Principal Investigator(s):
David Newcomb, Former University Researcher, Civil, Environmental and Geo-Engineering
Project summary:
Various projects throughout the state of Minnesota will be used to evaluate mixture properties with the QM- Superpave laboratory trailer. Data to be collected include typical construction tests such as air voids and aggregate gradations. Additional testing includes determination of mixture tensile strengths, and densities of gyratory-compacted samples. Round robin testing will be conducted so that a precision statement for both unconditioned and moisture conditioned tensile strengths can be developed. These statistics will be used along with both MnDOT laboratory and the field trailer data to formulate aggregate gradation specifications based on minimum values for VMA, asphalt film thickness, and unconditioned tensile strength. The current Marshall mix design method will be modified to include moisture sensitivity testing. Both tensile strength and net adsorption test results will be used to identify specific aggregate mineralogy that can be related to the durability of asphalt concrete mixtures. Critical concentrations of potentially detrimental aggregate mineralogy will also be estimated.