Aging and Rejuvenators: Evaluating Their Impact on High RAP Mixtures Fatigue Cracking Characteristics Using Advanced Mechanistic Models and Testing Methods

A major distress in asphalt mixtures is fatigue cracking. Many factors contribute to this condition, including aging. This is referred to as short-term aging during mixing and construction, and it is referred to as long-term aging during the service life of the pavement. There is a concern that the mixtures resulting from using larger amounts of reclaimed asphalt pavement (RAP) in new paving mixtures may tend to experience more fatigue cracking during the pavement's service life. The fact that the asphalt binder in the RAP is significantly aged explains this phenomenon. This already aged binder will be exposed to additional short and long-term aging in new paving mixtures. Generally a softer binder is used in order to alleviate the effect of the aged RAP binder on the new asphalt mixtures' cracking susceptibilities. However, it has been indicated in several studies that more aged binder can be allowed by asphalt rejuvenators to be incorporated into mixtures than exclusive use of a softer binder. This study's objectives were to use the conventional fatigue test, as well as recently developed mechanistic models and tests, to evaluate the effect of long-term aging on the fatigue characteristics of high-RAP mixtures modified with rejuvenators. These fatigue tests results were also compared in regards to each other to see if they provided similar performance trends. The four tests/models that were used are as follows: HMA Fracture Mechanics Model, Four Point Flexural Beam Fatigue Test, Semi-Circular Bending (SCB) Test, and the Simplified Visco-Elastic Continuum Damage Model (SVECD).


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  • Accession Number: 01607003
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 27 2016 11:56AM