DEVELOPMENT OF A NEW METHODOLOGY FOR CHARACTERIZING PAVEMENT STRUCTURAL CONDITION FOR NETWORK-LEVEL APPLICATIONS

Abstract

Huge quantities of bituminous mix in the form of seal coats and hot mix asphalt concrete (HMAC) thin overlays are applied by the Texas Department of Transportation (TxDOT) every year to improve ride quality and seal existing cracks, but these measures do not correct possible underlying weaknesses that will cause roughness or distress to quickly reappear. As a result, the overall pavement condition keeps deteriorating due to the structural deformation of pavement layers and the subgrade, even though surface treatments are applied periodically. The developed methodology introduces the Structural Condition Index (SCI). The SCI is based on the estimated effective Structural Number (SN), and its main purpose is to discriminate pavements that need structural reinforcement from the ones that are in sound structural condition. In addition, a contingent sampling procedure was developed to determine the minimum number of Falling Weight Deflectometer (FWD) tests required for each management section of pavements. The comprehensive guidelines were developed for using the SCI in the selection of the best maintenance and rehabilitation alternatives at network level. Finally, a pilot application of the SCI was carried out with several pavement rehabilitation projects to verify the validity of the developed SCI, with the intention that modifications would be made to the developed procedure if such a need is determined from the pilot application.