• Micaelo, Rui
• Costa, Margarida Sá Da
• Lopes, Pedro
• Carl, Cindy
• Leischner, Sabine
• Falla, G. Canon

Abstract

Asphalt mixture is a complex composite material due to the unique behaviour of<br/>bitumen and the variable microstructure. During fabrication the bitumen combines with<br/>the very fine aggregate particles to form the bituminous mastic that involves coarse<br/>aggregate particles and binds the mixture altogether. However, the bitumen<br/>characteristics change over time due to ageing, and the changes in the bituminous<br/>mastic affect asphalt’s performance and durability. The objective of this work is to<br/>analyse the evolution in the ductility behaviour of bituminous mastic with ageing. Two<br/>bituminous mastics fabricated with a paving grade bitumen and two mineral fillers were<br/>aged at different levels and characterized. Mastic ageing was imposed with the<br/>Pressure Ageing Vessel using different times of exposure in the chamber. The ductility<br/>behaviour of mastics was evaluated by means of the double-edge-notched tension test<br/>because it allows to distinguish the essential and plastic work contributions to ductile<br/>failure. The results showed that bitumen ageing has a detrimental effect on the<br/>performance of bituminous mastics. As expected, aged mastics become stiffer and less<br/>ductile. The largest variation in properties occurred from the original mastic to the first<br/>ageing level that simulated short-term ageing. The filler type affected the evolution of<br/>ductility behaviour with ageing. Furthermore, this work demonstrates the importance of<br/>using mastics in the characterization of asphalt materials instead of the bitumen.

Topics

• impedance spectroscopy
• microstructure
• mineral
• polymer
• laser emission spectroscopy
• composite
• aging
• durability
• ductility
• tension test