Modelling asphalt overlay as-built roughness based on profile transformation. Case for wheeled paver laydown operation

Abstract

ABSTRACT The smoothness achieved in pavement construction, or as-built roughness, has great importance in road engineering. Traditionally, as-built roughness has been studied in the literature from an empirical approach, based on the statistical correlation between the roughness IRI observed before and after the execution of paving works. In the case of asphalt overlays, this article highlight interactions in the construction process that limit the predictive capacity of the traditional empirical approach; demonstrating, through the frequency response of the paver screed and the IRI model, that fitting a before-after IRI type regression is insufficient to explain the variability observed in as-built roughness. From the preliminary analysis carried out an original approach to as-built IRI prediction is proposed, based on the modelling of the asphalt paver and its levelling response to surface roughness during the paving process. Formulation of linear systems that constitute the model are presented for the case of a wheeled paver without using of automatic levelling. Longitudinal profile data from the Long-Term Pavement Performance SPS-5 experiment was used to calibrate the model, obtaining a mean error of 0.22 m/km for the predicted IRI. The results obtained demonstrate the potential of the proposed approach as a modelling alternative.