DCP Criteria for Performance Evaluation of Pavement Layers

Abstract

The potential use of the dynamic cone penetrometer (DCP) for evaluation of the pavement distress state is investigated. A model to predict the distress level of pavement layers using penetration rate (PR) values of the subgrade and aggregate base course (ABC) layers is proposed based on the coupled contribution of the subgrade and the ABC materials. The developed distress model is validated using field data from four test sites. The two sites with good condition rating values (equal to 4 and 3) are found to have an unconfined PR-ABC value <4 mm/blow, a PR-subgrade value <25 mm/blow, and an ABC layer thickness that exceeds 152 mm (6 in.). A discrepancy that seems to appear in the field data (a high field California bearing ratio value corresponding to a PR-ABC value >4 mm/blow) is explained by the fact that field-measured California bearing ratio values for the ABC layer are affected by the strength of the underlying subgrade soils. This is especially observed in cases where the thickness of the ABC layer is <102 mm (4 in.). The framework of the established procedure can generally be used at other sites, properly taking into account differences in material properties.