Assessing the Potential for Sustainable Cold-Mix Asphalt Mixtures Based on Crumb-Rubberized Asphalt Binder

Abstract

Crumb-rubberized asphalt (CRA) binder has been widely used for several decades because it provides a nonhazardous disposal method for scrap tires and it improves some engineering properties of asphalt pavement. The energy consumption, atmospheric emissions, and storage stability of CRA binder are the issues limiting wider use of it. This study provides a novel method to introduce CRA binder into cutback cold-mix asphalt (CMA) remedying the drawbacks of CRA binder and achieving sustainable asphalt pavement in the entire construction process. The composition design of CMA mixture based on CRA binder was proposed based on the Brookfield viscosity, Marshall stability, and uniaxial compressive tests. The CMA mixture based on CRA binder further demonstrates excellent rutting resistance, crack resistance, and storage stability in laboratory experiments, despite being produced and stored at ambient temperature. An evaluation of sustainability shows that use of the CMA mixture based on CRA binder would provide a 58.94% decrease in energy consumption and a 81.42% decrease in greenhouse gas emissions, proving its great potential in sustainable construction of asphalt pavements.