CURRENT PROBLEMS OF HARDENING MONOLITHIC ROAD AND AERODROME CEMENT CONCRETE CURING

Studies of moisture loss from hardening monolithic cement concrete have been carried out. It was found that there is no consensus on the critical value of moisture loss from hardening concrete, at which shrinkage and cracking are possible, and there is no common understanding of the possible critical width of the shrinkage crack opening. It is shown that when the concrete hardens in air-dry conditions, its indicators, including durability, decrease by a factor of 2 or more. The critical value of moisture loss from hardening concrete was experimentally determined, which is 2 kg/m2. In this case, the deterioration of concrete properties as a result of rehydration of cement does not exceed 5 % and does not affect its durability. The possibility of restoring the properties of concretes, which were lost as a result of cracking during plastic shrinkage and contraction, has been experimentally proved if, after cracking, the concretes are placed for further hardening in a humid environment.

Bushlaibi, A. H., & Alshamsi, A. M. (2002). Efficiency of curing on partially exposed high-strength concrete in hot climate. Cement and concrete research, 32(6), 949-953. https://doi.org/10.1016/S0008-8846(02)00735-4

Domagala, L., Podolska, A. (2022) Effect of lightweight aggregate impregnation on selected concrete properties. Materials, 15(1), 198. https://doi.org/10.3390/ma15010198

Fordyce, P., Yrjanson, W.A. (1969). Modern design of concrete pavements. Transportation Engineering Journal of ASCE / Volume 95 Issue 3. https://doi.org/10.1061/TPEJAN.0000036

Gjorv O.E., Sakai, K. (1999). Concrete technology for a sustainable development in the 21st century. CRC Press. https://doi.org/10.1201/9781482272215

Havlasek, P, Jirasek, M. (2016). Multiscale modeling of drying shrinkage and creep of concrete. Cement and Concrete Research / Volume 85, 55-74. https://doi.org/10.1016/j.cemconres.2016.04.001

Highways. Part 1 Design. Part 2 Construction: DBN V.2.3-4:2015. National Standard of Ukraine. (2015). Kyiv: Miniregion of Ukraine (in Ukrainian). Retrieved from https://online.budstandart.com/ua/catalog/doc-page.html?id_doc=82894

Instructions for the construction of rigid pavements for highways: DSTU-N B V.2.3-36:2016. National Standard of Ukraine. (2016). Kyiv: Ukrarkhbudinform (in Ukrainian). Retrieved from https://online.budstandart.com/ua/catalog/doc-page.html?id_doc=65405

James, T., Malachi, A., Gadzama, E. W., & Anametemok, A. (2011). Effect of curing methods on the compressive strength of concrete. Nigerian Journal of Technology, 30(3), 14-20. Retrieved from https://www.ajol.info/index.php/njt/article/view/123538

Mannan, M. A., Basri, H. B., Zain, M. F. M., & Islam, M. N. (2002). Effect of curing conditions on the properties of OPS-concrete. Building and environment, 37(11), 1167-1171. https://doi.org/10.1016/S0360-1323(01)00078-6

Pawar, Y., Kate, S. (2020). Curing of concrete: a review. Nternational Research Journal Of Engineering And Technology (IRJET), Volume: 07, Issue: 08, 1820-1824. doi:10.13140/RG.2.2.32095.07848

Raheem, A. A., Soyingbe, A. A., & Emenike, A. J. (2013). Effect of curing methods on density and compressive strength of concrete. International Journal of Applied Science and Technology, 3(4). Retrieved from https://www.researchgate.net/profile/Aa-Raheem-2/publication/302415335_Effect_of_curing_methods_on_density_ _and_compressive_strength_of_concrete/links/5885f3c84585150dde4a7e01/Effect-of-curing-methods-on-density-and-compressive-strength-of-concrete.pdf

Recommendations for testing film-forming materials for the care of freshly laid concrete: ODMD RF. National Standard of Russia. (2014). Moskow: Rosavtodor (in Russian). Retrieved from https://files.stroyinf.ru/Index2/1/4293766/4293766081.htm

Taylor, P. C. (2013). Curing concrete. Boca Raton, FL: CRC press. Retrieved from https://books.google.com.ua/books?hl=uk&lr=&id=4QRrAAAAQBAJ&oi=fnd&pg=PP...(2013).+Curing+concrete.+Boca+Raton,+FL:+CRC+press.&ots=y4mqUTg5JG&sig=FWAa1CoRoIkbJG54GYcfp8KlhNE&redir_esc=y#v=onepage&q=Taylor%2C%20P.%20C.%20(2013).%20Curing%20concrete.%20Boca%20Raton%2C%20FL%3A%20CRC%20press.&f=false

Tolmachev, S.M., Belichenko O.A., Moskalenko, O., & Pocusa, Y. (2021). Study of the influence of modern super plasticizers on the properties of road cement concrete, 74-79. Kharkiv: publishing house of KhNUBA. https://doi.org/10.30977/BUL.2219-5548.2021.92.2.74

Vyrovoy, V.N., & other. (1982). Optimization of waste-free and energy-saving technologies of composite materials, 24. Kiev: Publishing House of the Society “Knowledge”. Retrieved from https://search.rsl.ru/ru/record/01001128621