Influence of limestone filler on the rheological properties of bituminous mastics through susceptibility master curves

Abstract

[EN] Temperature variations caused by seasonal changes and vehicle loads generate severe damage to asphalt layers. For a correct design, it is essential to carry out an adequate rheological characterization of both bitumen and bituminous mastic, since they are considered the weakest elements of the mixture. This article shows the results of the rheological behavior of mastics made of limestone filler and three types of binders, with a filler-bitumen ratio of 1/1, finding that the filler-bitumen interaction has a significant influence on asphalt mastics. Vehicle loads and climatic temperatures were simulated from MSCR and DSR tests to study the viscoelastic behavior of the bitumen and the mastic. Thus, stiffness, variation of the internal structure, viscosity, thermal susceptibility, permanent deformation, and cracking were determined. The results indicated that the filler causes an increase in the rigidity of the mastic for the whole range of temperatures and load frequencies, but this increase varies depending on the type of bitumen used. There is also no significant change in the phase angle variation between bitumens and mastics. This indicates that the bitumens maintain their internal structure when the filler is added, as well as considerably decreasing the accumulated strain in multiple stress creep recovery (MSCR) tests.