Sustainable Modification of Bitumen Using Waste Toner and Lignin

Area of Science:

• Materials Science
• Civil Engineering
• Environmental Science

Background:

• Integrating waste materials into road infrastructure is key for sustainability and resource efficiency.
• Short-term-aged 50/70-penetration-grade bitumen requires modification to extend its service life.
• Industrial waste toner powder and bio-based lignin offer potential as sustainable modifiers.

Purpose of the Study:

• To investigate the effects of waste toner powder and lignin on the properties of aged bitumen.
• To assess the potential of these additives in enhancing road infrastructure materials.
• To understand the microstructural changes and performance improvements in modified bitumen.

Main Methods:

• Modification of aged bitumen with varying percentages of waste toner powder (4-16%) and lignin (15-20%).
• Evaluation of physical consistency (penetration tests) and low-temperature flexibility (ductility tests).
• Microstructural analysis using Scanning Electron Microscopy (SEM) to observe additive distribution and bonding.

Main Results:

• Both waste toner and lignin increased bitumen stiffness, indicated by reduced penetration.
• Waste toner enhanced the polymer matrix, and lignin improved elastic components, boosting high-temperature stability.
• Ductility tests revealed a reduction in elongation, suggesting potential brittleness at low temperatures.
• SEM confirmed homogeneous distribution and good interfacial bonding of additives at lower concentrations.

Conclusions:

• Waste toner powder and lignin can effectively modify aged bitumen, increasing stiffness and high-temperature performance.
• Waste toner is particularly suitable for high-temperature road applications.
• Further research may be needed to address the observed reduction in low-temperature ductility.