Bitumen performance in pavements under extreme climatic conditions

Quality and properties of bitumen for asphalt pavements depend largely on chemical composition and structure, which are mainly controlled by the origin of the crude oil(s) and the processes used during manufacture. Bitumen composition and structure change during storage at high temperature and during production, transport and laying of asphalt mixtures. This so-called oxidative ageing can change the properties of bitumen dramatically. Ageing continues, although at a much slower rate, also in the asphalt pavement. Bitumen performance can be improved (modified) by incorporating additives (e.g. polymers or crumb rubber) in the bitumen. The level of improvement depends largely on type and amount of additives that are used and the modification process that is applied. These aspects are all briefly discussed in this paper. Special attention is given to the performance of (modified) bitumen under extreme climatic conditions (like prevailing in most parts of the Middle- East and Asia).

Keywords:

bitumen composition , bitumen structure , ageing , lowlhigh temperature performance , mechanical characterisation and bitumen improvement