Laboratory evaluation of gap graded rubber modified warm mix asphalt

Crumb Rubber (CR), if used in Gap-graded Hot Mix Asphalt (HMA), forms an excellent splash-&-spray resistant, durable and fatigue resistant HMA layer. The only drawback is the higher asphalt production temperature due to addition of CR. The higher production temperature can be reduced by using Warm Mix Additives with only concern being its effect on the performance. The paper contemplates the use of 1.5% Sasobit® with a view to achieve similar or better performance properties at lower mixing temperature. The results indicate an overall improvement in performance (in terms of rutting and fatigue) in light of the laboratory tests performed. The paper concludes with Gap-graded Warm Mix Asphalt (WMA) as a feasible solution when 1.5% Sasobit® is used as an additive.