Experimental determination of the optimum percentage of asphalt mixtures reinforced with Lignin

Abstract

This article has used lignin additive to improve the bitumen properties as well as the asphalt mixture performance. Therefore, Lignin added to the bitumen 60/70 in various weight percentage (3, 6, 9 and 12 percent). Then, its effect on various properties of bitumen, including penetration grade, softening point, ductility, viscosity, weight loss percent, permeability index, flash point, and Frass breaking point were compared. Then, Asphalt mixtures were made. The results of experiments show that, by adding lignin to bitumen, the penetration grade, softening point, permeability index, kinematic viscosity and flash point of bitumen were increased, but its ductility and Frass breaking point were reduced by increasing the lignin content. Also, the weight loss test revealed that lignin reduces the oxidation of bitumen at high temperatures and in the short term. The results of mechanical asphalt experiments also showed that the performance properties of the asphalt, in particular its Marshall stability would improve by using lignin up to 6%. Finally, Economic analysis was evaluated for a 3-way road. After observing the findings and summarizing the results (technical and economic), the optimal amount of lignin was determined equal to 6 percent.