Quantifying Longevity of Shotblasting Friction and Texture Improvements

Abstract: Shot blasting is a preservation technique for asphalt pavements that is usually applied to restore texture and friction. The improvement in friction and texture characteristics achieved with blasting is directly associated with the surface mix and the type of aggregate. Although some researchers have evaluated the initial friction and texture improvements obtained after shotblasting, most of these studies were conducted on accelerated test track facilities. Hence, this study examines the changes in friction and texture following the application of shotblasting to five different asphalt pavements. The primary aim is to assess both the immediate impact and the lasting effects of the treatment. To achieve this, the pavements selected were in good surface condition when the treatment was applied. The pavements were then divided into two sections: one treated with shot-blasting, and the other serving as a control section with no modifications. Friction and texture measurements were taken at various time points after construction in both sections, providing data to quantify the impact and duration of the shotblasting treatment. In terms of friction, the longevity of the shotblasting appears to be 1.2 years, and for texture, the longevity was closer to 3 years. However, in one of the sites surface texture components were affected by a deicing operation conducted 1 year after shotblasting, which may have influenced, especially in terms of friction, the observed trend in the second and third year. The results of this study will inform the use of shotblasting as a surface treatment to improve skid resistance.