A new backcalculation program, DYNABACK-VE, was used to backcalculate pavement layer properties with field data. DYNABACK-VE used a time domain viscoelastic dynamic solution (ViscoWave-II) as a forward routine and a genetic algorithm for backcalculation analysis. The genetic algorithm search method was selected because it had a high potential for converging efficiently to a global solution. The forward solution used continuous integral transforms (Laplace and Hankel) that were more appropriate for transient, nonperiodic signals in the time domain. The algorithm was implemented in C++ and coded for parallel processing with multithreading for achieving better computational efficiency. Field falling weight deflectometer load and defection sensor time histories from three sites (Waverly Road near Lansing, Michigan, and two long-term pavement performance sections) were used for validation. The backcalculated asphalt concrete modulus master curves were compared with those obtained from laboratory testing. Very good agreement was obtained. The new algorithm was capable of backcalculating reliably the master curve of the asphalt concrete layer (four sigmoidal coefficients and two time-temperature shift factors), the elastic moduli for the unbound base or subbase and subgrade materials, and the modulus of stiff layer and the depth to stiff layer, if present. The advantage of the new solution is that it can analyze the response of pavement systems in the time domain and can therefore accommodate time-dependent layer properties and incorporate wave propagation. Also, because the backcalculation is performed in the time domain, the algorithm is not sensitive to truncation in the deflection time histories. This is a significant improvement to the state of the art, since truncation of deflection time histories has prevented frequency domain backcalculation solutions from being successful when measured field data are used.


    Access

    Download

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Backcalculation of Asphalt Concrete Modulus Master Curve from Field-Measured Falling Weight Deflectometer Data


    Subtitle :

    Using a New Time Domain Viscoelastic Dynamic Solution and Genetic Algorithm


    Additional title:

    Transportation Research Record


    Contributors:


    Publication date :

    2014-01-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English