Evaluation effect of Evonik and Zycotherm on moisture sensitivity and rutting performance of Stone Mastic Asphalt Mixtures

The performance of asphalt mixtures against environmental factors such as moisture is important and many of the damages are directly affected by the water entering the pavement and weakening the bond between bitumen and aggregates. On the other hand, Stone Mastic Asphalt Mixture (SMA) is a kind of hot mix asphalt with coarse aggregate skeleton and a high percentage of bitumen and filler, which requires the use of additives due to drain down. Therefore, the objective of this research is to investigate the effects of nanomaterials on the moisture sensitivity of SMA asphalt mixtures. In this research were used, Calcareous aggregate, AC-60/70, two additive Evonik Dgosa in the amount of 0.15, 0.25 and 0.35%, and Zycotherm of 0.05, 0.1 and 0.15% of bitumen weight. AASHTO T283 (modified Lottman test), Resilient Modulus Ratio (RMR), dynamic creep and boiling water test were conducted to control moisture sensitivity and rutting performance. Results showed that Evonik up to 6% and Zycotherm (nanomaterial) up to 16% improve the performance of SMA asphalt mixtures against moisture.Adding Zycotherm (0.15% wt) to the asphalt mixture improves rutting resistance. Also, after analysing of these materials, it can be resulted that the effect of Zycotherm (nanomaterial) on the moisture properties and performance in the mixed state is more favorable than Evonik.