Samenvatting
In relation to close textured asphalt concrete as reference, porous surfacing achieves 4 dB(A) noise reduction. This figure refers to new surfacings. Traffic volume would have to be reduced by 60% to achieve same effect. The porous surfacing has 8-12 mm max aggregate size and 20-25% voids. It must be at least 4 cm thick. The cost is about 20% higher since polymer modified bitumen is used. No Danish experience is as yet available concerning durability. Apart from noise reduction, porous surfacings have good friction, no aquaplaning, reduced spray. The free-draining effect may complicate winter maintenance. This type of surfacing can be used to reduce noise in towns.