Relaxation Spectrum: Why It Matters and How to Correctly Develop One?

One of popular models to describe mechanical behavior of asphalt binder is the Generalized Maxwell Model (GMM), which is analogized as a large number of springs and dashpots connected in a parallel fashion. Theoretically, the continuous relaxation spectrum of GMM of a particular asphalt binder is unique and reflects its fundamental physicochemical characteristics. The commonly used approach is to search the relaxation spectrum from dynamic modulus test data. However, the calculation of the relaxation spectrum from dynamic modulus test data is an ill-posed problem. Although different approaches have been developed for the conversion of the dynamic modulus test data to relaxation spectrum, their validity remains unknown. In this research, a new determination of relaxation spectrum, which obtained by considerations of both static modulus test, such as relaxation modulus test, and dynamic modulus test is proposed and it is found the obtained spectrum is more realistic when one compare both data of relaxation modulus test and dynamic modulus test.