Analysis of Road Maintenance Sequences According to the Evolution of Distresses

Within the framework of the preventive maintenance policy carried out on the French national network, the pavements are subject to systematic distress monitoring programs and condition indicator measurements: sideways force coefficient, transverse unevenness and macrotexture. The methodology, formalized in 1992 as the "Quality Image of the National Roads" (IQRN), includes a triennial survey of the different distresses, with calculation of a total index. The analysis of such data made it possible to define laws of evolution for distresses, depending on the initial structures, traffic and successive maintenance operations. In order to complement this approach, a joint analysis of the pavement evolutions and maintenance sequences was undertaken. The work presented here analyses statistically the relations existing between the evolution of the observed distresses and the decisions made about maintenance. It also deals with the lifespan of a surfacing before being overlaid, according to observed pathology, and the choice of the technique used to answer this pathology. The selection considers asphalt pavements excluding cement stabilised bases. The study shows that there are implicit rules, more or less marked, concerning the priority given to maintenance, and the choice of the technique used (surface dressings, thin or thick asphalt overlays), according to the encountered problems (skid resistance, plastic deformation, fatigue or thermal cracking).