Eco-Friendly Modifiers for Sustainable Asphalt Pavements: Enhancing Ageing Resistance and Adhesion

Project Background 

Road transport infrastructure plays a crucial role in the transition towards sustainability and decarbonisation. Asphalt, composed of mineral aggregates and bitumen, remains the dominant surfacing material due to its excellent performance. The use of crumb rubber from scrap tyres to modify bitumen has gained popularity within the circular economy framework, offering significant economic and environmental benefits. 

However, Crumb Rubber Modified Bitumen (CRMB) faces two critical challenges. First, CRMB is highly susceptible to aging under heat, oxygen, and ultraviolet (UV) exposure, leading to deterioration and reduced pavement durability. Second, poor adhesion between bitumen and aggregates, which worsens over time, results in binder peeling, cracking, and pothole formation, negatively impacting driving safety and increasing maintenance costs. To address these challenges, this research will develop sustainable and durable asphalt pavements using industrial waste-modified CRMB and organic-modified aggregates. 

Training and Collaboration 

This is an interdisciplinary project at the intersection of pavement engineering, materials science, bioengineering, surface science, and polymer chemistry. The student will spend the first 24 months at the University of Liverpool (UoL) and the following 24 months at National Tsing Hua University (NTHU). 

Throughout the project, the student will benefit from strong support from supervisors and research teams across both institutions. The research will involve extensive laboratory work, analytical techniques, and simulation-based assessments to evaluate the effectiveness of new technologies. 

The project offers outstanding industry engagement opportunities. The student will collaborate closely with local materials companies, highway authorities, and research organisations, ensuring that findings are applicable to real-world challenges. These industry interactions will provide valuable insights and career development prospects in academia, research, and industry sectors. 

Project Structure 

Over the four-year period, the student is expected to achieve the following objectives: 

• Synthesis of renewable and eco-friendly anti-aging modifiers from by-products of the fertilizer and pulp industries to enhance the aging resistance of CRMB. 

• Organic modification of aggregates to improve adhesion between aggregates and CRMB, increasing pavement durability. 

• Development of an experiment-simulation framework (using molecular dynamics simulation or Finite Element Modelling) to: Investigate the adhesion mechanism between modified CRMB and organic aggregates before and after aging; Predict the performance and lifespan of sustainable rubberised asphalt pavements. 

This PhD offers an excellent platform for developing expertise in sustainable materials, computational modelling, and industry-driven research, preparing the candidate for a career in academia, industry, or public-sector organisations involved in transport infrastructure. 

We want all of our staff and Students to feel that Liverpool is an inclusive and welcoming environment that actively celebrates and encourages diversity. We are committed to working with students to make all reasonable project adaptations including supporting those with caring responsibilities, disabilities or other personal circumstances. For example, If you have a disability you may be entitled to a Disabled Students Allowance on top of your studentship to help cover the costs of any additional support that a person studying for a doctorate might need as a result. 

We believe everyone deserves an excellent education and encourage students from all backgrounds and personal circumstances to apply.