The use of Deflection Measurements in Pavement Management of the Primary Road Network of Wallonia, Belgium

The road authorities of the primary road network of motorways and main roads in Wallonia (Belgium) determined the priorities for road maintenance from surface characteristics such as roughness, skid resistance and rutting. Recently, they added the structural health (and primarily the bearing capacity) as a criterion for pavement management. The structural health of the road sections is estimated from deflection measurements obtained with Falling Weight Deflectometer and Curviameter. This paper presents the approach used to transform deflection measurements on rigid, semi-rigid and flexible pavements into several structural indicators that combine into a global indicator for residual life time expectance. For each of the measurement devices, three indicators were developed that evaluate some aspect of structural health of the road. Two indicators were developed that express the importance of traffic on the road. These five indicators are combined into a global indicator that allows classifying the road sections. The classification gives results similar to an evaluation by back-calculation as shown in the paper on a limited number of road sections. The approach described in the paper is a successful example of how to introduce the evaluation of structural performance in pavement management using the technique of simple computations from rough data collected by deflection measurement devices.