A MODEL OF WHOLE-LIFE FLEXIBLE PAVEMENT PERFORMANCE

A new 'whole-life' pavement performance model (WLPPM), which is capabl e of making deterministic pavement damage predictions due to realistic traffic and environmental loading, has been developed. A vehicle simu lation is used to generate dynamic tyre forces that are a function of distance along the road. These dynamic tyre forces are then combined w ith the appropriate pavement primary response influence functions (str ess, strain and displacement) to give primary response histories at re gularly spaced points along the pavement. The primary response histori es are then transformed into pavement damage (fatigue and permanent de formation) using an appropriate damage model. The result is an increme nt of damage at each point along the pavement due to a single vehicle pass. The pavement surface profile is then updated to reflect permanen t deformation damage and the layer material parameters are changed to, reflect fatigue damage. The procedure is then repeated for the next v ehicle pass. Particular attention is given to modelling strength varia tions in the pavement and dynamic tyre forces. The model is used to in vestigate the relationship between 'hot spots' (due to peak dynamic lo ads), 'weak spots' (due to initial pavement stiffness variations) and long-term pavement damage.