TY - JOUR
T1 - Increasing the efficacy of recycling agents with simultaneous addition of zinc diethyldithiocarbamate as an antioxidant
AU - Haghshenas, Hamzeh F.
AU - Fini, Elham
AU - Rea, Robert
AU - Khodaii, Ali
N1 - Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/2/15
Y1 - 2021/2/15
N2 - Recycling agents are commonly used to enhance the properties of aged asphalt binder. The aged asphalt binder found in reclaimed asphalt pavement is considerably oxidized and has lost a significant amount of its volatiles during its service life. Therefore, its performance characteristics need to be improved before it can fully function in new–pavement construction. Recycling agents are intended to modify performance characteristics; however, typical recycling agents are prone to oxidation, which renders them ineffective. It is hypothesized that the efficacy of recycling agents can be enhanced by simultaneous addition of antioxidants to the binder system. Therefore, in this paper, the synergy between three types of recycling agents (paraffinic oil, triglycerides and fatty acids, and tall oil) and zinc diethyldithiocarbamate (ZnDEC) as an antioxidant is examined using rheological characterization at high, ambient, and sub-zero temperatures. The study results show that the efficacy of recycling agents was improved with the addition of ZnDEC; however, the efficacy of the ZnDEC varied depending on the recycling agent used. The latter was attributed to the susceptibility of recycling agents to oxidation as well as the extent of synergy between a recycling agent and ZnDEC.
AB - Recycling agents are commonly used to enhance the properties of aged asphalt binder. The aged asphalt binder found in reclaimed asphalt pavement is considerably oxidized and has lost a significant amount of its volatiles during its service life. Therefore, its performance characteristics need to be improved before it can fully function in new–pavement construction. Recycling agents are intended to modify performance characteristics; however, typical recycling agents are prone to oxidation, which renders them ineffective. It is hypothesized that the efficacy of recycling agents can be enhanced by simultaneous addition of antioxidants to the binder system. Therefore, in this paper, the synergy between three types of recycling agents (paraffinic oil, triglycerides and fatty acids, and tall oil) and zinc diethyldithiocarbamate (ZnDEC) as an antioxidant is examined using rheological characterization at high, ambient, and sub-zero temperatures. The study results show that the efficacy of recycling agents was improved with the addition of ZnDEC; however, the efficacy of the ZnDEC varied depending on the recycling agent used. The latter was attributed to the susceptibility of recycling agents to oxidation as well as the extent of synergy between a recycling agent and ZnDEC.
KW - Aging
KW - Antioxidant
KW - Cracking
KW - Recycling agents
KW - Rutting
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U2 - 10.1016/j.conbuildmat.2020.121892
DO - 10.1016/j.conbuildmat.2020.121892
M3 - Article
AN - SCOPUS:85097708713
SN - 0950-0618
VL - 271
JO - Construction and Building Materials
JF - Construction and Building Materials
M1 - 121892
ER -