The application of rheology to the evaluation of bitumen ageing

Over the past few years, rheology has been extensively used in order to classify and evaluate bituminous binders according to their performance properties. This has led to a better knowledge of bitumen behaviour that occurs when subjected to different thermal and mechanical conditions, as seen during road construction and service in the field. In the present work, rheology has been applied to evaluate the properties of three vacuum residues before and after ageing. The influence of ageing on the rheological properties and temperature susceptibility was studied on whole vacuum residues and on their respective maltene fractions. Ageing produces fundamental modifications in the colloidal structure of both the vacuum residues and their maltenes fractions. The role of maltenes is important as the role of asphaltenes in determining the residue viscoelastic response. (C) 2000 Elsevier Science Ltd. All rights reserved.