Advanced surface texture assessment of roller compacted concrete pavement mixtures by an in-house optical surface profiler

Roller-compacted concrete (RCC) pavements have gained increasing attention, yet the literature still lacks quantitative insight into their surface texture and functional implications. This study evaluates RCC surface texture and skid resistance using both the Superpave gyratory compactor (SGC) and a roller compactor, and—under identical gradations and compaction protocols—compares these results directly with hot-mix asphalt (HMA). Surface topography was measured using an in-house three-dimensional (3D) optical profiler, and texture metrics were computed from parameters defined in ISO 25178-2; macrotexture was benchmarked with the sand patch test. Results show that SGC-compacted RCC does not replicate the field texture produced by roller compaction, so SGC data are used only for comparative trend evaluation. Roller-compacted RCC demonstrated greater macrotexture but lower wet British Pendulum Number (BPN) than HMA, consistent with the distinct functions of texture scales. RCC maintained coarser, less uniform microtexture, whereas HMA exhibited finer, sharper asperities and higher BPN. Strong agreement between 3D-derived macrotexture and mean texture depth (MTD) supports the measurement approach. The findings indicate that RCC can provide beneficial macrotexture for drainage but may require supplemental surface texturing to enhance microtexture for higher-speed applications.