Fatigue and Low Temperature Cracking Performance of Asphalt Mixes | Musharraf Zaman | IACMAG

Описание: Title: Fatigue and Low-Temperature Cracking Performance of Asphalt Mixes Containing RAP and RAS

Abstract:
With an increase in environmental awareness and sustainable development by the paving industry, the use of recycled materials such as reclaimed asphalt pavement (RAP) and reclaimed asphalt shingles (RAS) in asphalt pavement has increased significantly over the years.
However, concerns over the fatigue and low-temperature cracking performance of asphalt mixes containing moderate to high amounts of RAP and/or RAS have limited their use. This paper discusses the results of a laboratory study focused on the effect of RAP and RAS on the fatigue and low-temperature cracking performance of asphalt mixes. For this purpose, four asphalt mixes with different combinations of RAP and/or RAS were prepared in the laboratory. Four-point bending beam fatigue test and creep compliance test were conducted for evaluating
the fatigue and thermal cracking performance of the mixes, respectively. Also, indirect tensile strength test was conducted on all four mixes. It was observed that the fatigue life of the asphalt mixes improved with addition of 5% RAP and 5% RAS. However, fatigue life of the mixes
reduced with the addition of only 6% RAS to the mix. Also, initial flexural stiffness and indirect tensile strength were found to increase with addition of RAP and/or RAS. However, as a result of the increased stiffness with the addition of RAP and RAS, asphalt mixes exhibited a higher susceptibility to thermal cracking than the control mix without any RAP and RAS. The results of this study are expected to be helpful to designing asphalt mixes containing RAP and RAS without compromising their performance. Keywords: Recycled asphalt shingles (RAS); Reclaimed asphalt pavement (RAP); Fatigue life; Low-temperature cracking; Creep compliance.


Speaker Bio:
Musharraf Zaman holds the Aaren Alexander Professorship in Civil Engineering and Environmental Science and Alumni Chair Professorship in Petroleum and Geological Engineering at the University of Oklahoma (OU) in Norman. He has been serving as the Director of the Southern Plains Transportation Center (SPTC) – a consortium of eight universities in U.S. DOT Region 6 – for more than four years. He serves as the Editor-in-Chief of the International Journal of Geomechanics, ASCE and as the Executive Vice President of the International Association for Computer Methods and Advances in Geomechanics (IACMAG). He served as the Associate Dean for Research and Graduate Programs in OU Gallogly College of Engineering for more than eight years. Dr. Zaman has more than 35 years of experience in the areas of pavement materials and systems, geotechnical engineering, and geomechanics. At OU, he has received more than $30 Million in external funding, developed two new laboratories, and published 172 journal and 224 peer-reviewed conference proceedings papers and 12 book chapters. His research papers have own international-level awards from IACMAG and Indian Geotechnical Society. In 2011, he won the prestigious Outstanding Contribution Award, given by IACMAG, for life-long contributions in geomechanics.