Impact of Low Asphalt Binder for Coarse HMA Mixes Status: CompleteReport Date: 07/17/2017 Summary: Research showed that lower asphalt binder mixtures are susceptible to premature cracking. The current use of coarse-graded mix designs should be adjusted to narrow the gradation difference between larger and smaller aggregates in the mixes. While the research suggests such mixes should be used sparingly in Minnesota, it did not provide definitive data suggesting the practice should be stopped altogether. The practice may continue on a limited basis. Final Deliverables: Impact of Low Asphalt Binder for Coarse HMA Mixes (Report #2017-27) Research Confirms Low-Binder Asphalt Pavement Mixtures Prone to Cracking (Research Summary) Related Materials: Related Research: