Evaluation of Surface Density Nuclear Gauges for Acceptance Testing of AsphaltConcrete Overlays

摘要

This report documents field evaluations of a thin lift nuclear gauge and asurface moisture/density nuclear gauge for asphalt concrete mixtures. The study includes density determinations by conventional methods, density by nuclear methods and a review of literature. A field evaluation of two commercially available nuclear gauges was performed on an airport apron in New Albany, NY, a city road in Coffeeville, MS, a parking lot in Enid, MS, the east-west extension of the Pennsylvania Turnpike near Lebanon, PA, an airport runway extension in Saratoga, NY, and a test section at the U.S. Army Engineer Waterways Experiment Station (WES), in Vicksburg, MS. The basis of this study was to determine if densities obtained from surface density nuclear gauges correlate with corresponding densities measured in the laboratory from cored samples. The effects of gauge placement was also examined. Data from each project are included in the report. An analysis was performed on the data. Graphs were created for optimum visualization. Nuclear gauges of this type are recommended as quality control tools but not for quality assurance and acceptance. Due to excessive variability and high standard deviations between the nuclear gauges and laboratory densities, gauges are not recommended as the sole means of acceptance testing asphalt concretes. Asphalt concrete, Nuclear density gauge, Bulk density, Troxler.