Bitumen Technology: Chemical Composition and Rheological Behavior

Abstract

Modern techniques are being employed to carry out testing and characterizing bitumen. Attempts have been made to correlate the conventional physical tests (penetration test, softening point test) to modern techniques in order to reduce the amount of time taken to characterize samples. Here, we have studied the relation of Dynamic Shear Rheometry and Near Infra Red Spectroscopy with the conventional tests such as penetration test, softening point test, viscosity test. In order to study how chemical composition affects the properties of the bitumen, 28 bitumen samples from various crudes and different methods of processing were selected Good correlations for penetration and softening point values with the complex modulus as determined with the Dynamic Shear Rheometer were obtained with standard deviations close to the precision limits for the respective tests. It was also found that Near Infra Red Spectroscopy can be correlated with the conventional tests and that it has the ability to distinguish between fresh and the aged samples. SARA fractions and their ratios do not show a clear relation to the physical properties when considering all the samples, but show a trend when considering similar samples suggesting that properties are highly origin and processing dependent. These results can help in quicker screening of samples; for example, characterizing a bitumen sample takes one day but using these correlations we can potentially reduce the time to fifteen minutes.