|Project Description: Performance and long-term sustainability of granular roadways are dependent to a considerable degree on the quality of the aggregate materials used, which varies considerably from one source to another across Iowa. There are a wide range of granular material sources, each producing different qualities, supply amounts and prices.
In this project, the research team is conducting a laboratory and field tests to examine the link between quality and performance of granular aggregate materials used in unpaved road designs, using materials collected from various quarries in Iowa. Based on the laboratory test results, field test sections will be constructed using materials with different quality and aggregate sources. The field performance (abrasion resistance, freeze/thaw resistance, density, material loss, modulus, gradation change) of sections built with different quality materials will be compared. Then, a comprehensive cost-performance analysis will be conducted to evaluate the cost effectiveness of the different materials to determine whether it is economically advantageous to transport good quality aggregate materials from quarries located in different locations.