Pavement layer thickness variability evaluation and effect on performance life

Abstract

ABSTRACTThis paper aims to assess the sensitivity of road pavement design and predicted life to pavement layer thickness, accounting for the variations which commonly occur between the pavement design thickness specified and that actually constructed. The approach adopted in this research is to characterise the as-built pavement layer thickness variation, obtained from Ground Penetrating Radar (GPR) surveys, for lane 1 of a UK motorway site with flexible pavement construction. Firstly, an analysis is conducted for the selected UK motorway to explore the relationship between the specified construction tolerances and the actual thickness variability. Secondly, the paper proves how variability of layer thickness – while keeping all the other design parameters unchanged – affects the design life probability distribution. The results from this study show that asphalt layer thickness variation significantly affects the pavement performance, even when such variations are within the tolerances allowed by UK construction specifications. On the other hand, layer thickness variations in granular sub-base, within allowed limits, do not significantly affect the pavement performance.