AN EVALUATION OF TEMPERATURE DISTRIBUTION WITHIN ASPHALT PAVEMENTS AND ITS RELATIONSHIP TO PAVEMENT DEFLECTION

THE HISTORY IS REVIEWED OF THE VARIABLES THAT INFLUENCE THE MAGNITUDE OF DEFLECTION. THE SURFACE DEFLECTION (OR REBOUND) REMAINS THE MOST MEASURABLE RESPONSE OF A PAVEMENT TO AN APPLIED LOAD AND THE MOST CONVENIENT AND WIDELY USED METHOD OF MEASURING DEFLECTION IS WITH THE BENKELMAN BEAM. PAVEMENT SURFACE TEMPERATURE ALONE DOES NOT SUFFICE TO ACCOUNT FOR THE DEPENDENCY OF DEFLECTION UPON TEMPERATURE. SINCE TEMPERATURES AT DEPTHS ARE KNOWN TO INFLUENCE DEFLECTIONS, SUB-SURFACE TEMPERATURES MUST BE EITHER MEASURED IN SITU OR ESTIMATED FROM OTHER CORRELATIONS. RESEARCH WAS CONDUCTED TO: (1) DEVELOP A METHOD FOR ESTIMATING THE TEMPERATURE AT ANY DEPTH IN A FLEXIBLE PAVEMENT UP TO 12 INCHES THICK, AND (2) ANALYZE THE TEMPERATURE-DEFLECTION DATA GENERATED IN THE AASHO ROAD TEST TO SHOW THAT TEMPERATURE ADJUSTMENT FACTORS ARE GENERALLY APPLICABLE TO BENKELMAN BEAM DEFLECTION MEASUREMENTS OF BITUMINOUS PAVEMENT AND TO DETERMINE THE MAGNITUDE OF THESE ADJUSTMENT FACTORS. A PRACTICAL AND REASONABLY ACCURATE METHOD OF ESTIMATING THE TEMPERATURE DISTRIBUTIONS WITHIN FLEXIBLE PAVEMENT WAS DEVELOPED. THIS METHOD CAN BE USED TO ANALYZE DEFLECTION DATA AT ANY TIME IF THE HOUR OF THE DAY AND THE SURFACE TEMPERATURE ARE INCLUDED IN THE RECORDED DATA. THE RELATIONSHIP BETWEEN MEAN PAVEMENT TEMPERATURE AND DEFLECTION ALLOWS ANY DEFLECTION TEST VALUE TO BE ADJUSTED TO A REFERENCE TEMPERATURE IF THE MEAN TEMPERATURE OF THE PAVEMENT AT THE TIME OF TESTING IS KNOWN OR IS ESTIMATED BY THE METHOD OUTLINED. FURTHER STUDY IS NEEDED TO DETERMINE WHETHER THE AVERAGE AIR-TEMPERATURE HISTORY ADEQUATELY TAKES INTO ACCOUNT THE EFFECTS OF LATITUDE AND ALTITUDE UPON PAVEMENT TEMPERATURES. THEORETICAL ANALYSIS OF THE AASHO PAVEMENT DEFLECTION DATA BY THE TWO-LAYERED ELASTIC THEORY SHOWS A CURVI-LINEAR RELATIONSHIP BETWEEN MODULUS OF ELASTICITY OF ASPHALTIC CONCRETE AND TEMPERATURE. THE MAGNITUDE OF THE MODULI ARE SUCH THAT A STRAIGHTLINE RELATIONSHIP EXISTS BETWEEN MODULI AND THE MULTIPLICATIVE, TEMPERATURE-DEFLECTION, ADJUSTMENT FACTORS. AS ADDITIONAL TEMPERATURE-DEFLECTION DATA BECOME AVAILABLE THEY SHOULD BE ANALYZED TO VERIFY, OR MODIFY THE ADJUSTMENT FACTORS PRESENTED.

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Filing Info

  • Accession Number: 00205736
  • Record Type: Publication
  • Files: TRIS, STATEDOT
  • Created Date: Feb 24 1994 12:00AM