Evaluation of sun-oxidized carnauba wax as warm mix asphalt additive

In the present work, carnauba wax (CW) type 4 was used as an additive in warm mix asphalt (WMA) technology. Rheological experiments were performed with the binders to determine viscoelasticity properties such as complex shear modulus (G∗) and phase angle (δ). Binders were also evaluated in terms of its penetration and softening point. Master curves of G∗ and δ were obtained from the rheological data. Multi-stress creep and recovery (MSCR) test was used for determination of percent recovery and non-recoverable creep compliance of modified and neat asphalt cements. The effect of CW addition produced higher values of complex modulus when compared to the neat asphalt cement. The CW modified asphalt cement has also shown small values of δ in the range of frequency investigated, showing improved elastic properties. The use of CW as an additive allowed the hot mix asphalt (HMA) to be mixed and compacted using lower temperatures. Those values of reduction in mixing and compaction temperatures were obtained comparing the compaction densification index (CDI) and the traffic densification index (TDI) results with the ones found for conventional HMA.