Unravelling Porous Asphalt Concrete, Towards a Mechanistic Material Design Tool: Fid-Bau Portal

Unravelling Porous Asphalt Concrete, Towards a Mechanistic Material Design Tool

Huurman, M. / Mo, L. T. / Woldekidan, M. F.

PA (Porous Asphalt Concrete) is the standard surfacing material for the Dutch primary road network. More than 70% of this network is surfaced with PA. Ravelling, the loss of stone from the road surface, is in most cases by far decisive for PA service life. Ravelling resistance is mainly generated by the PA mixture performance and not by the pavement's structural design. This paper discusses the development and validation of a mechanistic Lifetime Optimization Tool for PA, LOT. LOT is based on Finite Element (FE) modelling on meso scale, i.e. the scale of stone chippings. Laboratory tests performed to obtain insight into the behaviour of PA mortar (binder) and the adhesive zones that bond stone to mortar are discussed. The forces acting on individual stones at the surface during the passage of a tyre are also discussed in the paper. Also FE models of the PA mixture's structural geometry are discussed. At the end of the paper validation of LOT brings it all together. For validation purposes full-scale ravelling tests, were done at STUVA in Germany. The tests considered four PA mixtures. For each mixture LOT calculations are compared to real PA performance. This validation indicates a very strong correlation between LOT and full-scale PA performance.