Using models to interpret data for monitoring and life prediction of deteriorating infrastructure systems

For environmental and for economic reasons, there is increased emphasis on extending the life of existing infrastructure and to design new infrastructure for longer, safe and effective service lives. Increasing use is being made of monitoring of performance and estimation of long-term reliability and safety, allowing also for the likelihood of long-term deterioration. To obtain optimal decision outcomes, reliance should be placed not only on data but also on accumulated scientific and engineering knowledge. In engineering, this is embodied in mathematical models. Ideally, these are of good quality, calibrated to ‘real world’ data and have prediction capabilities. Recently, developed models of this type are described for the corrosion of steel in marine environments and simplified to models suitable for engineering applications. An example is given of the prediction of the expected corrosion loss and of the likely future rate of corrosion for a mild steel structural element exposed to temperate seawater.