Determining structural strength of existing asphalt layer using condition survey data

Abstract

Immense amounts of pavement condition survey data have been collected at the network level by transportation agencies over years. Such valuable information now has seen an increase in use for a variety of purposes related to a project level application. In this study, a simple approach of relating the pavement condition survey data to the strength of existing asphalt concrete (AC) layers is presented. The proposed approach provides a valuable tool in the pavement preservation and overlay rehabilitation design through estimating the existing asphalt layer's structural characteristics based upon information generally available in any pavement management database. In a network-based pavement preservation projects' selection, the predicted structural characteristics of an existing asphalt layer provide a direct index in ranking of aged asphalt pavements. In an overlay rehabilitation design, when non-destructive deflection measurement is not immediately available, the developed prediction models can be used to determine a representative existing asphalt coefficient in a 1993 American Association of State Highway and Transportation Officials overlay thickness design, or to provide an estimated elastic modulus for existing AC layer that can be used as a Level 3 design input in the newly developed Mechanistic-Empirical Pavement Design Guide pavement rehabilitation analysis.