PARAMETERS FOR CLASSIFICATION OF FINE-GRAINED LATERITE SOILS OF GHANA

THE AVAILABLE LITERATURE INDICATES THAT ENGINEERING PROPERTIES AND FIELD PERFORMANCE OF TROPICALLY WEATHERED SOILS ARE INFLUENCED CONSIDERABLY BY FACTORS OF SOIL FORMATION, DEGREE OF WEATHERING (OR LATERIZATION), MORPHOLOGICAL CHARACTERISTICS, AND CHEMICAL AND MINERALOGICAL COMPOSITION AS WELL AS ENVIRONMENTAL CONDITIONS. CONSEQUENTLY, TEMPERATE-ZONE HIGHWAY AND AIRFIELD SOIL CLASSIFICATION SYSTEMS BASED ON PARTICLE SIZE DISTRIBUTION AND PLASTICITY ALONE ARE INADEQUATE FOR THESE SOILS. NUMEROUS FAILURES OF HIGHWAY AND AIRFIELD PAVEMENTS, BUILT WITH OR ON LATERITE SOILS, IN SPITE OF STRICT ADHERENCE TO ASTM GRADING AND PLASTICITY SPECIFICATIONS, HAVE CONFIRMED THE INAPPLICABILITY OF THE PRESENT TEMPERATE-ZONE CLASSIFICATION SYSTEM. THIS PAPER ATTEMPTS TO PROPOSE SOME USEFUL PARAMETERS FOR CLASSIFICATION OF FINE-GRAINED LATERITE SOILS OF GHANA. THE STUDY HAS REVEALED THAT MORPHOLOGY AND GENERAL CHARACTERISTICS (INCLUDING CHEMICAL AND MINERAL COMPOSITION) OF GHANA SOILS ARE INFLUENCED CONSIDERABLY BY THE WEATHERING SYSTEMS. FOR A GIVEN GENETIC SOIL GROUP, THE CONSISTENCY PARAMETERS, COLLOIDAL ACTIVITY, COMPACTION CHARACTERISTICS, SPECIFIC GRAVITY, FIELD MOISTURE EQUIVALENT, AND LINEAR SHRINKAGE HAVE FAIRLY GOOD CORRELATIONS WITH THE AMOUNT OF CLAY CONTENT. THE DIFFERENT DEGREES OF WEATHERING (OR LATERIZATION) OF THE SOIL TYPES FROM THE DIFFERENT CLIMATIC- VEGETATIONAL ZONES HAVE CONSIDERABLE INFLUENCE ON THE RELATION BETWEEN THE CLAY CONTENT AND THE PROPERTIES OF SOILS OVER DIFFERENT PARENT ROCKS. THE CONCLUSIONS REACHED SUGGEST THAT THE RESIDUAL FINE-GRAINED LATERITE SOILS OF GHANA MAY BE MOST ADEQUATELY CLASSIFIED FOR HIGHWAY PURPOSES ON THE BASIS OF SUCH FACTORS AS PARENT MATERIALS (GEOLOGICAL FORMATIONS), CLIMATIC-VEGETATIONAL CONDITIONS, DEGREE OF WEATHERING (OR LATERIZATION), AMOUNT OF CLAY CONTENT, AND LINEAR SHRINKAGE. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 57-79
  • Monograph Title: Soil: compaction, classification and laterites
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00230101
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 20 1972 12:00AM