Pavement skid resistance as a function of pavement surface and aggregate texture properties

Skid resistance depends on the macro- and micro-textural characteristics of pavement surface. Mean profile depth (MPD) is a widely used two-dimensional macro-texture indicator calculated from a single pavement surface profile, while pavement micro-texture is primarily affected by the characteristics of aggregates contained within the surface. In this study, twenty-two pavement sites, constructed using six common types of preventive treatments and eight typical sources of aggregates in Oklahoma, are selected as the field test beds. Pavement skid resistance and surface macro-texture data are collected in parallel at highway speeds using a grip tester and a high speed texture profiler, while aggregate properties under 3D are measured using a portable ultra-high resolution 3D laser imaging scanner. MPD values are calculated to represent surface macro-texture. Thirty-one 3D aggregate parameters in four categories (textural, feature, height, and material ratio & volume parameters) are investigated to characterise micro-texture attributes. The Pearson correlation coefficient matrix is computed within each category to exclude the parameters with strong correlations and remove their potential multi-collinearity during friction model development. Multivariate analysis is subsequently performed to examine the relationship between pavement skid resistance, and surface and aggregate texture properties. Eight texture parameters have showed statistical significance on pavement friction. Entropy (T(etp)textural parameter) and peak curvature (S(pc)feature based parameter) present the most significant influences on pavement friction, while MPD demonstrates the least impact. The developed model based on surface and aggregate texture properties can better predict pavement friction performance. The comprehensive analysis of texture properties could assist highway agencies understanding the appropriate characterisation of aggregates and developing aggregate selection guideline for optimised skid resistance.