Evaluation of Fracture Energy Parameters for Predicting Moisture-Induced Damage in Asphalt Mixes

Standard methods of screening asphalt mixes for moisture-induced damage are mostly empirical. These methods have not advanced with the same pace as new materials such as polymer-modified asphalt binders, Warm Mix Asphalt (WMA), and mixes containing Reclaimed Asphalt Pavement (RAP) were introduced to asphalt industry. This study was undertaken to assess the effectiveness of fracture energy parameters in capturing the moisture-induced damage potential of major groups of mixes, namely WMA, those containing RAP, and those containing an anti-strip agent. Plant-produced mixes consisting of an asphalt mix containing 1% hydrated lime, another containing 20% RAP, and a WMA mix containing 0.5% of a chemical WMA additive were evaluated by conducting indirect tension, semicircular bend, and indirect tensile asphalt cracking test before and after moisture-conditioning. Different parameters, namely tensile strength ratio, fatigue index, toughness index, critical strain energy release rate, and cracking tolerance index were determined. Binder bond strength tests were also conducted on a wide range of aggregates, asphalt binders, and additives. A novel approach that combined mix volumetric properties with adhesion measurements was used to determine the moisture susceptibility of mixes. The new method as a quick, inexpensive, and effective approach was found to have the potential to be used for screening mixes for stripping before producing them. Fracture energy parameters, while an excellent tool for evaluating the ductility of the mix, were not found to isolate the effect of moisture on mixes or capture stripping mechanism.

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  • English

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  • Accession Number: 01849371
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 23 2022 9:16AM