Fedchenko S. Improvement of the method of calculating the fire resistance of reinforced concrete beams and crossbars

Українська версія

Thesis for the degree of Doctor of Philosophy (PhD)

State registration number

0824U000025

Thesis Registration Form

0824U000025.pdf

Applicant for

Specialization

  • 261 - Пожежна безпека

Specialized Academic Board

4240

Cherkasy Fire Safety Institute named after Heroes of Chernobyl, National University of Civil Protection of Ukraine

Essay

The scientific novelty of the dissertation consists in revealing the patterns of changes in temperature distributions and strength of concrete in cross-sections of reinforced concrete beams and crossbars depending on the duration of thermal exposure to the standard fire temperature regime. At the same time: 1. For the first time, the regularities of the dependences of the parameters of the interpolation functionals, which describe the temperature distribution in the cross-section of reinforced concrete cross-sections, from the time of tests under high temperature conditions for predicting the strength degradation of concrete and reinforcing steel of the cross-sections have been revealed. 2. For the first time, the method of identifying the dependence of the coefficient of reduction of concrete strength on temperature was proposed, based on the interpolation of temperature distributions in the cross-sections of reinforced concrete cross-sections during their fire tests based on point temperature measurements in the concrete layers and the deformation mathematical model of the stress-strain state of the cross-sections under the conditions of thermal exposure of the standard fire temperature regime. 3. For the first time, the regularity of the temperature dependence of the coefficient of reduction of concrete strength for reinforced concrete beams and crossbars in the conditions of their fire tests was revealed using the proposed method of its identification. 4. The method of calculating the fire resistance of reinforced concrete beams and crossbars under the influence of the standard fire temperature regime has been improved as a result of using the obtained temperature dependence of the concrete strength reduction factor as part of the initial data to determine the time of onset of the limit state based on the loss of bearing capacity based on the solution of the strength problem according to the deformation mathematical model. 5. The field of application of the improved method of calculating the fire resistance of reinforced concrete building structures has gained further development, and the possibility of its application to assess the fire resistance of reinforced concrete beams and crossbars under the influence of the standard fire temperature regime, which allows more precisely determining the fire resistance class of the building structure based on the determination of the actual fire resistance limit, has been scientifically substantiated.

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Research papers

1. Федченко С. М. Дослідження зниження міцності бетону залізобетонного ригеля в умовах вогневих випробувань. Комунальне господарство міст.Серія: Технічні науки та архітектура. Харків: ХНУМГ ім. О.М. Бекетова. 2023. Т. 6. № 180. С. 176-186. https://khg.kname.edu.ua/index.php/khg/article/view/6208/6127

2. Федченко С. Обґрунтування методу ідентифікації механічних характеристик бетону залізобетонних ригелів за результатами вогневих випробувань. Надзвичайні ситуації: попередження та ліквідація: зб. наук. праць. Черкаси: ЧІПБ ім. Героїв Чорнобиля НУЦЗ України. 2023. Т. 7. № 1. С. 149-157. DOI: https://doi.org/10.31731/2524.2636.2023.7.1.149.157

3. Сідней С., Кобко В., Федченко С., Змага М., Заїка Н. Удосконалення зонного методу перевірки вогнестійкості пустотної плити. Надзвичайні ситуації: попередження та ліквідація: зб. наук. праць. Черкаси: ЧІПБ ім. Героїв Чорнобиля НУЦЗ України. 2022. Т. 6. № 1. С. 95–103. DOI: https://doi.org/10.31731/2524.2636.2022.6.1.95-102

4. Гвоздь В., Некора О., Сідней С., Неділько І., Федченко С., Тищенко Є. Дослідження вогнестійкості елементів сталевих каркасів промислових будівель з врахуванням рівня механічного навантаження. Надзвичайні ситуації: попередження та ліквідація: зб. наук. праць. Черкаси: ЧІПБ ім. Героїв Чорнобиля НУЦЗ України. 2021. Т. 5. № 1. С. 40–49. DOI: https://doi.org/10.31731/2524-2636.2021.5.1.-40–49

5. Kovalyshyn V., Pozdieiev S., Fedchenko S. Concrete walls conduct under the fireinfluence investigationusing final elements method. Надзвичайні ситуації: попередження та ліквідація: зб. наук. праць. Черкаси: ЧІПБ ім. Героїв Чорнобиля НУЦЗ України. Т. 4. 2018. С. 89–98. URI: https://fire-journal.ck.ua/index.php/fire/issue/view/4

6. Pozdieiev S., Nekora O., Fedcнenko S., Shnal T. Method of Identification of Mechanical Characteristics of Concrete of Reinforced Concrete Crossbars according to the Results of Fire Tests Construction Technologies and Architecture. Trans Tech Publications Ltd. 2023. C. 9 P. 59 - 66. DOI: https://doi.org/10.4028/p-kev0Ho

7. Pozdieiev S., Nekora O., Fedchenko S., Zaika N., Shnal T., Subota A., Nesukh M. Method for identifying the strength characteristics of concrete of a reinforced concrete crossbar during heating under conditions of fire. Eastern-European Journal of Enterprise Technologies. №3 (7(123)). 2023. DOI: https://doi.org/10.15587/1729-4061.2023.282205

8. Pozdieiev S., Shnal T., Kholod P., Fedchenko S., Nedilko I. Evaluation of fire resistance of reinforced concrete beams on the basis of use of parametric temperature curves of fire modes. AІР conference proceedings «Reliability and durability of railway transport engineering structure and buildings». Kharkiv:Ukrainian state university of railway transport. AIP 2684. 030034 (31.05.2023). DOI: https://doi.org/10.1063/5.0120002

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