Engineering method for calculating the temperature field in the cross-section of hollow-core reinforced concrete slabs under a standard fire
DOI:
https://doi.org/10.33408/2519-237X.2026.10-1.24Keywords:
hollow-core reinforced concrete slabs, standard fire temperature regime, fire resistance, numerical modeling, full factorial experiment, heat engineering problem, Ansys Workbench, void ratioAbstract
Purpose. To develop an engineering methodology for calculating the temperature field in the cross-section of hollow-core reinforced concrete slabs (150–250 mm thick) with symmetrically located (relative to the center of gravity) closed circular hollows (40 to 60 % volume) under unilateral standard fire exposure. This methodology is based on adapting a simplified solution to the nonlinear heat conduction equation for solid slabs using correction factors obtained through numerical modeling and taking into account the cross-sectional geometry, point coordinates, and heating duration.
Methods. Numerical modeling of heating of reinforced concrete slabs during a standard fire using the finite element method based on the design of a full factorial experiment. This study summarizes the modeling results and analyzes the influence of the geometric parameters of cross-section of the hollow-core slabs and the duration of standard fire exposure on the temperature field generated within the slabs. An existing methodology for calculating the temperature field in solid slabs exposed to a standard fire is adapted for application to hollow-core slabs.
Findings. The influence of the geometric parameters of hollow-core reinforced concrete slabs (thickness, volume of enclosed circular cavities) on the temperature field dynamics in the cross-section (at a depth of up to 0.3 of the structure's thickness) under unilateral standard fire exposure lasting from 30 to 180 minutes was determined. A regression equation was derived for determining the khol coefficient, which accounts for the temperature increment at a given distance from the heated surface in hollow-core slabs compared to their solid counterparts under unilateral standard fire exposure. An engineering methodology for assessing the temperature field in hollow-core reinforced concrete slabs (150–250 mm thick with a volume of enclosed circular hollows of 40–60 %) under standard fire exposure was developed.
Application field of research. The research results can be used by specialists on design, expert, and scientific organizations to solve simplified heat engineering problems of fire resistance for hollow-core reinforced concrete slabs, as well as to improve existing regulatory legal acts.
References
Batyanovskiy E.I. Tekhnologiya betonnykh i zhelezobetonnykh izdeliy [Technology of concrete and reinforced concrete products]: tutorial. Minsk: Vysshaya shkola, 2017. 305 p. (rus)
Sokolov S.V., Vagner P. Otsenka obstanovki s pozharami v mire [Assessment of the fire situation in the world]. Fire and Explosion Safety, 2024. Vol. 33, No. 6. Pp. 67–84. (rus). DOI: https://doi.org/10.22227/0869-7493.2024.33.06.67-84. EDN: https://elibrary.ru/VYWRYO.
Korolev D.S., Bondarenko E.A. Ognestoykost' kak bazovyy element sistemy protivopozharnoy zashchity zdaniy i sooruzheniy [Fire resistance, as a basic element of the fire-fighting protection systems for buildings and facilities]. Pozharnaya bezopasnost': problemy i perspektivy, 2018. Vol. 1, No. 9. Pp. 423–425. (rus). EDN: https://elibrary.ru/YQIGQP.
Zaytsev A.M., Bolgov V.A. Chislennoe modelirovanie progreva stroitel'nykh konstruktsiy dlya opredeleniya koeffitsienta teplootdachi pri pozharakh [Numerical modeling heating construction for determining heat transfer coefficient in case of fire]. Vestnik Voronezhskogo instituta GPS MChS Rossii, 2015. Vol. 1, No. 14. Pp. 19–26. (rus). EDN: https://elibrary.ru/TSVNLR.
Palevoda I.I., Nekhan' D.S. Reshenie teplotekhnicheskoy zadachi ognestoykosti tsentrifugirovannykh zhelezobetonnykh kolonn [A solution to the thermal problem of fire resistance of spun reinforced concrete columns]. Fire and Explosion Safety, 2021. Vol. 30, No. 2. Pp. 49–70. (rus). DOI: https://doi.org/10.22227/PVB.2021.30.02.49-70. EDN: https://elibrary.ru/ONYDWP.
Ba G., Miao J., Zhang W., Liu C. Influence of cracking on heat propagation in reinforced concrete structures. Journal of Structural Engineering, 2016. Vol. 142, No. 7. Aticle 04016035. 11 p. DOI: https://doi.org/10.1061/(asce)st.1943-541x.0001483.
Shirko A.V., Kamlyuk A.N., Palevoda I.I., Zaynudinova N.V. Teplotekhnicheskiy raschet ognestoykosti elementov zhelezobetonnykh konstruktsiy s ispol'zovaniem programmoy sredy ANSYS [Thermal engineering calculation of fire resistance of reinforced concrete structure elements using the ANSYS environment program]. Vestnik Komandno-inzhenernogo instituta MChS Respubliki Belarus', 2013. No. 2 (18). Pp. 260–269. (rus). EDN: https://elibrary.ru/SNFAML.
Palevoda I.I., Zhamoydik S.M., Nekhan' D.S. Ognestoykost' zhelezobetonnykh kolonn s konstruktivnoy ognezashchitoy [Fire resistance of reinforced concrete columns with structural fire retardance]. Fire and Emergencies: Prevention, Elimination, 2022. No. 2. Pp. 67–81. (rus). DOI: https://doi.org/10.25257/FE.2022.2.67-81. EDN: https://elibrary.ru/OBMPXF.
Roytman V.M. Inzhenernye resheniya po otsenke ognestoykosti proektiruemykh i rekonstruiruemykh zdaniy [Engineering solutions for assessing the fire resistance of designed and reconstructed buildings]. Moscow: Association «Pozharnaya bezopasnost' i nauka», 2001. 382 p. (rus)
Grinfel'd G.M., Moiseev A.V. Metody optimizatsii eksperimenta v khimicheskoy tekhnologii [Methods for optimizing experiments in chemical technology]: lecture notes. Komsomolsk-on-Amur: Komso-molsk-na-Amure State University, 2014. 74 p. (rus). ISBN: 978-5-7765-1102-8.
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