Erosion Potential of Stabilized Support Layers for Concrete Pavements and Overlays

The performance of concrete pavements and overlays is highly dependent on the uniformity, durability, and stability of the underlying support layers. Erosion of support layers can lead to pavement distresses and a reduction in pavement life. A review of existing erodibility performance tests that assessed stabilized support layers was first conducted to identify and evaluate their suitability for adaptation. The Hamburg wheel tracking device (HWTD) test was selected to assess the erosion potential of asphalt and cement stabilized support layers. Field testing with distress surveys, falling weight deflectometer, and coring was completed to obtain HWTD specimens and link laboratory results to pavement performance. The HWTD test was performed on cores obtained from in-service cement and asphalt stabilized support layers, a cold in-place recycling (CIR) mixture, and cement stabilized laboratory mixtures. As expected, an increase in cement content within cement stabilized mixtures decreases the likelihood of erosion with the HWTD. Additionally, conventional asphalt stabilized base layers were highly erosion resistant. Erosion resistant cement stabilized bases (including full-depth reclamation) should target an average HWTD erosion depth ≤2 to 4 mm (0.08 to 0.16 in.) after 10,000 load cycles based on the functional classification and expected traffic volume of the pavement section. Likewise, asphalt stabilized bases (including CIR and support layers for concrete overlays) should target an average HWTD erosion depth ≤12.5 mm (0.5 in.) after 7,500 load cycles with performance grade 64 binder.