Viscosity as a possible supplement to the empirical tests of bitumen

Abstract

The quality of bituminous binders used in the construction and maintenance of road surfaces is currently being assessed by empirical tests based on obtaining one value for specific boundary conditions that were designed around 100 years ago. However, these tests appear to be inadequate. Under laboratory conditions, all bitumen tests have the correct values, but if the bitumen binder is used in the asphalt mix in the road, sometimes we can see no standard properties and behavior than in the laboratory. We are increasingly faced with the issue of replacing empirical bitumen tests with performance related parameters as viscosity, complex shear modulus that can better and more accurately describe the behavior of bitumen not only in the laboratory but also in asphalt mixtures. In paper the viscosity results of ten bitumen samples (50/70 and PmB 45/80-75) at different temperatures are presented and compared with empirical tests as penetration and softening point.