Effect of aggregate properties on asphalt pavement friction based on random forest analysis

Pavement friction largely depends on surface texture characteristics, which are directly related to the corresponding aggregate properties. This study selected forty-five field pavement sites, which were constructed using seven typical types of aggregates available from eleven different quarries in Oklahoma, as the testing beds. Aggregate properties were characterized in the laboratory using the Aggregate Imaging System (AIMS), and pavement texture and friction data were collected in parallel in the field using a three-dimensional laser imaging system and Grip Tester. The traditional multivariate friction models were developed while several regression coefficients did not follow engineering judgment. Subsequently, the random forest analysis (RFA) was performed to evaluate the pavement surface friction subject to various aggregate properties. Loss of texture (%) is identified as the most significant aggregate characteristic for friction evaluation, accounting for 26.54% contribution to pavement surface friction. Traffic volume and temperature also exhibit significant impacts, with 31%, 14.7% contributions to pavement surface friction, respectively. This study is beneficial to better understand the effect of aggregate properties on pavement friction and to improve skid resistance performance in the field. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Pavement friction is largely influenced by surface texture characteristics, with loss of texture being identified as the most significant aggregate characteristic for friction evaluation. Traffic volume and temperature also have significant impacts on pavement surface friction.