The influence of nano sustainable additives on physical characteristics of modified asphalts

Construction of pavements of highways is considered the greatest environment for reutilizing waste materials. Hence; the choice of sustainable materials classifies a vital concept to design an innovative characteristic of pavements construction. The current study investigates the effect of using nano sustainable additives such as; nano slag and nano-metakaolin, at three contents (2, 4, 6) % by the asphalt weight. Physical characteristics, as viscosity, ductility, penetration, penetration index, softening point, were evaluated. Besides, the mixing process of modified asphalts was achieved use a shear blender set at (3000) rpm, for 30 mins. at 160 °C. General, the experimental results exhibited that optimistic influences of used nano additives on physical characteristics. The rotational viscosity and softening point values of modified asphalts containing (2, 4, 6) % of nano slag or nano metakaolin increased as, (43%,71%,80%),(42%,68%,92%) and (6%,12%,16%),(4%,14%,8%) respectively, in compared with base asphalt. As well as, the penetration value of modified asphalts reduced as, (13.5%,31.8%,38%), (9%,23%,44%) respectively. Correspondingly the ductility values of modified asphalt containing (2, 4, 6) % of nano slag or nano metakaolin reduced as (8%,16%,34%), (12%,20%,40%) respectively. The 4% nano slag or nano metakaolin showed the optimal results of viscosity, softening point, penetration, penetration index and ductility as, (720.710) C.p., (56,57)°C, (45,51) mm, (0.057,0.019), (105,100) cm respectively. Hence, the optimized modified asphalt with 4 % nano slag and 4% nano metakaolin produce the superior the physical properties as, (780) C.p,(59) °C,(42) mm,(0.404) & (100) cm respectively.