CrysPoM II
Crystallization In Porous Media
In memory of Olivier Coussy
organized by Civil and Mechanical Engineering, EMPA.
CRYSPOM II - An International Workshop on Crystallization In Porous Media
Scope
The workshop focuses on the fundamental research of crystallization in porous materials for a better understanding of the damage mechanism and development of preventive and protective treatments. Thermodynamics and kinetics of crystal growth, material damage by crystallization and failure, experimental techniques to study crystallization such as NMR, AFM, ESEM and SFA and models such as poromechanics or molecular dynamics are some of the topics that will be presented in CRYSPOM II.
The idea is to bring together leading researchers and Ph.D. students to provide for a constructive and open dialogue and to incite collaborations between theorists and experimentalists at an international level.
Invited speakers
- George W. Scherer, Princeton University, USA
- John Wettlaufer, Yale University, USA
- Marc Prat, Institut de Mecanique des Fluides de Toulouse, France
- Leo Pel, TU Eindhoven, The Nederlands
- Carlos Rodriguez-Navarro, Universidad de Granada, Spain
- Michael Steiger, Hamburg University, Germany
- Robert Flatt, Sika Technology AG, Switzerland
- Eric Doehne, Getty Conservation Institute, USA
Motivation
The longevity of many historic monuments and sculptures as well as of civil engineering buildings is threatened by diverse weathering processes, prominent among which is the stress exerted by salts and ice crystallizing in the pores of the material. As an example, these pictures show the advanced state of deterioration of a beautiful chapel in Yorkshire (UK), the Howden Minster in UK, which is suffering the damaging action of magnesium sulphate salts.
Salt weathering of stone (and of other construction materials and rocks) and frost damage results from the combined action of salt transport through the porous network and the in-pore crystallization under changing environmental conditions. The crystallization pressure exerted by the crystals on the pore surface is the main agent responsible for damage. New experimental methods such are contributing to a better understanding of the phenomena involved in salt weathering and frost damage. Increasing computational power permits numerical simulation of salt weathering processes from the molecular to the macroscopic scale. Indeed, continuum and discrete models can account for many of the remaining questions, particularly including the interaction between multiple phenomena.
We are still faced with several questions.
- How does nucleation and crystal growth take place within a pore network?
- How do the processes in the thin film affect the crystallization pressure?
- Does pore clogging enhance damage?
- Can we control the crystallization pressure?
- Can we control nucleation and crystal growth in the field?
- Under what conditions does salt crystallization lead to crack propagation and failure of the material?
- Can we predict damage when salt mixtures or the combined action of salt and swelling clays are involved?
By understanding better the chemomechanics of in-pore salt crystallization, more reliable protection of our buildings against salt weathering will become possible.