VERIFICATION AND CALIBRATION OF PDMAP AND COLD COMPUTER PROGRAMS --PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON THE STRUCTURAL DESIGN OF ASPHALT PAVEMENTS HELD DEFLT UNIVERSITY OF TECHNOLOGY, AUGUST 23-26 1982. VOL 1 AND 2. -- NETHERLANDS

This paper presents the results of a study which was conducted to verify and calibrate the distress prediction models included in the two computer programs pdmap and cold. The specific forms of distress considered were fatigue cracking and permanent deformation, which were covered by pdmap and low temperature cracking covered by cold. The required data for this study were obtained from the Florida Department of Transportation and were used in the verification and calibration of pdmap models. Utah Department of Transportation supplied the data for the verification and calibration of the model used in cold program. A brief description of the steps involved in this study is included in this paper. The method of verification and calibration of all the three models is also briefly described and the calibrated models along with their outputs are presented for comparison with the field observations. The results of this limited study indicated that pavements built with two different surface thicknesses (2" and 3") will require two fatigue distress prediction models. However, only one rate of rutting prediction model was needed to predict rut depths in most of the test sections (88% of total) within plus or minus 50% of the observed rut depths. The cold program was calibrated and used in comparing the predicted probability of cracking with the observed frequency of cracks in the field. The results of this comparison indicated that the model can predict the frequency of cracking qualitatively in pavements using the same grade of asphalt binder. Pavements using different grades of asphalts would probably need their own calibration of the prediction model.(a) for the covering abstract of the conference see IRRD 815640.