Determination of Fracture Properties of Warm Mix Asphalt at Low Temperatures Based on SCB Results

Warm mix asphalt (WMA) is used as innovative method of asphalt production that have several economic and environmental benefits. However, some ambiguities have been reported with regard to its performance against low-temperature cracking. In this work, Semi-Circular Bending (SCB) test that is used for fracture mechanics analysis of asphalt mixes was employed to study performance of WMA against low-temperature cracking. Hence, SCB testing was applied at three different temperatures (namely, 0, -10 and -20 °C) on pre-notched specimens. The results showed that WMA mixes produced using chemical additives were more resistant to low-temperature cracking compared with mixes produced using organic additives and foam bitumen technology. In addition, WMA specimens produced using foam bitumen technology was the weakest compared with other methods of production. Finally, it can be stated that performance of different types of WMA mixes at low-temperature conditions strongly depend on the adopted technology and the mix production circumstances (i.e. mixing temperature, additive contents and experimental conditions).