Hannelore Derluyn
My PhD project is entitled ‘Poromechanical modeling of salt damage in porous materials’. I want to explore the combined physical, chemical and mechanical processes causing salt damage in porous materials to get a better understanding of the complex phenomenon salt damage is. Even after decennia of research, still a range of unanswered questions concerning salt damage problems needs to be solved.
My research comprises experimental as well as modeling research. The aim is to develop a model which includes the damage evolution in porous materials due to salt crystallization. This model needs of course reliable experimental data. My aim is to perform and monitor cyclic salt contamination of porous materials until initialization and development of damage and to look at salt damage in the layered system of masonry (stone/mortar). In my research I want to focus on the salts sodium sulphate (Na2SO4) and sodium chloride (NaCl), as they are two of the most damaging salts mentioned in literature.
During my stay at Princeton I will work together with Rosa M. Espinosa. My focus is to understand the kinetics of sodium sulphate crystal growth and how to model this crystallization kinetics. To get correct crystallization models we need to understand when and how the different crystal phases of sodium sulphate form: this salt has two stable phases mirabilite Na2SO4.10H20 and thenardite Na2SO4(V) and two metastable phases heptahydrate Na2SO4.7H20 and metastable thenardite Na2SO4(III). With help of a cooling stage in combination with a microscope, we want to measure growth rates of the crystal phases and understand the different crystal formations with their determining parameters.
Simultaneously I want to learn about the salt crystallization tests used in Prof. Scherer’s research group, such as the warping experiment and the capillary rise experiment. They can be of great value for the experiments I want to perform in the framework of my PhD to validate my model.
