Document Archives

Laboratory Investigation of Lightweight Norlite Aggregate

• ID:

  1984

• ESCSI:

  6640.012

• Author:

  Geotechnical Engineers, Inc.; Keller, Thomas O. & Ronald C. Hirschfeld

• Publication Name:

  Report

• Type of Publication:

  Paper

• Publisher:

  Norlite Corporation

• Dated:

  1983

• Issue/Volume:

  April 11

• Other ID:

• Page(s):

  1-11 + tab, fig

• Reference List:

  N

• Abstract:

  The degree of compaction of Norlite aggregate required in the field depends on the application for which it would be used. Each field application must be evaluated to determine the relative importance of the aggregate’s shear strength (friction angle), compressibility, and unit weight after compaction.The friction angle for 3/4-in aggregate is 41° and the friction angle for 3/8-in aggregate is 43°. These friction angles are for aggregate placed in a loose condition and placed to depths no greater than 60 ft.
  For many backfilling applications the friction angle of the fill is an important parameter. For example, the friction angle of fill placed behind a retaining wall influences the design of the wall. For these applications, a friction angle of 40° can be used for design.
  Norlite aggregate can be used in these fill applications by simply dumping the aggregate in place without compaction. The aggregate can be placed in any lift thickness and at any water content.
  If Norlite aggregate is compacted in the field, for example, in lift thicknesses of 9 in. with a vibratory roller or heavy tractor, then the friction angle of the compacted aggregate will be greater than the friction angle of loose aggregate.
  In some fill applications the compressibility of Norlite aggregate after placement may be important. No compressibility testing of Norlite aggregate was performed as part of this investigation.