Evaluation of Binder Aging and its Influence in Aging of Hot Mix Asphalt Concrete: Technical Report

TxDOT Project 0-6009 was a comprehensive interdisciplinary research effort that has developed the ability to predict asphalt oxidative hardening over time and pavement depth, and the impact of this hardening on mixture durability. The many interrelated research and development accomplishments form three major elements: 1) Pavement Binder Oxidation Model Development (improved pavement temperature model, binder oxidation kinetics parameters, binder diffusion coefficients, model for predicting binder oxidation in pavements); 2) Mixture Test Development and Measurements (method for testing prismatic specimens cut from pavement cores, measurements of binder oxidation in pavements, measurements of binder oxidation in laboratory mixtures, evaluation of seal coat effectiveness); and 3) an HMA Mixture Design Approach That Includes Binder Oxidation (accelerated binder aging test, mixture design and analysis system, software user interface). Suggestions for implementation and future work include: 1) Introduce the software user interface to TxDOT engineers, 2) Adopt the accelerated aging test, 3) Implement a strategy for evaluating existing pavements by testing recovered binders for their oxidation and hardening kinetics, 4) Incorporate the pavement transport and thermal oxidation model into a new pavement design guide, 5) Further evaluate the effectiveness of maintenance treatments, 6) Further validate the pavement oxidation and hardening model, 7) Improve our fundamental understanding of oxidation kinetics chemistry and reaction kinetics, 8) Improve our fundamental understanding of the correlation between PAV and POV reaction kinetics parameters.