Erik Schlangen h.e.j.g.schlangen@tudelft.nl
Martin van de Ven m.f.c.vanderven@tudelft.nl
Porous asphalt is a great material both in terms of noise reduction and water drainage for a surface layer. In the Netherlands at the moment already 60% of the surface of the Highways is covered with (mostly single layer) porous asphalt. One of the major disadvantages of porous asphalt is the poor performance in terms of durability in comparison with dense graded asphalt. The main problem in the open asphalt concrete is caused by a mechanism called ravelling, which occurs after a couple of years and can increase very fast due to the friction of the tires of passing vehicles. Ravelling is the loss of aggregates form the surface layer of an asphalt road. The aggregates in the asphalt are hold together by a bituminous binder. Due to aging (temperature cycles, wetting-drying, UV and traffic loading) the properties of the binder change.
Two systems are popular at the moment: the recently introduced two-layer porous asphalt and the traditionally used single layer porous asphalt. Now the mean lifetime of two-layer porous asphalt surfacings is about 7 years. The primary goal of the project is to build in a self healing mechanism that the asphalt constantly repairs itself and that the lifetime of the two-layer porous asphalt is increased to 12 years. For the traditionally used single layer porous asphalt the intention is to obtain an increase of the mean lifetime form 10 to 14 years.
The project is carried out by the Microlab group of the Delft University of Technology, in collaboration with the group Road Engineering. Industrial partners who have shown their interest are Heijmans Infrastructuur BV, Altravie and INTRON BV.
The project has already led to a real application: A test track is made on Highway A58 in the Netherlands.
more on this project can be found on:
