Intermediate Temperature Fracture Resistance of Stone Matrix Asphalt Containing Untreated Recycled Concrete Aggregate

The sustainable alternative of blending natural limestone aggregates (NAs) with recycled concrete aggregate (RCA) was investigated in this research in order to encourage the utilization of recycled concrete in heavy traffic paving applications. The Marshall Mix design method was used to optimize mix designs containing 0%, 10%, 35% and 50% RCA. Single-edge notched beam (SENB) and semi-circular bending (SCB) tests were then applied and the fracture energy and fracture toughness determined. The tests were conducted at intermediate temperatures (5 °C, 15 °C, 25 °C) and varying notch depths (0.2H, 0.3H and 0.4H). Fracture energy and toughness did not consistently follow the behaviour of mixes with only NA; however, it was determined in this study that a RCA content between 10% and 35% would achieve peak loads, fracture energies and fracture toughness values comparative to a virgin mix.