Characterization of Hot-Mix Asphalt Containing Reclaimed Asphalt Pavement Material in Cold Climate: An Alaskan Experience
Reclaimed asphalt pavement (RAP) has been used for several decades in hot-mix asphalt (HMA) for paving purposes due to environmental and economical benefits. However, concerns still exist regarding using RAP in cold climate, as the dramatic increase in stiffness of HMA when RAP is added may lead to severe low temperature cracking. Meanwhile, if softer binder is used to compensate the stiffness increase in HMA containing RAP, heavy traffic rutting and moderate low-temperature cracking may occur. The above-mentioned concerns have limited RAP use in cold climate, especially in places like Alaska containing various climatic conditions, although there is currently a tendency of using high RAP content in asphalt industry. This paper presents a study to systematically characterize Alaskan HMA materials containing RAP. The HMA contained up to 35% RAP, including two regional asphalt binders, PG 52-28, and PG 52-40. The characterization included dynamic modulus, flow number and IDT creep tests. It was found that adding RAP led to higher dynamic modulus, higher flow number, and higher IDT creep stiffness of the mixture regardless of testing temperature, which means adding RAP could potentially result in a mixture with higher rutting resistance and lower low temperature cracking resistance. The results were found to be consistent on both PG 52-28 mixes and PG 52-40 mixes produced with materials from the Alaska Department of Transportation & Public Facilities (ADOT&PF) Northern Region. More complete evaluation from more mixes in Alaska and more performance related tests were recommended for future studies.
J. Liu and S. Zhao, "Characterization of Hot-Mix Asphalt Containing Reclaimed Asphalt Pavement Material in Cold Climate: An Alaskan Experience," Proceedings of the 4th International Conference on Sustainable Construction Materials and Technologies (2016, Las Vegas, NV), pp. 947-956, International Committee of the SCMT conferences, Aug 2016.
4th International Conference on Sustainable Construction Materials and Technologies, SCMT4 (2016: Aug. 7-11, Las Vegas, NV)
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Asphalt; Binders; Creep; Creep testing; Low temperature testing; Materials handling; Mixtures; Stiffness; Sustainable development; Temperature; Asphalt industries; Climatic conditions; Department of Transportation; Economical benefits; Low temperature cracking; Low temperature cracking resistance; Reclaimed asphalt pavements; Testing temperature; Asphalt pavements
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