Water distribution in concrete beams

Title: Water distribution in concrete beams
Author(s): S. Multon, F. Toutlemonde
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
ISSN: 1359-5997
Publisher: RILEM Publications SARL
Volume: 37
Issue: 270
Issue date: 2004-07-01
Publication year: 2004
Pages: 378 - 386
Total Pages: 9
Nb references: 22
Language: English

Abstract: This research aims at developing a new Thermal-Hydro-Mechanical coupling model (THM) for the simulation of the behavior of concrete at high temperature.
The final objective is the use of the model once fully validated to predict the risk of spalling of concrete and high-performance concrete (HPC) when they are subjected to fire load.
A new thermal-hydro-mechanical (THM) coupling model for high temperature has been developed based on the extension of the existing coupling THM model for moderate temperature [1, 3, 4].
This extension consists in considering the total pressure of the gas phase as an additional independent variable while this pressure was considered in the previous model as constant and equal to the atmospheric pressure.
Consequently, the new model is called THM+P.
This new model has been integrated into the general Finite Element code Symphony [9].
In the first part of this paper, we describe the mathematical formulation of the developed model which was based on the theory of the mechanics of unsaturated porous media mainly developed by Biot [10], Schrefler [11-13] and Coussy [14, 15].
The second part is dedicated to the numerical integration of the new model into Symphonie FE code.
Finally, the third part deals with a first validation of the model based on a comparison between the theoretical and the experimental results Kalifa [16].
The comparison based on concrete samples subjected to very high temperature shows a good qualitative and quantitative agreement between the test and the simulation.
The peak value of gas pressure is well predicted.
This can be due to the inaccuracy of some characteristic values of the concrete at very high temperature.
It is thus necessary to make a parametric study to evaluate the sensitivity of the results on the variation of these parameters.
This study must be performed notably on the permeability coefficient of the concrete which, in our opinion, plays a decisive role in the development of the quasi-saturated zones and consequently on the peaks of gas pressure.

Online publication: 2004-05-27
Classification: Scientific Reports
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/14031