PREDICTING DURABILITY: THE ROLE OF ADVANCED NUMERICAL MODELS

Prescribed lifetimes for infrastructural works, like concrete bridges and tunnels, of 100 to 150 years are no exceptions. On the basis of decades of experience with concrete structures it is certainly possible to make estimates of the expected performance and durability. However, the number of concrete mixtures with which we have a long-term experience is limited. The experience with the increasingly used new materials, new cements, new cement replacements and even completely new cement-based concepts, make us reluctant to extrapolate from only a few years of experience with these mixtures to design lives of 100 to 150 years. This contribution deals with the role of numerical simulation models in predicting durability of concrete structures. It will be shown how advanced computer programs are able to built virtual microstructures, which form the basis for the determination of transport properties and degradation processes. Specific features of 3D virtual micro-structures are discussed. Their potential for analyses of the effect of curing on the quality of cover concrete, the most important part of concrete structures in view of durability, is discussed. These microstructural models should be used in parallel with mesoand macro-structural simulation programs and well-considered inspection and maintenance programs.

• INTRODUCTION

• DURABLE CONCRETE STRUCTURES - KEY ISSUES

• TOWARDS PROBABILISTIC PREDICTIVE MODELS

• MULTI-SCALE MODELLING

• COVER CONCRETE

• CONCLUSIONS

• REFERENCES