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Improving Performance Characteristics of Construction Materials Manufactured by Pressing Technology
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Available online at www.sciencedirect.com Procedia Engineering00 (2017)000–000 Procedia Engineering00 (2017)000–000
ScienceDirect
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Procedia Engineering 206 (2017) 814–818
International Conference on Industrial Engineering, ICIE 2017 International Conference on Industrial Engineering, ICIE 2017
Improving Performance Characteristics of Construction Materials Improving Performance Characteristics of Construction Materials Manufactured by Pressing Technology Manufactured by Pressing Technology M. Butakova, S. Gorbunov* M. Butakova, S. Gorbunov*
South Ural State University, 76, Lenin Avenue, Chelyabinsk 454080, The Russian Federation South Ural State University, 76, Lenin Avenue, Chelyabinsk 454080, The Russian Federation
Abstract Abstract The development of the construction industry has necessitated the creation of efficient high-quality materials, the use of which is The thereduce construction hasconsumption necessitatedof theraw creation of efficient high-quality use ofshould whichbe is cost development efficient and of can energy industry costs and materials. The potential of thematerials, Portlandthe cement utilized to the and fullest, structures and concreteof products are the foundation of modern Q. The promising direction cost efficient canbecause reduce concrete energy costs and consumption raw materials. The potential of the Portland cement should be of solving thisfullest, problem in the concrete production of the piece of wall materials is tothe develop technologies using highpromising compression presutilized to the because structures and concrete products are foundation of modern Q. The direction of solving this problem in the production of the piece of wall materials is to develop technologies using high compression pressures. The sures.article discusses the experimental studies of the substructure formation of building materials of high-filled dispersion, as well as influence of technological factors on the of construction properties example, protecting supThethe article discusses the experimental studies of dynamics the substructure formationmaterials of building materials(for of high-filled dispersion,and as well as the influence of during technological factors on the impacts. dynamics of construction materials properties (for example, protecting and supporting structures) long-term operational © 2017 structures) The Authors. Published by Elsevier B.V.impacts. porting during long-term operational © 2017 Published Ltd. Peer-review under responsibility of Elsevier the scientific © 2017 The The Authors. Authors. Published by by Elsevier B.V. committee of the International Conference on Industrial Engineering. Peer-review under responsibility of committee of International Conference on Industrial Peer-review under strength; responsibility of the the scientific scientific of the theproducts; International Conference Industrial Engineering Engineering. Keywords: concrete; water absorption; stones;committee concrete masonry cement; compactingon pressure. Keywords: concrete; strength; water absorption; stones; concrete masonry products; cement; compacting pressure.
1. Introduction 1. Introduction For high-strength cement-based materials in recent decades it has been established entirely new methods and For high-strength cement-based materials in recent decades it has been established entirely new methods and technologies. technologies. In the production of building materials and pressing vibrocompression powder weights occupy an important In among the production of building materials and pressing vibrocompression powder weights occupy an important place the technological methods of producing finished products. place the technological methods of producing finished products. Theamong manufacturing techniques of traditional wall materials obtained by the method; semi-dry molding; followed manufacturing of traditional wall materials obtained by the method; molding; followed by The baking, steaming ortechniques by autoclaving, associated with high energy consumption, using semi-dry the compression pressure of by baking, 10-30 MPa.steaming or by autoclaving, associated with high energy consumption, using the compression pressure of 10-30 MPa.
* Butakova M.D. Tel.: +7-351-272-31-25. E-mail address: [email protected]. * Butakova M.D. Tel.: +7-351-272-31-25. E-mail address: [email protected]. 1877-7058 © 2017 The Authors. Published by Elsevier B.V. Peer-review the scientific committee 1877-7058 ©under 2017responsibility The Authors. of Published by Elsevier B.V.of the International Conference on Industrial Engineering . Peer-review under responsibility of the scientific committee of the International Conference on Industrial Engineering .
1877-7058 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the International Conference on Industrial Engineering. 10.1016/j.proeng.2017.10.556
2
M. Butakova et al. / Procedia Engineering 206 (2017) 814–818 M.D. Butakova / Procedia Engineering 00 (2017) 000–000
815
Using hyper-technology in the production of products manufactured without firing a promising solution to produce wall, road and facing materials [1]. Submissions received on these technologies differ from traditional following features: 1. The lower power consumption, since they do not manufacture. It requires heat and heat and humidity treatment; 2. The lower consumption of binder; 3. more extensive resource base, allowing the use of a readily available local natural raw materials, industrial wastes and by-products; When pressing powders main process parameters are pressing pressure, humidity and molding sand particle size distribution of aggregates mixture of fine filler and binder. [1, 2, 3] High-strength cement stone can be obtained by creating a uniform volume of high-density structure, which is achieved by compression, the selection of a rational size distribution, reduction of the W / C, the removal of the conditions for the emergence of irregularities and structural defects [4]. Pressing cement binding materials allows to obtain structures with maximally dense particle packing and low porosity. During hydration of these systems is formed a tight, substantially free of calcium hydroxide, cement rock compressive strength reaches 350-400MPa. [5] Also, according to an early study [6], especially the structuring of the powder mass in the process of molding flow through a series of successive stages. At the initial moment of the particle applying pressure move in the direction of the pressure vector, filling large pores and destroying bridges and arches, arising freely poured powder. The water acts as a lubricant, reducing friction between the particles and taking part in transmitting the pressure on the volume of the system. Deformation of the particles hardly occurs and reaches an equilibrium position of the structural elements of the material, the packing density is significantly increased relative to the initial state. But at the same density and the area of contact between the particles varies slightly, and the composite strength is low (prepressing stage). In the further application of pressure (compaction stage) reaches its maximum compaction mixture, characterized by a critical density, and the molding pressure for a given moisture content is critical. With increasing force pressing system "water - solid particles - entrapped air" behaves as an elastic body, and after removal of the load, it expands. The water, located between the solids of the moldable mixture, and the film weakening point contacts between the particles, which leads to a reduction in strength. This mechanism explains the presence of structure optimal pressure dispersion systems, working as an elastic body. [7-11]. When further increasing the compaction pressure (above 100 MPa) the powder particles starts deformation first elastic and then plastic with a change in the value of the contact surface. At the same time changing particle size of the mixture components. This increase in the proportion of plastic deformation and crushing of aggregate mass of the particles (which leads to the activation of its surface) and explain the observed increase in strength while the samples with increasing compaction pressure of more than 100 MPa. [12-17]. The mechanism of structure formation of disperse systems under very high pressure is interesting in itself, but most of the technologies for the production of extruded materials are focused on existing equipment, ensuring the achievement of optimal pressure range. How can we improve the strength characteristics of the materials in this case? Previously we have considered regularity of structure formation of pressed cement compositions according to the type and amount of mineral admixtures, surface-active agents and accelerator for hardening [6]. The purpose of this project is to study regularity of structure formation of pressed cement compositions depending on technological factors, as well as physical-mechanical properties of concrete including long term operational impacts. The following materials were used in the experimental researches. Binding material is Portland cement with mineral admixture CEM II/В-Ш 32,5Н produced by Dyckerhoff Korkino Cement, which satisfies the requirements of GOST 1108-2003 3 "Standard cements. Technical specifications" with actual mineral clinker composition: C3S = 65%, β-C2S = 13%, C3A = 7%, C4AF = 14%. Fine aggregate – quartz sand according to GOST 8637 with a fineness modulus of 2,37.
M. Butakova et al. / Procedia Engineering 206 (2017) 814–818 M.D. Butakova / Procedia Engineering 00 (2017) 000–000
816
3
2. Terms and conditions of the experiment. Test cylinders with diameter and height of 50 mm composed of a mixture of fine-grained concrete composition of 1:2.5 were prepared by pressing with two-sided punch with load application rate max4 kN/sec, followed by a static endurance of 10 sec at a fixed pressure. Curing conditions up to the test in 28 days of hardening – normal; following storage for 5 years – in open yard conditioned by climate patterns of Chelyabinsk. Design of experiments and processing of experimental results were carried out with the use of second-order Hartley plans in Cuba and plans simplex-lattice design of the third degree, followed by a graphic display of sufficient mathematical models [18, 19]. The influence of humidity mixture and compacting pressure on the compressive strength according to GOST 10180, total porosity of concrete according to GOST 12730.4 and frost resistance of concrete for the base method GOST 10060 have been tested. Singular results are shown in Table. 1 and in Figures 13. Table 1. Matrix plan of the experiment. Factor N
Conditions
Х1, percent age of moisture; %
Х2, compacting pressure, MPa
Сode
Amount
Сode
Amount
28 days
2100 days
-1
4
-1
20
14,6
22,7
0
6
-1
20
22,3
35,8
+1
8
-1
20
28,9
42,1
-1
4
0
45
13,3
21,9
0
6
0
45
24,1
30,7
Ultimate compressive strength, R, MPa, after
+1
8
0
45
31,6
44,3
-1
4
+1
70
16,6
34,2
0
6
+1
70
31,6
51,8
+1
8
+1
70
32,0
26,1
Note: 1 − freeze-thaw resistance was interpreted by a coefficient determined by the ratio of the strength of concrete samples after a given number of alternate freezing and thawing cycles to cube concrete test specimen.
3. Discussion of results As it has been shown previously [6], an increased compression pressure and the percentage of moisture (within certain limits) harden the molded cement compositions. The optimum compacting pressurecan be 45 MPa (moisture content 8% moldable mixture), whereas the compressive strength after 28 days of normal hardening is 31.6 MPa. Further compression pressure increase (up to 70 MPa) is followed byinsignificant strength increase (32.0 MPa). When molding pressureis 45 MPa,the optimum molding sand humidity is 8.0 ... 9.0. Shown in Fig. 1 findings in the later stages of hardening indicate that this pattern revealed essentially no change, even after a 5-year additional hardening. Gain strength is in the range of 40-60% can be consideredsuperfluous for the wall materials [20]. Evaluation of concrete frost resistance (Fig. 2). For the climatic conditions of the Ural region such parameter as resistance to frost is determining. For discussion of the results, Fig. 3 shows changing of total porosity of concrete prior to frost test. As expected, the rate freeze-thaw resistance ultimately depends on the porosity of the concrete [21]. These data show that at high molding pressureregular patterns of porosity influence on concrete strength and its resistance to frost change. In whole, frost-resistence value is over 100 F, which is an excellent indicator for wall materials.
4
M. Butakova et al. / Procedia Engineering 206 (2017) 814–818 M.D. Butakova / Procedia Engineering 00 (2017) 000–000
817
4. Conclusion Thus, the possibility of controlling the properties of fine-grained compacted concrete by optimizing the porosity through grain size composition regulation and introduction of an optimal amount of electrolyte to change the electrostatic effect between the interacting particles of the solid phase was experimentally confirmed. For the first time we obtained experimental data of properties evaluation of extruded materials over a long period of hardening in climate conditions of the South Urals.
Fig. 1. Dependence of concrete strength (MPa) of the moisture of the mixture (X1) and the compression pressure (X2) after 28 (A) and 2100 (B) days of hardening.
Fig. 2. Dependence of frost resistance of concrete (Kmrz) mixture from moisture (X1) and the compression pressure (X2) after 28 (A) and 2100 (B) days of hardening. The number of cycles of freezing and thawing - 100.
M. Butakova et al. / Procedia Engineering 206 (2017) 814–818 M.D. Butakova / Procedia Engineering 00 (2017) 000–000
818
5
Fig. 3 Dependence of total concrete porosity (%) on the moisture of the mixture (X1) and the compression pressure (X2) after 28 (A) and 2100 (B) days of hardening.
Acknowledgements The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0011. References [1] I.M Red, On the mechanism of increasing the strength of concrete with the introduction of micro filler, Concrete and reinforced concrete. 5 (1987) 10–11. [2] P.N. Chicken, A.V. Gavrilov, I.P. Pahrudinov, Influence of additives on the fine cement matrix, In Proc. Modern materials and technologies in construction, Novosibirsk, 2003, pp. 77–80. [3] V.V. Babkov, P.G. Komokhov, S.M. Kapitonov, R.I. Mirsaev, Mechanism of hardening cement using cords of fine fillers, Tsement. 9-10 (1991) 34–41. [4] N.B. Uriev, A.A. Potanin, The fluidity of the suspensions and powders, Chemistry, Moscow, 1992, 245 p. [5] V.S. Ramachandran (Ed.), Additives in concrete: handbook, Stroyizdat, Moscow, 1998, 567 p. [6] S.P. Gorbunov, S.N. Pogorelov, The mechanism of increasing the strength of the molded building materials, Bulletin of South Ural State University. 14(1) (2014) 38–41. [7] V.V. Babkov, V.H. Mokhov, C.M.Kapitonov, Destruction of cement Beto-new, Ufa, 2002, pp. 220–234. [8] A.A. Pascenco, Theory of cement, Budivelnik, Kiev, 1991, 168 p. [9] W. Kurdowski, C.M. George, F.R. Sorrentino, Special Cements, Riode-Janeiro.Finer. : 8th Intern. Congr. Chem. Cem, 1986, p p. 293–318. [10] I.Sh. Karimov, P.G Komokhov, .Aspects of the formation of high-strength and durable cement con-portation in concrete, Babkov V.V. technology, Math. universities. Page of. 4 (1996) 41–48. [11] I.N. Akhverdov, Fundamentals of Physics concrete, Stroyizdat, Moscow, 1981, 464 p. [12] V.V. Babkov, V.N. Mokhov A.A. Ananenko, A.F. Polak, Structural heterogeneity and strength of porous materials, Math. universities. Construction and architecture. 12 (1980) 64–70. [13] V.V. Babkov, AF Polak, Effect of dispersion on the strength of cement hydrate thereof, Cement. 9 (1980) 15–17. [14] V.V. Babkov, Patterns of communication structure and strength of concrete, Te plomassoperenos in the processes of structure formation and hydration binders: Tr. ITMO them, Lykov, Minsk, 1981, pp. 38–51. [15] V.V. Babkov, P.G. Komokhov, A.F. Polak, Aspects of durability of cement-foot stone, Cement. 3 (1988) 14–16. [16] V.V. Babkov, V.N. Mokhov, A.F. Polak, Fracture mechanics and strength of the splice, Hydration crystallization and structure formation of inorganic binders: Materials of coordination. ings of the Conference. when NIIZhB, Moscow, 1977, pp. 39–50. [17] V.V. Babkov, A.F. Polak, On the influence of the major structural and mechanical factors on the strength of the cement stone, Massoteplopere-nose in the preparation of high-strength construction material: Tr. ITMO them, Lykov, Minsk, 1978, pp. 43–48. [18] A.L. Shestakov, G.A. Sviridyuk, M.D. Butakova, The mathematical modelling of the production of construction mixtures with prescribed properties, Journal of Computational and Engineering Mathematics. 1 (2015) 100–110. DOI: 10.14529 / mmp150108. [19] V.A. Ascension, V.N. Broken, V.Y. Kersh, Modern methods of optimization of composite materials, Budivelnik, Kyiv, 1984, 144 p. [20] T.B. Arbuzova, V.Yu.Sukhov, M.V.Ryabova, The technology of composite extruded materials for general and special purpose, Construction Materials. 8 (1998) 10–12. [21] G.I. Gorchakov (Ed.), The composition, structure and properties of cement concrete, Stroyizdat, Moscow, 1975, 286 p.
ScienceDirect ScienceDirect
Available online at www.sciencedirect.com Procedia Engineering00 (2017)000–000 Procedia Engineering00 (2017)000–000
ScienceDirect
www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia
Procedia Engineering 206 (2017) 814–818
International Conference on Industrial Engineering, ICIE 2017 International Conference on Industrial Engineering, ICIE 2017
Improving Performance Characteristics of Construction Materials Improving Performance Characteristics of Construction Materials Manufactured by Pressing Technology Manufactured by Pressing Technology M. Butakova, S. Gorbunov* M. Butakova, S. Gorbunov*
South Ural State University, 76, Lenin Avenue, Chelyabinsk 454080, The Russian Federation South Ural State University, 76, Lenin Avenue, Chelyabinsk 454080, The Russian Federation
Abstract Abstract The development of the construction industry has necessitated the creation of efficient high-quality materials, the use of which is The thereduce construction hasconsumption necessitatedof theraw creation of efficient high-quality use ofshould whichbe is cost development efficient and of can energy industry costs and materials. The potential of thematerials, Portlandthe cement utilized to the and fullest, structures and concreteof products are the foundation of modern Q. The promising direction cost efficient canbecause reduce concrete energy costs and consumption raw materials. The potential of the Portland cement should be of solving thisfullest, problem in the concrete production of the piece of wall materials is tothe develop technologies using highpromising compression presutilized to the because structures and concrete products are foundation of modern Q. The direction of solving this problem in the production of the piece of wall materials is to develop technologies using high compression pressures. The sures.article discusses the experimental studies of the substructure formation of building materials of high-filled dispersion, as well as influence of technological factors on the of construction properties example, protecting supThethe article discusses the experimental studies of dynamics the substructure formationmaterials of building materials(for of high-filled dispersion,and as well as the influence of during technological factors on the impacts. dynamics of construction materials properties (for example, protecting and supporting structures) long-term operational © 2017 structures) The Authors. Published by Elsevier B.V.impacts. porting during long-term operational © 2017 Published Ltd. Peer-review under responsibility of Elsevier the scientific © 2017 The The Authors. Authors. Published by by Elsevier B.V. committee of the International Conference on Industrial Engineering. Peer-review under responsibility of committee of International Conference on Industrial Peer-review under strength; responsibility of the the scientific scientific of the theproducts; International Conference Industrial Engineering Engineering. Keywords: concrete; water absorption; stones;committee concrete masonry cement; compactingon pressure. Keywords: concrete; strength; water absorption; stones; concrete masonry products; cement; compacting pressure.
1. Introduction 1. Introduction For high-strength cement-based materials in recent decades it has been established entirely new methods and For high-strength cement-based materials in recent decades it has been established entirely new methods and technologies. technologies. In the production of building materials and pressing vibrocompression powder weights occupy an important In among the production of building materials and pressing vibrocompression powder weights occupy an important place the technological methods of producing finished products. place the technological methods of producing finished products. Theamong manufacturing techniques of traditional wall materials obtained by the method; semi-dry molding; followed manufacturing of traditional wall materials obtained by the method; molding; followed by The baking, steaming ortechniques by autoclaving, associated with high energy consumption, using semi-dry the compression pressure of by baking, 10-30 MPa.steaming or by autoclaving, associated with high energy consumption, using the compression pressure of 10-30 MPa.
* Butakova M.D. Tel.: +7-351-272-31-25. E-mail address: [email protected]. * Butakova M.D. Tel.: +7-351-272-31-25. E-mail address: [email protected]. 1877-7058 © 2017 The Authors. Published by Elsevier B.V. Peer-review the scientific committee 1877-7058 ©under 2017responsibility The Authors. of Published by Elsevier B.V.of the International Conference on Industrial Engineering . Peer-review under responsibility of the scientific committee of the International Conference on Industrial Engineering .
1877-7058 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the International Conference on Industrial Engineering. 10.1016/j.proeng.2017.10.556
2
M. Butakova et al. / Procedia Engineering 206 (2017) 814–818 M.D. Butakova / Procedia Engineering 00 (2017) 000–000
815
Using hyper-technology in the production of products manufactured without firing a promising solution to produce wall, road and facing materials [1]. Submissions received on these technologies differ from traditional following features: 1. The lower power consumption, since they do not manufacture. It requires heat and heat and humidity treatment; 2. The lower consumption of binder; 3. more extensive resource base, allowing the use of a readily available local natural raw materials, industrial wastes and by-products; When pressing powders main process parameters are pressing pressure, humidity and molding sand particle size distribution of aggregates mixture of fine filler and binder. [1, 2, 3] High-strength cement stone can be obtained by creating a uniform volume of high-density structure, which is achieved by compression, the selection of a rational size distribution, reduction of the W / C, the removal of the conditions for the emergence of irregularities and structural defects [4]. Pressing cement binding materials allows to obtain structures with maximally dense particle packing and low porosity. During hydration of these systems is formed a tight, substantially free of calcium hydroxide, cement rock compressive strength reaches 350-400MPa. [5] Also, according to an early study [6], especially the structuring of the powder mass in the process of molding flow through a series of successive stages. At the initial moment of the particle applying pressure move in the direction of the pressure vector, filling large pores and destroying bridges and arches, arising freely poured powder. The water acts as a lubricant, reducing friction between the particles and taking part in transmitting the pressure on the volume of the system. Deformation of the particles hardly occurs and reaches an equilibrium position of the structural elements of the material, the packing density is significantly increased relative to the initial state. But at the same density and the area of contact between the particles varies slightly, and the composite strength is low (prepressing stage). In the further application of pressure (compaction stage) reaches its maximum compaction mixture, characterized by a critical density, and the molding pressure for a given moisture content is critical. With increasing force pressing system "water - solid particles - entrapped air" behaves as an elastic body, and after removal of the load, it expands. The water, located between the solids of the moldable mixture, and the film weakening point contacts between the particles, which leads to a reduction in strength. This mechanism explains the presence of structure optimal pressure dispersion systems, working as an elastic body. [7-11]. When further increasing the compaction pressure (above 100 MPa) the powder particles starts deformation first elastic and then plastic with a change in the value of the contact surface. At the same time changing particle size of the mixture components. This increase in the proportion of plastic deformation and crushing of aggregate mass of the particles (which leads to the activation of its surface) and explain the observed increase in strength while the samples with increasing compaction pressure of more than 100 MPa. [12-17]. The mechanism of structure formation of disperse systems under very high pressure is interesting in itself, but most of the technologies for the production of extruded materials are focused on existing equipment, ensuring the achievement of optimal pressure range. How can we improve the strength characteristics of the materials in this case? Previously we have considered regularity of structure formation of pressed cement compositions according to the type and amount of mineral admixtures, surface-active agents and accelerator for hardening [6]. The purpose of this project is to study regularity of structure formation of pressed cement compositions depending on technological factors, as well as physical-mechanical properties of concrete including long term operational impacts. The following materials were used in the experimental researches. Binding material is Portland cement with mineral admixture CEM II/В-Ш 32,5Н produced by Dyckerhoff Korkino Cement, which satisfies the requirements of GOST 1108-2003 3 "Standard cements. Technical specifications" with actual mineral clinker composition: C3S = 65%, β-C2S = 13%, C3A = 7%, C4AF = 14%. Fine aggregate – quartz sand according to GOST 8637 with a fineness modulus of 2,37.
M. Butakova et al. / Procedia Engineering 206 (2017) 814–818 M.D. Butakova / Procedia Engineering 00 (2017) 000–000
816
3
2. Terms and conditions of the experiment. Test cylinders with diameter and height of 50 mm composed of a mixture of fine-grained concrete composition of 1:2.5 were prepared by pressing with two-sided punch with load application rate max4 kN/sec, followed by a static endurance of 10 sec at a fixed pressure. Curing conditions up to the test in 28 days of hardening – normal; following storage for 5 years – in open yard conditioned by climate patterns of Chelyabinsk. Design of experiments and processing of experimental results were carried out with the use of second-order Hartley plans in Cuba and plans simplex-lattice design of the third degree, followed by a graphic display of sufficient mathematical models [18, 19]. The influence of humidity mixture and compacting pressure on the compressive strength according to GOST 10180, total porosity of concrete according to GOST 12730.4 and frost resistance of concrete for the base method GOST 10060 have been tested. Singular results are shown in Table. 1 and in Figures 13. Table 1. Matrix plan of the experiment. Factor N
Conditions
Х1, percent age of moisture; %
Х2, compacting pressure, MPa
Сode
Amount
Сode
Amount
28 days
2100 days
-1
4
-1
20
14,6
22,7
0
6
-1
20
22,3
35,8
+1
8
-1
20
28,9
42,1
-1
4
0
45
13,3
21,9
0
6
0
45
24,1
30,7
Ultimate compressive strength, R, MPa, after
+1
8
0
45
31,6
44,3
-1
4
+1
70
16,6
34,2
0
6
+1
70
31,6
51,8
+1
8
+1
70
32,0
26,1
Note: 1 − freeze-thaw resistance was interpreted by a coefficient determined by the ratio of the strength of concrete samples after a given number of alternate freezing and thawing cycles to cube concrete test specimen.
3. Discussion of results As it has been shown previously [6], an increased compression pressure and the percentage of moisture (within certain limits) harden the molded cement compositions. The optimum compacting pressurecan be 45 MPa (moisture content 8% moldable mixture), whereas the compressive strength after 28 days of normal hardening is 31.6 MPa. Further compression pressure increase (up to 70 MPa) is followed byinsignificant strength increase (32.0 MPa). When molding pressureis 45 MPa,the optimum molding sand humidity is 8.0 ... 9.0. Shown in Fig. 1 findings in the later stages of hardening indicate that this pattern revealed essentially no change, even after a 5-year additional hardening. Gain strength is in the range of 40-60% can be consideredsuperfluous for the wall materials [20]. Evaluation of concrete frost resistance (Fig. 2). For the climatic conditions of the Ural region such parameter as resistance to frost is determining. For discussion of the results, Fig. 3 shows changing of total porosity of concrete prior to frost test. As expected, the rate freeze-thaw resistance ultimately depends on the porosity of the concrete [21]. These data show that at high molding pressureregular patterns of porosity influence on concrete strength and its resistance to frost change. In whole, frost-resistence value is over 100 F, which is an excellent indicator for wall materials.
4
M. Butakova et al. / Procedia Engineering 206 (2017) 814–818 M.D. Butakova / Procedia Engineering 00 (2017) 000–000
817
4. Conclusion Thus, the possibility of controlling the properties of fine-grained compacted concrete by optimizing the porosity through grain size composition regulation and introduction of an optimal amount of electrolyte to change the electrostatic effect between the interacting particles of the solid phase was experimentally confirmed. For the first time we obtained experimental data of properties evaluation of extruded materials over a long period of hardening in climate conditions of the South Urals.
Fig. 1. Dependence of concrete strength (MPa) of the moisture of the mixture (X1) and the compression pressure (X2) after 28 (A) and 2100 (B) days of hardening.
Fig. 2. Dependence of frost resistance of concrete (Kmrz) mixture from moisture (X1) and the compression pressure (X2) after 28 (A) and 2100 (B) days of hardening. The number of cycles of freezing and thawing - 100.
M. Butakova et al. / Procedia Engineering 206 (2017) 814–818 M.D. Butakova / Procedia Engineering 00 (2017) 000–000
818
5
Fig. 3 Dependence of total concrete porosity (%) on the moisture of the mixture (X1) and the compression pressure (X2) after 28 (A) and 2100 (B) days of hardening.
Acknowledgements The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0011. References [1] I.M Red, On the mechanism of increasing the strength of concrete with the introduction of micro filler, Concrete and reinforced concrete. 5 (1987) 10–11. [2] P.N. Chicken, A.V. Gavrilov, I.P. Pahrudinov, Influence of additives on the fine cement matrix, In Proc. Modern materials and technologies in construction, Novosibirsk, 2003, pp. 77–80. [3] V.V. Babkov, P.G. Komokhov, S.M. Kapitonov, R.I. Mirsaev, Mechanism of hardening cement using cords of fine fillers, Tsement. 9-10 (1991) 34–41. [4] N.B. Uriev, A.A. Potanin, The fluidity of the suspensions and powders, Chemistry, Moscow, 1992, 245 p. [5] V.S. Ramachandran (Ed.), Additives in concrete: handbook, Stroyizdat, Moscow, 1998, 567 p. [6] S.P. Gorbunov, S.N. Pogorelov, The mechanism of increasing the strength of the molded building materials, Bulletin of South Ural State University. 14(1) (2014) 38–41. [7] V.V. Babkov, V.H. Mokhov, C.M.Kapitonov, Destruction of cement Beto-new, Ufa, 2002, pp. 220–234. [8] A.A. Pascenco, Theory of cement, Budivelnik, Kiev, 1991, 168 p. [9] W. Kurdowski, C.M. George, F.R. Sorrentino, Special Cements, Riode-Janeiro.Finer. : 8th Intern. Congr. Chem. Cem, 1986, p p. 293–318. [10] I.Sh. Karimov, P.G Komokhov, .Aspects of the formation of high-strength and durable cement con-portation in concrete, Babkov V.V. technology, Math. universities. Page of. 4 (1996) 41–48. [11] I.N. Akhverdov, Fundamentals of Physics concrete, Stroyizdat, Moscow, 1981, 464 p. [12] V.V. Babkov, V.N. Mokhov A.A. Ananenko, A.F. Polak, Structural heterogeneity and strength of porous materials, Math. universities. Construction and architecture. 12 (1980) 64–70. [13] V.V. Babkov, AF Polak, Effect of dispersion on the strength of cement hydrate thereof, Cement. 9 (1980) 15–17. [14] V.V. Babkov, Patterns of communication structure and strength of concrete, Te plomassoperenos in the processes of structure formation and hydration binders: Tr. ITMO them, Lykov, Minsk, 1981, pp. 38–51. [15] V.V. Babkov, P.G. Komokhov, A.F. Polak, Aspects of durability of cement-foot stone, Cement. 3 (1988) 14–16. [16] V.V. Babkov, V.N. Mokhov, A.F. Polak, Fracture mechanics and strength of the splice, Hydration crystallization and structure formation of inorganic binders: Materials of coordination. ings of the Conference. when NIIZhB, Moscow, 1977, pp. 39–50. [17] V.V. Babkov, A.F. Polak, On the influence of the major structural and mechanical factors on the strength of the cement stone, Massoteplopere-nose in the preparation of high-strength construction material: Tr. ITMO them, Lykov, Minsk, 1978, pp. 43–48. [18] A.L. Shestakov, G.A. Sviridyuk, M.D. Butakova, The mathematical modelling of the production of construction mixtures with prescribed properties, Journal of Computational and Engineering Mathematics. 1 (2015) 100–110. DOI: 10.14529 / mmp150108. [19] V.A. Ascension, V.N. Broken, V.Y. Kersh, Modern methods of optimization of composite materials, Budivelnik, Kyiv, 1984, 144 p. [20] T.B. Arbuzova, V.Yu.Sukhov, M.V.Ryabova, The technology of composite extruded materials for general and special purpose, Construction Materials. 8 (1998) 10–12. [21] G.I. Gorchakov (Ed.), The composition, structure and properties of cement concrete, Stroyizdat, Moscow, 1975, 286 p.