THE LACROIX - L.C.P.C. DEFLECTOGRAPH

PAVEMENT DEFORMABILITY CAN BE CONVENIENTLY CHARACTERIZED THROUGH ITS DEFLECTION UNDER A GIVEN LOAD. THE DEFLECTOGRAPH MAKES IT POSSIBLE TO RECORD UP TO 8,000 DEFLECTION VALUES PER DAY AND THUS TO PROCEED TO A VERY DETAILED ANALYSIS OF PAVEMENT DEFORMABILITY. A TRUCK WITH A SINGLE REAR AXLE, LOADED TO 13 TONS, CARRIES THE MEASURING SYSTEM, WHICH COMPRISES TWO PROBE ARMS AND A REFERENCE BEAM. THE TRUCK IS DRIVEN AT APPROXIMATELY CONSTANT SPEED, WHILE THE MEASURING SYSTEM IS SUBJECTED TO INTERMITTENT DISPLACEMENT ALTERNATING WITH REST PERIODS. THE PROBE ARMS COME BETWEEN THE TYRES OF THE REAR WHEELS, AND THE DISPLACEMENT OF THEIR TIPS RELATIVE TO THE REFERENCE BEAM REPRESENTS THE PAVEMENT DEFLECTION. THIS DEFLECTION IS RECORDED DURING THE REST PERIOD OF THE MEASURING SYSTEM, WHICH IS THEN PULLED FORWARD AT TWICE THE SPEED OF THE TRUCK AND COMES TO REST AGAIN ON THE PAVEMENT FOR A NEW MEASUREMENT CYCLE. SYSTEMS FOR THE STATISTICAL ANALYSIS OF DATA GIVEN BY ALL THE DEFLECTOGRAPHS PRESENTLY IN SERVICE ARE BRIEFLY DESCRIBED. THE ANALYSIS IS CURRENTLY FOCUSSED ON THE DISTRIBUTION OF THE DEFLECTION VALUES EXCEEDING THOSE CONSIDERED AS ADMISSIBLE; BUT THANKS TO RECENT IMPROVEMENTS, TESTED ON A PROTOTYPE, IT WILL BE POSSIBLE TO STUDY THE RADII OF CURVATURE OF THE DEFLECTION CURVES, AND MORE GENERALLY THE WHOLE INFLUENCE LINE OF THE DEFLECTION. SOME EXAMPLES ARE GIVEN OF THE APPLICATION OF THE DEFLECTOGRAPHS TO THE DESIGN OF PAVEMENT OVERLAYS AND TO THE CONTROL OF THE BUILDING OF NEW PAVEMENTS. /AUTHOR/

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Filing Info

  • Accession Number: 00206665
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 1 1994 12:00AM