Comparative Study of Mechanistic-empirical Structural Design Methods Applied to Sustainable Asphalt Mixtures

Abstract

Introduction/ Background: Nowadays, there is a growing interest in achieving sustainable alternatives to conventional flexible pavements. The incorporation of recycled materials into asphalt mixtures has become a departure point. This study focuses on developing sustainable asphalt mixtures incorporating different residues to find a material that performs well on both technical and environmental grounds. Materials and Methods: Mixtures with recycled materials and others are compared on a pavement structure. A mechanistic-empirical pavement design method is used to carry out analyses in different conditions. A Life Cycle Assessment is conducted to consider the balance of positive and negative environmental aspects of each mixture and pavement structure. Results: The results indicate that all mixtures with sustainable features have a longer life span and an enhanced performance. They also incur higher impacts per tonne produced. However, the “avoided impact” is considered in their favour. Discussion: Mixtures with enhanced mechanical properties are key to achieving long-term environmental benefits. The usage of local materials is also essential. Conclusion: Proving that unconventional mixtures have a satisfactory performance requires innovative, properly calibrated models and a thorough material characterization. Accurately reflecting on their in-service behaviour is key to evaluating the environmental benefits. © 2024 Elsevier B.V., All rights reserved.