Analytical tool to shorten polishing time based on mean texture depth (MTD) of flexible pavements

The reproduction of asphalt pavement surface texture deterioration in the laboratory is usually lengthy. The objective of this work is to find an analytical tool to predict the steady-state mean texture depth (MTD) early in the experiment in order to save time. Data were obtained from laboratory testing carried out on eight job mix formulas of bituminous mixtures. Measurements were collected using the volumetric sand patch method for each hour of polishing. The basic parameter used for this study is the MTD, which is a measure of surface macrotexture. Based on nonlinear regression, an equation was developed to calculate the steady-state macrotexture. The main characteristic of the developed equation allows for calculating the steady-state macrotexture and the onset of steady state. This enables the experimenter to determine when steady state is reached at the desired tolerance during the test, thus reducing the testing time. It was concluded that testing time can be reduced significantly (around 50%-time savings), which may be received positively by highway materials’ agencies worldwide.