Dynamic Model of Polished Stone Value Attenuation in Coarse Aggregate

The polished stone value (PSV) of coarse aggregate is closely related to pavement skid resistance and traffic safety. However, the determination of the PSV of coarse aggregate is conventionally a time- and energy-intensive process. To facilitate the test process of PSV in materials selection and pavement design and for the prediction of the service life of aggregate materials in practical service, here a new mathematical model of PSV attenuation in coarse aggregate, which employs a physical polishing process analysis, is proposed. The PSVs of four types of coarse aggregates (calcined bauxite, granite, basalt, and limestone) were analyzed through a polishing experiment, and the corresponding mechanism was investigated via scanning electron microscopy analysis. The modeling results are in good agreement with experimental results. The aggregate PSV is affected by both the macrotexture and microtexture of the aggregate surface. The PSV due to the macrotexture exhibits a strong negative correlation with the Vickers hardness of the aggregates and decreases exponentially as the polishing time increases. The attenuation rate decreases as the fractal box dimension in the aggregate surface morphology increases. The primary factor influencing the macrotexture service life and the half-life is the aggregate surface morphology. The PSV due to the microtexture exhibits a strong positive correlation with the Vickers hardness of the aggregates, whereas there is a poor correlation with the aggregate surface morphology and polishing time. The proportion of the aggregate PSV due to the microtexture increases as the aggregate hardness increases. These results highlight the effectiveness of a new modeling approach that may potentially assist in predicting the anti-slip performance and durability of coarse aggregates.