THE ENGINEERING CHARACTERISTICS OF THE LATERITE GRAVELS OF GHANA

AS A RESULT OF THE STUDY OF ABOUT 45 TYPICAL LATERITE PROFILES IN THE VARIOUS GEOMORPHOLOGICAL REGIONS OF GHANA, A COMPREHENSIVE CLASSIFICATION OF LATERITES IS SUGGESTED. THE FOLLOWING FOUR TYPES OF LATERITE GRAVELS ARE CONSIDERED USEFUL ENGINEERING MATERIALS I.E. NODULAR OR CONCRETIONARY LATERITES, IRON STONE HARD PANS OR CAP ROCK, GROUND WATER LATERITES WITH DETRITAL QUARTZ, AND COLLAVIAL AND TERRACE LATERITES. A LARGE NUMBER OF THE LATERITES OF GHANA ARE MECHANICALLY WEAK AND TEND TO BREAK DOWN AS A RESULT OF WEATHERING AND TRAFFIC LOADING. A MOD. AGGREGATE IMPACT TEST (B.S.812) IS VERY USEFUL FOR RATING THE GRAVELS FROM THE POINT OF WEATHERING AND MECHANICAL STRENGTH. GRAVELS CONSIDERED SATISFACTORY AS A RESULT OF AGGREGATE IMPACT TEST ARE CLASSIFIED INTO FOUR GROUPS ON THE BASIS OF THEIR GRADING AND THEIR ENGINEERING CHARACTERISTICS. WITHIN EACH GROUP THERE IS A STRONG STATISTICAL RELATION BETWEEN FRACTION PASSING NO. 200 B.S. SIEVE OR PLASTICITY INDEX AND THE SATURATED C.B.R. VALUE. STRENGTH CHARACTERISTICS OF GRAVELS CAN BE ASSESSED BY MEANS OF SIMPLE PHYSICAL TESTS. A NEW PARAMETER, 'SUITABILITY INDEX,' WHICH DEPENDS ON THE TWO FRACTIONS OF GRAVELS NAMELY: PERCENTAGE RETAINED ON NO. 7 B.S. SIEVE, THE LIQUID LIMIT AND THE PLASTICITY INDEX OF THE FINES IS PROPOSED. THE SUITABILITY INDEX HAS A SIGNIFICANT RELATION WITH SOAKED C.B.R. VALUES AND IS THEREFORE A USEFUL PARAMETER FOR ASSESSING THE STRENGTH OF GRAVELS. /RRL/

Media Info

  • Serial:
    • Issue Number: 0

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Filing Info

  • Accession Number: 00229371
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS
  • Created Date: Apr 10 1971 12:00AM