The focus of this study was to explore the components' exchanges between recycled asphalt shingles (RAS) or reclaimed asphalt pavement (RAP) and virgin asphalt binders (VABs) in the asphalt mixes and to establish their effect on the rutting resistance of the extracted asphalt binders (EABs). Twelve plant mixes and twelve field mixes were gathered as examples of four Superpave mixes containing RAP or RAS. The plant mixes were reheated and compacted in the lab. The field mixes were collected as cores within 2 weeks after the ending of the construction process. The exchanged components were investigated using Fourier transform infrared (FTIR) spectroscopy and with the asphalts' components analyses. The FTIR indexes for the EABs from the plant mixes showed more aging components than the FTIR indexes for the EABs from the field mixes. More asphaltenes plus resins and fewer saturates plus aromatics were observed for the EABs from the plant mixes when compared twith the EABs from the field mixes. The FTIR spectra of the EABs from plant mixes containing RAS showed the styrene butadiene styrene (SBS) components, which were not observed for the field mixes' EABs. The SBS polymeric components in the EABs from the plant mixes formed three-dimensional network structures that increased the EABs' stiffness and elasticity characteristics. These components evolved the rutting resistances of EABs. Reheating the plant mixes in the lab before the compaction process increased the blending and components' exchanges between RAP/RAS and VABs.
E. Deef-Allah et al., "Components’ Exchanges between Recycled Materials and Asphalt Binders in Asphalt Mixes," Advances in Civil Engineering Materials, vol. 11, no. 1, pp. 94 - 114, ASTM International, Mar 2022.
The definitive version is available at https://doi.org/10.1520/ACEM20210105
Civil, Architectural and Environmental Engineering
Keywords and Phrases
asphalt components; components' exchanges; extraction and recovery; Fourier transform infrared; RAP; RAS; recycled materials; rutting resistance
International Standard Serial Number (ISSN)
Article - Journal
© 2023 ASTM International, All rights reserved.
07 Mar 2022