ABSTRACT
This chapter reviews the principal properties required from asphalt. The properties are grouped into properties generally applicable to all layers, those applicable to the structural layers, those applicable to the surface course and those applicable to the pavement generally. Traditionally, cracking was assumed generally to start at the bottom of the pavement and travel upwards because, considering the pavement as a beam that is loaded by being bent downwards at the centre, the highest stresses would be at the bottom. Water and oxidation can affect various properties of the asphalt. Resistance to water damage is included in the common properties because water can access the pavement from above, below or the side. The stiffness of asphalt is not as simple a property as it is for most structural materials because asphalt is visco-elastic in that it responds to loading in both a viscous and an elastic manner.
