EVALUATION OF A LARGE-SIZED VACUUM PYCNOMETER FOR MAXIMUM SPECIFIC GRAVITY DETERMINATIONS

A preliminary evaluation has been made of the suitability and limitations of the Yale pycnometer as a "rapid" test method for monitoring plant control. Modifications are confirmed. It assists with corrective measure analysis by providing both direction and relative magnitude of the diviation. Charting test data is shown to be highly level, and cities measurement sensitivity information. The study also confirms both accuracy and precision data. Other uses are cited, and comparison is made with the Illinois pressure method. Details are given of the procedure and checking when a plant is "lined out" on the new JMF following a product change, show a close check with the Illinois high pressure air test method. adequate for production control purposes. Tests may be run at any temperature from 60 to 155 F and then rational corrections may be made to adjust to maximum specific at 77 F. Temperature correction is accurate and independent of gradation or bitumen level. Repeatability is very satisfactory (standard deviation at 28 deg. of freedom= 0.0038). A slight but statistically significant difference in effective specific gravity of the combined aggregate as a function of bitumen level (0.006 points) and as a function of plant versus hand-mixing (also 0.00l points) is linked to a small difference in bitumen absorption of the order 0.08 percent (potentially significant for porous aggregates). The test shows promise as a rapid test method for monitoring the uniformity of production of a hot-mix plant. It provides numerical documentation that a significant

Media Info

  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: p. 491-534
  • Serial:
    • Volume: 43

Subject/Index Terms

Filing Info

  • Accession Number: 00125411
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 18 1975 12:00AM