Effects of Pulverization of Properties of Stabilized Bases

Pulverization of pavement base materials is routinely carried out for rehabilitation of roads through full-depth reclamation (FDR). The primary stabilizers currently used in Texas Department of Transportation (TxDOT) districts for FDR are cement, lime, and fly ash. The optimum stabilizer content is currently determined either based on experience or through a series of laboratory tests that evaluates the strength, stiffness and durability of the base-stabilizer mix. For lab testing, base materials are retrieved from the site way before pulverization. The change in gradation due to pulverization can significantly impact the base strength and stiffness. Phase I of this study consisted of an extensive laboratory study to determine the impact of changes in gradation on the desired stabilizer content of a base material. The impact of pulverization was also studied on an ongoing project. The results are provided in this report. It was found that the change in gradation indeed impacts the properties of the mix and should be considered in the design stages of FDR. In Phase II, the ways to address this matter will be investigated and reported.