DOI: https://doi.org/10.32347/2410-2547.2019.103.43-56

Thermal stress state of reinforced concrete floor slab

Mariia Barabash, Maryna Romashkina, Olga Bashynska

Abstract


The article provides research of the stress-strain state of a reinforced concrete floor slab under fire conditions according to refined method. The finite element model of the slab is created. At the first stage of the research, one solved the unsteady heat conduction problem. According to the solution of the problem, it is possible to obtain the temperature fields all over the section of the considered structural element at certain intervals of time. The second stage of the study is strength analysis. Due to the strength evaluation, it is possible to investigate the work of the floor slab at different time points of fire exposure. Several mathematical models are considered. These models correspond to different points in time of fire impact. In each design model of the floor slab, the strength and deformation characteristics of concrete and reinforcement were deepen in accordance with the section temperature. It made three types of fire resistance analysis of the structure: linear analysis, physically-nonlinear analysis, and physically-nonlinear analysis with taking into account the effect of creep. The results of comparison of the kinetic performance of the mathematical models in various problem statements are showed. The technique, which allows to take into account the influence of creep in the numerical simulation of fire effect is proposed.


Keywords


finite elements methods; structures; thermal stress state; numerical experiments; thermal conductivity; comparisons

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References


Eurocode 2. Proyektuvannya zalіzobetonnikh konstruktsіy. Chastina 1-2. Zagalnі polozhennya.

Rozrakhunok konstruktsіy na vognestіykіst: DSTU-N EN 1992-1-2:2012 [Design of reinforced concrete structures. Part 1-2. General. Fireresistancecalculationofstructures] (EN 1992-1-2:2004, IDT).

STO 36554501-006-2006 Pravila po obespecheniyu ognestoykosti I ognesokhrannosti zhelezobetonnykh konstruktsiy [Rules to ensure fire resistance and fire protection of reinforced concrete structures], Moskva: 2006.

EN 1992-1-2 (20014): Eurocode 2: Design of concrete structures – Part 1-2: General rules – Structural fire design [Authority: the European Union Per regulation 305/2011, directive 98/34/EC, Directive 2044/18/EC].

Guide for Modeling and Calculating Shrinkage and Creep in Hardened Concrete: ACI 209.2R-08. – U.S.A., American Concrete Institute, 2008. 48 p. (Guide for modeling and calculating).

Barabash M.S. Kompyuternoye modelirovaniye protsessov zhiznennogo tsikla obyektov stroitelstva: Monografiya [Computer simulation of the life cycle processes of construction objects: Monograph]. K.: Izd-vo «Stal», 2014. 301 p.

Gorodetskiy A.S., Barabash M.S. Uchet nelineynoy raboty zhelezobetona v PK LIRA-SAPR. Metod «Inzhenernaya nelineynost» [Accounting of non-linear work of reinforced concrete in SP LIRA-SAPR. Method "Engineering nonlinearity"]. // International Journal for Computational Civil and Structural Engineering. 2016. №. 12 (2). Pp. 92-98.

Savin O.B., Sobol V.M. Zmishanyi variatsiinyi funktsional v zadachakh povzuchosti ta poshkodzhuvanosti sterzhniv pry zghyni [Mixed variational functional in the problems of creep and damage of rods at bending]// Strength of Materials and Theory of Structures, 2018. №100. Pp. 115-123.

Iakovenko I., Kolchunov V.l. (2017). The development of fracture mechanics hypotheses applicable to the calculation of reinforced concrete structures for the second group of limit states. Journal of Applied Engineering Science, vol. 15(2017)3, article 455, pp. 366–375.

Arutyunyan N.Kh. Nekotoryye voprosy teorii polzuchesti [Some questions of the theory of creep]. M.: Gostekhteorizdat, 1952. 323 p.

Aleksandrovskiy S.V. Raschet betonnykh I zhelezobetonnykh konstruktsiy na temperaturnyye I vlazhnostnyye vozdeystviya (s uchetom polzuchesti) [Calculation of concrete and reinforced concrete structures with temperature and humidity effects (including creep)]. M.: Stroyizdat, 1966. 443 p.

Bažant, Z.P., Jirásek M. Basic properties of concrete creep, shrinkage, and drying // Solid Mechanics and its Applications. 2018. №. 225. Рp. 29-62.

Bažant Z.P., Jirásek M. Numerical analysis of creep problems // Solid Mechanics and its Applications, №. 225. 2018. Рp. 141-175.

Bazant Z.P., Cusatis G., Cedolin L. Temperature effect on Concrete Creep Modeled by Microprestress-Solidification Theory // Journal of engineering mechanics. 2004. Рp. 691-699.

Rahimi-Aghdam, S., Rasoolinejad, M., Bažant, Z.P. Moisture Diffusion in Unsaturated Self-Desiccating Concrete with Humidity-Dependent Permeability and Nonlinear Sorption Isotherm // Journal of Engineering Mechanics. №. 145 (5). 2019.

Rasoolinejad, M., Rahimi-Aghdam, S., &Bazant, Z.P. Correction to: Statistical filtering of useful concrete creep data from imperfect laboratory tests. Materials and Structures/Materiaux et Constructions . 2018. №. 51 (6).

Hubler M., Wendner R., Bažant Z. Statistical justification of model B4 for drying and autogenous shrinkage of concrete and comparisons to other models // Mater Structures. 2015. №. 48(4). Pp. 797–814.

Wendner R., Hubler M., Bažant Z. Optimization method, choice of form and uncertainty quantification of model B4 using laboratory and multi-decade bridge databases // Mater Structures. 2015. №. 48(4). Pp. 771–796.

Wendner R., Hubler M., Bažant Z. Statistical justification of model B4 for multi-decade concrete creep using laboratory and bridge databases and comparisons to other models. MaterStructures. 2015. №. 48(4) . Pp. 815–833

Krukovskiy P.G., Kovalev A.I., Chernenko K.A. Modelirovaniye teplovogo sostoyaniya I ognestoykosti mnogopustotnogo zhelezobetonnogo perekrytiya [Simulation of thermal state and fire resistance of hollow-core reinforced concrete floor ] // Zbіrniknaukovikh prats LDU BZhD. 2012. №. 21. Pp. 85-94.

Fomin S.L. Raschet ognestoykosti zhelezobetonnykh plit perekrytiya po utochnennym I uproshchennym metodam [Fire resistance calculation of reinforced concrete slabs according to refined and simplified methods ] // Zbіrniknaukovikh prats UkrDUZT. 2016. №. 161. Pp. 145–157.

Pyskunov S.O., Shkryl O.O. Vyznachennia trishchynostiikosti zakhysnoi obolonky yadernoho reaktoru pry termosylovomu navantazhenni [Determination of the crack resistance of the protective shell of a nuclear reactor with a thermosetting load]// Strength of Materials and Theory of Structures, 2018. №101. Pp. 60–66.

Pyskunov S.O., Shkryl O.O. Vyznachennia trishchynostiikosti zakhysnoi obolonky yadernoho reaktoru pry termosylovomu navantazhenni [Influence of temperature regimes on the stress-strain state of structures] // Strength of Materials and Theory of Structures, 2018. №101. С. 103–110.

Bashinskaya O.Yu., Pikul A.V., Barabash M.S. Resheniye zadachi termopolzuchesti betona metodom konechnykh elementov [Solution of the problem of concrete thermocreepiness by the finite element method] // sb. nauchn. trudov «Stroitelstvo. Materialovedeniye. Mashinostroyeniye», 2017. №. 99. Pp. 22-29.

BashinskayaO.Yu., Barabash M.S., Pikul A.V. Chislennoye modelirovaniye tsiklicheskogo temperaturnogo rezhima ekspluatatsii v PK «Lira-SAPR» [Numerical simulation of cyclic temperature model operation on the SP "Lira-SAPR"] // Vіsnik Odeskoї derzhavnoi akademіi budіvnitstva ta arkhіtekturi, 2017. №. 67. Pp. 13-19.

Diez P., Rodenas J.J., Zienkiewicz O.C. Equilibrated Patch Recovery error estimates: simple and accurate upper bounds of the error // International Journal for Numerical Methods in Engineering. 2007. №. 69 (10). Pp. 2075–2098.

Samuelsson A., Zienkiewicz O.C. History of the stiffness method // International Journal for Numerical Methods in Engineering. 2006. №. 67. Pp. 149–157.

Ibrahimbegovic A., Melnyk S. Embedded discontinuity finite element method for modeling of localized failure in heterogeneous materials with structured mesh: an alternative to extended finite element method // Computational Mechanics. 2007. №. 40 (1). Pp. 149–155.

Bazhenov V.A., Gulyar A.I., Maiboroda E.E., Piskunov S.O. Semianalytic Finite-Element Method in Continuum Creep Fracture Mechanics Problems for Complex-Shaped Spatial Bodies and Related Systems. Part 1. Resolving Relationships of the Semianalytic Finite-Element Method and Algorithms for Solving the Continuum Creep Fracture Problems // Strength of Materials. 2002. №. 34 (5). Pp. 425–433.


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