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Browsing by Author "Dunford, Alan"

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    Simulative Polishing In The Laboratory; Comparison With Traffic And Use To Investigate Aggregate Blending
    Dunford, Alan; Viner, Helen; Roe, Peter; Caudwell, Louise (2012)
    Two experiments with the Wehner-Schulze machine, which is designed to apply a controlled amount of polishing to and measure the friction of road surfacing products, are described and their results summarised. In the first experiment the polishing action of the machine is compared to the polishing action of traffic using UK roads. It is shown that there is a strong correlation between friction measured after polishing by traffic in a non-event location and friction measured after polishing in the machine. It is shown that polishing in the machine is more severe than that applied by free-rolling traffic on straight roads. In the second experiment, the machine is used to show that it may be possible to predict the long-term friction performance of asphalt prepared with a blend of coarse aggregates using a mass ratio formula.
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    Splash and Spray Assessment Tool Development Program: Final Report
    Flintsch, Gerardo W.; Tang, Lijie; Katicha, Samer W.; de León Izeppi, Edgar; Viner, Helen; Dunford, Alan; Nesnas, Kamal; Coyle, Fiona; Sanders, Peter; Gibbons, Ronald B.; Williams, Brian M.; Hargreaves, David; Parry, Tony; McGhee, Kevin K.; Larson, Roger M.; Smith, Kelly L. (Virginia Tech. Virginia Tech Transportation Institute, 2014-10-07)
    The effects of vehicle splash and spray are well known to motorists who have driven in wet weather conditions. Research suggests that splash and spray contribute to a small but measurable portion of road traffic accidents and are the source of considerable nuisance to motorists. Splash and spray from highway pavements also can carry a number of pollutants and contaminants. When deposited, these contaminants can be poisonous to plant life and accelerate the corrosion of roadway appurtenances. Splash and spray are individually definable processes that are the product of a number of different factors. Many parties have gone to great lengths to reduce the splash and spray created by motor vehicles, especially that from heavy vehicles, by retrofitting devices that alter the vehicle’s aerodynamics. Another possible solution to the problem is to change the characteristics of the highway pavement. Previous research shows that pavement geometry, drainage, texture, and porosity all contribute to splash and spray generation, but the exact mechanisms are largely unknown. A model capable of predicting the splash and spray propensity of pavements can be used by highway engineers to support decisions in highway maintenance and design. The project objective was to develop a simple and practical assessment tool to characterize the propensity of highway sections to generate splash and spray during rainfall and the impact of splash and spray on road users. This report summarizes the development of the splash and spray model and its implementation in an easy-to-use, practical tool.