Pavement skid resistance plays a crucial role in ensuring road safety and avoiding accidents.In the past,the laboratory evaluation of the skid resistance was carried out by studying only the coarse aggregates of the w...Pavement skid resistance plays a crucial role in ensuring road safety and avoiding accidents.In the past,the laboratory evaluation of the skid resistance was carried out by studying only the coarse aggregates of the wearing course.To overcome this drawback,the Wehner-Schulze(WS)machine was developed in Germany in the 1960s.This equipment,composed of a polishing unit and a measuring unit,has great potential in predicting pavement skid resistance and its evolution over time,but is still little known in the pavement community(especially outside Europe).For these reasons,there is a need of a comprehensive review of the existing technical-scientific literature concerning the use of the WS machine.Specifically,this paper focuses on the main factors affecting the skid resistance in WS tests,the correlation of WS data with other laboratory test methods and with field skid resistance/polishing,and the available prediction models that have been validated through WS measurements.The critical analysis of the existing literature highlights that it is possible to correlate WS data with typical skid resistance field measurements as well as WS polishing with traffic polishing,but further efforts are needed in this regard.Future work should focus especially on open-graded mixtures and innovative asphalt mixtures(e.g.,containing recycled materials and additives).From the perspective of pavement management,based on a theoretical background,the WS test results could be used as starting point for simplified prediction models of the in-situ skid resistance.展开更多
Pavement surface friction is a significant factor for driving safety and plays a critical role in reducing wet- pavement crashes. However, the current asphalt mixture design procedure does not directly consider fricti...Pavement surface friction is a significant factor for driving safety and plays a critical role in reducing wet- pavement crashes. However, the current asphalt mixture design procedure does not directly consider friction as a requirement. The objective of this study was to develop a surface friction prediction model that can be used during a wearing course mixture design. To achieve the objective, an experimental study was conducted on the frictional characteristics of typical wearing course mixtures in Louisiana. Twelve wearing course mixtures including dense-graded and open-graded mixes with different combinations of aggregate sources were evaluated in laboratory using an accelerated polishing and testing procedure considering both micro- and macro texture properties. In addition, the surface frictional properties of asphalt mixtures were measured on twenty-two selected asphalt pavement sections using different in situ devices including Dynamic Friction Tester （DFT）, Circular Texture Meter （CTM）, and Lock-Wheel Skid Trailer （LWST）. The results have led to develop a procedure for predicting pavement end-of-life skid resistance based on the aggregate blend polish stone value, gradation parameters, and traffic, which is suited in checking whether the selected aggregates in a wearing course mix design would meet field friction requirements under a certain design traffic polishing.展开更多
基金financially supported by the Sustainable Mobility Center (Centro Nazionale per la Mobilita Sostenibile-MOST), Spoke 7 (Connected Networks and Smart Infrastructure), Work Package 4 (Resilience of networks, structural health monitoring and asset management) under the National Recovery and Resilience Plan (Piano Nazionale di Ripresa e Resilienza-PNRR)funded by the European Union-NextGenerationEU
文摘Pavement skid resistance plays a crucial role in ensuring road safety and avoiding accidents.In the past,the laboratory evaluation of the skid resistance was carried out by studying only the coarse aggregates of the wearing course.To overcome this drawback,the Wehner-Schulze(WS)machine was developed in Germany in the 1960s.This equipment,composed of a polishing unit and a measuring unit,has great potential in predicting pavement skid resistance and its evolution over time,but is still little known in the pavement community(especially outside Europe).For these reasons,there is a need of a comprehensive review of the existing technical-scientific literature concerning the use of the WS machine.Specifically,this paper focuses on the main factors affecting the skid resistance in WS tests,the correlation of WS data with other laboratory test methods and with field skid resistance/polishing,and the available prediction models that have been validated through WS measurements.The critical analysis of the existing literature highlights that it is possible to correlate WS data with typical skid resistance field measurements as well as WS polishing with traffic polishing,but further efforts are needed in this regard.Future work should focus especially on open-graded mixtures and innovative asphalt mixtures(e.g.,containing recycled materials and additives).From the perspective of pavement management,based on a theoretical background,the WS test results could be used as starting point for simplified prediction models of the in-situ skid resistance.
文摘Pavement surface friction is a significant factor for driving safety and plays a critical role in reducing wet- pavement crashes. However, the current asphalt mixture design procedure does not directly consider friction as a requirement. The objective of this study was to develop a surface friction prediction model that can be used during a wearing course mixture design. To achieve the objective, an experimental study was conducted on the frictional characteristics of typical wearing course mixtures in Louisiana. Twelve wearing course mixtures including dense-graded and open-graded mixes with different combinations of aggregate sources were evaluated in laboratory using an accelerated polishing and testing procedure considering both micro- and macro texture properties. In addition, the surface frictional properties of asphalt mixtures were measured on twenty-two selected asphalt pavement sections using different in situ devices including Dynamic Friction Tester （DFT）, Circular Texture Meter （CTM）, and Lock-Wheel Skid Trailer （LWST）. The results have led to develop a procedure for predicting pavement end-of-life skid resistance based on the aggregate blend polish stone value, gradation parameters, and traffic, which is suited in checking whether the selected aggregates in a wearing course mix design would meet field friction requirements under a certain design traffic polishing.
