Sample Preparation Methods, Geometry and Temperature Control for Dynamic Shear Rheometers

摘要

The dynamic shear rheometer (DSR) can be considered to be one of the most complex and powerful instruments for characterising the flow properties of bitumen. This paper describes an investigation into the influence of three sample preparation methods (hot pour, silicone mould and weighing), different sample geometries and the importance of temperature control on the rheological parameters measured during DSR testing. The effect of the different sample preparation methods and sample geometry have been evaluated for a series of unmodified (penetration grade bitumen), process modified and polymer modified bitumens. The results indicate that a method involving the pouring of hot bitumen onto one of the plates of the DSR and then trimming the edge of the sample is the most consistent means of sample preparation. In addition, the magnitude of the measured rheological parameters are influenced by the sample preparation method with the silicone mould and weighing methods producing consistently higher and lower values of complex modulus compared to the hot pour method.