SHRINKING DEFORMATION OF BUILDING MATERIALS AND METHODS OF ITS REDUCTION

Construction materials manufactured with composite cement binders are characterized by shrinking deformation in the course of their hardening. The total deformation consists of three shrinkage types: contractional, humid and carbonizing. The analysis of crack propagation in building materials is important because its changes result in the reduction in the service life of building structures. Humid and carbonizing shrinkages are determined for various construction materials. It is found that contractional shrinkage of construction materials may significantly ex-ceed shrinking deformations which occur during material drying. Possible ways to decrease con-tractional shrinkage are considered. It is shown that one of the more effective ways to reduce shrinking deformations is forced carbonization of building mixes, especially at early stages of hardening.

1. Trudy vos'moi mezhdunarodnoi konferentsii "Usadka i dol-govechnost' betonnykh i zhelezobetonnykh konstruktsii" (Proc. 8th Int. Sci. Conf. on Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures). Ise-Shima, Japan, 2008.

2. Ceukelaire L.D., Nieuwenburg D.V. Accelerated carbonation of a blast-furnace cement concrete. Cement and Concrete Research. 1993. V. 23. Pp. 442–452.

3. Kozlova V.K. Ispol'zovanie zol teplovykh elektrostantsii v proizvodstve stroitel'nykh materialov [Fly ashes of thermal power plants in building materials production]. Barnaul, 1975. 144 p. (rus)

4. Houst Y. Carbonation shrinkage of hydrated cement paste. Proc. 4th Int. CANMET/ACI Conf. 1997. Pp. 481–491. Available:

5. http://infoscience.epfl.ch/record/29449/files/Houst_CS_1997.pdf (accessed December 4, 2015).

6. Kucharczyková B., Danjk P., Kocáb D., Misák P. Experimental analysis on shrinkage and swelling in ordinary concrete. Advances in Materials Science and Engineering. 2011. 11 p.

7. Babitskii B., Vasil'ev A.A. Grafoanaliticheskii metod prognozirovaniya karboni-zatsii betona [Graphic-analytical method for forecasting carbonization of concrete]. Vestnik Belorusskogo gosudarstvennogo universiteta transporta: nauka i transport. 2006. No. 1–2. Pp. 82–88. (rus)

8. Gil'mutdinov T.Z., Fedorov P.A., Latypov P.M. Rezul'taty issledovanii po usko-rennoi karbonizatsii betona i tsementnogo kamnya vo vlazhnykh usloviyakh ekspluatatsii [Studies on accelerated carbonation of concrete and cement stone in wet conditions]. Izvestiya, KGSU. 2016. No. 1. Pp 155–162. (rus)

9. Warda Ashraf. Carbonation of cement-based materials: Challenges and opportunities. Construction and Building Materials. September , 2016. Available: www.researchgate.net/publication/303600209_Carbonation_of_cement-based_materials_Challenges_and_opportunities?enrich Id=rgreq-995db362585b5532b3d11f069 1ebd296- XXX&enrichSource=Y292ZXJQYWdlOz MwMzYwMDIwOTtBUzo1NDg2NzkxMjk4NTM5NTJAMTUwNzgyNjcwNjcxNg%3D% 3D&el=1_x_3&_esc=publicationCoverPdf

10. Sarkisov Yu.S., Kozlova V.K., Bozhok E.V., Malova E.Yu., Manokha A.N. Vliyanie karbonatnykh dobavok na usadochnye deformatsii tsementnogo kamnya [Influence of carbonate additives on shrinkage deformation of cement stone]. Tekhnika i tekhnologiya silikatov. V. 25. No. 1. 2018. Pp. 7–11. (rus)

11. Il'evskii Yu.A., Matvievskii V.L., Kozlova V.K. Sposob opredeleniya ob"emnykh izmenenii sistemy tsement-voda-vozdukh [method to determine volumetric changes of cement-water-air system]. Author's Certificate N 372499, 1973. (rus)

12. Alksnis F.F. Tverdenie i destruktsiya gipsotsementnykh kompozitsionnykh mate-rialov [Hardening and destruction of gypsum-cement composite materials]. Lenongrad: Stroiizdat. 1988. 220 p. (rus)

13. Bulatov A.I., Danyushevskii .V.S. Tamponazhnye materialy [Plugging materials]. Nedra, 1987. 280 p. (rus)

14. Sorochkin M.A., Shchurov A.F., Safonov I.A. Sposob proizvodstva karbonizirovannykh izdelii [Method of producing carbonated products]. Author's Certificate N 376 338, 1973. (rus)

15. Kozlova V.K., Malova E.Yu., Likhosherstov A.A., Vol'f A.V. Puti povysheniya korrozionnoi stoikosti betona po otnosheniyu k sul'fatnoi i uglekislotnoi karbonatnoi korrozii [Methods of improving corrosion resistance of concrete in relation to sulfate and carbonate car-bon dioxide corrosion]. Sbornik materialov Vserossiiskoi nauchno-prakticheskoi konferentsii „Aktual'nye problemy stroitel'stva ekologii i energosberezheniya‟ (Proc. All-Russ. Sci. Conf. „Relevant Problems of Construction, Ecology and Energy-Saving‟). Tyumen', 2011, 27 p. (rus)