AN INTERPRETATION OF VIBRATION TESTS ON ROADS BY THE IMPEDANCE METHOD

A DESCRIPTION IS GIVEN OF NEWLY DEVELOPED LIGHT EQUIPMENT FOR VIBRATION TESTING OF ROAD CONSTRUCTIONS. SINUSOIDAL LOADING IS PRODUCED BY MEANS OF AN ELECTRODYNAMIC VIBRATOR EXERTING VERTICAL FORCES ON THE SURFACE OF THE ROAD OR LAYER UNDER TEST. THE EQUIPMENT, MOUNTED ON A SPECIAL TRAILER, IS EXTREMELY FLEXIBLE FOR APPLICATION TO THIS TYPE OF TEST AND PERMITS RELIABLE RESULTS TO BE OBTAINED UNDER A WIDE VARIETY OF CONDITIONS. TWO TYPES OF TEST HAVE BEEN CARRIED OUT' IN THE IMPEDANCE METHOD, THE RATIO OF FORCE TO RESULTANT VELOCITY IS MEASURED IN AMPLITUDE AND PHASE; IN THE WAVE PROPAGATION METHOD, WAVELENGTHS ALONG THE SURFACE ARE DETERMINED. TESTS ARE CARRIED OUT OVER A FREQUENCY RANGE FROM 10 C/S TO 500 C/S IN THE IMPEDANCE METHOD AND UP TO 1,000 C/S IN THE WAVE PROPAGATION METHOD. MEASUREMENTS HAVE BEEN CARRIED OUT ON AN EXPERIMENTAL ROAD IN WHICH WIDELY VARYING TYPES OF CONSTRUCTION HAD BEEN INCLUDED. FROM THE IMPEDANCE MEASUREMENTS IT WAS POSSIBLE TO ASCRIBE DYNAMIC PARAMETERS TO EACH LAYER OF THE CONSTRUCTION AND, FROM THESE, STRESSES AT VARIOUS DEPTHS; AND ENERGY LOSSES IN THE VARIOUS LAYERS HAVE BEEN CALCULATED. THE POTENTIALITIES OF VIBRATION TESTING IN THE CONTROL, DESIGN AND EVALUATION OF ROAD CONSTRUCTIONS ARE BRIEFLY REVIEWED. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 11-42
  • Monograph Title: Pavement design and evaluation 1963
  • Serial:

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Filing Info

  • Accession Number: 00203106
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Oct 28 1994 12:00AM