Impact of interlayer bonding conditions on cracking estimation in flexible pavements: MeDiNa pavement design methodology

This study investigates the influence of interlayer bonding conditions on the cracking prediction of flexible pavements using the MeDiNa mechanistic-empirical design method. The methodology was structured into three stages: (i) assessment of interlayer bonding conditions based on field measurements; (ii) calibration of transfer functions with variations in the sigmoidal parameters Z and n; and (iii) application of the calibrated functions to a reference pavement structure, including modifications to the software source code. Field measurements showed, for the monitored section, a tendency for the fully bonded assumption to align more closely with the measured vertical displacements and stresses. The calibration process showed that increasing Z delays crack initiation, while higher n values lead to steeper cracking progression curves. Simulations for the reference structure indicated lower predicted cracking when the fully bonded assumption was applied, within the context of the scenarios analyzed. Furthermore, the transfer function calibrated under the full bonding condition delayed the reaching of MeDiNa’s cracking performance threshold, indicating a shift in the predicted cracking progression for the scenario evaluated. These findings highlight how assumptions on interface modeling and input data can influence MeDiNa predictions for the scenarios evaluated.