Freeze-thaw effects on fatigue LIFE of hot mix asphalt and creep stiffness of asphalt binder

摘要

Freeze-Thaw (FT) tests are generally done on unbound materials. Very few studies are conducted on the FT effects on asphalt materials. This study investigated the effects of FT on asphalt concrete (AC) and binder samples in the laboratory. AC tested by beam fatigue test and indirect tensile strength test, whereas binder tested using bending beam rheometer. All the samples were subjected to 5, 10, 15, and 20 cycles of freezing and thawing in laboratory environment conditioning chamber. The FT conditioning decreases the fatigue life of the pavement by 30.7, 33.3, 46.7 and 37.23% for 5, 10, 15, and 20 FT cycles respectively. FT causes damage to the binder, which can be seen in the reduction of stiffness with increasing FT. The reduction in stiffness for 5, 10, 15, and 20 FT cycles is 7.1, 31.5, 38.9 and 41.1% respectively. Reduction of asphalt creep stiffness with an increase in FT cycles was found to be higher compared to the flexural strength of the asphalt concrete beam.