An Empirical Method for Calculating Wetness-Carbonization Stresses Emerges in Panels of Aerated Concrete, with Considering its Rheological Properties

An Empirical Method for Calculating Wetness-Carbonization Stresses Emerges in Panels of Aerated Concrete, with Considering its Rheological Properties The problem of estimating the shrinkage stresses taking the creep into account arising in the outer layers of the wall panels made of aerated concrete with a contemporaneous action of wetness and carbonization processes is considered. A practical calculation method is proposed for the determination of these stresses. The method is based on the classical approach and principles developed by Aleksandrovsky and Arutunyan for solving applied problems in the theory of creep but with considering the influence of wetness and carbonization on shrinkage, creep and stress relieving of autoclaved aerated concrete. The calculations performed by this method made it possible for the first time to obtain information about the development of intrinsic stresses in cellular concrete wall panels. This method allows also to determine their limiting total values at which shrinkage cracks can form on the surface of the wall panels and calculate their depth. This gives us the opportunity to develop technological and constructive activities aimed to improve the longevity of the aerated concrete wares.

M.A. GAZIEV, Candidate of Sciences (Enginering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Grozny State Oil Technical University named after acad. M.D. Millionshchikov (100, Isaev Street, Grozny, Chechen Republic 364061, Russian Federation)

1. Aleksandrovsky S.V. Raschet betonnyh i zhelezobetonnyh konstrukcij na izmenenija temperatury i vlazhnosti s uchetom polzuchesti [Сalculation of concrete and reinforced concrete structures for temperature and humidity changes taking into account creep]. Moscow: Stroyizdat. 1973. 417 p. 

2. Aleksandrovskiy S.V. Dolgovechnost’ naruzhnyh ograzhdajushhih konstrukcij [Durability of external building envelop]. Moscow: Stroyizdat. 2004. 332 p. 

3. Polzuchest’ i usadka betona i zhelezobetonnyh konstrukcij [Creep and shrinkage of concrete and reinforced concrete structures. Under the editorship of S.V. Alexandrovskij]. Moscow: Stroyizdat. 1976. 351 p. 

4. Arutyunyan N.H. Nekotorye voprosy teorii polzuchesti [Some questions in the Creep Theory]. Moscow- Leningrad: Gostekhizdat. 1952. 324 p. 

5. Arutyunyan N.H., Kolmanovsky V.V. Teorija polzuchesti neodnorodnyh tel [Creep Theory of heterogeneous bodies]. Moscow: Nauka. 1983. 336 p. 

6. Vasilyev P.I. Approximate method of creep deformations account at determination of temperature stresses in massive concrete slabs. Izvestiya of VNIIG. 1952. Vol. 47, pp. 120–128. (In Russia). 

7. Tamrazyan A.G., Esayan S.G. Mehanika polzuchesti betona [Creep Mechanics of concrete]. Moscow: MGSU. 2012. 524 p. 

8. Silaenkov E.S. Dolgovechnost’ izdelij iz jacheistyh betonov [Durability of products from aerated concrete]. Moscow: Stroyizdat. 1986. 176 p. 

9. Silenkov E.S., Bataev D.K.-S., Madziev H.N., Gaziev M.A. Povyshenie dolgovechnosti konstruktsii i izdelii iz melkozernistykh yacheistykh betonov pri ekspluatatsionnykh vozdeistviyakh [Increase of durability of building structures made from fine-grained concrete under operational impacts]. Grozny. 2015. 355 p. 

10. Slavcheva G.S., Chernyshov E.M. Algorithm for designing the structure of cement foam concrete by the complex of defined properties. Stroitel’nye Materialy [Construction Materials]. 2016. No. 9, pp. 58–64. (In Russian). 

11. Chernyshov E.M. Slavcheva G.S. Management of operational deformation and crack resistance of macro-porous (cellular) concrete, Part 1. The context of the problem and theory questions. Stroitel’nye Materialy [Construction Materials]. 2014. No. 1, pp. 105–112. (In Russian). 

12. Bataev D.K.-S., Gaziev M.A., Pinsker V.A., Chepurnenko A.S. The theory of shrinkage stress calculation in aerated concrete wall panels under carbonizing processes taking into account creep. Vestnik MGSU. 2016. No. 12, pp. 11–22. (In Russian). 

13. Apkarov Sh.I., Bataev D.K.-S., Gaziev M.A., Majiev H.N. Estimation of crack resistance of aerated concrete products in humid and carbonizing deformations taking into account stress relaxation. Vestnik DSTU. 2017. Vol. 44. No. 2, pp. 151–161. (In Russian). 

14. Gaziev M.A., Florova M.R. Karbonizatsiya i polzuchest’ gazozolobetona v panelyakh zhilykh zdanii na srednem Urale / V kn. Vliyanie klimaticheskikh uslovii i rezhimov nagruzheniya na deformatsii i prochnost’ konstruktsionnykh betonov i elementov zhelezobetonnykh konstruktsii [Carbonation and creep of aerated concrete in panels of residential buildings in the Middle Urals / In the book. Influence of climatic conditions and loading regimes on deformation and strength of structural concretes and elements of reinforced concrete structures]. Tbilisi. 1985, pp. 15–16. (In Russian). 

15. Gaziev M.A. Stress Relaxation in autoclaved aerated concrete taking into account their aging due to carbonation. Performance of composite building materials under the impact of various operational factors: Interuniversity collection. Kazan 1985, pp. 44–46. (In Russian). 

16. Batayev D.K.-S., Majiev H.N., Murtazaev S.-A.Yu., Gaziev M.A. Relaxation of compressive stresses in finegrained aerated concrete. Modern building materials, technologies and structures. Materials of the International Scientific and Practical Conference, dedicated to the 95th anniversary of the Grozny State Oil Technical University named after Academician M.D. Millionshchikov. Grozny. March 24–26, 2015, pp. 166–171. (In Russian). 

17. Fedin A.A. Nauchno- tehnicheskie osnovy proizvodstva i primenenija silikatnogo jacheistogo betona [Scientific and technical bases of production and application of silicate aerated concrete]. Moscow: Publishing GASIS. 2002. 264 p.