Modelling degradation processes of cement-based materials by means of mechanics of multi-phase porous media
Event details
| Date | 24.02.2017 |
| Hour | 12:15 › 13:00 |
| Speaker |
Prof. Dariusz Gawin Full Professor at Łódź University of Technology, Poland Bio: Prof. Gawin is ordinary professor at the Łódź University of Technology, Poland where he is the vice-rector of the University for Innovations and Development, and the Head of the Department of Building Physics and Building Materials. He got his PhD (with honours) in Civil Engineering at the Łódź University of Technology (Poland), Faculty of Civil Engineering and Architecture in 1990; and a Master (with honours) in Mechanical Engineering at the Gdańsk University of Technology (Poland), Institute of Naval Architecture in 1981. His current research interests are related to the durability of building materials, the numerical modelling of the mechanics of multiphase porous materials as well as sustainable buildings, energy efficiency and the energy auditing of a building. |
| Location | |
| Category | Conferences - Seminars |
Civil Engineering Seminar Series Spring 2017
Modelling degradation processes of cement-based materials by means of mechanics of multi-phase porous media
Prof. Dariusz Gawin
Full Professor at Łódź University of Technology, Poland
Abstract: A general approach to modelling various degradation processes in cementitious materials, due to combined action of variable hygral, thermal, chemical and mechanical loads, will be presented. Mechanics of multiphase porous media and damage mechanics are applied for this purpose. Kinetics of physico-chemical processes, like for example: cement hydration, salt crystallization/dissolution, calcium leaching, Alkali Silica Reaction (ASR), and water freezing/thawing, is described with evolution equations based on thermodynamics of chemical reactions. The mass-, energy- and momentum balances, the evolution equations describing chemical reactions and deterioration processes, as well as the constitutive and physical relations will be presented. The mutual couplings between the chemical, hygral, thermal and mechanical processes will be discussed, both from the viewpoint of physicochemical mechanisms and mathematical modelling. Numerical methods used for solution of the model governing equations will be presented. For this purpose the finite element method is applied for space discretization and the finite difference method for integration in the time domain.
Several examples of the model application for analysing transient chemo-hygro-thermo-mechanical processes in cementitious materials will be solved and discussed. The first example deals with concreting and maturing of massive structure. The second example concerns calcium leaching from a concrete wall due to chemical attack of pure water, exposed to gradients of both temperature and pressure. The third one describes cracking of concrete element, caused by development of expanding products of ASR. The fourth example concerns the salt crystallization during drying of a wall made of concrete/ceramic brick, causing degradation of a surface layer due to development of crystallization pressure. The last example concerns freezing and thawing of a wet concrete wall in variable temperature and relative humidity, causing frost damage.
Modelling degradation processes of cement-based materials by means of mechanics of multi-phase porous media
Prof. Dariusz Gawin
Full Professor at Łódź University of Technology, Poland
Abstract: A general approach to modelling various degradation processes in cementitious materials, due to combined action of variable hygral, thermal, chemical and mechanical loads, will be presented. Mechanics of multiphase porous media and damage mechanics are applied for this purpose. Kinetics of physico-chemical processes, like for example: cement hydration, salt crystallization/dissolution, calcium leaching, Alkali Silica Reaction (ASR), and water freezing/thawing, is described with evolution equations based on thermodynamics of chemical reactions. The mass-, energy- and momentum balances, the evolution equations describing chemical reactions and deterioration processes, as well as the constitutive and physical relations will be presented. The mutual couplings between the chemical, hygral, thermal and mechanical processes will be discussed, both from the viewpoint of physicochemical mechanisms and mathematical modelling. Numerical methods used for solution of the model governing equations will be presented. For this purpose the finite element method is applied for space discretization and the finite difference method for integration in the time domain.
Several examples of the model application for analysing transient chemo-hygro-thermo-mechanical processes in cementitious materials will be solved and discussed. The first example deals with concreting and maturing of massive structure. The second example concerns calcium leaching from a concrete wall due to chemical attack of pure water, exposed to gradients of both temperature and pressure. The third one describes cracking of concrete element, caused by development of expanding products of ASR. The fourth example concerns the salt crystallization during drying of a wall made of concrete/ceramic brick, causing degradation of a surface layer due to development of crystallization pressure. The last example concerns freezing and thawing of a wet concrete wall in variable temperature and relative humidity, causing frost damage.
Practical information
- Expert
- Free
- This event is internal
Organizer
Coordinators: Prof. Brice Lecampion and Prof. Katrin Beyer
Contact
- Prof. Lyesse Laloui