DEVELOPMENT OF A NUCLEAR SURFACE DENSITY GAGE FOR ASPHALTIC PAVEMENTS

THE NUCLEAR METHOD OF DENSITY DETERMINATION CAN BE APPLIED SUCCESSFULLY TO DENSITY MEASUREMENTS OF BITUMINOUS PAVEMENT. TEST RESULTS INDICATE THAT AN ACCURACY OF 1% CAN BE OBTAINED WITH THE P-22 SURFACE DENSITY PROBE USED IN CONJUNCTION WITH A FILTER WHEN A MAXIMUM OF TEN 2-MINUTE TRIALS ARE TAKEN AND THE DENSITY DOES NOT EXCEED 130PCF. THIS CAN BE REDUCED TO THREE 2-MINUTE TRIALS FOR AN ACCURACY OF 2%. AN ACCURACY OF BETTER THAN 2% CAN BE OBTAINED WITH THE PAVEMENT PROBE DEVELOPED IN THE LABORATORY USING A 3MC RADIUM-BERILLIUM SOURCE IF TWO 2 MINUTE TRIALS ARE TAKEN. THIS ACCURACY APPLIES OVER THE DENSITY RANGE OF 110 TO 150 PCF. DENSITY MEASUREMENTS OF ASPHALT PAVEMENT WILL BE AFFECTED BY A CHANGE IN DENSITY OF THE SUBGRADE WHEN THE P-22 SURFACE DENSITY PROBE AND FILTER ARE USED. IT IS REASONABLE TO EXPECT AN ERROR OF LESS THAN 2 PCF FOR PAVEMENTS HAVING A THICKNESS OF 3 IN. OR MORE AND A DENSITY RANGE OF 110 TO 140 PCF ON SUBGRADES HAVING THE SAME RANGE IN DENSITY. SUBGRADE DENSITY DOES NOT HAVE SIGNIFICANT EFFECT ON THE COUNT RATE FOR THE PAVEMENT DENSITY PROBE. SURFACE ROUGHNESS MAY PRODUCE ERRORS IN DENSITY MEASUREMENTS UP TO 2 1/2 PCF., AND IT SEEMS TO BE THE MOST CRITICAL FACTOR IN DENSITY MEASUREMENTS. THERE IS NO INDICATION THAT AGGREGATE GRADATION HAS AN EFFECT ON RESULTS OBTAINED BY NUCLEAR MEASUREMENT OF DENSITY. CHANGES IN COUNT RATE DUE TO CHANGES IN AMBIENT TEMPERATURE MAY REQUIRE A CORRECTION FACTOR WHEN THESE CHANGES BECOME EXTREME. IT IS POSSIBLE THAT THIS COULD CAUSE AN ERROR OF UP TO 5 PCF IF NOT CORRECTED. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 1-17
  • Monograph Title: Nuclear testing of asphaltic concrete pavement and soil subgrades
  • Serial:

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Filing Info

  • Accession Number: 00216356
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: May 13 1994 12:00AM