OVERLAY DESIGN PROCEDURE FOR PAVEMENT MAINTENANCE MANAGEMENT SYSTEMS

A methodology for flexible pavement rehabilitation and development of overlay thickness design curves for pavement maintenance management systems (PMMSs) is presented. The methodology is based on nondestructive testing of deflection basin measurements and on the rational approach that characterizes pavement response to major deterioration criteria, such as fatigue and rutting. Within the general framework, subgrade and pavement were classified into three categories of strength: weak, medium, and strong according to the measured deflection (at a distance of 1.80 m from the loading plate) and the surface curvature index parameter. With reference to these categories, a structural index (SI) was defined. Between the SI and overlay thickness there is a dependence that can be expressed by a design curves system related to different traffic categories and subgrade type. The present methodology can readily be incorporated as a subsystem within the general PMMS, and it enables fast solutions at the network level for economic evaluation and rehabilitation priority order determination of extensive road systems.