Experimental study and cost–benefit analysis of using polymer-modified binders for low-traffic roads in Minnesota

Polymer-modified binders (PMB) improve the mechanical properties of asphalt mixtures compared to unmodified binders. Although for high-traffic roads, the choice of superior products is obvious, for low-traffic roads, there is not enough information to determine if using a PMB is cost-effective considering its higher initial cost. This research investigates the use of PMBs for low-traffic roads, focusing on Minnesota pavements. First, a laboratory experimental study is performed to compare the low-temperature cracking properties of polymer-modified and unmodified binders and mixtures used in Minnesota. Then, historical pavement performance data are analysed to compare the field performance of modified and unmodified mixtures. Based on the experimental results, a life cycle cost analysis (LCCA) is conducted to compare the use of polymer-modified and unmodified binders. A sensitivity analysis is performed to assess the impact of key factors on the LCCA outcomes. The results show that using PMBs is expected to extend pavement service life by six years, and PMBs are more cost-effective than unmodified binders for low-traffic roads.