Evaluation of the Effect of Lignin and Glass Fiber on the Technical Properties of Asphalt Mixtures

The performance and the fundamental weaknesses of the asphalt mix have made the researchers think about modifying the technical properties of the asphalt mix by using the appropriate additives. The fiber spreads through the asphalt mix and prevents the development of the micro-cracks by producing a more coherent mix and increasing its durability. The present study, for the first time, has used two additives, lignin and glass fiber (6 and 12 mm in length), to improve the performance of asphalt mix. Mixing was done in a way that lignin and glass fiber were added to the bitumen and aggregates, respectively. According to the results, the length of the used glass fiber has a significant effect on the Marshall Resistance and asphalt mix performance so that glass fiber in 6 mm length has reduced the Marshall strength and glass fiber in 12 mm length has increased the Marshall strength. Moreover, the results of resilient modulus indicate that having a stable percentage of fiber and an increasing lignin percentage, it behaves differently at two temperatures of 15 and 25 degrees C, confirming once again the fact that the length of fiber plays a decisive role on the result of resilient modulus.