The article presents the results of dynamic modulus tests carried on the asphalt concrete (AC16W). Thesinusoidal load was applied to the samples in accordance with DTC-CY method. The neat bituminous binder (penetrationgrade 35/50) was modified by means two synthetic waxes, coming from the Fischer-Tropsch raction, with variousmolecular weights and softening point temperature results (hard and softer). The relaxation phenomenon in terms ofchanges in complex modulus and phase angle was evaluated using the modified Huet-Sayegh (2S2P1D). Estimatedmodel parameters pointed out that the addition of the synthetic wax with the high (hard wax) and the low (softer wax)molecular weight raised the stiffness of the bituminous binder in relation to the reference bitumen 35/50. The applicationof the modified Huet-Sayegh model showed that the presence of the synthetic wax in the bitumen significantly affectedthe stiffness modulus of considered asphalt concretes. Basing analysis on Cole-Cole diagram it was found significantdifferences in the viscoelastic behaviour between the reference asphalt concrete and the asphalt concretes with syntheticwaxes. In contrast, there were no significant differences between viscoelastic properties of tested asphalt concretesmodified, used in the experiment, synthetic waxes. Furthermore, the sensitivity to the loading time of asphalt concretescontaining both synthetic waxes was marginal.

DOI: https://doi.org/10.3846/enviro.2017.141