The Feasibility of Using Lignin as Modifier for Asphalt Cement

Modifying asphalt cement is an effective approach to enhance the performance of asphalt concrete. This study evaluates the physical properties of lignin-modified asphalt (LMA) at various lignin percentages. The initial step involved extracting lignin from the pinus wood sawdust using the soda process. Subsequently, the extracted Soda Lignin Powder (SLP) was characterized through Fourier transformation infrared spectroscopy (FTIR), and Scanning Electron Microscopy-Energy Dispersive X-ray Analysis (SEM/EDX) to examine the changes in the chemical structure of lignin after extraction by soda process. Following this, three asphalt blends containing varying amounts of SLP (2%, 4%, 6%) by weight of asphalt cement were produced to assess physical properties such as penetration, softening point, ductility, and rotational viscosity test. The findings indicate that incorporating SLP into asphalt cement increases stiffness and viscosity compared to virgin asphalt cement, with increasing SLP content. These results suggest that lignin presents significant enhancement to the performance of asphalt cement under high service temperature conditions.