Calibration of Non-Nuclear PQI Gauges and Field Comparison of PQI and Nuclear Gauge Densities

A traditional quality control and quality assurance tool for asphalt pavement in-place density is a nuclear density gauge. There tend to be problems, however, in nuclear-based devices associated with storage, equipment handling, and licensing. A non-nuclear device that determines asphalt pavement layer density based on the principle of electrical impedance and associated materials' dielectric constants is the Pavement Quality Indicator (PQI), manufactured by TransTech Systems, Inc. Six field projects were used to generate field data to this end for calibration of a PQI 301 gauge. PQI gauge performance was compared in four field projects with a nuclear density gauge and was validated against laboratory densities (AASHTO T 166) measured from selected pavement extracted cores. There was observation that in all cases for PQI density with 95% certainty, 5-point data can be used instead of 13-point data. Better correlation was exhibited by PQI densities when the PQI was used before the pneumatic roller. Similar performance was exhibited by a PQI gauge calibrated with 5 cores and a PQI gauge calibrated with 10 cores. When the PQI gauge was used before the pneumatic roller, it was noticed that PQI 301 produced better coefficient of determination than the nuclear gauge when the PQI gauge was used. Finally, that for calibration purposes, both mean squared error values as well as R-squared values should be used.

  • Availability:
  • Authors:
    • Wasiuddin, Nazimuddin Mohammad
    • Zaman, Musharraf M
    • Commuri, Sesh
  • Publication Date: 2009-9

Language

  • English

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Filing Info

  • Accession Number: 01145246
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 5 2009 6:11PM