Reconsideration of tyre-pavement input parameters for the structural design of flexible pavements

Abstract

Pavement/vehicle interaction is one of the growing areas in asphalt pavement design. Traffic volumes have increased considerably over the past few decades, and not only are modern trucks carrying heavier payloads, but they are also using fewer tyres which have higher inflation pressures and hence higher contact stresses than was previously the case. The aim of this paper is to highlight the variabilities associated with actual measured three-dimensional tyre-pavement contact loading/stress regimes of modern truck tyres. Tyre-pavement contact stress measurements were carried out on a busy national road (N3) in South Africa from the port of Durban to the inland province of Gauteng. The three-dimensional tyre-pavement contact stress regimes of 45 227 individual tyres were measured using the Stress-In-Motion (SIM) system. In addition, the loading on each tyre was also captured. This measurement series was performed at slow (< 5 km/hr) creep speed conditions at a controlled weigh-bridge as part of the N3 Traffic Control Centre (N3-TCC) near Heidelberg in SA. Mechanistic Analysis indicated that near surface Strain Energy of Distortion (SED) may be utilised for pavement rutting studies in this asphalt layers.