The work described is an initial investigation into the potential effect on friction characteristics of incorporating reclaimed asphalt (RA) into thin surface course systems.
A brief review of current practice is presented and a study is proposed to investigate the variability of RA and its effect on friction, when incorporated into asphalt prepared in the laboratory. It is shown that, when the RA is sourced from a surface course, the effect on friction is very small even when it is combined in relatively large proportions with virgin aggregate with moderate resistance to polishing.
A number of scenarios are presented and it is suggested that there are some instances where the amount of RA incorporated into the surface course might be restricted only by consideration of the resulting durability rather than by concerns about the resulting skid resistance. However, if the RA is from mixed sources then, until further analysis suggests otherwise, the amount incorporated in new surface courses should be limited, as it is now.

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