The effect of lignin on mechanical and dynamical properties of asphalt mixtures

The present article has studied the mechanical and dynamic properties of asphalt mixtures containing lignin. At first, the Fatigue Life (FL) and Resilient Modulus (RM) tests performed on the samples, and then the Marshall Stability (MS) test carried out on them. Lignin was added to asphalt mixtures with 3, 6, 9, and 12%. The RM test performed at a frequency of 1 Hz, with a haversine load at 5, 25, and 40 degrees C. In addition, the Fatigue test performed at three levels of tensile stress (250, 350, and 450 kPa) at 20 degrees C with a haversine load and a loading time of 250 ms with a rest period of 1250 ms. The results indicated that by using lignin up to 6%, the performance properties of asphalt, in particular, MS, RM, and its FL, would improve. Also, as the percentage of additives in the mixture increased, the samples' thermal sensitivity decreased. On the other hand, the economic analysis results indicated that adding lignin to 6% would make the asphalt mixture economical. Finally, the results of the two-factor statistical analysis of the RM and FL indicate that a combination of temperature-lignin and lignin-stress affects the RM and FL.