Experimental investigation of the road performance of terminal blend rubber asphalt mixture with different dry-way additives

Abstract

Using wet-way composite modification method may result in the amount of ground tire rubber (GTR) in terminal blend rubber asphalt (TB) undetectable. So, it is of great interest to find out if dry-way modification method can substitute for wet-way composite modified asphalt to address the shortcomings of TB mixture. A laboratory experiment was developed for performance evaluation of TB asphalt mixtures with dry –way use polymer additives. The results showed that: (1) 5 hours was recommended as optimum processing time, since no obvious difference existed after TB asphalt modifying for 5 h and 7 h. (2) The incorporation of anti-rutting agent PLAST.S, GTR, polyester fiber (PF) and styrene-butadiene-styrene block copolymer (SBS) improved the rutting stability, resistance against low-temperature cracking, moisture stability and fatigue life of TB asphalt mixture, especially when PLAST.S and PF were used. (3) The use of GTR and PF brought obvious increase of mixing torques, resulting in more challenges to the workability of TB asphalt mixtures, whereas mixture with PLAST.S did not have a statistically significant difference with TB asphalt mixture. Therefore, according to the results obtained, PF can be used to replace TB/SBS composited modified asphalt since the two shared the most similar improvement of the properties of TB asphalt mixtures, while PLAST.S and GTR were also considered as good choices for modifying the TB asphalt mixture in dry-way.