Temperature and Loading Rate Susceptibility of Bituminous Mixtures on Monotonic Testing

Abstract

Listen

Translate article

The loading rate and temperature susceptibility of bituminous materials is of great importance. Their modulus and phase angle are strongly affected by any change of these two variables. For that reason, many researchers have explored the time-temperature superposition principle that assumes a thermo-rheologically simple behavior, i.e., all curves have the same characteristic time variation law with temperature. Nowadays it is common to obtain the so-called master curve of any bituminous material (binder, mastic or mixture) using dynamic testing. A side from that, several monotonic test methods have been proposed recently to obtain the cracking resistance of asphalt mixtures at low and intermediate temperatures. Many of them are focused on extracting ductility related parameters at temperatures close to 20 °C. Since the cracking resistance of the mixtures is strongly related with their stiffness and phase angle, it is also dependent on the loading rate and the test temperature. Joining these two concepts, this paper presents the efforts to analyze the influence of loading rate and test temperature in the different parameters that can be extracted from a monotonic test, such as the Fenix test. By testing different mixtures at different temperatures and different loading rates, the influence of these three variables in the different parameters that characterize the stiffness and ductility of the mixtures was analyzed. Finally, the possibility of obtaining a sort of master curve or an absolute reference value for each mixture in terms of any of the parameters considered was explored.