Matthew David Nicholas Willcox

Flat-track tyre testing commonly employs sandpaper as a flexible test surface; however, its macro‑ and micro‑texture differs significantly from real asphalt, typically requiring scaling procedures to approximate road conditions. This study evaluates " Asphaltant " , a newly developed asphalt‑replicating surface produced by the Global Center for Automotive Performance Simulation ('GCAPS', United States) for flat-track testing, as a more representative alternative. Frictional interactions between tread rubber and both Asphaltant and conventional 120‑grit sandpaper were examined using a laboratory friction rig. A tread block‑level approach was adopted to isolate rubber–surface friction mechanisms and to explore a wider range of friction conditions than is accessible through full tyre testing. Friction coefficient data collected across a range of sliding speeds and temperatures were transformed into friction master curves using the Williams–Landel–Ferry method. The resulting master curves showed that sandpaper produced higher friction levels at lower sliding speeds, whereas Asphaltant demonstrated comparatively higher friction at elevated sliding speeds. Additionally, Asphaltant exhibited a 15% lower peak friction coefficient than sandpaper and displayed a broader curve shape, in agreement with previously reported measurements on real asphalt. These trends match tyre‑level measurements in which sandpaper typically produces greater tyre forces than real road surfaces. Overall, the results indicate that Asphaltant provides frictional behaviour that is more representative of asphalt than sandpaper, thus offering a potential route for more realistic tyre test data and resultant vehicle simulations.