Method for identifying the strength characteristics of concrete of a reinforced concrete crossbar during heating under conditions of fire
DOI:
https://doi.org/10.15587/1729-4061.2023.282205Keywords:
reinforced concrete crossbar, concrete strength reduction factor, fire resistance, concrete strengthAbstract
This paper proposes a method that makes it possible to study the patterns of changes in the concrete strength of reinforced concrete crossbars depending on the heating temperature under fire conditions by interpreting the results of their standard fire tests. For the implementation of this method, it is proposed to use similar data obtained using mathematical modeling based on the finite element method and given material properties, including the curve of concrete strength reduction recommended by the guidelines, as data included in the set of measurement results during fire tests depending on temperature. Such data are time dependences of temperature indicators at individual cross-section points and time dependence of the maximum deflection of the crossbar. The article proposes an interpolation method that makes it possible to set the temperature at any point of the section based on the approximation of the isotherms by parabolas with a variable indicator of their power. A method based on the mathematical interpretation of temperature indicators obtained using the proposed interpolation method and the curve of the dependence of the maximum deflection on time using a deformation model for describing the stress-strain state is proposed to identify the dependence of the concrete strength of reinforced concrete crossbars.
The work also shows that the results obtained using the proposed method of identifying concrete strength reduction coefficients are adequate as their relative error is on average no more than 7 %. Based on the results, the possibility of its application to study the regularities of the decrease in the strength of reinforced concrete crossbars under fire conditions has been proven
References
- Liu, C., Zhou, B., Guo, X., Liu, C., Wang, L. (2023). Analysis and prediction methods for the static properties of reinforced concrete beams under fire. Structures, 47, 2319–2330. doi: https://doi.org/10.1016/j.istruc.2022.12.041
- Casandjian, C., Challamel, N., Lanos, C., Hellesland, J. (2013). Bibliography. Reinforced Concrete Beams, Columns and Frames, 279–292. doi: https://doi.org/10.1002/9781118639511.biblio
- Kodur, V., Banerji, S. (2020). Comparative fire behavior of reinforced concrete beams made of different concrete strengths. Proceedings of the 11th International Conference on Structures in Fire (SiF2020). doi: https://doi.org/10.14264/bd10594
- Quagliarini, E., Clementi, F., Maracchini, G., Monni, F. (2016). Experimental assessment of concrete compressive strength in old existing RC buildings: A possible way to reduce the dispersion of DT results. Journal of Building Engineering, 8, 162–171. doi: https://doi.org/10.1016/j.jobe.2016.10.008
- Johnson, R. P., Wang, Y. C. (2019). Composite Structures of Steel and Concrete: Beams, Slabs, Columns and Frames for Buildings. John Wiley & Sons. doi: https://doi.org/10.1002/9781119401353
- Dmitriev, I., Lyulikov, V., Bazhenova, O., Bayanov, D. (2019). Calculation of fire resistance of building structures in software packages. E3S Web of Conferences, 91, 02007. doi: https://doi.org/10.1051/e3sconf/20199102007
- De Souza, R. C. S., Andreini, M., La Mendola, S., Zehfuß, J., Knaust, C. (2019). Probabilistic thermo-mechanical finite element analysis for the fire resistance of reinforced concrete structures. Fire Safety Journal, 104, 22–33. doi: https://doi.org/10.1016/j.firesaf.2018.12.005
- Shchipets, S. D. (2014). Metod vyznachennia temperaturnykh poliv u pererizakh nesuchykh stin za rezultatamy yikh vyprobuvan na vohnestiykist. Naukovyi visnyk Ukrainskoho naukovo-doslidnoho instytutu pozhezhnoi bezpeky, 1 (29), 79–84.
- Kilpatrick, A. E., Gilbert, R. I. (2017). Simplified calculation of the long-term deflection of reinforced concrete flexural members. Australian Journal of Structural Engineering, 19 (1), 34–43. doi: https://doi.org/10.1080/13287982.2017.1368071
- EN 1992-1-2 (2004) (English): Eurocode 2: Design of concrete structures - Part 1-2: General rules - Structural fire design. Available at: https://www.phd.eng.br/wp-content/uploads/2015/12/en.1992.1.2.2004.pdf
- Nekora, O., Slovynsky, V., Pozdieiev, S. (2017). The research of bearing capacity of reinforced concrete beam with use combined experimental-computational method. MATEC Web of Conferences, 116, 02024. doi: https://doi.org/10.1051/matecconf/201711602024
- Gedam, B. A. (2021). Fire resistance design method for reinforced concrete beams to evaluate fire-resistance rating. Structures, 33, 855–877. doi: https://doi.org/10.1016/j.istruc.2021.04.046
- Shnal, T., Pozdieiev, S., Nuianzin, O., Sidnei, S. (2020). Improvement of the Assessment Method for Fire Resistance of Steel Structures in the Temperature Regime of Fire under Realistic Conditions. Materials Science Forum, 1006, 107–116. doi: https://doi.org/10.4028/www.scientific.net/msf.1006.107
- Kovalyshyn, V., Pozdieiev, S., Fedchenko, S. (2018). Concrete walls conduct under the fireinfluence investigationusing final elements method. Zbirnyk naukovykh prats ChIPB imeni Heroiv Chornobylia NUTsZ Ukrainy «Nadzvychaini sytuatsiyi: poperedzhennia ta likvidatsiia», 4, 89–98. Available at: https://sci.ldubgd.edu.ua/jspui/handle/123456789/6482
- Aliş, B., Yazici, C., Mehmet Özkal, F. (2022). Investigation of Fire Effects on Reinforced Concrete Members via Finite Element Analysis. ACS Omega, 7 (30), 26881–26893. doi: https://doi.org/10.1021/acsomega.2c03414
- Tsvetkov, R., Shardakov, I., Shestakov, A., Gusev, G., Epin, V. (2017). Deformation monitoring of load-bearing reinforced concrete beams. Procedia Structural Integrity, 5, 620–626. doi: https://doi.org/10.1016/j.prostr.2017.07.028
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2023 Serhii Pozdieiev, Olga Nekora, Svitlana Fedchenko, Nataliya Zaika, Taras Shnal, Andriy Subota, Mykhailo Nesukh
This work is licensed under a Creative Commons Attribution 4.0 International License.
The consolidation and conditions for the transfer of copyright (identification of authorship) is carried out in the License Agreement. In particular, the authors reserve the right to the authorship of their manuscript and transfer the first publication of this work to the journal under the terms of the Creative Commons CC BY license. At the same time, they have the right to conclude on their own additional agreements concerning the non-exclusive distribution of the work in the form in which it was published by this journal, but provided that the link to the first publication of the article in this journal is preserved.
A license agreement is a document in which the author warrants that he/she owns all copyright for the work (manuscript, article, etc.).
The authors, signing the License Agreement with TECHNOLOGY CENTER PC, have all rights to the further use of their work, provided that they link to our edition in which the work was published.
According to the terms of the License Agreement, the Publisher TECHNOLOGY CENTER PC does not take away your copyrights and receives permission from the authors to use and dissemination of the publication through the world's scientific resources (own electronic resources, scientometric databases, repositories, libraries, etc.).
In the absence of a signed License Agreement or in the absence of this agreement of identifiers allowing to identify the identity of the author, the editors have no right to work with the manuscript.
It is important to remember that there is another type of agreement between authors and publishers – when copyright is transferred from the authors to the publisher. In this case, the authors lose ownership of their work and may not use it in any way.
