VOID PARAMETERS OF CONCRETE CORES FROM A SECTION OF I-64

In the hope of determining whether variables in unit weight were caused by variations in the air void system or segregation of the aggregate, micrometric air void and aggregate analyses were made on 24 core samples from six test sections of I-64 near Charlottesville, Virginia. The test design included paver speeds of 3, 4.25, 5.5, 11, 12, and 14 ft/min (0.0152, 0.0261, 0.0279, 0.061, and 0.071m/s), vibrator frequencies ranging from 130 to 167 revolutions/sec, and slumps from 1 to 2.75 in. (25.4 to 70 mm). Analyses showed that for any particular concrete, the faster the motion of the vibrators through the concrete and the greater the spacing, the less the consolidation will be. Between batches, the greater the slump or workability is, the greater the consolidation achieved by a set of vibrator conditions. Frequencies of the vibrators used covered such a narrow range that no correlation between frequency and consolidation was possible. Insufficient sampling precluded the determination of aggregate segregation. For the type of concrete and kind of vibrators used, data seem to indicate that, if the slump approaches 1 in. (25.4 mm), then the forward speed of the vibrator screed should be no more than 6 ft/min (0.0305 m/s) when the spacing of the vibrators is about 2 ft (0.61 m). Higher speeds will probably produce high-void, low abrasion-resistant areas of pavement.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 27-36
  • Monograph Title: PORTLAND CEMENT CONCRETE
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00264914
  • Record Type: Publication
  • ISBN: 0309022959
  • Files: TRIS, TRB
  • Created Date: Feb 11 1975 12:00AM