Fracture properties and potential of asphalt mixtures containing graphene oxide at low and intermediate temperatures

This work aimed to investigate the fracture resistance of asphalt mixtures containing graphene oxide (GO) using fracture mechanics. Three dense-graded asphalt mixtures with 9.5, 13.2, and 16 mm nominal maximum aggregate size (NMAS) were modified with varying GO contents. Semi-circular bending (SCB) fracture tests were conducted to determine the fracture properties of the asphalt mixtures. Results showed that mode I fracture toughness (K-IC) and fracture energy (G(f)) at -20 degrees C, -10 degrees C, and 0 degrees C were significantly improved with the addition of GO. Likewise, increasing trends in J-integral were observed with increasing GO content at 0 degrees C, 10 degrees C, and 20 degrees C. The variations of the fracture mechanic parameters suggested that adding GO could help in enhancing the fracture performance at low and intermediate temperatures. The fracture properties showed a high dependency on test temperature. An increase in NMAS resulted in increased fracture strength of the mixtures. Additionally, a two-parameter Weibull distribution model was utilised to further investigate the fracture results. The fracture toughness of the asphalt mixtures was found to comply with the two-parameter Weibull distribution. Response surface methodology (RSM) was used to develop prediction models for the fracture properties. The proposed models exhibited a high degree of correlation.