A.A. SEMYONOV, Candidate of Sciences (Engineering), General Manager (info@gs-expert.ru) «GS-Eхpert», ООО (18, office 207, the 1st Tverskoy-Yamskoy Lane, 125047, Moscow, Russian Federation)

The State of the Russian Market of Ceramic Wall Materials
The state of the industry of ceramic wall materials in Russia is analyzed. Data on available production capacities, volumes, regional and commodity structures of ceramic wall materials production are presented. It is shown that the part of the analyzed products totals about 50% of the total consumption of piece wall materials. Two scenarios of prognosis of ceramic wall materials market development in Russia in 2014–2016 are presented.

Keywords: statistics, analysis of market, ceramic wall materials.

А.Yu. STOLBOUSHKIN, Candidate of Sciences (Engineering) (stanyr@list.ru) Siberian State Industrial University (42, Kirova Street, Kemerovo region, Novokuznetsk, 654007, Russian Federation)

Influence of the Wollastonite Additive on the Structure of Wall Ceramic Materials from Technogenic and Natural Resources
The results of investigations of the possibility of application of wollastonite ore as a corrective additive in ceramic charge based on technogenic and natural materials is offered in cur­ rent paper. It has been established the total number of acicular particles after grinding wollastonite ore and the dependence of their shape on the size fractions. It was revealed that the grinding of wollastonite additive leads to decrease of the firing shrinkage for all types of used raw materials. The influence of fine wollastonite ore additives on the structure formation of wall ceramic materials produced from the tailings of the slimy iron ore, waste coal and Novokuznetsk’s loam were found. During the liquid phase sintering process, wollastonite acicular particles perform the reinforcing role and influence positively on the process of structure formation of pottery clay raw materials and waste coal. The introduction of wollastonite addi­ tives in charge of slimy iron ore wastes impairs the physical and mechanical properties of wall ceramics within the absence of clay minerals.

Keywords: iron ore wastes, coal wastes, wollastonite ore, structure forming, wall ceramic materials.

References
1. Tyul’nin V.A., Tkach V.R., Eirikh V.I., Starodub tsev N.P. Vollastonit – unikal’noe mineral’noe syr’e mnogotselevogo naznacheniya. [Wollastonite – unique mineral for all-purpose use]. Мoscow: Publishing House «Ruda i metally». 2003. 144 p. (In Russian).
2. Ciullo P., Robinson S. Wollastonite – versatile func tional filler. Paint and Coatings Industry. 2009. No. 11, pp. 50.
3. Kozyrev V.V. Raw source of wollastonite for ceramic in dustry. Building materials industry. Series 5. Ceramic in dustry: Review info. М.: VNIIESM. 1989, Isssue 2, pp. 1–68. (In Russian)
4. Rokhvarger E.L., Belopol’skii M.S., Dobuzhinskii V.I. etc. Novaya tekhnologiya keramicheskikh plitok. [New technologies of ceramic tiles]. Мoscow: Stroizdat. 1997. 232 p. (In Russian).
5. Matveev M.A., Nurullaev Z.P. About application of wol lastonite for front effective ceramic production. Sbornik trudov VNIIStrom [VNIIStrom Proceedings]. 1968, Issue 13, pp. 12–22. (In Russian).
6. Stolboushkin А.Yu., Storozhenko G.I. The use of slime iron-ore waste of Kuzbass in technology of wall ceramic materials. Stroitel’nye Materialy [Construction Materials]. 2009. No. 4, pp. 77–80. (In Russian).
7. Stolboushkin А.Yu., Ivanov А.I., Druzhinin S.V., etc. Pore structure characterristics of wall ceramics made from waste coal. Stroitel’nye Materialy [Construction Materials]. 2014. No. 4, pp. 46–51. (In Russian).
8. Karapet’yants M.Kh. Obshchaya i neorganicheskaya khi miya [General and inorganic chemistry]. Мoscow: Chemistry. 1981. 632 p. (In Russian).
9. Stolboushkin А.Yu. Theoretical bases of ceramic matrix composites forming based on technogenic and natural raw materials. Stroitel’nye Materialy [Construction Materials]. 2011. No 2, pp. 10–13. (In Russian).
10. Kurczyk H.G. Diopsid and wollastonite synthetische Rohstoffe fur die Keramik. 11. Anwendung von synthe tischen Erdalkalisilicaten in keramischen Massen. Berichte der Deutschen Keramischen Gesellschaft. 1978. Vol. 55. No. 5, pp. 262–265.

A.P. ZUBEKHIN, Doctor of Sciences (Engineering), A.V. VERCHENKO, Engineer, N.D. YATSENKO, Candidate of Sciences(Engineering) (natyacen@yandex.ru) South-Russian State Polytechnic University named after M.I. Platov (132 Prosveshcheniya St., Novocherkassk, Rostov Region, 346428, Russian Federation)

Dependence of Porcelain Stoneware Strength on its Phase Composition
Results of the study of strength characteristics of ceramic granite with the use of porcelain clays, alkaline kaolin, zeolite tuff and gabbro­diabase depending on its phase composition are considered. It is established that the strength of ceramics is predetermined by the amount of crystalline and X­ray amorphous phases, favouring the formation of a single conglomerate.

Keywords:porcelain stoneware, crystalline phase, glass phase, metakaolinite, strength.

References
1. Khimicheskaya tekhnologiya keramiki [Chemical tech nology of ceramics]. Edited by Guzman I.Ya. Moscow: «Stroimaterialy». 2012. 496 p.
2. Zubekhin A.P., Yatsenko N.D. Theoretical bases of in novative technologies of construction ceramics. Stroitel’nye Materialy [Construction Materials]. 2014. No. 1–2, pp. 89–92. (In Russian).
3. Salakhov A.M., Salakhova R.A. Keramika vokrug nas [Ceramic around us]. Moscow: «Stroimaterialy». 2008. 160 p.
4. Baucia J.A., Koshimizu Jr.L., Giberton C., Morelli M.R. Estudo de fundentes alternativos para uso em formulações de porcelanato. Cerâmica. 2010. No. 56, pp. 262–272.
5. Ryshchenko M.I., Fedorenko E.Yu., Chirkina M.A. etc. Microstructure and properties of low-temperature porcelain. Steklo i keramika. 2009. No. 11, pp. 26–29. (In Russian).
6. Borkoev B.M. Study of the structure and properties of low-temperature firing porcelain. Mezhdunarodnyi zhur- nal eksperimental’nogo obrazovaniya. 2012. No. 6, pp. 98–100. (In Russian).
7. Zubekhin A.P., Verchenko A.V., Galenko A.A. Manufacture of ceramic granite on the basis of zeolite containing batches. Stroitel’nye Materialy [Construction Materials]. 2014. No. 4, pp. 52–54. (In Russian).
8. Brykov A.S. Khimiya silikatnykh i kremnezemsoder zhashchikh vyazhushchikh materialov [Chemistry silicate binders and siliceous materials]. Saint-Petersburg: SPbGTI(TU). 2011. 147 p.

A.I. NIKITIN¹, General Manager (nikitin-dekarta@mail.ru); G.I. STOROZHENKO², Doctor of Sciences (Engineering), Director; L.K. KAZANTSEVA ³ , Doctor of Sciences (Engineering); V.I. VERESHCHAGIN ⁴ , Doctor of Sciences (Engineering)
1 OOO «Baskei Keramik» (1b, Stepana Razina Street, Chelyabinsk, 454111, Russian Federation)
2 OOO «Baskei» (4a, Inzhenernaya Street, Novosibirsk, 630090, Russian Federation)
3 Institute of Geology and Mineralogy, SB RAS (3, Koptyug Prospect, Novosibirsk, 630090, Russian Federation)
4 National Research Tomsk Polytechnic University (30, Lenin Avenue, Tomsk, 634050, Russian Federation)

Heat-Insulating Materials and Products on the Basis of Tripolis of Potanin Deposit
Production of granulated foam materials on the basis of one­stage technology from tripolis of Potanin Deposit without preliminary melting in glass has been organized at “Baskey Ceramic” Enterprise in Chelyabinsk Oblast. Production of heat­insulating products is based on the synthesis of hydrated polymer sodium silicates (Na₂O∙mSiO₂∙nH₂O) in alkali composi­ tions on the basis of siliceous rocks with the following thermal processing of semi­finished product and obtaining of a final product – porous granules of cellular structure. Depending on conditions of tripoli treatment, “Baskey Ceramic” produces granulated heat­insulating material with different poured density from 180 up to 400 kg/m ³. At present technologies of production of piece heat­insulating products – blocks, slabs and panel – are developed.

Keywords: foam glass, granulate, tripoli, heat­insulating material.

References
1. Ivanov K.S. Insulating material for thermal stabilization of soils. Kriosfera Zemli. 2011. Vol. XV. No. 4, pp. 120– 122. (In Russian).
2. Kaz’mina O.V., Vereshchagin V.I., Semukhin B.S., Abiyaka A.N. Low-temperature synthesis of glass granulate batches based on siliceous components for foam. Steklo i keramika. 2009. No. 10, pp. 5–8. (In Russian).
3. Ketov P.A. Production of construction materials from hydrated polysilicates. Stroitel’nye Materialy [Construction Materials]. 2012. No. 11, pp. 22–24. (In Russian).
4. Kazantseva L.K., Storozhenko G.I., Nikitin A.I., Kiselev G.A. Heat insulators based on silica clay raw materials. Stroitel’nye Materialy [Construction Materials]. 2013. No. 5, pp. 85–89. (In Russian).
5. Kazantseva L.K. Particulars of foam glass manufacture from zeolite-alkali batch. Glass and Ceramics. 2013. Vol. 70. Issue 7–8, pp. 277–281.

D.R. DAMDINOVA¹, Doctor of Sciences (Engineering) (damdinova@mail.ru), N.N. ANCHILOEV¹, Engineer; V.E. PAVLOV², Candidate of Sciences (Engineering)
1 East Siberia State University of Technology and Management (40V, Klyuchevskaya Street, Ulan-Ude, 670013, Republic of Buryatia, Russian Federation)
2 Autonomous institution «State Examination of the Republic of Buryatia» (35, Krasnoarmeiskaya Street, Ulan-Ude, 670034, Republic of Buryatia, Russian Federation)

Foam Glasses of Cullet – Clay – Sodium Hydroxide System: Compositions, Structures and Properties
A new approach to the design of compositions of multi­component aluminoo­silicate batch for producing the foam glass with improved strength characteristics is considered. Prediction of structure and properties of foam glasses on the basis of cullet, clays, alkali component and gas­forming agents is made with the use of physical­chemical methods of study: X­ray phase analy­ sis, electronic microscopy as well as with the involvement of the method of mathematical planning of experiment. Study of the phase composition of the original clay raw materials and foam glass has been conducted. It is established that in case of foam glasses of the cullet – clay – sodium hydroxide system the incorporation of 2–3% of carbonate and carbon gas­forming agents into the batch (over the dry batch mass) leads to the increase of average density of foam glass and, as a consequence, its strength. When using limestone improving the physical­mechanical properties of foam glass can be explained by crystallization of omphacite. When using anthracite the growth of density and strength of foam glasses is mainly due to the improvement of porous structure of the material. The results obtained contribute to the expansion of the sphere of foam glass application, as a structural­heat insulating material, for example.

Keywords: foam glass, limestone, anthracite, omphacite, X­ray phase analysis.

References
1. Beregovoy V.A., Korolev E.V., Proshina N.A., Berego voy A.M. Methods of selection and substantiation of compo nent composition of raw mixes for production of heat insulation foam claydite-concretes. Stroitel’nye Materialy [Construction Materials]. 2011. No. 6, pp. 66–59. (In Russian).
2. Ketov A.A. Preparation of construction materials from hydrated polysilicates. Stroitel’nye Materialy [Construc tion Materials]. 2012. No. 11, pp. 22–24. (In Russian).
3. Vavrenyuk S.I., Abramov V.E. Volcanic glass of Primorskiy Krai – the raw material for producing foamed glass. Vestnic VSGUTU. 2012. No. 2 (37), pp. 198–200. (In Russian).
4. Kazantseva L.K., Storozhenko G.I., Nikitin A.I., Kiselev G.A. Heat insulators based on silica clay raw materials. Stroitel’nye Materialy [Construction Materials]. 2013. No. 5. pp. 85–88. (In Russian).
5. Patent RF 2503647. Sposob polucheniya stroitel’nogo ma teriala [A method for producing a building material]. Damdinova D.R., Pavlov V.E., Davletbaev M.A., Alekseeva E.M. Declared 06.08.2012. Published 10.01.2014. Bulletin No. 1. (In Russian).
6. Stakhovskaya N.E., Chervonyi A.I. Foam glass from un sorted scrap glass. Stroitel’nye Materialy [Construction Materials]. 2012. No. 11, pp. 24–28. (In Russian).
7. Tatsuki Tsu-Mory. Omphacite-diopside vein in an om phacitite block from the Osayama serpentinite melange, Sangun-Renge metamorphic belt, southwestern Japan. Mineralogical Magazine. 1997. Vol. 61, pp. 845–852.

O.V. KAZ’MINA, Doctor of Sciences (Engineering) (kazmina@tpu.ru), V.I. VERESHCHAGIN, Doctor of Sciences (Engineering) National Research Tomsk Polytechnic University (30 Lenin Avenue, Tomsk, 634050, Russian Federation)

Methodological Principles of Synthesis of Foam-Glass-Crystal Materials According to Low-Temperature Technology *
The research in possibility to regulate the process of producing foam­glass­crystal materials from low­temperature quenched cullet by means of optimization of the composition and structure of the material is presented. Optimal values of validity criteria of compositions of batch, granulates, and foam­forming mixes for producing the finished material are estab­ lished. It is shown that the strength of foam­glass­crystal material depends on its micro­and macrostructures stipulated by viscosity and temperature conditions as well as on the pres­ ence of crystal phase particles in the interpore partition.

Keywords: foam­glass­crystal material, strength, low­temperature synthesis, macrostructure, crystal phase.

References
1. Chul-Tae Lee. Production of alumino-borosilicate foamed glass body from waste LCD glass. Journal of Industrial and Engineering Chemistry. 2013. Vol. 19, pp. 1916–1925.
2. Fernandes H., Andreola F., Barbieri L., Lancellotti I., Pascual MJ., Ferreira JMF. The use of egg shells to pro duce cathode ray tube glass foams. Ceramics International. 2013. Vol. 39, pp. 9071–9078.
3. Guo H.W., Gong Y.X., Gao S.Y. Preparation of high strength foam glass-ceramics from waste cathode ray tube. Materials Letters. 2010. Vol. 64, pp. 997–999.
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. Yatsenko E.A., Smolii V.A., Kosarev A.S., Dzyuba E.B., Grushko I.S., Gol’tsman B.M. Physical-chemical prop erties and structure of foamed slag glass based on thermal power plant wastes. Glass and Ceramic. 2013. Vol. 70. No. 1–2. pp. 3–6.
6. Damdinova D.R., Pavlov V.E., Alekseeva E.M. Foam glass as the base for facing materials with controlled po rous structure. Stroitel’nye Materialy [Construction Materials]. 2012. No. 1, pp. 44–45. (In Russian).
7. Kaz’mina O.V., Vereshchagin V.I., Abiyaka A.N. Expansion of raw materials base for production of foam-glass-crystal materials. Stroitel’nye Materialy [Construction Materials]. 2009. No. 7, pp. 54–56. (In Russian).
8. Kaz’mina O.V., Vereshchagin V.I., Semukhin B.S., Abiyaka A.N. Low-temperature synthesis of the quenched cullet from the silica-based batch in production of foam materials. Glass and Ceramics. 2009. Vol. 66. No. 9–10, pp. 341–344.
9. Elistratova A.V, Kaz’mina O.V. Investigation of the in fluence of crystallization processes on the properties of foam glass-ceramic materials. Izvestiya vysshikh ucheb nykh zavedenii. Fizika. 2013. Vol. 56. No. 12/2, pp. 105– 109. (In Russian).
10. Kaz’mina O.V., Vereshchagin V.I., Semukhin B.S., Mukhortova A.V., Kuznetsova N.A. Effect of crystalline phase partitioning interporous strength glass crystalline foam. Izvestiya vysshikh uchebnykh zavedenii. Fizika. 2011. Vol. 54. No. 11/3, pp. 238–241. (In Russian).

B.Ya. TROFIMOV, Doctor of Sciences (Engineering) (tbya@mail.ru, L.Ya. KRAMAR, Doctor of Sciences (Engineering), South Ural State University (National Research University) (76, Lenina Ave., 454080, Chelyabinsk, Russian Federation)

Deformations and Durability of Concrete During Cyclic Freezing
Theoretical substantiation and experimental verifications of reasons for frost aggression in concrete are presented. Features of effect of freezing in salt solutions on the cement stone and concrete are considered. It is shown that the requirements of standards to ensure the air entrainment in the course of production of frost­resistant road and hydraulic concretes are not always effective for high­strength concretes. It is established that to ensure the frost resistance of high­strength concretes without air entrainment, the low water­cement­ratio and the use of active mineral additives which favour the formation of low­basic calcium hydro­silicates of the gel­like structure resistant to leaching are necessary.

Keywords: road concrete, hydraulic concrete, frost­resistance, cyclic freezing and thawing, air entrainment, ice formation, porosity, deformation, active mineral additives.

References
1. Nili M., Ehsani A., Shabani K. Influence of nano-SiO2 and micro-silica on concrete performance. Proceeding Second International Conference on Sustainable Construction Materials and Technologies. June 28–30 (2010). Universita Ploitecnica delle marchs, Ancona, Italy, 2010, рр. 1–5. (In Russian).
2. Palecki S. Influence of ageing on the Frost salt resis tance of High Performance Concrete. International Conference on Building Materials, 18-th ibausil. 2012, рр. 2–61. (In Russian).

L.A. URKHANOVA¹, Doctor of Sciences (Engineering) (urkhanova@mail.ru), S.A. LKHASARANOV¹, engineer, S.P. BARDAKHANOV ², Doctor of Sciences (Physics and Mathematics)
1 East Siberia State University of Technology and Management (40 B, structure 1, Klyuchevskaya Street, 670013, Ulan-Ude, Russian Federation)
2 Institute of Theoretical and Applied Mechanics, Siberian Branch of Russian Academy of Sciences (4/1, Institutskaya Street, 630090, Novosibirsk, Russian Federation)

Modified Concrete with Nano-Disperse Additives
Issues of the use of nano­disperse silica (NS) obtained at the electron accelerator in the technology of binders and concrete are considered. The comparative analysis of efficiency of using NS in cement with the industrially produced pyrogenic NS “HDK H20 Wacker” is presented. Indexes of specific electric conductivity and pH of water with additives Tarkosil­05 and Tarkosil­20 are determined by the method of conductometry. The change in the phase composition and microstructure of cement stone is shown with the help of RFA and EMA methods. Concrete compositions with NS with improved physical­mechanical and construction­operational characteristics are produced.

Keywords: modified concrete, nano­silica, microstructure, hydration.

References
1. Chernyshev E.M., Artamonova O.V., Slavcheva G.S. Conceptions and bases of nano-modification technolo gies of building composites structures. Part 2: On the problem of conceptual models of nano-modifying the structure. Stroitel’nye Materialy [Construction Materials] 2014. № 4, рр. 73–83. (In Russian).
2. Bazhenov Yu.M., Lukuttsova N.P., Matveeva E.G. Research of influence of nanomodified additives on the strength and structural parameters of fine grained concrete. Vestnik MGSU. 2010. № 2, pp. 215–218. (In Russian).
3. Pukharenko Yu.V., Aubakirova I.U., Nikitin V.A., Letenko D.G., Staroverov V.D. Modification of cement composites by mixed nanocarbon materials of the fuller oid type. Tekhnologii betonov. 2013. № 12 (89), pp. 13– 15. (In Russian).
4. Bhuvaneshwari B., Saptarshi Sasmal, Baskaran T., Iyer Nagesh R. Role of Nano Oxides for Improving Cementitious Building Materials. Journal of Civil Engineering and Science. 2012. Vol. 1. Issue 2, pp. 52–58.
5. Quercia G. Hüsken G. Brouwers H.J.H. Water demand of amorphous nano silica and its impact on the workabil ity of cement paste. Cement and Concrete Research. 2012. Vol. 42, pp. 344–357.
6. Nomoyev A.V., Lygdenov V. Ts. Influence of nanopow der of dioxide of silicon on wear resistance of a paint and varnish covering. Nanotekhnologii v stroitel’stve: scientific Internet-journal. 2010. No. 3, pp. 19–24. http://www. nanobuild.ru/magazine/nb/Nanobuild_3_2010.pdf (date of the address 22.07.2014).
7. Urkhanova L.A. Bardakhanov S.P., Lkhasaranov S.A. Beton of the increased durability on composite knitting. Stroitel’nye Materialy [Construction Materials] 2011. № 4, pp. 23–25. (In Russian).
8. Pavlenko N.V., Bukhalo A.B., Strokova V.V., Nelyubo va V.V., Sumin A.V. Nanocrystalline components based modified binder for cellular composites. Stroitel’nye ma terialy [Construction materials] 2013. № 2, pp. 20–25. (In Russian).

V.N. MORGUN¹, Candidate of Sciences (Engineering) (morgun_vlad@bk.ru); P.N. KUROCHKA², Doctor of Sciences (Engineering), A.Yu. BOGATINA ², Candidate of Sciences (Engineering); L.V. MORGUN³ , Doctor of Sciences (Engineering), E.E. KADOMTSEVA³, Candidate of Sciences (Engineering)
1 Academy of Architecture and Arts of the Southern Federal University (105/42, Bolshaya Sadovaya Street, Rostov-on-Don, 344006, Russian Federation)
2 Rostov State Transport University (2, Rostovskogo Strelkovogo Polka Narodnogo Opolcheniya Square, Rostov-on-Don, 344038, Russian Federation)
3 Rostov State University of Civil Engineering (162, Sotcialisticheskaya Street, Rostov-on-Don, 344022, Russian Federation)

Issues of Bar Reinforcement Bond with Concrete and Fiber Concrete
An analysis of requirements to properties of modern reinforced concrete structures operating under the influence of reversal and dynamic loads shows that low tensile strength of con­ cretes is a system shortcoming which predetermines their limited operating reliability. The most modern method of reducing negative sequences of this shortcoming is dispersal rein­ forcement of concretes with fibers. Results of the experimental studies of the influence of dispersal reinforcement with synthetic fibers on the bond strength of bar metal and glass­plas­ tic armature with concrete and fiber concrete are presented. It is shown that in spite of the fact the incorporation of conglomerate structure of synthetic fibers into the concrete compo­ sition leads to reducing its compression strength the bond between bar reinforcement and fiber concrete increases. This result makes it possible to predict the increase in energy consumption for destruction of building products made of fiber concrete reinforced with bar reinforcement.

Keywords: concrete of conglomerate structure, fiber concrete, bond strength, metal bar reinforcement, glass plastic bar reinforcement.

References
1. Rabinovich F.N. Kompozity na osnove dispersno armirovan nykh betonov. Voprosy teorii i proektirovaniya, tekhnologi ya, konstruktsii. [Composites based on dispersion-reinforced concrete. Theory and projection questions, technology, de signs]. Monograph. Moscow: ASV. 2004. 560 p.
2. Kheintts A. Fibrous concrete. Application prospects. Beton i zhelezobeton. Oborudovanie. Materialy. Tekhnologii. Yearbook.2009. No. 2, pp. 92 – 94. (In Russian).
3. Talantova K.V., Mikheev N.M. Stalefibrobeton i konstrukt sii na ego osnove. [Steel fiber concrete and designs on his basis.] Monograph. St. Petersburg: PGUPS. 2014. 280 p.
4. Morgun L.V., Morgun V.N., Smirnova P.V., Batsman M.O. Dependence of the speed of formation of foam concrete structure on the temperature of the raw materi als. Stroitel’nye Materialy [Construction Materials]. 2008. No. 6, pp. 50 – 52. (In Russian).
5. Petrova T.M., Sorvacheva Yu.A. Internal corrosion of concrete as a factor reducing the durability of objects of transport construction. Nauka i transport. Transportnoe stroitel’stvo. 2012. No. 4, pp. 56 – 60. (In Russian).
6. Stark J. Alkali-Kieselsaure-Reaktion. F.A. Finqer insti tute fur Baustoffkunde. 2008. 139 p.
7. Upravlenie protsessami tekhnologii, strukturoi i svoistvami betonov. [Management of technology processes, structure and properties of concrete]. Edited by E.M. Chernyshev, E.I. Shmit’ko. Voronezh: VGASU. 2002, pp. 78 – 124.
8. Gerega A.N., Vyrovoi V.N. Management properties of composite materials. Percolation approach. Vestnik OGASA. 2005. No. 20, pp. 56 – 61. (In Russian).
9. Morgun L.V., Morgun V.N., Pimenova E.V., Smirnova P.V., Nabokova Ya.S. Possibility of using non-autoclaved fibrous-foam concrete in large-panel housing construc tion. Stroitel’nye Materialy [Construction Materials]. 2011. No. 3, pp. 19 – 21. (In Russian).
10. Rozental’ N.K. Corrosion and protection of concrete and reinforced concrete structures of wastewater treatment plants. Beton i zhelezobeton. 2011. No. 2, pp. 78 – 85. (In Russian).
11. RILEM Recommendations for the Testing and Use of Constructions Materials. 1994. 618 р.

M.S. YELSUFYEVA, Engineer, V.G. SOLOVYEV, Candidate of Sciences (Engineering), A.F. BURYANOV, Doctor of Sciences (Engineering) (rga-service@mail.ru) Moscow State University of Civil Engineering (26, Yaroslavskoe Highway, Moscow, 129337, Russian Federation)

The use of Expanding Additives in Steel Fiber Concrete
Results of the study of influence of expanding additives on deformations and strength properties of steel fiber concrete are presented. It is established that the introduction of various expanding additives multi­directionally influences on deformations of steel fiber concrete depending on the matrix strength and reinforcement coefficient and makes it possible to pro­ duce the composites with their own deformation within the limits from ­0.084 up to 0.271 mm/m at the age of 28 days. Dependences of strength properties of steel fiber concretes with expanding additives on the values of finite deformations are determined. The optimal complex use of expanding additives (10% of cement mass) and steel fiber in composite composi­ tions makes it possible to increase additionally their compressive strength up to 18.4% and the bending tensile strength up to 16.3%. The effect obtained is explained by the occurrence of a pre­stressed fiber frame in the matrix of composite material, formation of which is possible under certain conditions.

Keywords: steel fiber concrete, expanding additive, deformations, pre­stressed fiber frame.

References
1. Titov M.Y. Concretes with increased strength on the basis of expanding additives. Stroitel’nye Materialy [Construction Materials]. 2012. No. 2, pp. 84–86. (In Russian).
2. Zvezdov A.I., Budagyants L.I. Once again about the na ture of the expansion of concrete on the basis of self stressing cement. Beton i zhelezobeton. 2001. No. 4, pp. 3–5. (In Russian).
3. Rabinovich F.N. Kompozity na osnove dispersno armirovannykh betonov [The composites on the basis of dispersed-reinforced concretes]. Moscow: ASV. 2011. 642 p.
4. Solovyev V.G., Buryanov A.F., Yelsufyeva M.S. Features of the production of steel fibre concrete products and designs. Stroitel’nye Materialy [Construction Materials]. 2014. No. 3, pp. 18–21. (In Russian).

B.S. BATALIN , Doctor of Sciences (Engineering), Counsellor of RAACS, M.P. KRASNOVSKIKH, Master (krasnovskih@yandex.ru) Perm State National Research University (15, Bukireva Street, Perm, 614990, Russian Federation)

Durability and Heat Resistance of Foam Polystyrene
At present foamed polymer materials occupy an extensive sector at the world plastic market, they total up to 10% of the total volume of polymer resins consumption. The world market of foamed materials continues to actively develop, at that foam polystyrene is one of the most popular foamed plastics after foam polyurethane. Its part is a quarter of the world demand. A change in operational properties of foam polystyrene, which is widely used in construction, can take place as a result of photo­oxidative and thermal­oxidative processes leading to change in the molecular mass and molecular­mass distribution. In addition, the reason for changing operational properties can be structural changes which occure during the time and under the effect of relatively low temperature. The successful use of any polymer material under various conditions depends on its ability to preserve its operational properties, i.e. on its durability.

Keywords: foam polystyrene, polymer heat insulation, oxidative destruction of polymers, thermal­oxidative destruction.

References
1. Savkin Yu.V. Russian Market of Foam Polystyrene: Tasks, Achievements, Prospects. Stroitel’nye Materialy [Construction Materials]. 2012. No. 2, pp. 18–20. (In Russian).
2. Yasin Yu.D., Yasin V.Yu., Li A.V. Expanded polystyrene. Resource and material aging. Durability of designs. Stroitel’nye Materialy [Construction Materials]. 2002. No. 5, pp. 33–35. (In Russian).
3. Batalin B.S., Evseev L.D. Operation Properties of Expanded Polystyrene Cause Concern. Stroitel’nye Materialy [Construction Materials]. 2009. No. 10, pp. 55–58. (In Russian).
4. Filatov I.S. Klimaticheskaya ustoichivost’ polimernykh materialov [Climatic stability of polymeric materials]. Moscow: Nauka. 1983. 216 p.
5. Pavlov N.N. Starenie plastmass v estestvennykh i iskusst vennykh usloviyakh [Aging of plastic in natural and artifi- cial conditions]. Moscow: Khimiya. 1982. 224 p.
6. Anan’ev A.I., Lobov O.I., Mozhaev V.P., Vyazovchen ko P.A. The actual and predicted durability of polystyrene foam plates in external protecting designs of buildings. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2003. No. 7, pp. 5–10. (In Russian).
7. Li A.V. Durability of energy-efficient polymer-contain ing enclosing structures. Cand. Diss. (Engineering). Khabarovsk. 2003. 143 p. (In Russian).
8. Emanuel’ N.M., Buchachenko A.L. Khimicheskaya fizika molekulyarnogo razrusheniya i stabilizatsii polim erov [Chemical physics of molecular destruction and stabilization of polymers]. Moscow: Nauka. 1988. 368 p.
9. Kokanin S.V. Research of durability of heat-insulating materials on the basis of expanded polystyrene. Cand. Diss. (Engineering). Ivanovo. 2011.170 p.

L.A. EROKHINA, Candidate of Sciences (Engineering), A.S. GRABAREV, Engineer (grabarev88@gmail.com) Ukhta State Technical University (13, Pervomaiskaya Street, Ukhta, 169300, Republic of Komi, Russian Federation)

Condition of Lightweight Concrete Walls Operating in the North
Data on the condition of lightweight concrete in enclosing structures of buildings on expiration of their design life are presented. Monitoring and taking of readings of temperature and humidity in the wall structure were made during 10 years. A significant increase in air humidity inside the every structure and appearance of condensate in cold winter months even in the structure of material little absorbing the moisture is revealed. Changes of an enclosure structure on the test stand shows that the homogeneous structure of ceramsite­gas concrete more meets its purpose under conditions of the North. Comfort conditions for living are saved in apartments during decades. This material can be used for manufacturing enclosing structures. Variants are offered, if necessary, to reduce the density and increase the heat resistance of walls.

Keywords: ceramsite­gas concrete, heat resistance, foam polystyrene, micro­filler, moisture content, condensate.

References
1. Sedip S.S Heat and humidity conditions haydite concrete exterior walls of residential panel buildings with addi tional insulation. Stroitel’nye Materialy [Construction Materials]. 2007. No. 6, pp. 52–53. (In Russian).
2. Vavrenyuk S.V.,Rudakov V.P. The use of cellular con cretes under conditions of the south of the Russian far east. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2013. No. 12, pp. 6–7. (In Russian).
3. Rakhimbaev Sh.M., Anikanova T.V. On the influence of pore size and shape on the thermal performance of cellular concrete. Beton i Zhelezobeton. 2010. No. 1, pp. 10–13. (In Russian).
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7. Protasevich A.M., Leshkevich V.V., Krutilin A.B. Moisture conditions of building external walls under conditions of the Republic of Belarus. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2013. No. 9, pp. 37–40. (In Russian).
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S.V. FEDOSOV¹, Doctor of Sciences (Engineering), Academician of RAACS, President (prezident@ivgpu.com); V.G. KOTLOV², Candidate of Sciences (Engineering), Counsellor of RAACS; R.M. ALOYAN ¹, Doctor of Sciences (Engineering), Corresponding Member of RAACS, Rector; F.N.YASINSKI ³, Doctor of Sciences (Physics and Mathematics); M.V.BOCHKOV¹ , Engineer
1 Ivanovo State Polytechnical University (20, Mart 8th Street, Ivanovo, 153037, Russian Federation)
2 Volga State University of Technology (3, Lenin Square, Yoshkar-Ola, Republic of Mari El, 424000, Russian Federation)
3 Ivanovo State Power Engineering University (34, Rabfakovskaya Street, Ivanovo, 153003, Russian Federation)

Simulation of Heat-Mass Transfer in the Gas-Solid System at Dowel Joints of Timber Structures Elements. Part 2. Dynamics of Temperature Fields at Arbitrary Law of Changes of Air Environment Temperature
Physical and mathematical models of heat transfer in the timber of dowel joint are presented. The physical model is based on the idea about timber as a colloid capillary­porous body. It is shown that due to the significant difference of thermo­physical properties of a metal dowel and timber (above all, the coefficients of heat conductivity and temperature diffusivity dif­ fer by an order and more) the change of dowel’s temperature takes place in accordance with the change of operational air environment; at that, temperature profiles determined by the thermal conductivity law are formed in the wood. The mathematical model is based on the non­linear differential equation of heat conductivity of parabolic type with the non­linear boundary conditions of the first and second kind and on the general function which determines the initial temperature distribution. In case of the use of the “micro­processes” method the problem is linearized, its numerical­analytic solution becomes possible. Graphic illustrations of model calculations are presented.

Keywords: dowel, timber, heat and mass transfer, “micro­processes” method.

References
1. Fedosov S.V., Kotlov V.G., Aloyan R.M., Yasinski F.N., Bochkov M.V. Simulation of heat and mass transfer in the gas-solid system in dowel connection of wooden structures elements. Part.1. General physical and mathe matical problem. Stroitel’nye Materialy [Construction Materials]. 2014. No. 7, pp. 86–91. (In Russian).
2. Lykov A.V., Mikhailov Yu.A. The theory of heat and mass transfer. Moscow – Leningrad: Gosenergoizdat. 1963, 536 p.
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8. Patent RF No. 127775. Cl. E 04 B 1/49. Krepezhnyi ele ment dlya soedineniya derevyannykh detalei [Fixing ele ment for connecting wooden parts]. Kotlov V.G., Sharynin B.E., Muratova S.S. Published 10.05.2013 Bulletin No. 13. 3 p. (In Russian).
9. Goetz K.-G., Hoor D., Mohler K., Natterer Yu. Atlas of wooden structures. Moscow: Stroiizdat. 1985. 272 p.
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A.A. SAKOVICH¹, Candidate of Sciences (Engineering) (aa_sak@tut.by), D.M. KUZ’MENKOV², Engineer
1 Belarusian State Technological University (13a, Sverdlova Street, 220006, Minsk, Belarus)
2 Research and Design and Production Republican Unitary Enterprise «Institute NIISM» (23, Minina Street, Minsk, 220014, Republic of Belarus)

Producing of Synthetic Gypsum from Dolomite and Sulfuric Acid and Its Recrystallization in α-CaSO4∙0,5H2O in Magnesium Sulfate Solution
An analysis of the raw materials base for producing gypsum binders in the Republic of Belarus is presented. In connection with the absence of natural raw material in Belarus and diffi­ culties of technical and economical character of phosphogypsum processing in gypsum binder the reasonability and prospectivity of producing the synthetic gypsum from dolomite by means of its sulfuric acid decomposition with obtaining of high quality CaSO₄∙2H₂O and MgSO₄ solution is substantiated. Availability of high quality dolomite and cheap sulfuric acid makes it possible to produce from them synthetic СaSO₄∙2H₂O and magnesium sulfate which is used for magnesia cement preparation. In the course of structurally controlled synthesis, parameters of the process ensuring the production of desired product of required morphology have been developed. Values of Н₂SO₄ concentrations, the order of reagents discharge, temperature­time parameters of the synthesis are optimized. Technological parameters of the process ensuring the recrystallization of gypsum into α­CaSO₄∙0,5H₂O in 25% solution of magnesium sulfate with obtaining the desired product of G8–G10 mark suitable both for construction and medical application are presented.

Keywords: gypsum bonding, synthetic gypsum, dolomite, acid decomposition.

References
1. Meshcheryakov Yu.G., Fedorov S.V. Promyshlennaya pererabotka fosfogipsa [Industrial processing of phospho gypsum]. Saint Petersburg: Stroiizdat SPb. 2007. 104 p.
2. Kuz’menkov M.I. Technology of complex processing of dolomite into mineral binding materials and technical products. Latest achievements in the field of import substi tution in chemical industry and building materials produc tion: materials: Materials. International scientific and tech nical conference. Minsk: BSTU. 2012. Vol. 1, pp. 6–11. (In Russian).
3. Kuz’menkov M.I., Starodubenko N.G., Marchik E.V. Oxychloride cement from local raw material. Concep tual aspects of the problem. Proceedings of the Belarusian State Technological University. Chemistry and technology of inorganic substances. 2007. Vol. XV, pp. 51–53. (In Russian).
4. Gubskaya A.G. Production of gypsum binder and goods from natural and technogenic raw materials. Stroitel’nye Materialy [Construction Materials]. 2008. No. 3, pp. 73–75. (In Russian).
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6. Klimenko V.G., Balakhonov A.V. X-ray phase analysis of gypsum raw material of various genesis and products from its thermo processing. Izvestiya vuzov. Stroitel’stvo. 2009. No. 10, pp. 26–31. (In Russian).
7. Kuz’mina, V.P. Influence mechanism of nanoagents on gypsum products. Nanotekhnologii v stroitel’stve. 2012. No. 3, pp. 98–106. (In Russian).
8. Petropavlovskii K.S. Investigation of system dispersibility characteristics on the basis of calcium sulfate dehydrate. Vestnik Tverskogo gosudarstvennogo tekhnicheskogo uni versiteta. 2010. No. 16, pp. 38–40. (In Russian).