Available online at www.sciencedirect.com ScienceDirect Procedia Engineering 165 (2016) 1771 – 1775 15th International scientific conference “Underground Urbanisation as a Prerequisite for Sustainable Development” New Geoecoprotective Properties Of The Construction Materials For Underground Infrastructure Development Larisa Svatovskayaa, Maxim Sychovb, Anastasia Sychovac, Marina Gravitd,* a Emperor Alexander I St Petersburg State Transport University (PGUPS), Moskovsky pr 9, St Petersburg, 190031, Russia b St Petersburg State Institute of Technological (Technical University), Moskovsky pr 26, St Petersburg, 190013, Russia c Mozhaisky Military Space Academy, Zhdanovskaya st 13, St Petersburg, 197198, Russia d Peter the Great St Petersburg Polytechnic University, Politekhnicheskaya st 29, Saint-Petersburg, 195251, Russia Abstract The point of the paper is to introduce new characteristics of the underground construction materials which are important for geoecoprotection of infrastructure in the sense of durability and wastewater resistance The main idea is using absorption ability of underground constructions on the cement base It was shown that utilization of silica sol solution instead of water allows one to improve more than 50% main properties of the concrete on the cement base Because of that the new technology of fabrication of the underground constructions on the cement base has been suggested (silica sol absorption technology, SAT - technology) Underground construction ability to absorb water has been investigated using wastewater with heavy metal ions Such kind of water has been absorbed by construction and detoxication of wastewater was demonstrated due to formation of heavy metal ions silicates in pores and capillary of material 2016Published The Authors Published by Elsevier Ltd © 2016 by Elsevier Ltd This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the 15th International scientific conference “Underground Peer-review under scientific committee of the 15th International scientific conference “Underground Urbanisation as a Urbanisation as aresponsibility Prerequisite of forthe Sustainable Development Prerequisite for Sustainable Development Keywords: underground, geoecoprotection, cement, building constructions * Corresponding author Tel.: +7-921-912-64-07 E-mail address: marina.gravit@mail.ru 1877-7058 © 2016 Published by Elsevier Ltd This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the 15th International scientific conference “Underground Urbanisation as a Prerequisite for Sustainable Development doi:10.1016/j.proeng.2016.11.921 1772 Larisa Svatovskaya et al / Procedia Engineering 165 (2016) 1771 – 1775 Introduction The main idea of the paper is the utilization of cement based construction materials’ ability to absorb silica sol and heavy metal ion solutions for the two objectives – strengthening of the constructions if we have nanosolution and detoxication of the wastewater if we have heavy metal ion solution Such kind of problems are being observed in the paper [1], especially important is to take into account donor-acceptor properties of solid surface [2-11] Phenomenon of the water absorbtion is known well enough for the underground building and the reason of such kind of the phenomenon is pores and capillaries in the solid materials on the cement base But instead of underground water it is passible to use silica sol solution in the early time of structure hardening and heavy metal ion solution in the time of underground exploitation of the building construction Under such kind of conditions new calcium silicate hydrates are formed if it has been used silica sol or heavy metal ion hydrates if it has been used heavy metal ion solution The construction strengthening takes place because of the formation of new hydrates of calcium silicate in the pores and capillaries, and the detoxication from heavy metal ions takes place because of heavy metal hydrates formation From thermodynamics point of view reactions between silica sol, heavy metal ions and construction material on the cement base are allowed because of the negative Gibbs energy, table [12-23] Table Thermodynamics of the some underground building system on the cement base Reactions Ca(OH)2 + 2(SiO2·H2O)* = CaO·2SiO2·2H2O + H2O 2Ca(OH)2+SiO2∙H2O=2CaO∙SiO2∙1,17H2O+1,83H2O 5Ca(OH)2 + 6(SiO2·H2O) = 5CaO·6SiO2·5,5H2O + 5,5H2O 5CaO∙6SiO2∙5,5H2O + Pb2+aq** + 2OH-aq+ 5H2O(ж) → Pb(OH)2(т) + 5CaO∙6SiO2∙10,5H2O(т) 5CaO∙6SiO2∙5,5H2O + Cd2+aq **+ 2OH-aq+ 5H2O(ж) → Cd(OH)2(т) + 5CaO∙6SiO2∙10,5H2O(т) 5CaO∙6SiO2∙5,5H2O + Fe3+aq **+ 3OH-aq+ 5H2O(ж) → Fe(OH)3(т) + 5CaO∙6SiO2∙10,5H2O(т) 5CaO∙6SiO2∙5,5H2O + Ni2+aq + 2OH-aq+ 5H2O(ж) → Ni(OH)2(т) + 5CaO∙6SiO2∙10,5H2O(т) 5CaO∙6SiO2∙5,5H2O + Cu2+aq **+ 2OH-aq+ 5H2O(ж) → Cu(OH)2(т) + 5CaO∙6SiO2∙10,5H2O(т) kJ/mol -169.14 -95.32 -584.80 -91.96 -91.42 -221.90 -108.54 -120.63 *SiO2∙H2 O – silica sol **Pb(II); Cd(II); Fe(III); – Сu(II) heavy metal ions According to the table it is possible to form new calcium silicate hydrates (№1, 2, 3) and it is possible to form heavy metal ion hydroxides (№4,5,6,7,8) Also helps very low solubility of heavy metal ion hydroxides, lower, than 10-15 [15] Because of the formation of new calcium silicate hydrates, the improvement of the construction properties is observed And because of formation of hydroxides of heavy metal ions, the detoxication of wastewater takes place (purification of water from heavy metal ions) The strengthening provides the durability of the underground construction and because of that it can be named as “geoecoprotective” one The detoxication of wastewater in underground space from heavy metal ions by means of underground constructions on the cement base is important for environment protection Experiment Samples of concrete on the cement base and different additives have been used Samples were sinked in the silica sol solutions of 1, 2, and 30% concentrations Time for start of saturation – 1, 3, 5, days from the start of concrete article hardening, saturation time – till the end of process (till achievement of constant weight) Then in 28 days age samples were tested according to the usual procedures [15] It has been found, that the best concentration for start of the absorption was 1,5-3% silica sol, time for absorption – 2-3 days from the concrete hardening start Then properties of the best sample obtained as described above were compared with properties of reference sample (table 2) The second part of research was the following Samples of concrete of different classes after 28 days of hardening were soaked in the solution with heavy metal ions with different concentrations Change of chemical composition of solutions after that was investigated It was found that used samples are able to absorb heavy metal ions from the solution and after that solution are purified from ions (Table 3), so detoxication of the solution from heavy metal ions was demonstrated 1773 Larisa Svatovskaya et al / Procedia Engineering 165 (2016) 1771 – 1775 Table Improvement of concrete properties after silica sol absorption, % Parameter Compressive strength Bending strength Impact resistance Water notpermentility Low-temperature resistance, cycles Hardness Water absorption Porosity Contraction Abrasion resistance Improvement, % + 52 + 42 + 32 + 23 + 50 + 25 - 60 - 56 - 52 - 38 Table Wastewater detoxication properties of concrete samples Concrete class, B Cd(II) 138 8 0.75 15 25 Absorbed heavy metal ions, g/ton Pb(II) 160 15 12 Cu(II) 60 According to the table 3, the level of the absorption of heavy metal ions is different It depends on class of concrete samples (strength) Results and Discussion New position in the paper is reactions in the pores and capillaries of the construction materials with silica sol solution and heavy metal ion containing solutions Technology of using of such kind of properties improvements using silica sol absorption is suitable for monolith concrete underground construction and silica sol strengthening is good enough as well for any kind of concrete articles Table Classification building constructions Nature silicate calcium hydrates, pH > silicate calcium hydrates, pH > silicate sulfat hydrates, pH = Reactions in pores and capillaries of the stone of the stone Absorbing solution Soling; SiO2∙nH2O – silica sol; Al(III) –solution; Al3+ + 6OH- = [AlO3]3- + 3H2O Fe(III) – solution Fe3+ + 6OH- = [FeO3]3- + 3H2O Organic, solution, for example, acid phenylic Pb(II)-solution ions silicate aluminate SiO2∙nH2O – silica hydrates, sol pH > 2C6H5OH + Ca(OH)2 = Ca(C6H5O)2 + 2H2O Pb2+ + CaSO4∙2H2O = PbSO4↓ + Ca2+ + 2H2O Soling Gibbs energy, Ͳ Δ ʹͻͺ ǡ kJ Negative New phases of the reactions Silicate calcium hydrates Aluminate calcium hydrates Negative Phenate Negative Sulphats with very low solubility Negative Alumosilicate hydrates Geoecoprotection due to durability decreasing of danger Detoxication of heavy metal ions durability If wastewater has been polluted with heavy metal ions, the detoxication takes place It was confirmed by practice during exploitation of underground concrete blocks strengthened with silica sol technology and blocks have shown almost no water absorption Sol absorption technology (SAT) should be recommended for common concrete articles 1774 Larisa Svatovskaya et al / Procedia Engineering 165 (2016) 1771 – 1775 for decrease of water absorption Also concrete blocks were investigated in the underground space in the presence of wastewater polluted with heavy metal ions The result of the test was the same as one for the concrete examples, decribed above So, it is possible to use silica sol solution technology for improvement of properties more than 50 percent and because of that new technology of fabrication of underground construction articles on the cement base is suggested (Sol absorption technology, SAT) In addition, construction articles on the cement base may be used for detoxication of wastewater from heavy metal ions In the table is shown classification of the construction on the different cement According to the table it is possible to achieve geoecoprotection for every time and reaction in the poros and capillaries have been named lithosynthesis In the table is shown the derection of the improvement of the geoecoprotective properties according to the thermodynamic parameters of the building construction Table Thermodynamic parameters of phases and geoecoprotective properties Phasa M, g/mol Thermodynamic parameters -∆H0298 kJ/mol СaSO4∙2H2O 172 1810 -∆G0298 kJ/mol 1796 5СaO∙6SiO2∙5.5H2O 740 10685 9870 5СaO∙6SiO2∙10H2O 830 12169 11065 3CaO∙Al2O3∙3CaSO4∙31H2O 1236 17183 14865 Direction of improvement of properties n/n Conclusions Improvement of properties of cement based underground construction articles is achieved by absorption of silica sol solution It was shown that suggested approach provides articles with new geoecoprotective property, namely ability to purify wastewater from heavy metal ions References [1] L.B Svatovskaya, M.M Shershneva, M Baidarashvily, A.M Sychova, M M Sychov, M.V Gravit Geoecoprotective Properties of Cement and Concrete Against Heavy Metal Ions Geoecoprotective Properties of Cement and Concrete Against Heavy Metal Ions Proceedia Engineering 117 (2015) 350-354 [2] О.A Cheremisina, M.M Sychev, S.V Myakin, V.G Korsakov, V.V Popov, N.Y Artsutanov, Dispersing effects on the donor-acceptor properties of the surface of ferroelectrics Russian Journal of Physical Chemistry 76 (9) (2002) 1472-1475 [3] S.V Myakin, V.G Korsakov, T.I Panova, E.A Sosnov, Yu.C Fomchenkova, M M Sychov, O.A Shilova, Effect of the Modification of Barium Titanate on the Permittivity of Its Composites with Cyanoethyl Ester of Polyvinyl Alcohol Glass Physics and Chemistry 37(6) (2011) 624-628 Larisa Svatovskaya et al / Procedia Engineering 165 (2016) 1771 – 1775 1775 [4] G Korsakov, S A Alekseev, M M Sychov, M N Tsvetkova, E V Komarov, B Lee, S V Myakin, and V Vasil’eva, Estimation of the Permittivity of Polymeric Composite Dielectrics from the Surface Characteristics of the Filler Using a Thermodynamic Model Russian Journal of Applied Chemistry 80(11) (2007) 1931-1935 [5] L.B Svatovskaya, M.M Sychov, Activated hardening of cement, (Leningrad, Building-published house, 1983) [6] L B Svatovskaya, L.L Maslennikova and others Thermodynamical and electronic aspects of the building materiel properties, St.Peterburg, Building published house, 2004 [7] M.M Sychov, S.V Mjakin, Y Nakanishi, V.G Korsakov, I.V Vasiljeva, V.V Bakhmetjev, O.V Solovjeva, E.V Komarov Study of active surface centers in electroluminescent ZnS:Cu,Cl phosphors Appl Surf Sc 244(1-4) (2005) 461-464 [8] V G Korsakov, S A Alekseev, M M Sychev, M N Tsvetkova, E V Komarov, B Lee, S V Myakin, and I V Vasil’eva Estimation of the Permittivity of Polymeric Composite Dielectrics from the Surface Characteristics of the Filler Using a Thermodynamic Model Russian Journal of Applied Chemistry 80(11) (2007) 1931–1935 [9] M.M Sychov, N.V Zakharova, S.V Mjakin Effect of milling on the surface functionality of BaTiO3 - CaSnO3 ceramics Ceramics International 39 (2013) 6821–6826 [10] Bakhmet'ev V.V., Sychev M.M., Korsakov V.G A model of active acid-base surface sites for zinc sulfide electroluminescent phosphors Russian Journal of Applied Chemistry 83(11) (2010) 1903-1910 [11] M Sychov, Y Nakanishi, H Kominami, Y Hatanaka, and K Hara Optimization of Low-Voltage Cathodoluminescence of ElectronBeam-Evaporated Y2O3:Eu Thin Film Phosphor Jap J of Appl Phys.47(9) (2008) 7206-7210 [12] Sychov, M., Nakanishi, Y., Vasina, E., Eruzin, A., Mjakin, S., Khamova, T., Shilova, O., Mimura, H Core-shell approach to control acidbase properties of surface of dielectric and permittivity of its composite, Chem Letters 44(2) (2015) [13] S.V.Myakin, M.M.Sychov, E.S.Vasina, A G Ivanova, O A Zagrebel’nyi, I.N.Tsvetkova, O.A Shilova Relationship between the composition of functional groups on the surface of hybrid silicophosphate membranes and their proton conductivity, Glass Physics and Chemistry 40(1) (2014) 97–98 [14] S V Mjakin, T S Minakova, V V Bakhmetyev, M M Sychov Effect of the surfaces of Zn3(PO4)2:Mn2+phosphors on their luminescent properties, Russian Journal of Physical Chemistry A January 90(1)(2016) 240-245 [15] L.B Svatovskaya and others «Improvement of the level of the concrete properties by means of surface modification», Transport construction (2016) 30-32 [16] L.B Svatovskaya and others «Geoecoprotective properties of building systems on the mineral binder base», Monogragh, PGUPS, 2016 [17] N Gubeljak, J Predan, D Kozak, J Tuma, B Kovacic, P Konjatic, J Sertic, Strojarstvo 51(4) (2009) 263-271 [18] B Kovacic, R Kamnik, M Premrov, N Gubeljak, J Predan, Z Tisma, Strojniski Vestnik, Journal of Mechanical Engineering 54(5) (2008) 364-371 [19] W Greiner, L Neisse, H Stocker «Thermodynamics and statistical mechanics», Springer-Verlag, 1995 [20] V.V Bakhmet'ev, M.M Sychev, V.G Korsakov A Model of Active Acid-Base Surface Sites for Zinc Sulfide Electroluminescent Phosphors, Russian Journal of Applied Chemistry 83(11) (2010) 1903-1910 [21] M Hammady «The metod of the modification of the concrete by means of nanosolution», www.spgasu.ru [22] P Perrot «A to Z of Thermodynamics», Oxford University Press (2004) [23] M Gravit, S Antonov, O Nedryshkin, E Nedviga, V Pershakov Fire Resistant Panels for the Tunnel Linings, MATEC Web Conf, 73 (2016) DOI: http://dx.doi.org/10.1051/matecconf/20167304 ... Because of the formation of new calcium silicate hydrates, the improvement of the construction properties is observed And because of formation of hydroxides of heavy metal ions, the detoxication of. .. lithosynthesis In the table is shown the derection of the improvement of the geoecoprotective properties according to the thermodynamic parameters of the building construction Table Thermodynamic... (purification of water from heavy metal ions) The strengthening provides the durability of the underground construction and because of that it can be named as ? ?geoecoprotective? ?? one The detoxication of