EVALUATION OF THE TTI GYRATORY COMPACTOR

THE EVALUATION IS DESCRIBED OF A GYRATORY COMPACTOR DEVELOPED BY THE TEXAS TRANSPORTATION INSTITUTE FOR THE SOLE PURPOSE OF PRODUCING SPECIMENS OF HIGH UNIFORMITY FOR REPETITIVE TRIAXIAL TESTING. THE MATERIAL SELECTED FOR USE IN THE EVALUATION WAS A CRUSHED LIMESTONE. IN PRIOR INVESTIGATIONS REPLICATE SPECIMENS MADE FROM THIS LIMESTONE EXHIBITED SOMEWHAT ERRATIC BEHAVIOR. IN FACT, THIS MATERIAL WAS BY FAR THE MOST TROUBLESOME IN THIS RESPECT OF SEVERAL MATERIALS TESTED. NEVERTHELESS, IT IS AN EXCELLENT FLEXIBLE BASE MATERIAL AND WIDELY USED IN THIS STATE. THE EVALUATION OF THE COMPACTOR RESULTED IN AN OPERATING PROCEDURE THAT WILL PRODUCE NEARLY IDENTICAL TEST SPECIMENS OF THIS MATERIAL OVER A WIDE RANGE OF MOISTURE CONTENTS AND DENSITIES. IT WAS FOUND THAT COMPACTED SPECIMENS HAD REPLICATION ERRORS IN DENSITY OF LESS THAN 0.4 PCF, IN MOISTURE CONTENT OF LESS THAN 0.1 PER CENT, AND IN UNCONFINED COMPRESSIVE STRENGTH OF LESS THAN 8 PSI. THE AUTHORS BELIEVE THAT THE OBSERVED REPLICATION ERRORS ARE SMALLER THAN IS NOW POSSIBLE WITH ANY OTHER KNOWN METHOD OF PREPARING SIMILAR SPECIMENS OF GRANULAR MATERIALS FOR TESTING. ALSO, IT IS BELIEVED THAT THE REPLICATION ERRORS ARE OF THE SAME ORDER OF MAGNITUDE AS NOW ACCEPTED IN STANDARD CONCRETE, BRICK, AND WOOD TESTING. EQUATIONS WERE DEVELOPED THAT RELATE THE COMPACTED DENSITY AND MOISTURE CONTENT OF THE LIMESTONE SPECIMENS TO THE MOLDING MOISTURE CONTENT AND COMPACTOR VARIABLES. THESE EQUATIONS SHOW THAT TEST SPECIMENS CAN BE PREPARED OVER A WIDE RANGE OF PRESELECTED MOISTURE CONTENTS AND DENSITIES. EXPECTED ERRORS IN THE PRESELECTED MOISTURE CONTENTS AND DENSITIES OF TEST SPECIMENS ARE LESS THAN 0.2 PER CENT FOR MOISTURE CONTENT AND LESS THAN 1.0 PCF FOR DENSITY. /AUTHOR/

  • Supplemental Notes:
    • Hpr-1/7/, BPR-25, STATE 99
  • Corporate Authors:

    Texas Transportation Institute

    Texas A&M University System, 1600 E Lamar Boulevard
    Arlington, TX  USA  76011

    Texas State Department of Highways & Public Transp

    11th and Brazos Streets
    Austin, TX  USA  78701

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  USA  20590
  • Authors:
    • Moore, W M
    • Milberger, L J
  • Publication Date: 1968-2

Subject/Index Terms

Filing Info

  • Accession Number: 00210394
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, ATRI, STATEDOT
  • Created Date: Jun 18 1994 12:00AM