Evaluation Method for Jointed Concrete Airfield and Pavements

In order to harmonize FWD condition surveys on concretee pavements in the Netherlands, CROW's committee UEC1 has developed an structural evaluation procedure for jointed concrete airfield pavements. The committee has developed procedures for in-situ testing and models for determining of the mechanical pavement properties based on FWD measurements. With respect to the foundation of the slab-on-grade model, the Pasternak foundation was chosen as an attractive alternative for the Winkler foundation. The introduction of Pasternak's shear constant in Winklcr's model allows for the removal of the discrepancies between Westergaard's theory and multilayer theory, while great advantages of Westergaard's model (edge and corner loadings) can be maintained. Codes for backcalculation and a stress model have been programmed. Consideration is given to the evaluation of varying pavement components such as slab thickness, support conditions, load transfer efficiency, material properties and fatigue behaviour. The remaining structural life can be derived from traffic data and material strength using mechanical pavement properties of a slab-on-grade. Insight is given in the relationship between the number of tests and the reliability of the structural life deleuniiiation.