, Professor, Civil, Environmental and Geo-Engineering
Polymer modified binders (PMB) have been shown over the decades to have superior rheological and mechanical properties compared to unmodified asphalts. However, the higher costs of PMBs has prevented a wider use of these materials. While for high traffic roads, the choice of superior products is more obvious, for lower volume roads, there isn't always enough information to allow engineers to determine if using a PMB is cost-effective in the long run. For example, for a job of 50,000 t, a difference of $12 per ton results in an additional cost of $600k, which is very significant for local roads authorities.
In Minnesota, the necessity of understanding the benefits of using polymer modification, which provides
superior resistance to cracking, is even greater, since asphalt pavements largely fail due to low temperature
cracking. Many local agencies use polymer modified binders, mainly PG 58Ha??34 (Grade C), in the asphalt mixtures for the wearing course, which reduce the occurrence of transverse cracking. However, the answer to the question "how costa??effective is the use of the Grade C binder, especially
when compared to the cheaper PG58Sa??28 (Grade B) binder", is not known.
The main goal of the proposed research is to provide a well-informed answer to the above question. This will be accomplished by documenting and analyzing existing performance data, reviewing relevant case studies, performing experimental work on various asphalt binders and mixtures to evaluate their
low temperature cracking resistance, and conducting a benefit-cost analysis to provide recommendations on when to use Grade B and Grade C for lower volume roads.
- Project number: 2022014
- Start date: 06/2021
- Project status: Active
- Research area: Infrastructure
Asphalt, Low-volume roads