Performance properties and carbon emissions of cold mix cold laid asphalt rubber mixture pavement

Abstract: Based on the indoor experiments and a test section constructed in the G5 expressway project, a comprehensive study was implemented regarding the performance properties and environmental characteristics of cold mix cold laid asphalt rubber mixture. Results showed that the Marshall stability and dynamic stability of the cold mix asphalt rubber mixture were greater than those of the hot mix dense graded asphalt crushed stone, but its residual stability was slightly lower than the latter. Both the high-temperature stability and water stability could meet technical requirements for pavement middle and lower layer asphalt mixtures. In addition, the total in-construction carbon emissions of cold mix asphalt rubber mixture are 2970.77kg per 1000m2, which are mainly caused by transportation and paving and rolling stages and accounted for 47.1% and 51.9% of the total emissions. While the in-construction emissions of hot mix dense graded asphalt crushed stone are 6151.80kg per 1000m2, which are mainly resulted from heating of aggregates and asphalt as well as the fuel consumption of transportation, paving and rolling machinery. The carbon emissions of hot mix asphalt mixture are about twice that of cold mix asphalt rubber mixture, indicating cold mix mixture greatly reduced carbon dioxide and harmful gas emissions and lowered personnel labor intensity, showing outstanding environmental advantages.