High Friction Surfacing Systems using Blends of Natural Aggregate and Calcined Bauxite

Abstract

High friction surfacing (HFS), bonded to a road surface at high risk locations, has beenshown to significantly reduce road fatalities and serious injuries, i.e., HFS saves lives. Calcinedbauxite is the preferred aggregate for use in HFS systems due to its unique ability to resistpolishing and abrasion by vehicle tires. Calcined bauxite is expensive, negatively impacts theenvironment due to mining, production and transporting processes and has come under supplypressures in recent years. This paper investigates the potential for blending natural aggregates withcalcined bauxite for use in HFS systems. The experiments involved subjecting HFS specimens tolaboratory simulated trafficking and testing for skid resistance, texture depth and mass loss. Thetesting was carried out in laboratories in Spain and Northern Ireland. The findings suggest thatthere is the potential to reduce the amount of calcined bauxite used in HFS systems by replacing apercentage of the calcined bauxite with high PSV natural sandstone or volcanic tuff aggregate. Theimpact of this research could reduce the risks associated with supply issues to the HFS industry,reduce environmental impact by using less calcined bauxite in HFS systems and reduce costsassociated with the aggregate component of HFS systems—enabling road authorities to installmore systems at high risk locations to further reduce fatalities and serious injuries on their roads