Hot-mix asphalt pavement frictional resistance as a function of aggregate physical properties

Abstract

Aggregates were tested for acid insolubility, differential wear (DW), and frictional resistance and along with physical data were correlated to aggregate frictional resistance. Physical data included bulk specific gravity, per cent absorption, per cent loss from impact, and per cent loss from brine freeze/thaw. It was observed that the aggregates used had a negligible amount of insoluble material and therefore had an insignificant effect on the frictional resistance. Terminal frictional resistance increased with decreasing bulk specific gravity, and increased with increasing per cent absorption and per cent loss from impact. Correlation between terminal frictional resistance and brine loss was moderate. DW measurements were taken on stone–slag aggregate blends to determine the effectiveness of blends used in pavement mixtures. DW results indicated that the high-friction component of each blend could be improved by blending with softer carbonate aggregates, which also may be more cost effective.

Keywords:

• friction
• skid resistance
• polish resistance
• aggregate
• hot-mix asphalt

Acknowledgements

The authors wish to acknowledge the support of INDOT, the Joint Transportation Research Program at Purdue University, and the Federal Highway Administration. The contents of this report reflect the views of authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the INDOT or the Federal Highway Administration at the time of publication.