COMPARISON OF THE DYNAFLECT WITH THE BENKELMAN BEAM

A STUDY WAS CONDUCTED TO COMPARE THE EFFICIENCY OF THE DYNAFLECT DYNAMIC LOADING DEVICE WITH THAT OF THE BENKELMAN BEAM IN MEASURING PAVEMENT DEFLECTIONS. TEST SECTIONS HAVING A SUBGRADE RATIO, LOUISIANA BEARING RATIO (LBR), OF 32 WERE TESTED USING A 20 KIP AXLE LOAD. TWO SETS OF READINGS WERE OBTAINED AT EACH STATION FOR BOTH THE BENKELMAN BEAM AND THE DYNAFLECT. IT IS CONCLUDED THAT IN MANY CASES ACTUAL CHANGES IN LOAD CARRYING OF THE PAVEMENT MAY BE MASKED BY THE HIGH DEGREE OF VARIABILITY IN THE BENKELMAN BEAM AND PROCEDURE. IN SUCH CASES MORE TESTS WOULD BE REQUIRED FOR THE BENKELMAN BEAM THAN FOR THE DYNAFLECT WHICH IS CAPABLE OF MEASURING DEFLECTIONS WITH MUCH GREATER PRECISION. A COST ANALYSIS INDICATED THAT THE PURCHASE OF THE DYNAFLECT UNIT CAN BE JUSTIFIED ON THE BASIS OF SAVINGS AND OPERATION COST ALONE IF THE WORK LOAD EXCEEDS APPROXIMATELY 55 DAYS PER YEAR. CONSIDERATION SHOULD ALSO BE GIVEN TO USE OF THE DYNAFLECT FOR PURPOSES OTHER THAN PAVEMENT DEFLECTIONS. IT MIGHT BE USED AS A CONSTRUCTION CONTROL METHOD AS A SUPPLEMENT TO THE MORE EXPENSIVE PLATE BEARING OR FIELD CBR TESTS. IT IS RECOMMENDED THAT THE FLORIDA STATE ROAD DEPARTMENT SHOULD SUBSTITUTE A DYNAFLECT UNIT FOR THE BENKELMAN BEAMS CURRENTLY BEING USED FOR DEFLECTION MEASUREMENTS IN THE SATELLITE AND PAVEMENT PERFORMANCE ANALYSIS PROGRAM.

  • Supplemental Notes:
    • No 96, 13 PP, 4 FIG, 1 TAB
  • Publication Date: 1966

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  • Accession Number: 00206685
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 18 1994 12:00AM