scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Numerical analysis of hygro-thermal behaviour and damage of concrete at high temperature

01 Jan 1999-Mechanics of Cohesive-frictional Materials (John Wiley & Sons, Ltd.)-Vol. 4, Iss: 1, pp 37-74
TL;DR: In this article, a computational analysis of hygro-thermal and mechanical behavior of concrete structures at high temperature is presented, and the evaluation of thermal, hygral and mechanical performance of this material, including damage effects, needs the knowledge of the heat and mass transfer processes.
Abstract: A computational analysis of hygro-thermal and mechanical behaviour of concrete structures at high temperature is presented. The evaluation of thermal, hygral and mechanical performance of this material, including damage effects, needs the knowledge of the heat and mass transfer processes. These are simulated within the framework of a coupled model where non-linearities due to high temperatures are accounted for. The constitutive equations are discussed in some detail. The discretization of the governing equations is carried out by Finite Elements in space and Finite Differences in time. Copyright © 1999 John Wiley & Sons, Ltd.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, a mathematical model for analysis of hygrothermal behavior of concrete as a multi-phase porous material at high temperatures, accounting for material deterioration, is presented, starting from macroscopic balances of mass, energy and linear momentum of single constituents.

271 citations

Journal ArticleDOI
TL;DR: In this article, a new numerical model of hygro-thermal and hydration phenomena in concrete at early ages and beyond is presented, where all changes of material properties are expressed as functions of hydration degree, and neither as maturity nor as equivalent hydration period.
Abstract: Part 1 of the paper presents a new numerical model of hygro-thermal and hydration phenomena in concrete at early ages and beyond. This is a solidification-type model where all changes of material properties are expressed as functions of hydration degree, and neither as maturity nor as equivalent hydration period as in maturity-type models. A mechanistic approach has been used to obtain the governing equations, by means of an averaging theory of Hassanizadeh and Gray, also called hybrid mixture theory. The developments start at the micro-scale and balance equations for phases and interfaces are introduced at this level and then averaged for obtaining macroscopic balance equations. Constitutive laws are directly introduced at macroscopic level. The final equations, mass (water species and dry air), energy and momentum balance equations, have been written in terms of the chosen primary variables: gas pressure, capillary pressure, temperature and displacements. An evolution equation for the internal variable, hydration degree, describes hydration rate as a function of chemical affinity, considering in addition to the existing models, an effect of the relative humidity on the process. The model takes into account full coupling between hygral, thermal and chemical phenomena, as well as changes of concrete properties caused by hydration process, i.e. porosity, density, permeability, and strength properties. Phase changes and chemical phenomena, as well as the related heat and mass sources are considered. Two examples showing possibilities of the model for analysis of autogenous self-heating and self-desiccation phenomena, as well as influence of the ambient relative humidity and the concrete element dimensions upon hygro-thermal performance and shrinkage of the elements, are presented and discussed. Copyright © 2006 John Wiley & Sons, Ltd.

268 citations

Journal ArticleDOI
TL;DR: In this paper, the authors analyzed the effect of the amount of polypropylene (PP) fibers on the spalling behavior of normal-strength in-situ concrete without and with PP-fibers (1.5 kg/m3).

227 citations

Journal ArticleDOI
TL;DR: In this paper, a fully coupled non-linear formulation is designed to predict the behaviour and potential for spalling, of heated concrete structures for fire and nuclear reactor applications, with emphasis placed upon the real processes occurring in concrete during heated based on tests carried out in several major laboratories around Europe as part of the wider HITECO research programme.
Abstract: This paper presents the basic principles and details of the physical, mathematical and numerical models forming the main structure of the numerical analysis of the thermal, hydrol and mechanical behaviour of normal, high-performance and ultra-high performance concrete structures subjected to heating. A fully coupled non-linear formulation is designed to predict the behaviour and potential for spalling, of heated concrete structures for fire and nuclear reactor applications. Concrete is considered as a multiphase material consisting of a solid phase, two gas phases and three water phases. The physical model is described with emphasis being placed upon the real processes occurring in concrete during heated based on tests carried out in several major laboratories around Europe as part of the wider HITECO research programme. Examples of preliminary outputs are presented in the form of isoline diagrams compared with those obtained from experiment.

217 citations

Journal ArticleDOI
TL;DR: Gawin et al. as mentioned in this paper investigated damage-temperature-stress level-permeability interactions in structural concrete and found that at lower than 80% of the peak stress, the variation of permeability is small and it is slightly influenced by the stress.

216 citations


Cites background or result from "Numerical analysis of hygro-thermal..."

  • ...[18] a power type relationship between the temperature and the permeability of concrete may be considered....

    [...]

  • ...Our experimental results are also consistent with the formula proposed by Gawin and coworkers [18]....

    [...]

References
More filters
Book
01 Jan 1989
TL;DR: In this article, the methodes are numeriques and the fonction de forme reference record created on 2005-11-18, modified on 2016-08-08.
Abstract: Keywords: methodes : numeriques ; fonction de forme Reference Record created on 2005-11-18, modified on 2016-08-08

17,327 citations

Book
01 Jan 1972
TL;DR: In this paper, the Milieux poreux Reference Record was created on 2004-09-07, modified on 2016-08-08 and the reference record was updated in 2016.
Abstract: Keywords: Ecoulement souterrain ; Milieux poreux Reference Record created on 2004-09-07, modified on 2016-08-08

12,446 citations

Book
01 Jan 1979
TL;DR: The reference record was created on 2004-09-07, modified on 2016-08-08 as discussed by the authors, using the reference record of the Ecoulement souterrain reference record.
Abstract: Keywords: Ecoulement souterrain Reference Record created on 2004-09-07, modified on 2016-08-08

2,933 citations

Book
01 Jan 1988
TL;DR: In this article, the authors present the definitive work on the subject by one of the world's foremost hydrologists, designed primarily for advanced undergraduate and graduate students of ground water hydrology, soil mechanics, soil physics, drainage and irrigation engineering and sanitary, petroleum and chemical engineering.
Abstract: This is the definitive work on the subject by one of the world's foremost hydrologists, designed primarily for advanced undergraduate and graduate students of ground water hydrology, soil mechanics, soil physics, drainage and irrigation engineering, and sanitary, petroleum and chemical engineering. 335 black-and-white illustrations. Exercises, with answers.

1,616 citations

Book ChapterDOI
TL;DR: In this article, the authors present a general theory that provides a starting point for the construction of special theories so that various drying processes can be studied analytically without recourse to an enormous computational effort.
Abstract: Publisher Summary The well-known transport equations for continuous media are used to construct a rational theory of simultaneous heat, mass, and momentum transfer in porous media. Several important assumptions regarding the structure of the gas–liquid system in a drying process are made that require theoretical or experimental confirmation. This chapter presents a general theory that provides a starting point for the construction of special theories so that various drying processes can be studied analytically without recourse to an enormous computational effort. It analyzes the motion of a liquid and its vapor through a rigid porous media. The development of the relevant volume averaged transport equations, which describe the drying process, is also focused. The transport of momentum in the gas phase and the laws of mechanics are applied to the drying process. The thermal energy equations are considered by forming the total thermal energy equation, and the problem of determining the mass average velocities in the gas and liquid phases are also discussed.

1,062 citations