12.
  2. Derkach V.N., Orlovich R.B. Voprosy kachestva i dolgovechnosti oblitsovki sloistykh kamennykh sten [Issues of Quality and Durability of the Lining of Layered Stone Walls]. Inzhenerno-stroitel'nyy zhurnal [Magazine of Civil Engineering]. 2011, no. 2. Available at: http://www.engstroy.spb.ru Date of access: 5.12.12.
  3. Soon-Ching Ng, Kaw-Sai Low, Ngee-Heng Tioh. Newspaper Sandwiched Aerated Lightweight Concrete Wall Panels — Thermal inertia, transient thermal behavior and surface temperature prediction. Energy and Buildings. 2011, vol. 43, no. 7, pp. 1636—1645.
  4. Sami A. Al-Sanea, Zedan M.F. Effect of Thermal Bridges on Transmission Loads and Thermal Resistance of Building Walls under Dynamic Conditions. Applied Energy. 2012, vol. 98, pp. 584—593.
  5. Chengbin Zhang, Yongping Chen, Liangyu Wu, Mingheng Shi. Thermal Response of Brick Wall Filled with Phase Change Materials (PCM) under Fluctuating Outdoor Temperatures. Energy and Buildings. 2011. vol. 43, no. 12, pp. 3514—3520.
  6. Pinsker V.A., Vylegzhanin V.P. Teplofizicheskie ispytaniya fragmenta kladki steny iz gazobetonnykh blokov marki po plotnosti D400 [Thermophysical Test of a Segment of Masonry Walls Made of Aerated Concrete Blocks Mark with the Density D400]. Inzhenernostroitel'nyy zhurnal [Magazine of Civil Engineering]. 2009, no. 8. Available at: http://www.engstroy.spb.ru Date of access: 10.07.13.
  7. Knat'ko M.V., Gorshkov A.S., Rymkevich P.P. Laboratornye i naturnye issledovaniya dolgovechnosti (ekspluatatsionnogo sroka sluzhby) stenovoy konstruktsii iz avtoklavnogo gazobetona s oblitsovochnym sloem iz silikatnogo kirpicha [Laboratory and Field Studies of Durability (Operating Life) of a Wall Structure Made of Autoclave Aerated Concrete with Facing Layer made of Sand-lime Brick]. Inzhenerno-stroitel'nyy zhurnal [Magazine of Civil Engineering]. 2009, no. 8. Available at: http://www.engstroy.spb.ru Date of access: 10.07.13.
  8. Ogorodnik V.M., Ogorodnik Yu.V. Nekotorye problemy obsledovaniya zdaniy s otdelkoy litsevym kirpichom v Sankt-Peterburge [Some Problems of the Inspection of Buildings having Face Brick Finishing in St. Petersburg]. Inzhenerno-stroitel'nyy zhurnal [Magazine of Civil Engineering]. 2010, no. 7. Available at: http://www.engstroy.spb.ru Date of access: 7.02.12.
  9. Snegirev A.I., Al'khimenko A.I. Vliyanie temperatury zamykaniya pri vozvedenii na napryazheniya v nesushchikh konstruktsiyakh [The Influence of Circuit Temperature on the Stresses in the Process of Construction of Load-bearing Structures]. Inzhenerno-stroitel'nyy zhurnal [Magazine of Civil Engineering]. 2008, no. 2. Available at: http://www.engstroy.spb.ru Date of access: 7.02.12.
  10. Karpilovskiy V.S. SCADOFFICE. Vychislitel'nyy kompleks Scad [SCADOFFICE. Computing System Scad]. Moscow, 2011, pp. 274—283.

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Role of transverse joints in regulation of the reinforced concrete face stress-strain state

Vestnik MGSU 12/2018 Volume 13
  • Podvysotckii Aleksei A. - Mosoblgidroproekt Candidate of Technical Sciences, Head of Hydrotechnical Department, Mosoblgidroproekt, 1 Energetikov st., Dedovsk, 143532, Russian Federation.
  • Sainov Mikhail P. - Moscow State University of Civil Engineering (National Research University) (MGSU) Candidate of Technical Sciences, Associate Professor, Associate Professor of Department of Hydraulics and Hydraulic Engineering, Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.
  • Soroka Vladislav B. - SpetsNovostroy engineer, SpetsNovostroy, 20 Communal quarter, Krasnogorsk, 143405, Russian Federation.
  • Lukichev Roman V. - Moscow State University of Civil Engineering (National Research University) (MGSU) bachelor Hydraulics and Hydraulic Engineering Department, Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.

Pages 1533-1545

Introduction. Deals with the results of studying effectiveness of arranging transverse joints in the face as the means of regulation of its stress-strain state. At present reinforced concrete faces are constructed without being cut height-wise and transverse joints may be arranged only at the end of the dam construction stages. This is validated by the fact that experience in construction of flexible (discontinuous) faces has not demonstrated the required level of safety of this structural design. However, in the dams of the up-to-date structural designs, maintaining the face integrity is not guaranteed: cracks appeared in reinforced concrete faces at a number of high dams. Formation of cracks in faces should be attributed to presence of tensile stresses, whose values exceed concrete tensile strength. To prevent seal failure of the seepage-control element it is feasible to provide arrangement of the transverse joint in the face section where tensile stresses may be expected. Materials and methods. The studies were conducted on the example of a 100 m high dam with the aid of numerical modeling. Rockfill was considered as a lineally deformed material, but computations were conducted for a wide range of the soil linear deformation modulus: from 60 to 480 МPа. Steel reinforcement was considered in the face. Transverse joints were modelled with the aid of contact finite elements. Results. By the results of numerical modeling the tensile stresses appear in the uncut face due to bending deformations and deformations of longitudinal extension. The most hazardous is the face lower section. At this section the longitudinal tensile force and considerable moment are acting. Transverse joints are feasible to be arranged in this particular section of the face. Conclusion. It was revealed that the main positive effect of the transverse joint arrangement is in decreasing the value of longitudinal tensile force perceived by the face. Impact of the transverse joint on bending moments has a local effect and covers the section of the limited length. Moreover, at arranging joints the values of bending moments may increase. We may recommend arrangement of a transverse joint in the face which is parallel to the perimeter joints only in the face lower part which is subject to longitudinal deformation.

DOI: 10.22227/1997-0935.2018.12.1533-1545

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RELATIONSHIP BETWEEN SHEAR STRESS AND FATIGUESTRENGTH OF METALLIC MATERIALS

Vestnik MGSU 4/2013
  • Gustov Yuriy Ivanovich - Moscow State University of Civil Engineering (MGSU) Doctor of Technical Sciences, Professor, Department of Machinery, Machine Elements and Process Metallurgy, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; +7 (499) 183-94-95; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Voronina Irina Vladimirovna - Moscow State University of Civil Engineering (MGSU) Senior Lecturer, Department of Building and Hoisting Machinery, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; +7 (499) 182-16-87; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Allattouf Hassan Lattouf - Moscow State University of Civil Engineering (MGSU) postgraduate student, Department of Mechanic Equip- ment, Details of Machines and Technology of Metals, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 31-37

The authors have demonstrated that coefficients of deformation and strength of metals can be applied to identify interrelationship between their shear stress and fatigue strength values.δThe authors have found that coefficient of proportionality ƒconnecting tensileвstrength σand hardness HB of magnesium alloys varies between 0.353 – 0.366 withthe average value equaling to 0.359. The coefficient of proportionality connecting shear stress τср and hardness HB varies between 0.246 – 0.267, and its average value equals to 0.254. Ratio S of shear stress to fatigue strength varies within 1.365 – 1.481, and its average value is equal to 1.410. For aluminum alloys, the above values are lower by 43% and 42%, respectively.δFor carbon steels, the coefficient of proportionality ƒ= 0.312 – 0.349, its averageδvalue is equal to 0.333, and for alloy steels, ƒ= 0.289 – 0.351, its average value is equalto 0.325. Coefficients of proportionality connecting the shear stress and hardness of carbon and alloy steels are equal to 0.172 – 0.229 and 0.134 – 0.223, with their average values being equal to 0.202 and 0.183.Therefore, the authors believe that the relation of shear stress values to fatigue strength values of the above non-ferrous and ferrous metals is close to one.

DOI: 10.22227/1997-0935.2013.4.31-37

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  2. Gustov Yu.I., Gustov D.Yu., Voronina I.V. Metodologiya opredeleniya tribo-tekhnicheskikh pokazateley metallicheskikh materialov [Methodology for Identification of Tribo-engineering Values of Metallic Materials]. Teoreticheskie osnovy stroitel’stva: XV Slovatsko-rossiysko-pol’skiy seminar: sb. dokladov. [Theoretical Fundamentals of Civil Engineering. 15th Slovac-Russian-Polish Workshop. Collected Reports]. Moscow, 2007, pp. 339—342.
  3. Gustov Yu.I. Tribotekhnika stroitel’nykh mashin i oborudovaniya [Tribo-engineering of Construction Machinery and Equipment]. Moscow, MGSU Publ., 2011, 192 p.
  4. Gustov Yu.I., Gustov D.Yu., Yarmolik N.V. Vybor materialov dlya tribosistem i metallo-konstruktsiy stroitel’noy tekhniki [Selection of Materials for Tribosystems and Metal Structures of Construction Machinery]. Interstroymekh — 2008. Materialy Mezhdunar. nauch.-tekhn. konf. [Interstroymech – 2008. Works of International Scientific and Technical Conference]. Vladimir, 2008, vol. 2, pp. 35—40.
  5. Gustov Yu.I. Energotopograficheskiy metod issledovaniya iznosostoykosti metallov [Power Topography Method of Research into Wear Resistance of Materials]. Novoe v metallovedenii. Nauchno-prakticheskiy seminar. Sb. dokladov. [Metal Science News. Scientific and Practical Workshop. Collected Reports.] Moscow, MGSU Publ., 2009, pp. 3—7.
  6. Tylkin M.A. Spravochnik termista remontnoy sluzhby [Reference Book for Repair Service Heat- Treaters]. Moscow, Metallurgiya Publ., 1981, 647 p.
  7. Babichev A.P., Babushkina I.A., Bratkovskiy A.M. Fizicheskie velichiny [Physical Values]. Moscow, Energoatomizdat Publ., 1991, 1232 p.
  8. Arzamasov B.N., Solov’eva T.V., Gerasimov S.A. Spravochnik po konstruktsionnym materialam [Reference Book of Structural Materials]. Moscow, MGTU im. N.E. Baumana Publ., 2005, 640 p.
  9. Sorokin V.G., Volosnikova A.V., Vyatkin S.A. Marochnik staley i splavov [Book of Steel and Alloy Grades]. Moscow, Mashinostroenie Publ.,1989, 640 p.

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