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Change to Poster Presentation at the Conference

Asphalt Binder and Mixture Characterization

Session: Meet the Author - Poster Session PS-2

1373036 - Oxidative gas-based aging method for loose asphalt mixtures

Thursday, June 15, 2023

3:00 PM – 4:30 PM CST

Room: Governor's Grand Ballroom
Salon ABC

TRACK: Poster Presentation

Primary Author(s)

Anand Sreeram, PhD

Research Fellow
University of Cambridge
cambridge, England, United Kingdom

Presenter(s)

Anand Sreeram, PhD

Research Fellow
University of Cambridge
cambridge, England, United Kingdom

Co-Author(s)

Dheeraj Adwani, MTech

Graduate Research Assistant
University of Texas at Austin
Austin, TX, United States

Presenter(s)

Dheeraj Adwani, MTech

Graduate Research Assistant
University of Texas at Austin
Austin, TX, United States

Co-Author(s)

Benjamin Arras, n/a

Graduate Research Assistant
University of Texas at El-Paso, United States
Daniel Blomdahl, n/a

Graduate Research Assistant
University of Texas at Austin, United States
Pawel Misztal, n/a

Assistant Professor
University of Texas at Austin, United States
Amit Bhasin, Ph.D., P.E.

Professor
Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, TX, USA
Austin, Texas, United States

The simulation of field aging using laboratory techniques is an essential prerequisite in the design of high-quality asphalt mixtures. Previous studies in this area have indicated the potential to use an accelerated method for aging loose mixtures using highly oxidative gases, namely ozone and other reactive oxygen species (ROS). Based on that, the present work was concerned with the investigation of the accelerated aging mechanisms in effect and upscaling of the experimental setup to accommodate larger quantity of mixes. Firstly, the chemical transformations and real time oxidation products formed under an ozone rich environment were compared to an air-based environment for three binders using a Vocus proton transfer reaction (PTR-TOF) time-of-flight mass spectrometer. It was observed that the formation of oxygenated species was significantly higher under an ozone rich environment, indicating higher levels of oxidation. The high-resolution level characterization of the oxidation series of several different molecules provided definitive evidence to support the previous hypothesis of using ozone and ROS to fast-track the oxidation of asphalt mixtures. Following this, an experimental method was developed to age up to nine kilograms (kg) of loose mixtures obtained from a mixing plant using ozone and ROS, in a duration of 22 h. After aging, different properties of the mixtures were compared to analogous mixtures aged as per a benchmark method of loose mixture aging at 95 °C for 5 days in a laboratory oven. The various results obtained from the IDEAL-CT tests, rheological and chemical property analyses of extracted binders clearly illustrated the effectiveness of the oxidative gas based aging method for the accelerated aging of loose mixtures, providing comparable levels of aging as traditional methods. Overall, the work conducted in this study provides comprehensive results regarding critical aspects of the developed method and alludes to the opportunity for wide scale applicability.

Learning Objectives:

Attendees can expect to learn the following from this session:

Participants will be able to understand the importance of loose mixture aging of asphalt mixtures.
To demonstrate the effect of oxidative gases to accelerate aging of asphalt mixtures
To showcase a more efficient and practical method to age loose mixture in a laboratory setting