Benefit Cost Analysis of Aggregate Options for a Granular Roadway

Material costs and hauling costs are considerable portions of construction costs for granular roadways. It is more desirable for county engineers to use granular materials from nearby sources to reduce hauling costs. However, the quality of the granular materials differ from source to source and directly relates to the serviceability and sustainability of granular roadways. Heavy traffic loads and freeze-thaw weathering deteriorates surface aggregates and leads to several distresses such as material loss, rutting, and potholes and results to require more frequent maintenance. However, the use of more durable aggregates from a source with higher hauling time rather than low-quality materials from a nearby source could reduce the maintenance costs. Therefore, a process for evaluating the performance of the granular roadways based on cost-effectiveness would be desirable for local road engineers in reducing the overall costs during the service life of a roadway. In this study, laboratory and field tests were conducted to examine the link between the quality and the performance of granular aggregate materials used in granular road applications, and materials were tested and observed from various quarries in Iowa on field test sections. The field performance (modulus, dust production, and surface roughness) and, a comprehensive cost-performance analysis was conducted to evaluate the cost-effectiveness of the various materials to determine whether it was economically advantageous to transport more durable aggregate materials from distant sources rather than using locally available materials of lower quality