Sufficient bonding between the hot mix asphalt (HMA) layers is essential to ensure the desiredstructural capacity of a pavement. Further progression of delamination and associated cracksmay result in stripping of the lower layers due to the intrusion of moisture or may develop otherdangerous distresses that will require frequent maintenance, and may lead to premature need formajor rehabilitation.Promising nondestructive test (NDT) procedures and equipment that have the potentialand their effectiveness to address the problem were investigated. The most promising NDTmethods, which included the Ground Penetrating Radar, seismic methods, mechanical impulsemethods and thermography, were extensively evaluated on a controlled pavement section thatwas specifically constructed to simulate an airfield. The section contained various levels ofdebonding at different depths and with different asphalt mixes. These methods were alsoevaluated at two major airports to assess their capabilities and practicality under actual fieldconditions. Impulse Response and ultrasonic surface waves were the most successful methods,followed by the Falling Weight Deflectometer.Even though the focus of this study was airfield pavements, the outcomes are alsoapplicable in many project-level highway applications. Based on the theoretical and practicalstrengths and limitations of the different methods, work is still needed to utilize the promisingtechnologies for network level applications. The most effective methods are too slow and therapid methods require significant improvements to their interpretation algorithms to be viable asa network level tool.
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