How would high temperature affect the laying bituminous pavement?

In general, bituminous materials are also broadly classified into two types, namely bitumen macadams and hot-rolled asphalts. During compaction, the increase of temperature causes the reduction of viscosity of binder. The binder acts as a lubricant among aggregates particles because it is mobile in a fluid state under high temperatures. The internal resistance between the bituminous materials is drastically reduced resulting in the formation of a mixture with better aggregate interlock.

Bitumen macadams mainly contain continuously graded aggregates. Compaction of this type of bituminous material is eased with an increase of mix temperature as the lubricating effect of reduced viscosity of binder
helps in the rearrangement of aggregates.

The aggregate of hot-rolled asphalt are not well graded. With a rise in mixing temperature, the binder will stay unset and the mixture has little resistance to compaction.

This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.