Publication
Title
Oxidation of bitumen : molecular characterization and influence on rheological properties
Author
Abstract
Rheological properties such as stiffness, elasticity, and viscosity are crucial parameters for the use of bitumen as a construction material. In bitumen oxidation studies, the increased viscosity has often been related to an increase in polar interactions from oxygen-containing compounds, like carbonyl groups. In this study, bitumen was subjected to two oxidation processes, aging and air blowing. Aging was performed using the rolling thin film oven test (RTFOT) and the pressure aging vessel (PAV), whereas air blowing was conducted in a laboratory unit. This investigation gives more insights in the changes observed during oxidation and highlights the differences between aging and air blowing. Moreover, the oxidation tests provide bitumen samples of increasing viscosity, which are used to evaluate relations between molecular and viscoelastic characteristics. As a comparison, the changes observed in harder bitumen samples prepared by a continued distillation are also included. As expected, the evolution of rheological properties with oxidation time is very similar in the PAV and in the air-blowing unit, although the timescales are very different. Fourier transform infrared spectroscopy (FT-IR) and acidity measurements reveal clear differences in the formation of oxygen-containing functional groups depending on the oxidation process. UV-visible spectroscopy shows that during aging as well as during air blowing, larger conjugated aromatic compounds are formed. These findings suggest that the formation of polyaromatic compounds may be the main contributor to the increase in elasticity and viscosity during oxidation.
Language
English
Source (journal)
Rheologica acta. - Darmstadt
Publication
Darmstadt : 2016
ISSN
0035-4511
Volume/pages
55:4(2016), p. 315-326
ISI
000373160800005
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 10.05.2016
Last edited 13.11.2017
To cite this reference