UC Pavement Research Center
Wu, Rongzong, John T. Harvey, Jeremy D. Lea, Angel Mateos, Shuo Yang, Noe Hernandez (2021) Updates to CalME and Calibration of Cracking Models. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-20-97
The CalME flexible pavement simulation and design software program has been completely recoded as a web-based application called CalME 3.0. CalME 3.0 retains the same incremental-recursive damage approach and the same forms for damage models and transfer functions as CalME 2.0, which was validated using accelerated pavement testing data from Heavy Vehicle Simulator (HVS) test sections and the WesTrack experiment.
The following enhancements and additions are all included in the revised program. First, the old software’s fatigue cracking transfer functions for hot mix asphalt (HMA) on aggregate base, cement-stabilized bases, and portland cement concrete have been recalibrated using a new approach for the calibration of mechanistic-empirical pavement design methods; this approach uses “big data” from pavement management systems, explicitly and separately considers between-project and within-project variability, and uses tens to hundreds of times more performance data than are used in conventional calibration methods. Second, the updated program also includes new damage models and transfer functions for in-place recycling materials, including full-depth recycling (FDR) with foamed asphalt plus cement and cement stabilization, and partial-depth recycling (PDR) with emulsified asphalt and foamed asphalt plus cement. Third, the program now has been given the ability to model PDR using cold central plant recycled (CCPR) materials. Fourth, new damage models have been introduced for cement-stabilized bases and cement-stabilized and lime-stabilized subgrade materials to correct problems with the models in CalME 2.0. Fifth, minimum aggregate base thicknesses were developed based on calculations of permanent deformation under construction traffic. Lastly, simplified methods were developed for estimating subgrade stiffnesses (resilient modulus) based on dynamic cone penetrometer (DCP) tests, California bearing ratio (CBR) tests, and R-value tests.
It is recommended that CalME 3.0 be implemented for pavement design, that the calibration be updated with new data approximately every 3 to 5 years, that Caltrans traffic databases be checked before they are used again for recalibration, and that use of the recently updated Caltrans DIME database of as-built data be considered for future calibrations.