Development of skid resistance in relation to quality of coarse aggregate : the development of instruments for risk control relating to the development of skid resistance (Track 1)

With the new contract types used by the Directorate-General for Public Works and Water Management (DPW) the contractor is given more freedom and responsibility in its choice of products offered. DPW basically prescribes the function of a particular product, but does not describe in detail what the product should be. This report describes an initial study into the development of instruments to predict the skid-resistance development of bituminous surfacing. Based on a literature study performed previously and experiences from other European countries, the study was limited to experiments using the Wehner/Schulze test. The test of the predictive power of the Wehner/Schulze test was performed on 9 different asphalt mixes. The study shows that the Wehner/Schulze test can be used to distinguish an asphalt mix in which coarse aggregate with a low Polished Stone Value (PSV) has been used from a similar asphalt mix in which coarse aggregate with a high PSV has been used. This gives the test the power to predict the skid-resistance development of bituminous surfacing. The validation in track two should ascertain to what extent the Wehner/Schulze test is really the most suitable instrument.