A SCIENTIFIC EXPLANATION OF THE PLASTIC LIMIT OF SOILS

TESTS CONDUCTED ON SOILS WITH PLASTIC LIMITS OF 17 TO 34 PER CENT MOISTURE INDICATE THAT THE PLASTIC LIMIT OF SOILS HAS PHYSICAL EXISTENCE AS A DEFINITE POINT ON THE MOISTURE-SUCTION CURVE. THIS CURVE RELATES THE EXTERNAL PRESSURE OR VACUUM APPLIED TO A TUBE OF WATER TO THE AMOUNT OF WATER THAT WILL BE WITHDRAWN OR FLOW INTO THE TUBE THROUGH A SINTERED GLASS PLATE FROM A SOIL SPECIMEN. THE LENGTH OF THE TUBE OF WATER IS RELATED TO THE SUCTION FORCES, AND THE LOGARITHM OF THIS LENGTH IN CENTIMETERS IS KNOWN AS PF. FOR SOILS COMPACTED TO A BULK DENSITY OF 1.6 G/CU. CM, THE PLASTIC LIMIT IS SHOWN TO CORRESPOND TO THE MOISTURE CONTENT AT PF 0.5 ON THE WETTING CURVE OR PF 1.5 ON THE DRYING CURVE. ALTHOUGH HUMAN ERROR PRESENT IN THE TEST IN ASTM METHOD D 424 IS ELIMINATED BY THIS METHOD, THIS TEST IS NOT LIKELY TO REPLACE THE ONE IN METHOD D 424 BECAUSE A 40 TO 45 HR PERIOD IS REQUIRED FOR MOISTURE EQUILIBRIUM TO BE ACHIEVED. THIS TEST DOES, HOWEVER, PROVIDE A MORE SCIENTIFIC EXPLANATION OF PLASTIC LIMIT, AND MAY BE USED TO DETERMINE MORE PRECISELY WHETHER CERTAIN SOILS ARE NONPLASTIC. /RRL/A/

  • Supplemental Notes:
    • Vol 1, No 1, PP 164-179, 9 FIG, 5 TAB, 5 REF
  • Authors:
    • Uppal, H L
  • Publication Date: 1966-3

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00233812
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS
  • Created Date: Aug 1 1994 12:00AM