Influence of Magnetite on Electrical Conductivity of Mortar Mix

Results of the study of influence of a magnetite additive on the electric conductivity of mortar mix and strength characteristics of cement mortar after hardening are presented. The research was conducted when the magnetite powder of different dispersion was included in the mortar composition. Particles of magnetite of the size smaller that 0.1 mm were used as the first additive. The fine powder with the size of particles of 258±74 nm, obtained as a result of grinding the magnetite at the planetary ball mill, served as the second additive. Measuring the electrical conductivity of the mortar mix was carried out at the current frequency of 25 Hz – 1 kHz. Introduction of the magnetite powder in an amount of 1–20% of the cement mass in the composition of the mortar mix improves its electric conductivity, in particular, the current frequency of 50 Hz by 8–70%, at the current frequency of 120 Hz by 25–100%. The increase in the flexural strength of samples with addition of 3% of magnetite powder is 18.5%, when compressing – 30%. The introduction of the same amount of finely dispersed magnetite has led to increasing the flexural strength up to by 40%, compressive strength – up to by 20%.

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

Northern (Arctic) Federal University named after M.V. Lomonosov (17, Severnaya Dvina Embankment, Arkhangelsk, 163002, Russian Federation)

1. Chung D.D.L. Electrically conductive cement-based materials. Advances in Cement Research. 2014. Vol. 16. No. 4, pp. 167–176. 
2. Silvestre J., Silvestre N., de Brito J. Review on concrete nanotechnology. European Journal of Environmental and Civil Engineering. 2016. Vol. 20. No. 4, pp. 455–485. 
3. Nivethitha D., Srividhya S., Dharmar S. Review on mechanical properties of cement mortar enhanced with nanoparticles. International Journal of Science and Research (IJSR). 2016. Vol. 5. Iss. 1, pp. 913–916. https:// www.ijsr.net/archive/v5i1/NOV152794.pdf. 
4. Ильичев В.А., Мангушев Р.А. Справочник геотехника. Основания, фундаменты и подземные сооруже- ния. М.: АВС, 2016. 1040 с. 
4. Ilichev V.A., Mangushev R.A. Spravochnik geotekhnika. Osnovaniya, fundamenty i podzemnye sooruzheniya [Geotechnical handbook. Foundations engineering and underground constructions]. Moscow: АВС. 2016. 1040 p. 
5. Borucka-Lipska J., Kierno ycki W., Guskos N., Dudek M.R., Ho D.Q., Wolak W., Mar M., Kozio J.J., Kalaga J.K. On magnetite concentrate grains with respect to their use in concrete. International Journal of Engineering Research & Science. 2016. Vol. 2, pp. 97–103. 
6. Lee H.-S., Kwon S.-J. Effects of magnetite aggregate and steel powder on thermal conductivity and porosity in concrete for nuclear power plant. Advances in Materials Science and Engineering. 2016 Vol. 2016. http://dx.doi. org/10.1155/2016/9526251. 
7. Sikora P., Horszczaruk E., Cendrowski K., Mijowska E. The influence of nano-Fe₃O₄ on the microstructure and mechanical properties of cementitious composites. Nanoscale Research Letters. 2016. Vol. 11. DOI: 10.1186/ s11671-016-1401-1. 
8. Лесовик Р.В., Агеева М.С., Чернышева Н.В. Активация мелкозернистого бетона на железосодержащих техногенных песках магнитным полем // Вестник БГТУ им. В.Г. Шухова. 2011. № 1. С. 24–28. 
8. Lesovik, R.V., Ageeva M.S., Chernysheva N.V. Activation of fine-grained concrete containing ferriferous technogenic sands by magnetic field. Vestnik BGTU im. V.G. Shukhova. 2011. No. 1, pp. 24–28. (In Russian). 
9. Amin M.S., El-Gamal S.M.A., Hashem F.S. Effect of addition of nano-magnetite on the hydration characteristics of hardened Portland cement and high slag cement pastes. Journal of Thermal Analysis and Calorimetry. Vol. 112, No. 3, pp. 1253–1259. https://doi. org/10.1007/s10973-012-2663-1.