When wetting or draining structured soil material, particularly clods, on suction and pressure plates, interposal of a fine-grained material between sample and plate can be used to improve the efficiency of contact and hence the rate of transfer of water. The particle size range best suited to any given applied suction may be approximately determined using a theory of packing. It is found in most cases that material with a particle size range lying within the silt or silt and fine sand fraction should suffice. Various materials - grinding powders, glass beads, diatomaceous earth and soil separates - were tested for moisture retention at suctions up to 10 bars. Overall the most readily prepared suitable material of those tested is a soil separate containing a high percentage of very stable micro-aggregates in the size range 5-76 micro meters. At suctions less than 0.20 bar diatomaceous earth is the most suitable of those materials tested. (A) /TRRL/

  • Corporate Authors:

    Commonwealth Bureau of Roads, Australia

    60 Collins Street
    Melbourne, Victoria 3000,   Australia 
  • Authors:
    • McIntyre, D S
    • Watson, C L
  • Publication Date: 1975


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 11 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00139029
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Technical Paper 26
  • Files: ITRD, TRIS
  • Created Date: Dec 1 1976 12:00AM