Comparing Chemical Stabilizers for Improving Iowa Granular Road Bearing Capacity

Granular roads in Iowa are essential for transporting agricultural goods and providing access to isolated regions such as those containing rural homes. Regular maintenance is necessary to ensure the safety and comfort of all types of vehicles, including heavy farm and quarry trucks, as well as local residents’ cars. Strength and stability of a road’s aggregate layer are critical to the overall performance and longevity of granular roads. This study seeks to evaluate the performance of different chemical stabilizers for improving aggregate layer strength. Limestone, the primary aggregate utilized in Iowa was used in the study, and three proprietary chemical stabilizers were tested, including two ionic-based stabilizers and a single enzyme-based stabilizer. Laboratory-based California Bearing Ratio (CBR) tests were used to measure the strength. The optimized subgrade soil fraction that provided the highest CBR value was found to lie between 6 and 8%. The data were analyzed using a two-way Analysis of Variance (ANOVA) test that showed that the number of curing days, the type of chemical, and their interaction played a significant role in the CBR value of aggregate materials. Overall, this study highlights the importance of chemical stabilizers in improving the strength of granular roads in Iowa and provides valuable insights with respect to road maintenance and construction.