Preliminary study on the correlation between two-dimension surface texture and friction

The friction of pavement is mainly determined by the microtexture of the surface layer. However, the finer degree of microtexture makes it impossible to observe with naked eye. The object of this study was to develop a High Definition Scan Texture Machine (HDSTM) with 2D Laser CCD to support previous research on the correlation between texture and friction. In addition, this study proposed seven different parameters and sought to find an index for an ideal correlation that could represent the entire pavement texture. By assessing the test results, the Segment of Average Profile Depth (SAPD) was selected as the texture parameter for the threshold standard of pavement friction out of various 2D texture parameters. The SAPD had high correlation with British Pendulum Number (BPN) in wet and dry surface conditions and the texture data had sufficient samples to support the high correlation with BPN. Based on the results of in this study, 2D texture, SAPD, is recommended as an important index for engineers to evaluate the surface friction in the Highway Maintenance Office.