ABSTRACT
The ageing of materials in civil engineering structures is a natural phenomenon. Corrosion of steel in concrete structures and fatigue of steel are examples of daily observed deterioration processes in structures now infrastructure becomes aged. The challenge for the nearby future is to keep the structures reliable at a high level of performance while the structure itself ages without having to spend huge amounts of money.
For lifetime optimization, service life prediction, time-variant reliability and life cycle cost, time is a dominant factor. Engineering on these performances of a structures requires reliable predictions of how a structure functions in time. In time the materials used in the structure will change due to ageing. The origin of these changes are primary from the natural change in materials. A material will age even when it is not used at all. Other factors will influence the ageing process. The environment and its use of the material will influence the ageing process and can lead to enhancement of the rate of ageing.
To improve the forecast of life time of structures knowledge of ageing is required. This knowledge can be gained with fundamental research on the chemistry, life science, physics, electromagnetism, mechanics, mathematics and design in respect to ageing. This research requires a multidisciplinary and multi-level scale approach. The Delft Centre of Materials initiated the Ageing Centre at the Delft University of Technology. Its goal is to investigate and model ageing phenomena at fundamental materials level and to make ageing predictable at the level of materials, devices, structures and systems.
This paper presents the framework that will be used by the Ageing Centre with which the balance can be made between the required performance and the require efforts to maintain this performance. The framework also shows how knowledge of the materials gained from inspections and tests are used to make reliable predictions of material changes and how this can be used for life cycle engineering of civil structures.
