There are many sources of CO₂ emissions in the world. This study concentrates on two of the most important sources of CO₂ emissions. The first one is from Portland cement production as a main component of Portland cement concrete (PСC), which is the main pillar of the construction industry. The second source is due to the burning of rice husk (RH) from rice industry. Based on this information, if different types of nanosilica particles that can be extracted from rice husk, preventing its random burning, and replace part of Portland cement (PC) in PC concrete as a pozzolanic material, which can be considered as a multiple solution for solving the previous mentioned problems of CO2 emissions. The main objective of this study is to investigate the pozzolanic activity of these nano particles (NPs) as it can be used as cement replacement material. Also, give an important usage of rice husk by extracting the nanoparticles from rice husk instead of the random burning of it. An extensive experimental program has been conducted to examine the pozzolanic activity of different nanosilica particles extracted from rice husk using two testing methods. The first method is the electrical conductivity measurement and the second is the strength activity index according to ASTM C311, in each method there are different types of nanosilica (NS) compared to silica fume (SF), which well known as pozzolanic material and also compared to Marble Powder as an inert waste material. The results of the electrical conductivity method show that, the Nanosilica 1 has superior pozzolanic activity compared to the other materials used in this study. On the other hand, the using of the second method (strength activity index) both NS and SF almost give the same pozzolanic activity, it may be related to that, the nanoparticles didn’t disperse in the cement matrix. According to these results the nanosilica could be used as a good replacement of Portland cement due to its pozzolanic activity, which leads to lower emissions of hazards gases in cement manufacturing as well as using the rice husk as waste material.

N. El ASHKAR, Professor of Structural Engineering (This email address is being protected from spambots. You need JavaScript enabled to view it.)
A. MORSY Assoc. Prof., Structural Engineering (This email address is being protected from spambots. You need JavaScript enabled to view it.)
A. TAREK, Teacher assistant (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Arab Academy for Science, Technology and Maritime Transport (Alexandria, Egypt)

1. Greenhouse Gas Emissions. United States Environmental Protection Agency. January 19, 2017. https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions (date of access 19.06.2018)
2. Sabrah B.A., El-Aleem S. Abd, Gouda H. Physico-mechanical and chemical properties of composite cement containing high percentages of mechanically activated Egyptian slag. International Journal of Engineering Research & Technology. 2014. Vol. 3 (9), pp. 1446–1457.
3. Abd El. Aziz, S. Abd El-Aleem, Heikal M., El-Didamony H. Hydration and durability of sulphate-resisting and slag cement blends in Caron’s Lake water. Cement and Concrete Research. 2005. Vol. 35. Iss. 8, pp. 1592–1600.
4. El-Didamony H., S. Abd El-Aleem Mohamed, Gouda H. Durability performance of blended cements incorporating Egyptian SRC and GBFS in Aggressive Water. International Journal of Innovative Science and Modern Engineering (IJISME). 2015. Vol. 3. Iss. 9, pp. 23–35.
5. Bahurudeen A., Kaisar Wani, Mirza Abdul Basit, Manu Santhanam Assesment of pozzolanic performance of sugarcane bagasse ash. Journal of Materials in Civil Engineering. 2016. Vol. 28 Iss. 2. https://ascelibrary.org/doi/10.1061/%28ASCE%29MT.1943-5533.0001361
6. Pavía S., Walker R., Veale P., Wood A. Impact of the properties and reactivity of rice husk ash on lime mortar properties. Journal of Materials in Civil Engineering. 2014. Vol. 26. Iss. 9. https://ascelibrary.org/doi/10.1061/%28ASCE%29MT.1943-5533.0000967
7. Ulukaya Serhan, Yüzer Nabi. Assessment of pozzolanicity of clay bricks fired at different temperatures for use in repair mortar. Journal of Materials in Civil Engineering. 2016. Vol. 28 Iss. 8. https://ascelibrary.org/doi/10.1061/%28ASCE%29MT.1943-5533.0001560
8. Bentz Dale P., Durán-Herrera Alejandro, Galvez-Moreno Daniel. Comparison of ASTM C311 Strength Activity Index testing vs. testing based on constant volumetric proportions. Journal of ASTM International. 2011. Vol. 9. Iss. 7. DOI: 10.1520/JAI104138
9. Rice Market Monitor. Food and Agriculture Organization of the United Nations. 2016. Vol. XIX Iss. 3. http://www.fao.org/fileadmin/templates/est/COMM_MARKETS_MONITORING/Rice/Images/RMM/RMM-Oct16_H.pdf
10. Heikal Mohamed, Aziz M. Abd El., El-Aleem S. Abd, El-Didamony H. Effect of polycarboxylate on rice husk ash Pozzolanic cement. Silicates Industriels. 2004. Vol. 69 (9–10), pp. 73–84.
11. El-Aleem Mohamed Saleh Abd. Activation of granulated blast-furnace slag using lime rich sludge in presence and absence of rice husk ash. International Journal of Innovative Technology and Exploring Engineering. 2015. Vol. 5. Iss. 3, pp. 43–51.
12. Chen Haoran, Wang Weixing, Martin Jarett C., Oliphant Adam J., Doerr Paige A., Xu Jeffery F. Extraction of lignocellulose and synthesis of porous silica nanoparticles from rice husks: a comprehensive utilization of rice husk biomass. ACS Sustainable Chem. Eng. 2013. Vol. 1. Iss. 2, pp. 254–259. https://pubs.acs.org/doi/abs/10.1021/sc300115r
13. El-Alfi E.A., Radwan A.M., Abd El-Aleem S. Effect of limestone fillers and silica fume pozzolana on the characteristics of sulfate resistant cement pastes. Ceramics Silikaty. 2004. Vol. 48. Iss. 1, pp. 29–33.
14. Abd-El.Aziz M.A., Aleem S. Abd. El., Heikal Mohamed. Physico-chemical and mechanical characteristics of pozzolanic cement pastes and mortars hydrated at different curing temperatures. Construction and Building Materials. 2012. Vol. 26. Iss. 1, pp. 310–316.
15. Abd-El-Aleem S., Abd-El-Aziz M.A., El-Didamony H. Calcined carbonaceous shale pozzolanic Portland cement. Egyptian Journal of Chemistry. 2002. Vol. 5. Iss. 3, pp. 501–517.
16. ASTM Standard C311-05: Standard Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans for Use in Portland-Cement Concrete.
17. ASTM Standard C125: Standard terminology Relating to concrete and concrete Aggregates.
18. Heikal Mohamed, Abd El-Aleem S., Morsi W.M. Characteristics of blended cements containing nano-silica. Housing & Building National Research Center (HBRC) Journal. 2013. Vol. 9, pp. 243–255.
19. Abd El-Aleem S., Heikal Mohamed, Morsi W.M. Hydration characteristic, thermal expansion and microstructure of cement containing nano-silica. Construction and Building Materials. 2014. Vol. 59. Iss. 30, pp. 151–160.
20. Saleh Abd El-Aleem, Abd El-Rahman Ragab. Chemical and physico-mechanical properties of composite cements containing micro- and nano-silica. International Journal of Civil Engineering and Technology. 2015. Vol. 6, pp. 5, pp. 45–64.
21. Saleh Abd El-Aleem Mohamed, Wafaa Mohamed Morsi. Performance of nano-modified cement pastes and mortars in Caron’s lake water. International Journal of Engineering and Advanced Technology. 2015. Vol. 4. Iss. 6, pp. 80–94.
22. El-Didamony H., Abd El-Aleem S., Abd El-Rahman Ragab. Hydration behavior of composite cement containing fly ash and nanosized-SiO₂. American Journal of Nano Research and Applications. 2016. Vol. 4. Iss. 2, 6–16.
23. Kizilkanat Ahmet B., Oktay Didem, Kabay Nihat, Tufekci M. Mansur. Comparative experimental study of mortars incorporating pumice powder or fly ash. Journal of Materials in Civil Engineering. 2016. Vol. 28. Iss. 2 https://ascelibrary.org/doi/10.1061/%28ASCE%29MT.1943-5533.0001407
24. Hoppe Filho J., Garcez M.R., Medeiros M.H.F., Silva Filho L.C.P., Isaia G.C. Reactivity assessment of residual rice-husk ashes. Journal of Materials in Civil Engineering. 2017. Vol. 29. Iss. 6. https://ascelibrary.org/doi/10.1061/%28ASCE%29MT.1943-5533.0001820
25. Velázquez Sergio, Monzó José M., Borrachero María V., Payá Jordi. Assessment of the pozzolanic activity of a spent catalyst by conductivity measurement of aqueous suspensions with calcium hydroxide. Materials (Basel). 2014. Vol. 7. Iss. 4, pp. 2561–2576. doi: 10.3390/ma7042561
26. Donatello S., Tyrer M., Cheeseman C.R. Comparison of test methods to assess pozzolanic activity. Cement and Concrete Composites. Vol. 32. Iss. 2, pp. 121–127. https://doi.org/10.1016/j.cemconcomp.2009.10.008
27. Filipponi Luisa, Sutherland Duncan. NANOTECHNOLOGIES: Principles, Applications, Implications and Hands-on Activities. A compendium for educators. https://ec.europa.eu/research/industrial_technologies/pdf/nano-hands-on-activities_en.pdf

The method of obtaining a porous ceramic material from an aluminosilicate mixture of a waste from the production of granite rubble and clay without the use of blowing agents at a low calcination temperature is proposed. It is shown that the composition of clay from various deposits (“Haidukovka”, “Osetki”, “Kustiha”, “Lukoml”) influence the process of expansion. The local clay “Kustiha” in its composition is the most optimal, as it contains a small amount of aluminum oxide (6–10%) and a significant amount of free quartz (16–22%). It has been established that the addition of sodium hydroxide solution to the aluminosilicate mixture leads to its swelling during firing. The optimum concentration of sodium hydroxide to swell the mixture is 15%. A mechanism for the formation of porous ceramics with alkaline activation of the initial mixture of clay and granitoid sifting is proposed. The alkalization of the mixture due to the addition of sodium hydroxide, when heated, results in the formation of temperature-resistant structural hydroxyl groups in the material when the aluminosilicate surface is dehydroxylated, and then the aluminosilicates are melted to a pyroplastic state, promoting sintering of the mixture. The free water, distributed in the mass of the initial mixture, when heated goes into a gaseous state, which leads to the formation of pores that form a cellular structure during calcination. It is shown that the optimal pores size of the ceramic material is reached when the calcination temperature of the charge is 950°C. This calcination temperature is about 200°C lower than the temperature needed for the production of expanded clay, which means obtaining such a porous ceramic material is more energy efficient.

S.N. LEONOVICH¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
D.V. SVIRIDOV², Doctor of Sciences (Chemistry) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
A.L. BELANOVICH², Candidate of Sciences (Chemistry) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
L.S. KARPUSHENKOVA², Candidate of Sciences (Chemistry) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
S.A. KARPUSHENKOV², Candidate of Sciences (Chemistry) (karpushenkоThis email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ Belarusian National Technical University (65, Nezavisimosti Avenue, Minsk, 220013, Republic of Belarus)
² Belarusian State University (4, Nezavisimosti Avenue, Minsk, 220030, Republic of Belarus)

1. Sirazin M.G. Warm ceramics – a promising material for housing in Russia. Stroitel’nye Materialy [Construction Materials]. 2006. No. 4, pp. 18–19. (In Russian).
2. Abdarakhimova E.S., Abdarakhimova V.Z. Optimization of the continent of light fraction ASH in ceramic tile mixtures. Glass and Ceram. 2006. Vol. 63. No. 3–4, pp. 95–96. (In Russian).
3. Rashad A.M. Lightweight expanded clay aggregate as a building material – An overview. Construction and Building Materials. 2018. Vol. 170, pp. 757–775. DOI: https://doi.org/10.1016/j.conbuildmat.2018.03.009
4. Kazantseva L.K., Vereshchagin V.I., Ovcharenko G.I. Foamed ceramic insulation materials from natural raw materials. Stroitel’nye Materialy [Construction Materials]. 2001. No. 4, pp. 33–35. (In Russian).
5. Kuzmina O.V., Vereshchagin V.I., Abiyaka A.N. Expansion of the raw material base for the production of foam-crystalline materials. Stroitel’nye Materialy [Construction Materials]. 2009. No. 7, pp. 54–56. (In Russian).
6. Rugele K., Lehmhus D., Hussainova I., Peculevica J., Lisnanskis M., Shishkin A. Effect of fly-ash cenospheres on properties of clay-ceramic syntactic foams. Materials (Basel). 2017. No. 10 (7). 828. DOI: https://doi.org/10.3390/ma10070828
7. Puertas F., Santos R., Alonso M.M., del Rio M. Alkali-activated cement mortars containing recycled clay-based construction and demolition waste. Ceramics-Silikaty. 2015. No. 59 (3), pp. 202–210.
8. Toropkov N.E., Kutugin V.A. The dependence of the physico-chemical properties of clay raw materials in the technology of expanded clay. Mezhdunarony nauchno-issledovatel’sky zhurnal. 2014. No. 11, pp. 52–54 (In Russian).
9. Damdinova D.R., Hardaev P.K., Anchiloev N.N., Tokurenov B.V. Study of the possibility of obtaining foam ceramics using local clay and cullet.Building complex of Russia. The science. Education. Practice: materials of the international scientific-practical conference.Ulan-Ude. 2012, pp. 203–205. (In Russian).
10. Damdinova D.R, Hardaev P.K., Karpov B.A., Zonhiev M.M. Technological methods for obtaining foam glass with adjustable pore structure. Stroitel’nye Materialy [Construction Materials]. 2007. No. 6, pp. 68–69. (In Russian).
11. Prud’homme E., Michaud P., Joussein E., Peyratout C., Smith A., Rossignol S. In situ inorganic foams prepared from various clays at low temperature. Applied Clay Science. 2011. Vol. 51. No. 1–2, pp. 15–22. DOI: https://doi.org/10.1016/j.clay.2010.10.016
12. Bai C., Colombo P. Processing, properties and applications of highly porous geopolymers: A review. Ceramics International.2018. Vol. 44. No. 14, pp. 16103–16118. DOI: https://doi.org/10.1016/j.ceramint.2018.05.219
13. Duxson P., Fernandez-Jimenez A., Provis J.L., Lukey G.C., Palomo A., van Deventer J.S.J. Geopolymer technology: the current state of the art.Journal of Materials Science. 2007. Vol. 42. No. 9, pp. 2917–2933. DOI: 10.1007/s10853-006-0637-z
14. Kazantseva L.K., Rashchenko S.V. Chemical processes during energy-saving preparation of lightweight ceramics.Journal of the American Ceramic Society. 2014. Vol. 97. No. 6, pp. 1743–1749. DOI: https://doi.org/10.1111/jace.12980
15. Vereshchagin V.I., Sokolova S.N. Granulated foam glass-insulating insulation material of zeolite rocks. Stroitel’nye Materialy [Construction Materials]. 2007. No. 3, pp. 66–67. (In Russian).

The possibility of using a composite binder and fiber to improve the physical and mechanical characteristics of autoclaved foam concrete is theoretically justified and experimentally confirmed. It is shown that the replacement of Portland cement in the foam concrete with binder composite TMTS-70 can increase its strength by 35%. Modified basalt fiber in the process of autoclaving acts as an active substrate for crystallization of hydration products of clinker minerals, prevents corrosion of fiber components of cement stone, leads to an increase in its adhesion to the matrix of the cemented substance, which together with composite binder TMTS-70 makes it possible to increase the strength class in comparison with the control composition of foam concrete from B1,5 to B2,5. Also, dispersed reinforcement of foam concrete helps to reduce the average pore size in the foam concrete matrix, while maintaining the average density, which improves the thermal insulation characteristics of foam concrete, reducing its thermal conductivity. Thus, multi-criteria optimization is carried out and rational limits of variation of prescription-technological factors for the production of autoclaved foam concrete are established.

A.L. POPOV, Engineer (This email address is being protected from spambots. You need JavaScript enabled to view it.)
V.V. STROKOVA, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Belgorod State Technological University named after V.G. Shukhov (46, Kostyukova Street, Belgorod, 308012, Russian Federation)

1. Nelyubova V.V. Improving the efficiency of production of silicate autoclave materials using a nano-dispersed modifier. Stroitel’nye Materialy [Construction Materials]. 2008. No. 9, pp. 89–92. (In Russian).
2. Svatovskaya L.B., Sycheva A.M., Eliseeva N.N. Improving the quality of non-autoclaved foamed concrete with nano-size additives. Nanotekhnologii v stroitel’stve: a scientific online journal. 2011. No. 1, pp. 50–62. (In Russian).
3. Mestnikov AE, Semenov S.S., Fedorov V.I. Production and use of autoclaved foamed concrete in Yakutia. Fundamental’nye issledovaniya. 2015. No. 12–3, pp. 490–494. (In Russian).
4. Volodchenko A.N., Strokova V.V. Improving the efficiency of autoclave hardening silicate cellular materials. Vestnik Severo-Vostochnogo federal’nogo universiteta im. M.K. Ammosova. 2017. No. 2 (58), pp. 60–69. (In Russian).
5. Kaftaeva M.V., Nikitin P.N. On the choice of sand for autoclaved cellular concrete in the Republic of Bashkortostan. Tekhnologii bettonov. 2012. No. 1–2 (66–67), pp. 12–14. (In Russian).
6. Strokova V.V., Cherevatova A.V., Nelyubova V.V. Silicate autoclave materials based on highly concentrated binding cement. Stroitel’nye Materialy [Construction Materials]. 2007. No. 10, pp. 10–16. (In Russian).
7. Popov A.L., Strokova V.V., Nelyubova V.V. Features of composite binder on quartz-feldspath sand. Stroitel’stvo i tekhnogennaya bezopasnost’. 2018. No. 12 (64), pp. 63–70. (In Russian).
8. Popov A.L., Nelyubova V.V. Features of the design of autoclaved materials with mineral fibers. Modern problems of construction and life support: safety, quality, energy and resource saving: collection of articles of V All-Russian scientific-practical conference.Yakutsk. March 29, 2018, pp. 155–158. (In Russian).
9. Klyuev S.V., Klyuev A.V., Lesovik R.V. Optimal design of high-quality fiber-reinforced concrete. Bulletin of BSTU named after V.G. Shukhov. 2015. No. 6, pp. 119–121. (In Russian).
10. Aloyan R.M., Ovchinnikov A.A., Akimov A.V. Investigation of the influence of the silica modifier on the mineralogical composition and strength properties of gasconcrete. Nauchnoe obozrenie. 2016. No. 2, pp. 6–13. (In Russian).
11. Ovchinnikov A.A., Akimov A.V., Khozin R.R. Porometric features of gas silicate and their influence on the properties of cellular concrete.Informatsionnaya sreda vuza. 2016. No. 1 (23), pp. 389–394. (In Russian).
12. Babaev V.B., Strokova V.V., Nelyubova V.V., Savgir N.L. On the alkali resistance of basalt fiber in the cement system. Bulletin of BSTU named after V.G. Shukhov. 2013. No. 2, pp. 63–66. (In Russian).
13. Babaev V.B., Strokova V.V., Nelyubova V.V. Basalt fiber as a component for micro-reinforcement of cement composites. Bulletin of BSTU named after V.G. Shukhov. 2012. No. 4, pp. 58–61. (In Russian).

One of the ways to increase the durability of the external wall panels of cellular concrete is the use of pre-stressed reinforcement, which can significantly increase their stiffness and crack resistance. The article presents the results of experimental studies of tension losses in the reinforcement due to the creep of concrete for pre-stressed aerated concrete elements. It is established that these losses linearly depend on the initial level of compression in aerated concrete in the range from 0.3 to 0.6 of its prismatic strength and constitute 22–30%. Residual stresses in the stressed reinforcement range from 136 to 245 MPa, which is sufficient to ensure the operational crack resistance of large-size products of aerated concrete during moisture exchange and carbonizing processes. The obtained results are the basis for further development of the method for calculating stress losses in the reinforcement due to the aerated concrete creep, as well as when preparing recommendations for the design and manufacture of pre-stressed enclosing structures of cellular concrete.

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

Grozny State Oil Technical University named after Academician M.D. Millionshchikov (100, Kh.A. Isaeva Avenue, Grozny, Chechen Republic, 364061, Russian Federation)

1. Silaenkov E.S. Dolgovechnost’ izdelii iz yacheistykh betonov [longevity of products from aerated concrete]. Moskov: Stroyizdat. 1986. 176 p.
2. Silaenkov 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.
3. Silaenkov E.S., Kantor S.L., Gaziev M.A. Uchet polzuchesti betona vsledstvie karbonizatsii pri raschete napryazhennogo sostoyaniya yacheisto-betonnykh stenovykh panelei [Accounting for the creep of concrete due to arbonization at calculating the stress state of aerated concrete wall panels]. The durability of structures from autoclaved concretes. Tallinn. 1987. Part I, pp. 160–163.
4. Pinsker V.A., Solovey Zh.B., Pochtenko A.G., Kesli E.O., Churkina V.A. Opyt ekspluatatsii domov s yacheisto-betonnymi ograzhdeniyami [Experience in the operation of houses of aerated concrete wall panels]. Tallinn. 1984. Part II, pp. 190–192.
5. Timakov U.V., Bezborodov V.A., Sprengert T.K. Naturnye obsledovaniya naruzhnykh sten zdaniya iz gazobetona [Field surveys of the exterior walls of the building are made of aerated concrete]. Tallinn. 1984. Part II, pp. 193–198.
6. Chernyshov E.M., Vlasov V.V., Bautina E.I. Prognozirovanie polnogo i ostatochnogo resursov ograzhdayushchikh konstruktsii iz yacheistogo betona [Prediction of the total and residual resources of wall panels made of aerated concrete]. Rostov-on-Don: Rostov state building Universities. 2007. 194 p.
7. Fedin A.A. Nauchno-tekhnicheskie osnovy proizvodstva i primeneniya silikatnogo yacheistogo betona [Scientific and technical bases of production and application of silicate aerated concrete]. Moscow: GASIS. 2002. 264 p.
8. 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).
9. Gaziev M.A. An empirical method for calculating wetness-carbonization stresses emerges in panels of aerated concrete, with considering its rheological properties.Stroitel’nye Materialy[Construction Materials]. 2018. No. 3, pp. 75–79. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2018-757-3-75-79.
10. Chernyshov E.M., Slavcheva G.S. Management of operational deformation and crack resistance of macro-porous (aerated) concrete. Part 1. The Context of the problem and theory questions.Stroitel’nye Materialy[Construction Materials]. 2014. No. 1, pp. 105–112. (In Russian).
11. Furmanov B.A., Nudel V.S., Kurshpel V.Kh. Factory production of prestressed aerated ash concrete panels.Beton i zhelezobeton.1984. No. 6, pp. 14–16. (In Russian).
12. Kurshpel V.Kh., Makarichev V.V., Filippov B.P. Wall panels of aerated concrete with a combined reinforcement.Beton i zhelezobeton.1986. No. 12, pp. 7–8. (In Russian).
13. Bataev D.K.-S., Gaziev M.A., Pinsker V.A. Experience of research and implementation of pre-stressed wall panels made of autoclave cellular concrete.Experience of production and use of cellular concrete of autoclave curing: Materials of the 9th International Scientific and Practical Conference.Minsk: Kolorgrad. 2016. pp. 83–85.
14. Mailyan D.R., Bataev D.K.-S., Mazhiev K.N., Gaziev M.A. Complex researches in the field of creation of crack-resistant wall panels from aerated concrete with prestressed reinforcement.Materials Science Forum.2018. Vol. 931, pp. 252–257 https://doi.org/10.4028/www.scientific.net/MSF.931.252
15. Krivitsky M.Ya., Levin N.I., Schastnyy A.N. Polzuchest’ avtoklavnykh yacheistykh betonov s uchetom nekotorykh tekhnologicheskikh faktorov [Creep of autoclave aerated concrete taking into account some technological factors]. Production and application of products from cellular concrete. Moscow: Stroyizdat. 1968, pp. 105–120.

The results of the evaluation of the effect of photocatalytic composite material (PCM) of TiO₂–SiO₂ system synthesized by sol-gel method on the properties of the cement system are presented. The properties of the synthesized PCM – chemical and mineral composition, micro-structural features, depending on the ratio of raw materials – tetrabutoxytitanium and diatomite powder are determined. The synthesized PCM differ in the content of anatase and quartz, the distribution of anatase crystals on the surface of diatomite particles. The deposition of tumors on the surface of the diatomite is selective, anatase accumulations are observed on particles having a developed amorphized surface. Whereas the crystallized particles of diatomite with a smooth surface remain uncovered with new formations of anatase. Established the dependence of rheological parameters of cement paste, compressive strength and ability to self-cleaning of cement stone from the composition of PCM, in particular, the content of SiO₂ and TiO₂. It is shown that the ability to self-purification of cement stone with synthesized PCM is close to the sample with industrial nano-scale photocatalyst while maintaining the level of compressive strength. Both synthesized PCMs can be recommended for the production of self-cleaning cement composites. They can be obtained on the basis of domestic raw materials, the technology of their production is simple and does not require special equipment. The composition of the used PCM, namely the ratio of anatase and silica, should be chosen depending on the purpose and operating conditions of the structures.

M.V. LABUZOVA, Bachelor (This email address is being protected from spambots. You need JavaScript enabled to view it.)
E.N. GUBAREVA, Bachelor (This email address is being protected from spambots. You need JavaScript enabled to view it.)
Y.N. OGURTSOVA, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
V.V. STROKOVA, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Belgorod State Technological University named after V.G. Shukhov (46, Kostyukova Street Belgorod, 308012, Russian Federation)

1. Arai Y., Tanaka K., Khlaifat A.L. Photocatalysis of SiO₂-loaded TiO₂. Journal of Molecular Catalysis A.2006. No. 243, pp. 85–88. DOI: http://dx.doi.org/10.1016/j.molcata.2005.08.016
2. Zhao L., Yu J., Cheng B. Preparation and characterization of SiO₂/TiO₂ composite microspheres with microporous SiO₂ core/mesoporous TiO₂ shell. Journal of Solid State Chemistry. 2005. Vol. 178 (6), pp. 1818–1824. DOI: http://dx.doi.org/10.1016/j.jssc.2005.03.024
3. Strokova V.V., Gubareva E.N., Ogurtsova Y.N. Evaluation of the properties of the silica raw materials as a substrate as component of composite photocatalytic material. Vestnik Belgorodskogo gosudarstvennogo tekhnologicheskogo universiteta im. V.G. Shukhova.2017. No. 2, pp. 6–12. DOI: http://dx.doi.org/10.12737/23819 (In Russian).
4. Labuzova M.V., Gubareva E.N., Ogurtsova Yu.N., Strokova V.V. Properties of photocatalytic composite material based on silica raw materials. Vestnik Belgorodskogo gosudarstvennogo tekhnologicheskogo universiteta im. V.G. Shukhova.2018. No. 8, pp. 85–92. DOI: http://dx.doi.org/10.12737/article_5b6d5863076c49.45633399 (In Russian).
5. Yener H.B., Helvaci S.S. Effect of synthesis temperature on the structural properties and photocatalytic activity of TiO₂/SiO₂ composites synthesized using rice husk ash as a SiO₂ source. Separation and Purification Technology.2015. Vol. 140, pp. 84–93. DOI: http://dx.doi.org/10.1016/j.seppur.2014.11.013
6. Nandanwar R., Ingh P., Syed F.F., Haque F.Z. Preparation of TiO₂/SiO₂ nanocomposite with non-ionic surfactants via sol-gel process and their photocatalytic study. Oriental Journal of Chemistry. 2014. Vol. 30. No. 4, pp. 1577–1584. DOI: http://dx.doi.org/10.13005/ojc/300417
7. Hela R., Bodnarova L. Research of possibilities of testing effectiveness of photoactive TiO₂ in concrete. Stroitel’nye Materialy [Construction Materials]. 2015. No. 2, pp. 77–81. (In Russian).
8. Timokhin D.K., Geranina Yu.S. Durability cement concrete with the addition of titanium dioxide in the urban environment aggressive. Tekhnicheskoe regulirovanie v transportnom stroitel’stve.2016. No. 2 (16), pp. 9–12. (In Russian).
9. Borgarello E., Kapone K., Gverrini D.L. Development of photocatalytic cement-based materials: situation and perspectives. Tsement i ego primenenie.2017. No. 6, pp. 74–77. (In Russian).
10. Lukuttsova N.P., Pykin A.A., Postnikova O.A., Golovin S.N., Borovik E.G. The structure of cement stone with dispersed titanium dioxide in daily age. Vestnik Belgorodskogo gosudarstvennogo tekhnologicheskogo universiteta im. V.G. Shukhova.2016. No. 11, pp. 13–17. (In Russian). 
11. Lukuttsova N.P., Postnikova O.A., Soboleva G.N., Rotar’ D.V., Ogloblina E.V. Photo-catalytic pavement on the basis of additive of nano-disperse titanium dioxide. Stroitel’nye Materialy [Construction Materials]. 2015. No. 11, pp. 5–8. (In Russian).
12. Murashkevich A.N., Alisienok O.A., Zharskii I.M. Physicochemical and photocatalytic properties of nanosized titanium dioxide deposited on silicon dioxide microspheres. Kinetika i kataliz.2011. Vol. 52. No. 6, pp. 830–837. (In Russian).
13. Cherkasov V.D., Buzulukov V.I., Tarakanov O.V., Emel’yanov A.I. Structure formation of cement composites with addition of modified diatomite. Stroitel’nye Materialy [Construction Materials]. 2015. No. 11, pp. 75–77. (In Russian).
14. Le Saoût, G., & Ben Haha, M. (2011). Effect of filler on early hydration. InÁ. Palomo, A. Zaragoza, & J. C. López Agüí(Eds.), Cementing a sustainable future (p. (7 pp.). Madrid, Spain: Instituto de Ciencias de la Construcción «Eduardo Torroja».
15. Guo M.-Z., Maury-Ramirez A., Poon C.S. Self-cleaning ability of titanium dioxide clear paint coated architectural mortar and its potential in field application.Journal of Cleaner Production.2016. No. 112, pp. 3583–3588. DOI: http://dx.doi.org/10.1016/j.jclepro.2015.10.079

The use of organic modifying agents in the composition of the cement composition in significant concentrations actualizes the problem of their influence on the properties of the formed organo-silicate adducts. In this regard, it became necessary to study the effect of the molecular structure of the modifying disaccharide on the properties of dispersions of synthetic calcium silicates obtained by thermolysis from the corresponding modified calcium hydrosilicates. The properties of silicate-calcium dispersion (SCD) depending on the structure of the modifying carbohydrate and the effect of SCD additives on the technological properties of cement systems are determined by the methods of photocolorimetry, dynamic light scattering, viscometry, electron microscopy. The combination of dynamic light scattering and scanning electron microscopy determined the bimodal nature of the particle size distribution and the SCD morphology. It was found that these parameters do not depend on the molecular structure of the modifying carbohydrate. The molecular structure of the modifying carbohydrate determines the degree of carbohydrate occlusion by the silicate matrix and the nature of the effect of residual free modifying carbohydrate in the SCD on the properties of the modified cement system. It is found that SCD, modified by sucrose, has the greatest plasticizing activity, compared with SCD, modified by lactose, and maltose. It was found that the introduction of SCD in the cement binder is accompanied by a decrease in the normal density of the cement paste, the level of maximum reduction in the normal density depends on the type of modifying carbohydrate in the SCD composition.

E.A. SHOSHIN¹, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
V.V. STROKOVA², Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ Yuri Gagarin State Technical University of Saratov (77, Polytechnicheskaya Street, Saratov, 410054, Russian Federation)
² Belgorod State Technological University named after V.G. Shukhov (46, Kostyukova Street, Belgorod, 308012, Russian Federation)

1. Camille Nalet, AndréNonat. Ionic complexation and adsorption of small organic molecules on calcium silicate hydrate: Relation with their retarding effect on the hydration of C3S.Cement and Concrete Research. 2016. Vol. 89, pp. 97–108. https://doi.org/10.1016/j.cemconres.2016.08.012
2. Linghong Zhang, Lionel J.J. Catalan, Raymond J. Balec, Andrew C. Larsen, Hassan Haji Esmaeili, Stephen D. Kinrade. Effects of saccharide set retarders on the hydration of ordinary portlandcement and pure tricalcium silicate.Journal of the American Ceramic Society.2010. Vol. 93. [1], pp. 279–287. DOI: 10.1111/j.1551-2916.2009.03378.x
3. Camille Nalet, AndréNonat Retarding effectiveness of hexitols on the hydration of the silicate phases of cement: Interaction with the aluminate and sulfate phases.Cement and Concrete Research. 2016. Vol. 90, pp. 137–143. https://doi.org/10.1016/j.cemconres.2016.09.018
4. Cheung J., Jeknavorian A., Roberts L., Silva D. Impact of admixtures on the hydration kinetics of Portland cement.Cement and Concrete Research.2011. Vol. 41, pp. 1289–1309. https://doi.org/10.1016/j.cemconres.2011.03.005
5. Camille Nalet, AndréNonat Effects of hexitols on the hydration of tricalcium silicate.Cement and Concrete Research. 2017. Vol. 91, pp. 87–96. https://doi.org/10.1016/j.cemconres.2016.11.004
6. Nalet C., Nonat A. Impacts of hexitols on the hydration of a tricalcium aluminate-calcium sulfate mixture.Cement and Concrete Research.2016. Vol. 89, pp. 177–186. https://doi.org/10.1016/j.cemconres.2016.08.017
7. Lasheras-Zubiate M., Navarro-Blasco I., Fernández J.M.,Álvarez J.I. Effect of the addition of chitosan ethers on the fresh state properties of cement mortars.Cement and Concrete Composites. 2012. Vol. 34, pp. 964–973. https://doi.org/10.1016/j.cemconcomp.2012.04.010
8. Paulo Henrique Silva Santos Moreira, Julio Cezar de Oliveira Freitas, Renata Martins Braga, Renata Mendonça Araújo, Miguel Angelo Fonseca de Souza. Production of carboxymethyl lignin from sugar cane bagasse: A cement retarder additive for oilwell application.Industrial Crops and Products.2018. Vol. 116, pp. 144–149. https://doi.org/10.1016/j.indcrop.2018.01.073
9. Poinot T., Govin A., Grosseau P. Influence of hydroxypropylguars on rheological behavior of cement-based mortars.Cement and Concrete Research.2014. Vol. 58, pp. 161–168. https://doi.org/10.1016/j.cemconres.2014.01.020
10. Poinot T., Bartholin M.C., Govin A., Grosseau P. Influence of the polysaccharide addition method on the properties of fresh mortars.Cement and Concrete Research.2015. Vol. 70, pp. 50–59. https://doi.org/10.1016/j.cemconres.2015.01.004
11. Brumaud C., Baumann R., Schmitz M., Radler M., Roussel N. Cellulose ethers and yield stress of cement pastes.Cement and Concrete Research.2014. Vol. 55, pp. 14–21. https://doi.org/10.1016/j.cemconres.2013.06.013
12. Patural L., Marchal P., Govin A., Grosseau P., Devès O. Cellulose ethers influence on water retention and consistency in cement-based mortars.Cement and Concrete Research.2011. Vol. 41, pp. 46–55. https://doi.org/10.1016/j.cemconres.2010.09.004
13. Smitha B.J., Rawala A., Funkhouser G.P., Roberts L.R., Gupta V., Israelachvilia J.N., Chmelka B.F. Origins of saccharide-dependent hydration at aluminate, silicate, and aluminosilicate surfaces.PNAS. 2011. Vol. 108. No. 22, pp. 8949–8954. http://dx.doi.org/10.1073/pnas.1104526108
14. Smitha B.J., Funkhouser G.P., Roberts L.R., Gupta V., Chmelka B.F. Reactions and Surface Interactions of Saccharides in Cement Slurries.Langmuir: the ACS journal of surfaces and colloids.2012. Vol. 28, pp. 14202–14217. http://dx.doi.org/10.1021/la3015157
15. Young J.F. A review of the mechanisms of set-retardation in Portland cement pastes containing organic admixtures.Cement and Concrete Research.1972. No. 2 (4), pp. 415–433. https://doi.org/10.1016/0008-8846(72)90057-9
16. Kanchanason V., Plank J. Effect of calcium silicate hydrate – polycarboxylate ether (C–S–H–PCE) nanocomposite as accelerating admixture on early strength enhancement of slag and calcined clay blended cements.Cement and Concrete Research.2019. Vol. 119, pp. 44–50. https://doi.org/10.1016/j.cemconres.2019.01.007
17. Conte T., Plank J. Impact of molecular structure and composition of polycarboxylate comb polymers on the flow properties of alkali-activated slag.Cement and Concrete Research.2019. Vol. 116, pp. 95–101. https://doi.org/10.1016/j.cemconres.2018.11.014
18. Шошин Е.А., Широков А.А. Исследование электрокинетического потенциала модифицированных углеводами цементных паст на начальной стадии гидратации //Вестник БГТУ им. Шухова.2015. № 5. С. 235–240.
18. Shoshin E.A. Shirokov A.A. Research of electrokinetic potential of the cement pastes modified by carbohydrates at an initial stage of hydration.Vestnik BGTU im. Shukhova.2015. No. 5, pp. 235–240. (In Russian).
19. Шошин Е.А., Строкова В.В. Абсорбция сахарозы продуктами гидратации портландцемента //Бутлеровские сообщения.2018. Т. 56. № 12. С. 171–180. DOI: jbc-01/18-56-12-171
19. Shoshin E.A., Strokova V.V. Sucrose absorption by products of hydration of the portlandtsement. Butlerovskie soobshcheniya. 2018. Vol. 56. No. 12, pp. 171–180. (In Russian). ROI: jbc-01/18-56-12-171
20. Шошин Е.А., Поляков А.В., Буров А.М. О возможности синтеза наносиликатов кальция методом термолиза модифицированных смесей опока–СаО, подвергнутых совместному измельчению в присутствии воды //Вестник БГТУ им. Шухова.2016. № 3. С. 152–158.
20. Shoshin E.A., Polyakov A.V., Burov A.M. The possibility of synthesis of calcium nanosilicates by termolisez of the modified mixes opoka–SAO, subjected to joint crushing in water presence.Vestnik BGTU im. Shukhova.2016. No. 3, pp. 152–158. (In Russian).
21. Шошин Е.А. Силикатный наполнитель, получаемый методом термолиза модифицированных гидросиликатов цемента //Строительные материалы.2017. № 7. С. 16–19. DOI: https://doi.org/10.31659/0585-430X-2017-750-7-16-19
21. Shoshin E.A. Silicate filler obtained by the method of thermolysis of modified cement hydrosilicates.Stroitel’nye Materialy[Construction Materials]. 2017. No. 7, pp. 16–19. DOI: https://doi.org/10.31659/0585-430X-2017-750-7-16-19. (In Russian).
22. Шепеленко Т.С., Саркисов Ю.С., Горленко Н.П., Цветков Н.А., Зубкова О.А. Процессы структурообразования цементных композиций, модифицированных добавками сахарозы //Инженерно-строительный журнал.2016. № 6 (66). C. 3–11. doi: 10.5862/MCE.66.1
22. Shepelenko T.S., Sarkisov U.S., Gorlenko N.P., Tsvetkov N.A., Zubkova O.A. Structure-forming processes of cement composites, modified by sucrose additions.Magazine of Civil Engineering.2016. No. 6 (66), pp. 3–11. DOI: 10.5862/MCE.66.1
23. Шепеленко Т.С., Зубкова О.А., Субботина Н.В., Лучникова Е.Е., Зыкеев Г.А. Композиционные цементы, содержащие сахарозу //Вестник Томского государственного архитектурно-строительного университета.2017. № 5. С. 151–158.
23. Shepelenko T.S., Zubkova O.A., Subbotina N.V., Luchnikova E.E., Zykeev G.A. The composite cements containing sucrose.Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel’nogo universiteta.2017. No. 5, pp. 151–158. (In Russian).

At present, to improve the quality of building materials, products and structures, it is proposed to use the existing methods of regulating the “manufacturer – builder” relationship. At the same time, there is a possibility that the introduction of new tightening measures of influence by the state in the form of burdensome mandatory confirmation of compliance of products can lead to the opposite effect – a decrease in quality. At the same time, the formation of a quality control system with due regard for the assessment of the experience and business reputation of manufacturers of construction products will increase the transparency of the market, functioning on the trust principles. This approach meets the European principles of entry into the market of construction products and contributes to the development of healthy competition, the elimination of unscrupulous manufacturers, reducing the volume of counterfeit and falsified construction products.

Yu.V. PUKHARENKO, Doctor of Sciences (Engineering), Corresponding member of RAACS (This email address is being protected from spambots. You need JavaScript enabled to view it.)
V.D. STAROVEROV, Candidate of Sciences (Engineering)
A.A. GERASIMENKO, student

St. Petersburg State University of Architecture and Civil Engineering (4, 2-d Krasnoarmeyskaya st., St. Petersburg, 190005, Russian Federation)

1. Inspections have to borrow in activity less and less weight. https://www.kommersant.ru/doc/3873378 (Date of access 27.02.2019). (In Russian).
2. Yavorskii A.A., Martos V.V., Voitovich V.A. System approach to ensuring quality of concrete works on the building site.Concrete and reinforced concrete – a prospection: scientific works of III All-Russian (II International) conferences on concrete and reinforced concrete.Moscow: 2014. Vol. 4, pp. 383–391. (In Russian).
3. Certification did not solve a cement falsification problem – the expert. https://www.radidomapro.ru/ryedktzij/proyzvodsvo-materialov/stroymateriali/sertifikatziia-ne-reschila-problemu-faligsifikatzi-63315.php (Date of access 27.02.2019). (In Russian).
4. What did obligatory certification of cement as it stands for the industry bring? http://dom.iastr.ru/biznes/1418-chto-prinesla-obyazatelnaya-sertifikaciya-cementa-v-nyneshnem-vide-dlya-otrasli.html (Date of access 25.02.2019). (In Russian).
5. Chetverik N.P. What kind of construction control do we need, or toothlessness is not needed by the construction community.Stroitel’nye Materialy, oborudovanie, teknologii XXI veka.2012. No. 9 (164), pp. 43–45. (In Russian).
6. Chetverik N.P. Construction compliance monitoring as analog of the state construction supervision.Stroitel’nye Materialy, oborudovanie, teknologii XXI veka.2012. No. 11 (166), pp. 46–49. (In Russian).
7. Bal’kin V.M. Construction compliance monitoring and building security.Vestnik SGASU. Gradostroitel’stvo I arkhitektura.2013. No. 3 (11), pp. 40–41. (In Russian).
8. Chetverik N.P. Laboratory control within construction control as the security system basis in construction.Stroitel’nye Materialy, oborudovanie, teknologii XXI veka.2011. No. 5 (148), pp. 23–24. (In Russian).
9. The annual report on activity of Federal Service for Environmental, Technological and Nuclear Supervision in 2017. Federal Service for Environmental, Technological and Nuclear Supervision. Moscow. 2018. 420 p. (In Russian).
10. Ermolina A.Yu. Selection of suppliers of material and technical resources in construction organizations.Ekonomicheskie nauki.2009. No. 8 (57), pp. 307–311. (In Russian).

Composite materials combine heterogeneous components in their composition, varying the ratio of which it is possible to obtain materials with the required set of properties. These materials include cement asphalt concrete, which is a semi-rigid composite containing thermodynamically incompatible types of binders (bitumen and cement). Taking into account that the fuel ashes to varying degrees have a positive effect on the properties of both organic and inorganic binders of hydration hardening, it is necessary to determine the stage of introduction of fuel ashes into the raw material mixture when obtaining the final material by a separate and sequential method. In this regard, the paper presents the results of a study of the variability of physico-chemical and structural features of fuel ashes, studies their activity with respect to the most chemically active component of cement asphalt-Portland cement, as well as makes a comparative analysis of the effect of ashes on the change of structural-mechanical and visco-elastic properties of bitumen. High calcium ash of Nazarovskaya TPP and low-calcium ash of Troitskaya SDPS (state district power station) were subjected to the studies. As a result of the analysis of calculated indicators of the quality of ashes and empirical data of the activity index in relation to Portland cement, the dependence of changes in these parameters on the composition and structural features of fuel ashes is established. Comparative analysis of structural and mechanical and visco-elastic properties makes it possible to establish the feasibility of each of the types of ashes depending on the changes of the temperature interval of exploitation of bitumen.

A.Yu. MARKOV, Engineer-Researcher ((This email address is being protected from spambots. You need JavaScript enabled to view it.)
V.V. STROKOVA, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
I.Yu. MARKOVA, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Belgorod State Technological University named after V.G. Shukhov (46, Kostyukova Street, Belgorod, 308012, Russian Federation)

1. Kazarnovskaya E.A., Gezentsvey L.B. Study of the properties of cement-asphalt concrete. Trudy SoyuzdorNII. 1968. No. 27, pp. 79–100. (In Russian).
2. Boguslavsky A.M., Chan Ngok Min, Dorgany V.V. and others. Cement-asphalt concrete – material for road and airfield pavements. Avtomobil’nye dorogi. 1985. No. 4, pp. 14–16. (In Russian).
3. Goglidze V.M. Poluzhestkie kompozitsionnye dorozhnye pokrytiya [Semi-rigid composite pavements]. Tbilisi: Metzneereba. 1988. 63 p.
4. Schmidt M., Vogel P. Stoffeigenschaften xon HGT mit Albeton und Altasphalt. Strassen und Tiefbau. 1988. Vol. 42. No. 1, pp. 5–10.
5. Verenko V.A., Asipenko A.A. Concretes on organohydraulic binders for arranging structural layers of pavements. Science – education, manufacturing, economics: materials of the 14th International Scientific and Technical Conference. Minsk: BNTU. 2016. Vol. 3, pp. 26–27. (In Russian).
6. Verenko V.A. Dorozhnye kompozitnye materialy. Struktura i mekhanicheskie svoistva / pod red. I.I. Leonovicha [Road composite materials. Structure and mechanical properties eddited by I.I. Leonovich]. Minsk: Navuka i tekhnka. 1993. 246 p.
7. Verenko V.A. Road concretes on organohydraulic binders (theory and practical application). Diss… Doctor of Sciences (Engineering). Minsk. 1998. 178 p. (In Russian).
8. Miroshnichenko S.I. Composite material on the complex binder for the construction of roads. Diss… Candidate of Sciences (Engineering). Belgorod. 2007. 183 p. (In Russian).
9. Kolosov A.A. Modified cement-asphalt-concrete mixtures for the repair of road coatings by the method of cement rendering. Diss… Candidate of Sciences (Engineering). Belgorod. 2003. 179 p. (In Russian).
10. Gridchin A.M., Dukhovny G.S., Miroshnichenko S.I., Logvinenko A.A. Investigation of the influence of climatic factors on the physico-mechanical characteristics of cement-asphalt concrete. Modern methods of road construction and organisation of traffic safety: an international scientific-practical Internet conference. Belgorod: BSTU. 2007, pp. 77–80. (In Russian).
11. Balabanov V.B., Nikolaenko V.L. Rolled road ash-concrete. Arkhitektura i stroitel’stvo Rossii. 2012. No. 1, pp. 19–24. (In Russian).
12. Markova I.Yu., Strokova V.V., Dmitrieva T.V. The influence of fly ash on the viscoelastic characteristics of road bitumen. Stroitel’nye Materialy [Construction Materials]. 2015. No. 11, pp. 28–31. (In Russian).
13. Strokova V.V., Markova I.Y., Dmitrieva T.V., Shiman A.A. The influence of fly ashes from power plants on rheological properties of bitumen binder. Journal of Fundamental and Applied Sciences. 2016. No. 8 (2S), pp. 1487–1498.
14. Lebedev M.S., Chulkova I.L. Study of rheological characteristics of bitumen composites with different fly ashes. Vestnik Belgorodskogo gosudarstvennogo tekhnologicheskogo universiteta im. V.G. Shukhova. 2016. No. 11, pp. 45–52.
15. Putilin E.I., Tsvetkov V.S. Putilin E.I., Tsvetkov V.S. Obzornaya informatsiya otechestvennogo i zarubezhnogo opyta primeneniya otkhodov ot szhiganiya tverdogo topliva na TES [Overview of national and foreign experience in the use of wastes from burning of solid fuels in thermal power plants]. Moscow: SouzDorNII, 2003.

The scientific bases of a comprehensive methodology of environmental assessment of man-made waste and their large-scale utilization in the production of building materials and products have been developed. Possibility to use the specified anthropogenic waste as raw materials for production of construction materials at the simultaneous solution of ecological problems of territories due to their large-scale utilization is substantiated. Technological operations, which make up the life cycle of fine marble waste, are identified and ranked. The main negative factors of formation of a large amount (about 50 thousand tons annually) of waste of various fractions are shown on the example of the Koelga white marble deposit. The properties of fine waste of white marble are given, the technology of their involvement as a raw component in the production of ceramic bricks is proposed. It is shown that the utilization of the total accumulated volume of fine waste of white marble will make it possible to produce more than 120 million pieces of ceramic bricks of different colors of the normal format. A block-scheme of the life cycle and negative environmental effects of drill cuttings placement has been developed. As an example, it is proposed to use the drilling cuttings of Bovanenkovskoye oil, gas and condensate field in the technology of production of ceramic bricks, the accumulated reserves of which are more than 1.2 million tons and occupy over 1000 hectares of land. By processing drill cuttings into ceramic bricks of semi-dry pressing it is possible to produce about 15 million pieces of bricks of normal format. Also due to the mineral and disperse composition the drill cuttings can be used in mortars and dry mixtures, the production of road bases, pavement tiles, large residues on the sieves can be used for the fiber-concrete mixture for ballasting underwater pipelines.

D.V. ORESHKIN, Doctor of Sciences (Engineering)
I.V. SHADRUNOVA, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
T.V. CHEKUSHINA Candidate of Sciences (Engineering), (This email address is being protected from spambots. You need JavaScript enabled to view it.)
A.N. PROSHLYAKOV, research scientist (This email address is being protected from spambots. You need JavaScript enabled to view it.)

N.V. Mel’nikov Institute of Comprehensive Exploitation of Mineral Resources, Russian Academy of Sciences (4, Kryukovsky tupik, Moscow, 111020, Russian Federation)

1. Oreshkin D.V. Ecological problems of integrated development of the subsoil with large-scale utilization of technogenic mineral resources and wastes in the production of building materials. Stroitel’nye Materialy [Construction Materials]. 2017. No. 8, pp. 55–63. DOI:10.31659/0585-430X-2017-751-8-55-63 (In Russian).
2. Telichenko V.I., Oreshkin D.V. Materials science aspects of geo-ecological and environmental safety in construction. Ecology of urbanized territories. Ekologiya urbanizirovannykh territoriy. 2015. No. 2, pp. 31–33. (In Russian).
3. Meshcheryakov Yu.G., Kolev N.A., Fedorov S.V., Suchkov V.P. Production of granulated phosphogypsum for the cement industry and building products. Stroitel’nye Materialy [Construction Materials]. 2009. No. 5, pp. 104–106. (In Russian).
4. Chanturia V.A., Chaplygin N.N., Vigdergauz V.E. The strategy of reducing, recycling and recycling of mining waste in research of the Russian Academy of Sciences Proceedings of the international meeting “Modern problems of complex processing of natural and man-made mineral raw materials” (Plaksinsky readings-2005). Saint Petersburg: Roza Mira. 2005, pp. 230–235.
5. Trubetskoy K.N., Kaplunov D.R. and others. Kompleksnoe osvoenie mestorozhdenii i glubokaya pererabotka mineral’nogo syr’ya [Integrated development of deposits and deep processing of mineral raw materials]. Moscow: Nauka. 2010. 437 p.
6. Chaplygin N.N. Osnovaniya ekologicheskoi teorii kompleksnogo osvoeniya nedr [The basis of the ecological theory of integrated development of mineral resources]. Moscow: IPKON RAN. 2006. 102 p.
7. Ekologicheski orientirovannaya pererabotka gornopromyshlennykh otkhodov [Environmentally oriented processing of mining waste] / Chanturia V.A. end as., Ed. V.A. Chanturia and I.V. Shadrunova, Moscow: Sputnik+. 2018, 210 p.
8. Oreshkin D.V., Papichev V.I., Zemlyanushnov D.Yu., Popov P.V. Ecological problems of the territories in the mining process and the processing of marble, their solutions. Gornyy Zhurnal. 2018. V. 40. No. 1, pp. 88–91. DOI: 10.17580/gzh.2018.01.16. (In Russian).
9. Zemlyanushnov D.Yu., Sokov V.N., Oreshkin DV, Skanavi N.A. Utilization of fine wastes of marble processing in the production of facial ceramics. Herald of ISTU. Vestnik IRGTU. 2014. No. 9 (92), pp. 122–126. (In Russian).
10. Zemlyanushnov D.Yu., Sokov V.N., Oreshkin D.V. The use of fine wastes of marble processing in the technology of facing ceramics. Scientific and Technical Bulletin of the Volga region. Nauchno-tehnicheskii vestnik Povolgiya. 2014. No. 4, pp. 108–114. (In Russian).
11. Zemlyanushnov D.Yu., Sokov V.N., Oreshkin D.V. Ecological and economic aspects of the use of fine marble waste in the production of ceramic facing materials. Vestnik MGSU. 2014. No. 8, pp. 118–126. DOI: 10.22227/1997-0935.2014.8. (In Russian)
12. Moumouni A., Goki N.G. Chaanda M.S. Geological Exploration of Marble Deposits in Toto Area, Nasarawa State, Nigeria. Natural Resources. 2016. No. 7, pp. 83–92. http://dx.doi.org/10.4236/nr.2016.72008
13. Rekus I.G., Shorina O.S. Fundamentals of ecology and environmental management. Moscow: Publishing House of MGUP. 2012. 146 p.
14. Oreshkin D.V., Sakharov G.P., Chebotaev A.N., Kurbatova A.S. Geoecological problems of disposal of drill cuttings in Yamal. Vestnik MGSU. 2012. No. 2, pp. 125–129. DOI: 10.22227/1997-0935.2012.2. (In Russian).
15. Oreshkin D.V., Chebotarev A.N., Perfilov V.A. Disposal of drilling sludge in the production of building materials. Procedia Engineering. 2015. Vol. 111, pp. 607–611.
16. Chebotaev A.N. The possibility of disposal of drill cuttings from the Bovanenkovskoye field in the production of building materials. Construction of oil and gas wells on land and at sea. Stroitel’stvo neftyanykh i gazovykh skvazhin na sushe i na more. 2015. No. 9, pp. 25–28. (In Russian).
17. Epiphany V.I. Achievements and problems of exploration and fuel and energy complex of Russia. Drilling and oil. Bureniye i neft’ .2013. No. 3, pp. 3–7. (In Russian).

The problems arising when determining the thermal conductivity of building materials for norm-setting and practical application are presented. It is shown that the thermal conductivity of the material in the dry state, determined in the laboratory, differs from the calculated thermal conductivity under operating conditions, the correct purpose of which is the most important task of modern standardization. The first part highlights the aspects which are not reflected in the current standard with the method for thermal conductivity measurement – GOST 7076–99, but which are often found in testing practice: measurement of thermal conductivity of gas-filled polymer materials and samples with high thickness, features of the instrument base when measuring the thermal conductivity, as well as proposals for actualizing this standard are formulated. The second part presents the criticism of the experimental method for determining the calculated thermal conductivity and concludes that the thermal conductivity under specified operating conditions can only be determined by calculation. The attempts to implement the standard-analogue of ISO 10456:2007 are described and the reasons for the impossibility of its application in the Russian Federation are shown. The methods for determining the calculated thermal conductivity based on the use of the coefficient of thermo-technical quality, which will form the basis of the developed National Standard “Heat-Insulating Materials and Products in Enclosing Structures of Buildings. Methods for Determining Thermo-Technical Indicators under Operating Conditions” are presented. The experimental method for determining the coefficients of the thermo-technical quality of building materials is developed and described.

P.P. PASTUShKOV^{1, 2}, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ Research Institute of Building Physics Russian Academy Architecture and Construction sciences (21, Lokomotivniy Driveway, Moscow,127238, Russian Federation)
² Institute of Mechanics Lomonosov Moscow State University (1, Michurinsky Avenue, Moscow, 119192, Russian Federation)

1. Fokin K.F. Stroitel’naya teplotekhnika ograzhday-ushchih chastej zdanij. 5-e izd. [Construction heat engineering of the enclosing parts of buildings. 5th ed.]. Moscow: AVOK-PRESS. 2006. 252 p.
2. Gagarin V.G., Pastushkov P.P. The change in time of thermal conductivity of gas-filled polymer insulating materials. Stroitel’nye Materialy [Construction Mateials]. 2017. No. 6, pp. 28–31. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2017-749-6-28-31
3. Gagarin V.G., Pastushkov P.P. Determination of the calculated moisture content of building materials. Promyshlennoe i grazhdanskoe stroitel’stvo. 2015. No. 8, pp. 28–33. (In Russian).
4. Kiselev I.Ya. Improving the accuracy of determining the thermophysical properties of insulating building materials with regard to their structure and characteristics of operational impacts. Doctor diss. (Engineering). Moscow. 2006. 366 p. (In Russian).
5. Gagarin V.G. Theory of state and moisture transfer in building materials and heat-shielding properties of enclosing structures of buildings. Doctor diss. (Engineering). Moscow. 2000. 396 p. (In Russian).
6. Kupriyanov V.N., Yuzmuhametov A.M., Safin I.Sh. The effect of moisture on the thermal conductivity of wall materials. State of the matter. Izvestiya Kazanskogo gosudarstvennogo arhitekturno-stroitel’nogo universiteta. 2017. No. 1 (39), pp. 102–110. (In Russian).
7. Kunzel H. Aerated concrete. Heat and moisture behavior. Wiesbaden. Berlin: Bauverlag. 1970. 120 p.
8. Pastushkov P.P. The influence of the moisture regime of enclosing structures with external plaster layers on the energy efficiency of thermal insulation materials. Cand. diss. (Engineering). Moscow. 2013. 169 p. (In Russian).
9. Pastushkov P.P., Gagarin V.G. Studies of the dependence of thermal conductivity and the coefficient of thermal quality on the density of autoclaved aerated concrete. Stroitel’nye Materialy [Construction Materials]. 2017. No. 5, pp. 26–28. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2017-748-5-26-28
10. Kiselyov I.YA. Features of heat transfer through mineral wool products. Academia. Arhitektura i stroitel’stvo. 2017. No. 2, pp. 103–105. (In Russian).

On the example of small and medium-sized historical cities of Nizhny Novgorod Oblast (former county towns and commercial-industrial villages) the article deals with regional varieties of “brick style” of the turn of XIX–XX centuries. The preconditions of its wide distribution connected with the original traditions of brick production on the basis of local raw materials and aesthetic preferences of customers from merchants and peasants are revealed. The regularities of the use of “brick style” in the architecture of county towns, where it is represented by separate public and industrial buildings, and large commercial-industrial villages, in the residential development of which it has become a mass phenomenon, are determined. It is established that the local features of the “brick style”, due to the traditions of decorativeness, rooted in folk architecture and artistic crafts of the Nizhny Novgorod Province, clearly manifested in the architecture of estates and mansions of commercial-industrial villages. Most of these objects were built without the participation of architects with academic education, by the forces of hereditary builders-contractors, collecting artels. Having developed a certain range of decorative forms, the master-masons created many new options for the design of facades that determined the morphological and stylistic diversity of the houses. The construction of public and industrial buildings in the “brick style”, on the contrary, was the sphere of activity of professional architects, which confirms the authorship of architects of Nizhny Novgorod established for a number of objects. Here the predominance of rationalistic tendencies dictated by considerations of practical usefulness and utility is revealed. The singularity of church buildings is noted (in contrast to provincial cities and ordinary villages). The relevance of studying the “brick style” in connection with the preservation of regional traditions of red brick construction is emphasized.

A.V. LISITSYNA, Candidate of Architecture (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Nizhny Novgorod State University of Architecture and Civil Engineering (65, Il’inskaya Street, Nizhny Novgorod, 603950, Russian Federation)

1. Khudin A.A. Eklektika [Eclecticism]. Nizhny Novgorod: Begemot. 2017. 256 p.
2. Inchik V.V. “Brick style” and getting the front brick in St. Petersburg province in the XIX century. Vestnik grazhdanskikh inzhenerov. 2018. No. 5, pp. 117–122. DOI: 10.23968/1999-5571-2018-15-5-117-122 (In Russian).
3. Gel’fond A.L. The concepts of creation of a comfortable urban environment of small historic cities. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2018. No. 12, pp. 31–35. (In Russian).
4. Kirichenko E.I. Russkaya arkhitektura 1830–1910 godov [Russian architecture of 1830–1910]. Moscow: Iskusstvo. 1978. 400 p.
5. Gorodetskii raion: illyustrirovannyi katalog pamyatnikov istorii i kul’tury. Pod red. A.V. Lisitsynoi [Gorodetsky district: an illustrated catalogue of historical and cultural monuments. Edited by A.V. Lisitsyna]. Nizhny Novgorod: Kvarts. 2013. 504 p.
6. Lisitsyna A.V., Kabatova V.N. Portret vremeni: Arkhitektura goroda Bogorodska Nizhegorodskoi oblasti [Portrait of time: architecture of the town of Bogorodsk in the Nizhny Novgorod region]. Nizhny Novgorod. 2008. 144 p.
7. Illyustrirovannyi katalog ob”ektov kul’turnogo naslediya (pamyatnikov istorii i kul’tury), raspolozhennykh na territorii Pavlovskogo raiona Nizhegorodskoi oblasti. Pod red. A.V. Lisitsynoi [Illustrated catalogue of cultural heritage objects (historical and cultural monuments) located on the territory of Pavlovsky district of Nizhny Novgorod region. Edited by A.V. Lisitsyna]. Nizhny Novgorod: Kvarts. 2015. 560 p.
8. Krylova O.F. “Brick style” of the mid XIX – early XX centuries in the architecture of Pavlovo. Privolzhskii nauchnyi zhurnal. 2016. No. 3, pp. 80–85. (In Russian).
9. Illyustrirovannyi katalog ob”ektov kul’turnogo naslediya (pamyatnikov istorii i kul’tury), raspolozhennykh na territorii Lyskovskogo raiona Nizhegorodskoi oblasti. Pod red. A.L. Gel’fond [Illustrated catalogue of cultural heritage objects (historical and cultural monuments) located on the territory of Lyskovsky district of Nizhny Novgorod region. Edited by A.L. Gel’fond]. Nizhny Novgorod: Kvarts. 2016. 520 p.
10. Gradostroitel’stvo Rossii serediny XIX – nachala XX veka. Kn. 2. Pod. red. E.I. Kirichenko [The urban planning of Russia in the mid XIX – early XX centuries. Vol. 2. Edited by E.I. Kirichenko]. Moscow: Progress-Traditsiya. 2003. 560 p.
11. Bubnov Yu.N. Arkhitektura Nizhnego Novgoroda serediny XIX – nachala XX veka [Architecture of Nizhny Novgorod in the mid XIX – early XX centuries]. Nizhny Novgorod: Volgo-Vyatskoe knizhnoe izdatel’stvo. 1991. 176 p.
12. Krylova O.F. The evolution of the “brick style” in the architecture of Nizhny Novgorod in the mid XIX – early XX centuries. Privolzhskii nauchnyi zhurnal. 2017. No. 1, pp. 96–100. (In Russian).
13. Arzamas: illyustrirovannyi katalog pamyatnikov istorii i kul’tury. Pod red. A.L. Gel’fond [Arzamas: an illustrated catalogue of historical and cultural monuments. Edited by A.L. Gel’fond]. Nizhny Novgorod: Kvarts. 2013. 528 p.
14. Balakhninskii raion: illyustrirovannyi katalog pamyatnikov istorii i kul’tury. Pod red. E.V. Khodakovskogo [Balakhninsky district: an illustrated catalogue of historical and cultural monuments. Edited by E.V. Khodakovsky]. Nizhny Novgorod: Kvarts. 2011. 224 p.
15. Gubanov A.V., Boroznov S.A. To the question of studying the types of volume-spatial solutions of state wine warehouses in the late XIX – early XX centuries. Vestnik Permskogo natsional’nogo issledovatel’skogo politekhnicheskogo universiteta. Stroitel’stvo i arkhitektura. 2014. No. 1, pp. 16–32. (In Russian).

The reasons for the formation of a brown plaque on a light clinker brick for paving (white, light gray) during operation are studied. Tests of brick were conducted, its mineralogical composition was determined, the nature of the secondary color of the bricks and materials of the base when laying brick were studied. There are two reasons for the formation of plaque associated with laying bricks. The area on which clinker brick was laid was characterized by the level of mineralized groundwater close to the surface, and evaporation of moisture from the surface prevailed over its absorption by the soil in the warm season of the year. I.e., all dissolved in the ground water salts migrated to the surface of the bricks through well permeable sandy masonry joints between products. The base under the bricks contained ferruginous minerals, particularly hematite, when hydrating which the hydroxides of iron were formed. Hematite also reacted with sulphates in groundwater with the formation of ferric sulphates. This confirms the higher sulfur content in areas with plaque and the presence of a film similar to crystalline hydrates. The analysis of the studies conducted made it possible to develop recommendations for performance of paving works with clinker bricks, to develop measures for elimination of already available plaque. The results of the studies proved that the loss of the aesthetic appearance of the clinker bricks for paving was caused not due to poor quality of brick, but the imperfection of the technology of its laying.

V.D. KOTLYAR¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
Yu.V. TEREKHINA¹, Engineer (This email address is being protected from spambots. You need JavaScript enabled to view it.)
A.V. KOTLYAR¹, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
R.A. YASHCHENKO¹, Engineer (This email address is being protected from spambots. You need JavaScript enabled to view it.)
Yu.V. POPOV², Candidate of Sciences (Geology and Mineralogy) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ Don State Technical University (1, Gagarina Square, Rostov-on-Don, 344010, Russian Federation)
² Southern Federal University (105/42, Bolshaya Sadovaya Street, Rostov-on-Don, 344006, Russian Federation)

1. Kotlyar V.D., Terekhina Yu.V., Kotlyar A.V. Features of properties, application and requirements to a clinker brick. Stroitel’nye Materialy [Construction Materials]. 2015. No. 4, pp. 72–74. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2015-724-4-72-74
2. Schlegel I.F. About rational application of a clinker brick (as discussion). Stroitel’nye Materialy. [Construction Materials]. 2017. No. 8, pp. 42–44. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2017-751-8-42-43
3. Ezerskii V.A. Clinker. Technology and properties. Stroitel’nye Materialy. [Construction Materials]. 2011. No. 4, pp. 79–81. (In Russian).
4. Korepanova V.F., Grindfeld G.I. Production of a clinker brick at Nikolsky brick-works of the LSR Group. Stroitel’nye Materialy [Construction Materials]. 2014. No. 4, pp. 10–13. (In Russian).
5. Kara-sal B.K.O., Seren Sch.V., Sat D.H.O Clinker brick on the basis of nonconventional materials. Izvestiya vysshikh uchebnykh zavedenii. Stroitel’stvo. 2018. No. 4 (712), pp. 51–58. (In Russian).
6. Kotlyar A.V. Technological properties the argillitopodobnykh of clays by production of a clinker brick. Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel’nogo universiteta. 2016. No. 2 (55), pp. 164–175. (In Russian).
7. Kotlyar A.V., Lapunova K.A., Lazareva Y.V., Orlova M.E. Effect of Argillites Reduction Ratio on Ceramic Tile and Paving Clinker of Low-Temperature Sintering. Materials and Technologies in Construction and Architecture. Materials Science Forum Submitted. 2018. No. 931, pp. 526–531.
8. Yacenko N.D., Golovanova S.P. Whiteness of minerals of ceramics and clinker of the white portlandtsement depending on the content of chromophores. Prom-Engineering: works of the international scientific and technical conference. FGBOU VPO “southern Ural State University” (national research university). 2015. pp. 136–140.
9. Bozhko Yu.A. Technological and esthetic features of a brick brick in modern architecture. Vestnik nauki i obrazovaniya Severo-Zapada Rossii. 2017. Vol. 3. No. 1, pp. 148–153. (In Russian).