The use of the UNIBAS-MPT triaxial press in the definition of the master curves of the complex modulus of asphalt concrete

The Authors propose the definition of an operative theoretical-experimental protocol for the construction of the Master Curves of the complex modulus of asphalt concrete, by using the UNIBAS-MPT triaxial press. Starting from the experimental definition of the Creep Compliance curve related to “pseudo-dynamic” cyclic tests and adopting at the same time a generalized mechanical model, they propose the methodology of the successive residuals, leading to the operative definition of the complex modulus after defining the viscoelastic components of the model associated with the tested materials. In addition, the definition of the complex model allows the construction of the isothermals of the asphalt concrete mixes and, thus, the description of the complex modulus as function of the load frequency at a fixed temperature. Finally, by referring to the Time-Temperature Superposition principle, the Master Curves of the tested materials are found. They are a fundamental instruments for the rheological characterization of the asphalt concretes with changes of temperature and load frequency.