TY - JOUR
T1 - Quantification of the effect of bindersource on flexibility of long-term ged asphalt concrete
AU - Zhu, Zehui
AU - Singhvi, Punit
AU - Ali, Uthman Mohamed
AU - Ozer, Hasan
AU - Al-Qadi, Imad L.
N1 - Publisher Copyright:
© National Academy of Sciences: Transportation Research Board 2020.
PY - 2020/7/3
Y1 - 2020/7/3
N2 - Asphalt concrete (AC) aging reduces the resistance of flexible pavements to fatigue, thermal, and block cracking. Therefore, it is critical to understand the effects of AC aging on flexible pavement serviceability. Binder source has a significant effect on AC long-term aging. Therefore, it is necessary to develop a reliable, practical, and systematic method to quantify the effect of binder source on AC cracking resistance. Seven laboratory mixes were designed and produced at three asphalt binder replacement (ABR) levels using various binders, but same binder performance grade (PG). The AC mixes were tested using the Illinois Flexibility Index Test (I-FIT) under unaged and long-term aged conditions. Standard Superpave tests and temperature-frequency sweep tests, were conducted on virgin binders under various aging conditions. By comparing the binder rheological parameters and flexibility index (FI) of long-term aged AC specimens, the DTc and m-value after 40-h of aging using a pressure aging vessel (PAV) were identified as valid indicators to reflect the effects of the binder source on AC long-term flexibility. A minimum DTc of -8_C and m-value of 0.280 were proposed as the preliminary thresholds. A new parameter, Dm, which is defined as the mvalue of 20-h PAV-aged binder minus the m-value of a 40-h PAV-aged binder, correlates well with the aging rate of AC. A binder with a high Dm may induce an excessive drop in flexibility after long-term aging.
AB - Asphalt concrete (AC) aging reduces the resistance of flexible pavements to fatigue, thermal, and block cracking. Therefore, it is critical to understand the effects of AC aging on flexible pavement serviceability. Binder source has a significant effect on AC long-term aging. Therefore, it is necessary to develop a reliable, practical, and systematic method to quantify the effect of binder source on AC cracking resistance. Seven laboratory mixes were designed and produced at three asphalt binder replacement (ABR) levels using various binders, but same binder performance grade (PG). The AC mixes were tested using the Illinois Flexibility Index Test (I-FIT) under unaged and long-term aged conditions. Standard Superpave tests and temperature-frequency sweep tests, were conducted on virgin binders under various aging conditions. By comparing the binder rheological parameters and flexibility index (FI) of long-term aged AC specimens, the DTc and m-value after 40-h of aging using a pressure aging vessel (PAV) were identified as valid indicators to reflect the effects of the binder source on AC long-term flexibility. A minimum DTc of -8_C and m-value of 0.280 were proposed as the preliminary thresholds. A new parameter, Dm, which is defined as the mvalue of 20-h PAV-aged binder minus the m-value of a 40-h PAV-aged binder, correlates well with the aging rate of AC. A binder with a high Dm may induce an excessive drop in flexibility after long-term aging.
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U2 - 10.1177/0361198120930717
DO - 10.1177/0361198120930717
M3 - Article
AN - SCOPUS:85092319825
SN - 0361-1981
VL - 2674
SP - 605
EP - 616
JO - Transportation Research Record
JF - Transportation Research Record
IS - 9
ER -