TY - JOUR
T1 - Influence of mix design parameters on asphalt concrete aging rate using I-FIT specimens
AU - Zhu, Zehui
AU - Singhvi, Punit
AU - Espinoza-Luque, Arturo Francisco
AU - Ozer, Hasan
AU - Al-Qadi, Imad L.
N1 - Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2019/3/10
Y1 - 2019/3/10
N2 - Aging is considered an important factor contributing to the deterioration of asphalt concrete (AC) pavements. As a result of aging, the resistance of AC pavements to various forms of cracking including fatigue, thermal, or block is reduced. Therefore, it is critical to understand the effect of aging on AC pavement cracking development and identify the effect of AC mix design parameters on the aging rate. A wide range of AC surface mixes was investigated in this study using the Illinois Flexibility Index Test (I-FIT) after the specimens were subjected to various lab-simulated aging conditions. The flexibility index (FI), an I-FIT outcome parameter, decreases consistently after long-term aging. This effect is primarily due to changes in the post-peak slope, which represents crack growth rate. The effect of mix design parameters on FI deduction rate (or aging rate) was analyzed using statistical methods. Single and multiple linear regression techniques were implemented to identify the significant of AC mix design parameters on the aging rate. The effect of voids in mineral aggregate (VMA), low-temperature true grade, asphalt binder replacement (ABR), mix type, and effective asphalt content was found to be significant. The increase of ABR, effective asphalt content, and VMA, and/or a decrease of low-temperature true grade induce a decrease in the aging rate of AC.
AB - Aging is considered an important factor contributing to the deterioration of asphalt concrete (AC) pavements. As a result of aging, the resistance of AC pavements to various forms of cracking including fatigue, thermal, or block is reduced. Therefore, it is critical to understand the effect of aging on AC pavement cracking development and identify the effect of AC mix design parameters on the aging rate. A wide range of AC surface mixes was investigated in this study using the Illinois Flexibility Index Test (I-FIT) after the specimens were subjected to various lab-simulated aging conditions. The flexibility index (FI), an I-FIT outcome parameter, decreases consistently after long-term aging. This effect is primarily due to changes in the post-peak slope, which represents crack growth rate. The effect of mix design parameters on FI deduction rate (or aging rate) was analyzed using statistical methods. Single and multiple linear regression techniques were implemented to identify the significant of AC mix design parameters on the aging rate. The effect of voids in mineral aggregate (VMA), low-temperature true grade, asphalt binder replacement (ABR), mix type, and effective asphalt content was found to be significant. The increase of ABR, effective asphalt content, and VMA, and/or a decrease of low-temperature true grade induce a decrease in the aging rate of AC.
KW - Aging kinetics
KW - Aging rate
KW - Asphalt concrete
KW - Flexibility index
KW - Linear regression
KW - Long-term aging
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U2 - 10.1016/j.conbuildmat.2018.12.099
DO - 10.1016/j.conbuildmat.2018.12.099
M3 - Article
AN - SCOPUS:85058942765
SN - 0950-0618
VL - 200
SP - 181
EP - 187
JO - Construction and Building Materials
JF - Construction and Building Materials
ER -