Hayato TOGASHI

The effects of the modified asphalt using the special resin on the performance of asphalt mixtures

Osamu TAKAHASHICTakeshi NAKAMURA

In general, modified asphalt is used for improving various physical properties of asphalt mixture, i.e., shear resistance, fatigue resistance and moisture resistance. Therefore, it is necessary to evaluate the physical properties of asphalt binder when the new special resin was added to the conventional modified asphalt binder.
The study investigated the effects of two different the asphalt binders, namely the Polymer Modified Type II (PMT II) and the PMT II using the special resin, on the asphalt mixtures. Four different tests, i.e., the Elastic Recovery Test, the Force Ductility Test, the wheel tracking test (WTT), the three points bending test (TPBT) were examed to evaluate the elastic recovery force test, the stress relaxation characteristics of the binder, the rutting, and the cracking resistance, respectively. The design asphalt binder contents were chosen at 4.2% and 5.2%, and the special resin contents were performed at 0%, 10%, 20%.
The results indicated that the dense asphalt mixture with 20 mm -nominal maximum particle size (NMPS) using the polymer modified asphalt II showed better resistance to damage  than 5 mm and 13 mm NMPS mixtures. Moreover, the results illustrated that the mixtures of the PMT II using the special resin and the PMT II had the same values of elastic recovery rate, the FD value, and fatigue fracture resistance. However, the stress relaxation time of mixtures using the special resin was slightly shorter than the mixtures containing the polymer-modified Asphalt Type II. The results of the WTT also demonstrated that the dynamic stability of asphalt mixtures increased with the increase in the special resin content. In addition, the TBBT showed that compared to the PMT II mixtures, the mixtures of the PMT II using the special resin had the lower strain at failure at the normal temperature range.