An Approach Towards the Understanding and Design of the Pavement’s Textural Characteristics Required for Optimum Performance of the Tyre

Abstract

Pavement wet skid resistance is characterized and governed by its macro-texture required to dissipate bulk water, and its micro-texture, essential for the creation of real areas of contact with the tread rubber.

Pavement macro-texture is also a major factor controlling noise generation, spray generation, and ride performance of tyres; and the micro-texture helps control the wear rate of tyres.

A theoretical approach to optimise the potential real area of contact between the rolling tyre and the pavement whilst maintaining adequate water drainage is discussed. The resulting macro-texture recommendation is shown to produce lower tyre noise and superior ride characteristics to other surfaces with similar levels of water dissipation.

The minimum level of micro-texture is related to the thickness of the water film; increasing levels of micro-texture are shown to increase tyre wear without a proportional increase in the wet friction. Direct observation of micro-texture characteristics of various aggregates has led to levels of maximum and minimum levels of micro-texture being suggested. The concepts of micro- and macro-texture optimisation have been applied to a new form of wearing course mix design currently undergoing road trials. The results from these experiements are used to support the theoretical approach.

Improved pavement surfaces will influence tyre design, some aspects of which are discussed.