NUMERICAL SIMULATION OF SURFACE PROPERTIES

Material properties of building and construction elements are requested to last for an increasingly longer lifetime. Long-term quality of cementitious building materials and material properties finds its roots in the development of the microstructure in a structure's early lifetime. The microstructure's quality plays an essential role in current and future maintenance plans as well. Degradation of material properties in the longer term is, to a large extent, the result of a change of the microstructure's quality. Aggressive substances might have succeeded in passing through the surface cover layer of structural elements and in affecting the microstructures integrity. The capillary pore structure that enables aggressive substances to intrude into the cement paste microstructure is dominated by the permeability of the concrete cover. It facilitates the potential movement of substances through the hardening paste. In the paper, numerical simulations will be presented, providing results about the relationship between the interface permeability of structural elements and the evolution of the micro-structural properties. Simulations of cement pastes with different water/cement ratios, clearly demonstrate a movement of capillary water through the concretes cover layer. The simulation models are part of a multi-scale approach to predict the short and long-term performance of concrete structures.

• INTRODUCTION

• MULTI-SCALE MODELLING

• MODEL DESCRIPTION

• TOWARDS SURFACE PROPERTIES

• OUTLOOK AND CONCLUSIONS

• REFERENCES