Towards prediction of the thermal spalling risk through a multi-phase porous media model of concrete

Gawin, Dariusz; Pesavento, Francesco; Schrefler, B. A.

doi:10.1016/j.cma.2005.10.021

Cited by 138 publications

(95 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For this reason, even after several tens of minutes of fire duration the temperature of the inner part of wall remains almost unchanged [15]. Due to moisture evaporation, the water content in the surface zone decreases to a very low value and a sharp front, separating the moist and dry material, moves slowly inwards, see Figure 2.…”

mentioning

confidence: 99%

“…At this front intensive evaporation takes place, increasing considerably the vapor pressure. The maximum values of vapor and gas pressures increase initially, [32], then they remain constant as the surface temperature increases and the front moves inwards [15].…”

mentioning

confidence: 99%

“…The maximum value of gas pressure usually occurs at the position where the temperature equals $160°C to 220°C, [15]. In the region with lower temperatures, below about 130°C, the gas pressure increase is caused mainly by a growth of the dry air pressure due to heating.…”

mentioning

confidence: 99%

“…In the regions with higher temperature the effects of a rapid increase of vapor pressure due to heating and temperature-dependence of the saturation vapor pressure predominate. At temperatures 160°C to 350°C the gas in the material pores consists mainly of water vapor [15]. The gradients of vapor pressure (and related gradients of vapor concentration) cause the vapor flow (due to advection and diffusion) both towards the surface and inwards.…”

mentioning

confidence: 99%

“…The highest values of gas pressure usually correspond to the temperatures 170°C to 280°C [32], and this is also the range where thermal spalling of concrete occurs. Physical causes of the phenomenon, and in particular a role played by elastic strain energy of a constrained thermal dilatation accumulated in the surface layer and by a high value of gas pressure, are discussed in detail in [15].…”

mentioning

confidence: 99%

See 4 more Smart Citations

An Overview of Modeling Cement Based Materials at Elevated Temperatures with Mechanics of Multi-Phase Porous Media

Gawin

Pesavento

2011

Fire Technol

View full text Add to dashboard Cite

Abstract. Application of mechanics of multi-phase porous media for modeling cement based materials at high temperature is presented. The considerations are based on the mathematical model of mechanistic type, developed by the authors within recent years. The model has been previously experimentally validated and successfully applied for analyzing performance of various concrete structures at high temperature. Physical phenomena in a concrete element heated during a fire are described and analyzed, confirming multi-phase nature of concrete in these conditions. Main stages of the mathematical model development by means of hygrothermo-mechanics of porous media are briefly presented. The mass, energy and linear momentum conservation equations at micro-scale are given and averaged in space to obtain the macroscopic form of the equations. Some main key-points in modeling cement-based materials at high temperature are discussed. Final form of the model equations and method of their numerical solution are presented. The model is validated by comparison with some published results of experimental studies. Two examples of the model application for numerical simulation of concrete structures exposed to fire conditions, including also a cooling phase, are analyzed.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

An Overview of Modeling Cement Based Materials at Elevated Temperatures with Mechanics of Multi-Phase Porous Media

Gawin

Pesavento

2011

Fire Technol

View full text Add to dashboard Cite

show abstract

Computational Concrete Mechanics

Lackner

Pichler

Traxl

et al. 2017

Encyclopedia of Computational Mechanics Second Edition

View full text Add to dashboard Cite

This chapter contains a report on recent developments in the field of computational concrete mechanics, introducing the multiscale concept for simulation of cement‐based materials and, in case of reinforced concrete Reinforced Concrete (RC), of the steel–concrete interaction. Within the framework of this concept, several scales of observation are considered simultaneously in the numerical analysis. Alternatively, material properties, which serve as input for macroscopic analyses, are related to properties of the material phases and their assemblage at finer scales of observation. The benefits of multiscale approaches in computational concrete mechanics are illustrated by the analysis of real‐life structures subjected to various loading conditions, including mechanical loading and thermal and chemical attacks. Macroscopic material properties for plain and reinforced concrete that are related to finer scales of observation are employed.

show abstract

Sensitivity analysis applied to finite element method model for coupled multiphase system

Nanhorngue

Pesavento

Schrefler

2012

Num Anal Meth Geomechanics

Self Cite

View full text Add to dashboard Cite

Today multiphysics problems applied to various fields of engineering have become increasingly impor- tant. Among these, in the areas of civil, environmental and nuclear engineering, the problems related to the behaviour of porous media under extreme conditions in terms of temperature and/or pressure are particularly relevant. The mathematical models used to solve these problems have an increasing complexity leading to increase of computing times. This problem can be solved by using more effective numerical algorithms, or by trying to reduce the complexity of these models. This can be achieved by using a sensitivity analysis to determine the influence of model parameters on the solution. In this paper, the sensitivity analysis of a mathematical/numerical model for the analysis of concrete as multiphase porous medium exposed to high temperatures is presented. This may lead to a reduction of the number of the model parameters, indicating what parameters should be determined in an accurate way and what can be neglected or found directly from the literature. Moreover, the identification parameters influence may allow to proceeding to a simplification of the mathematical model (i.e. model reduction). The technique adopted in this paper to performing the sensitivity analysis is based on the automatic differentiation (AD), which allowed to develop an efficient tool for the computation of the sensitivity coefficients. The results of the application of AD technique have been compared with the results of the more standard finite difference method, showing the superiority of the AD in terms of numerical accuracy and execution times. From the results of the sensitivity analysis, it follows that a drastic simplification of the model for thermo-chemo-hygro-mechanical behaviour of concrete at high temperature, is not possible. Therefore, it is necessary to use different model reduction techniques in order to obtain a simplified version of the model that can be used at industrial level

show abstract

Towards prediction of the thermal spalling risk through a multi-phase porous media model of concrete

Cited by 138 publications

References 25 publications

An Overview of Modeling Cement Based Materials at Elevated Temperatures with Mechanics of Multi-Phase Porous Media

An Overview of Modeling Cement Based Materials at Elevated Temperatures with Mechanics of Multi-Phase Porous Media

Computational Concrete Mechanics

Sensitivity analysis applied to finite element method model for coupled multiphase system

Contact Info

Product

Resources

About