Mechanistic Design of Silent Asphalt Mixtures and Its Validation

The Netherlands is a densely populated country. As a result traffic noise reduction is an important issue. The policy of the government with respect to traffic noise is best reflected in the obligation to apply noise reducing Porous Asphalt (PA) on the primary road network. At the moment close to 90% of the Dutch primary road network is surfaced with some type of noise reducing PA. The main disadvantage of PA is its reduced raveling resistance and raveling is in most cases by far decisive for PA service life. By assignment of the Centre for Transport and Navigation of the Dutch Ministry of Transport, Public Works and Water Management the Delft University of Technology was assigned to develop a Lifetime Optimization Tool (LOT) that is able to explain PA raveling. In this paper the development of LOT is discussed. It is shown that LOT is a mechanistic tool on meso scale, i.e. the scale of individual stone particles. LOT combines the effects of mixture geometry, the loading applied to the mixture and the mechanical behavior of mixture components. After explaining the principles on which LOT is based LOT is validated by execution of full scale raveling tests on four PA mixtures. Synergy between test results and LOT explained performance is shown and discussed. During the 2008/2009 Dutch winter, which was the coldest in 12 years, severe raveling damage in PA developed at some sections of motorway. Further validation was achieved by the definition of a representative Dutch motorway pavement. LOT was then applied to explain the raveling performance of that pavement under a range of temperatures. It was shown that the observed development of raveling damage during the coldest winter days is well explained by LOT. Finally a comparison between LOT explained raveling performance and past performance is made. Hereto use was made of two recently completed research projects reported in literature. This comparison indicates that the development of raveling is highly dependent on a combination of traffic, cold days, void ratio, bitumen content and grading. It is shown that LOT explains the effects of all these variables. The paper comes to the conclusion that it is possible to develop mechanistic performance based mixture design tools. For PA such a tool was developed and validated. The insights obtained by that tool open the way to further optimize PA raveling performance.

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  • English

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  • Accession Number: 01328041
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 20 2011 11:22AM