ACTIVATION OF CEMENT AND ITS INFLUENCE ON STRUCTURE FORMATION OF CEMENT-CONTAINING COMPOSITIONS
DOI:
https://doi.org/10.31650/2786-6696-2023-6-82-89Keywords:
cement, activation, exothermic heating, mechanically activated binder.Abstract
The article discusses issues related to the mechanochemical activation of the cement binder in a specially designed rotary counterflow mill. The given brief description of the design of a counterflow mill gives a general idea of the principle of its operation as an activator of the surface zone of a mineral binder. Typically, a positive characteristic of mineral binders is their rapid increase in strength. Therefore, scientific research related to the development of technology aimed at intensifying the processes of structure formation of cement paste and stone based on it is relevant. The use of this technology makes it possible to significantly increase the specific surface area of cement during its activation, reduce the setting time, increase the amount of chemically bound water and intensify the exothermic heating of hardening cement stone. The presented experimental data made it possible to optimize the activation period of the binder, which ranged from 60 to 600 seconds. It has been established that the optimal time from the point of view of the energy intensity of the process is the activation period of the binder for 300 seconds. During this activation period, there is an increase in the specific surface area of cement by an average of 8...10%, acceleration of setting time by 50...60 minutes, an increase in the amount of chemically bound water at 28 days of age from 13 to 16.3%, an increase in the maximum temperature of exothermic heating cement stone from 53.8 to 64.0 °C. A further increase in the activation period (up to 600 seconds) has little effect on the change in the listed properties. The effect of mechanochemical activation is significantly reflected in the compressive strength of cement stone. It has been established that activation of cement for 300 seconds causes an increase in the compressive strength of cement stone from 48 to 57 MPa, that is, by almost 20%. The effect of mechanochemical activation of cement is enhanced by the introduction of quartz sand into its composition. It has been experimentally established that the activation of cement with the addition of 20% quartz sand increases the strength of the filled cement stone by almost 30% relative to the strength of the stone using unadded cement that is not subject to mechanical activation.
References
[1] V.Iu. Sokoltsov, H.S. Shpiler, "Vplyv stanu kremnezemu na yoho reaktsiinu zdatnist", Mat-ly VI mizhnarodnoi naukovo-tekhnichnoi WEB konferentsii "Kompozytsiini materialy", Kyiv: NTTU. KPI, 2012, pp. 64-66.
[2] L.I. Dvorkin, O.L. Dvorkin, Proektuvannia skladiv betoniv. Monohrafiia. Rivne: NUVHP, 2015.
[3] L.I. Dvorkin, Vysokomitsni shvydkotverdnuchi betony ta fibrobetony. Dvorkin L.I., Babych Ye.M., Zhytkovskyi V.V., Bordiuzhenko O.M., Kochkarov D.V., Filipchuk S.V., Kovalyk I.V., Kovalchuk T.V., Skrypnyk M.M. Rivne: NUVHP, UNSPECIFIED, 2017.
[4] Johann Plank, Christian Hirsch, "Impact of zeta potenzial of early cement hydration phases on superplasticizer adsorption", Cement and Concrete Research: Germany, no. 37, pp. 537-542, 2007.
[5] O.V. Usherov-Marshak, Khimichni i mineralni dobavky v beton. Kharkiv: Koloryt, 2005.
[6] A.V. Usherov-Marshak, A.V. Kabus, "Funktsionalno-kineticheskii analiz vliyaniya dobavok na tverdenie tsementov", Neorganicheskie materiali, Tom 52, no. 4, pp. 479-484, 2016.
[7] Kh.S. Sobol, "Kontseptsiia zastosuvannia modyfikovanykh kompozytsiinykh tsementiv u budivelnomu vyrobnytstvi", Visnyk NULP: Teoriia i praktyka budivnytstva, no. 520, pp.179-182, 2004.
[8] Kh.S. Sobol, T.Ie. Markiv, M.A. Sanytskyi, H.V. Kohuch, "Vplyv aktyvnykh mineralnykh dodatkiv na vlastyvosti kompozytsiinykh tsementiv", Visnyk NULP: Khimiia, tekhnolohiia rechovyn ta yikh zastosuvannia, no. 488, pp. 274-278, 2003.
[9] V.V. Tokarchuk, V.Iu. Sokoltsov, V.A. Sviderskyi, "Vplyv skladu mineralnykh dobavok na vlastyvosti tsementiv", Tekhnologicheskii audit i rezervi proizvodstva, no. 3(5), pp. 9-12, 2014.
[10] Z. Giergiczny, J. Malolepszy, J. Szwabowski, J. Sliwinski, Cementy z dodatkami mineralnymi w technologii betonow nowei generacji. Gorazdze cement. Opole, 2002.
[11] Composite cements modified by chemical admixtures. Proc. International conference. Kosice (Slovakia), 2005. pp. 102-107.
[12] R.F. Runova, Yu.L. Nosovskyi, Tekhnolohiia modyfikovanykh budivelnykh rozchyniv. Kyiv: KNUBA, 2007.
[13] T. Kropyvnytska, M. Sanytsky, J. Geviuk, "Properties of Portland-composite cements with zeolite tuff", Journal of Civil Engineering Environment and Architecture, JCEEA, T.XXXV, no. 65(3/18), pp. 25-34, 2018.
[14] V.V. Troian, Dobavky dlia betoniv i budivelnykh rozchyniv. Kyiv: Aspekt-Polihraf, 2010.
[15] I.V. Barabash, Mekhanokhimichna aktyvatsiia mineralnykh viazhuchykh rechovyn. Odesa: Astroprynt, 2002.
[16] I.V. Barabash, I.M. Babii, K.O. Streltsov, "Intensive separate technology and its influence on the properties of cement-water compositions, solutions and concretes on their basis", Modern construction and architecture, Issue no. 2, pp. 44-51, 2022.
[17] G. Khainike, Tribokhimiya. Moskva: Mir, 1987.
[16] D.O. Pirohov, I.V. Barabash, "Vplyv rezhymu aktyvatsii na vlastyvosti tsementu, tsementnoho tista ta kameniu na yoho osnovi", Zbirnyk tez mizhnarodnoi naukovo-tekhnichnoi konferentsii "Strukturoutvorennia ta ruinuvannia kompozytsiinykh budivelnykh materialiv ta konstruktsii", Odesa: ODABA. 2023, pp.109-110.
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