A new approach for integrating environmental, social and economic factors to evaluate asphalt mixtures with and without waste tires

Abstract

In the context of making roads more sustainable, this study compares two asphalt mixes: one conventional, and one with end-of-life tyres (ELT), using a multi-criteria decision-making method focused on the advantages among the different alternatives called "Choosing by Advantages" (CBA). The aim is to answer whether it is appropriate to use ELT in asphalt mixtures in developing countries, and what environmental impacts its use generates in road construction. This research is based on a case study of a road construction project in Chile. The main results are as follows: 1) the use of rubber bitumen (RB) is more advantageous than the use of conventional bitumen, and 2) the cost required for the manufacture and execution of RB is 1.4 times higher than the cost of conventional mixing; however, the cost of maintenance of RB is lower. Finally, research shows that it is convenient to use ELT in asphalt mixes, as it generates social and environmental improvements, such as reducing IRI variability over time, minimizing noise and reducing greenhouse gas emissions.