ABSTRACT
Porous Asphalt (PA) is used extensively as a surface layer on highways in the Netherlands. PA has a relatively high void content and because of this possesses excellent noise absorbing and drainage properties. It however brings with it a large disadvantage too; PA surface layers require maintenance quite often. The main failure mode, in 75% of occasions, is raveling, which is defined as loss of aggregate from the surface of the asphalt pavement. An experimental program was set up at DUT to explore the effects of lignin modification on the raveling resistance of PA. A penetration bitumen 70/100 was used as a reference and was modified with both 5% and 10% kraft lignin. Subsequently, mortars (fresh and aged) and PA specimens were produced and empirical, rheological and mechanical testing was carried out. From the results it is concluded that kraft lignin counteracts ageing and drainage but low temperature characteristics are not improving.
