Evaluation of Fracture Resistance of SMA Mixtures with Various Percentages of TLA-RAP Through the Semi-circular Bend (SCB) Test

Flexible pavements during their life experience different distresses such as deformation and cracking. To minimize the damages more durable mixes such as Stone Matrix Asphalt (SMA) were developed. However, this came with additional construction cost which influenced the growing trend of having economical, sustainable and durable pavements. Aggregates manufactured from Recycled Asphalt Pavement (RAP) are considered to be a suitable sustainable aggregate to blend in new asphalt mixes. The study aimed to evaluate the fracture behaviour of SMA surface mixes designed with various percentages of Trinidad Lake Asphalt (TLA) recycled aggregate contents (10–50%) using the semi-circular bend (SCB) under different notched depths and temperature. The effects of notched depths and temperatures on the ultimate fracture strength and fracture energy were analysed. The results indicate that the notch depth has no significant effects on the fracture toughness and the fracture energy, but the RAP content has relatively obvious effects on the fracture energy, which shows that the optimum RAP ranges are between 30 and 35%. The temperature (5–25 °C) has significant effects on the ultimate loads, fracture energy, and fracture toughness. The results showed that SMA mix with optimized RAP had better resistance to fracture behaviour when compared to conventional SMA mix.