Physical-Chemical Bases for the Creation of Extra-Light Concretes of New Modifications with High Rates of Thermal Engineering Quality

Number of journal: 6-2022
Autors:

Yarmakovsky V.N.,
Kadiev D.Z.

DOI: https://doi.org/10.31659/0585-430X-2022-803-6-15-19
УДК: 691.32

 

AbstractAbout AuthorsReferences
Analysis of modern ideas about the mechanism of the main heat transfer processes in capillary-porous building materials, including extra-lightweight aggregate concretes (ELAC) shows that when assessing, regulating and predicting their thermal conductivity, one should proceed from the moment that heat transfer in them, as in a multiphase dispersed system, is carried out either through conductive thermal conductivity (TC), which is the main heat transfer mechanism for such a capillary-porous material as lightweight aggregate concrete, or together with TC and thermal radiation (TR). The data analysis of the domestic and foreign studies on the thermal conductivity of both capillary-porous building materials and ELAC shows that there is a reserve for increasing the heat-shielding functions of the external enclosing structures of buildings made from such concretes, estimated at least 30%. As a result of the analysis and generalization of literature data on experimental studies, the regularities of the influence of the following structural and technological factors on the thermal conductivity of lightweight concretes and their components at a constant density of concrete were established: the grain shape of a large porous aggregate and the glass phase content in it, the optimality of the factor determined by the relative content of fine (F) and coarse (C) aggregates (F/(F+C)), the use of active mineral additives in the ELAC. On the basis of the established laws, the main provisions of the technology of heat-insulating lightweight concretes are determined, which, in the current state of their production, reduces the coefficient of thermal conductivity in a state of equilibrium humidity by 20–30% while maintaining the density of aggregates and concretes, which determines their strength and deformation characteristics.
V.N. YARMAKOVSKY, Candidate of Sciences (Engineering), Chief Researcher, Honorary Member of the Russian Academy of Architecture and Construction Sciences, Expert of the Russian Academy of Sciences, member of the International Federation for Structural Concrete (fib) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
D.Z. KADIEV, Junior Researcher (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Research Institute of Building Physics of the Russian Academy of Architecture and Building Sciences (NIISF RAACS) (21, Lokomotivny Driveway, Moscow, 127238, Russian Federation)

1. Bogoslovsky V.N. Stroitel’naya teplofizika [Construction thermophysics]. Moscow: Vysshaya shkola, 1982. 415 p.
2. Kammerer I.S. Teploizolyatsiya v promyshlennosti i stroitel’stve [Thermal insulation in industry and construction]. Moscow: Stroyizdat, 1965. 377 p.
3. Kaufman B.N. Teploprovodnost’ stroitel’nykh materialov [Thermal conductivity of building materials]. Moscow: Stroyizdat, 1955. 159 p.
4. Misnar A. Teploprovodnost’ tverdykh tel, zhidkostei, gazov i ikh kompozitsii [Thermal conductivity of solids, liquids, gases and their compositions]. Moscow: Mir, 1968. 460 p.
5. Tachkova N.A. The influence of the grain composition of porous aggregates and other factors on the thermal conductivity of lightweight aggregate concrete. Diss... Candidate of Technical Sciences. Moscow, 1966. 217 p.
6. Itskovich S.M. Krupnoporistyi beton [Large-pored concrete]. Moscow: Stroyizdat, 1977. 117 p.
7. Meinert Z. Teplozashchita zhilykh zdanii [Thermal protection of residential buildings]. Moscow: Stroyizdat, 1985. 204 p.
8. Yarmakovsky V.N., Pustovgar A.P. The scientific basis for the creation of the composite binders class characterized of the low heat conductivity and low sorption activity of the cement stone. Procedia Engineering. 2015. No. 5, pp. 12–17.

For citation: Yarmakovsky V.N., Kadiev D.Z. Physical-chemical bases for the creation of extra-light concretes of new modifications with high rates of thermal engineering quality. Stroitel’nye Materialy [Construction Materials]. 2022. No. 6, pp. 15–19. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2022-803-6-15-19


Print   Email