Structural Analysis for APT Sections Based on Deflection Parameters

This paper reviews the use of pavement structural condition indicators determined through deflection measurements as a means to monitor structural capacity. The deflection measurements were performed with a road surface deflectometer and a falling weight deflectometer on the various test tracks of an accelerated pavement test (APT) facility. The indicators estimation was based on the deflection data collected from different structures, and it was observed that it is feasible to improve the backcalculation analysis and help overcome some of the limitations associated with such a procedure. For this research, Radius of Curvature, AREA, Normalized AREA, BLI (Upper layers), MLI (Middle layers), and LLI (Lower layers) were the analyzed parameters. Each parameter is related to the structural condition of particular pavement layers. Therefore, the parameters allow general characterization of the pavement layers, and make it possible to detect deteriorated layers. The pavement structures were trafficked by means of an APT at the PaveLab facility at the University of Costa Rica. The deflection parameters were calculated through the APT data, showing the possible use of these indicators at the pavement management system level in Costa Rica, helping the categorization of the pavement structures in service, mainly because the parameters require few input data, and are useful where the available structural condition information is limited. The data presented in this paper show the variation of the different condition indicators throughout the service life of the analyzed pavement structures. The data are also used to compare different structures, their characteristics, and the change in their stiffness associated with damage.