Indices-Based Healing Quantification For Bituminous Materials

In the present study, three-point bending tests are carried out using single-edge notched beam specimens of bitumen and mastic to quantify healing. Experiments are conducted at a controlled displacement rate of 1 mm per minute at -15 degrees C. After the crack propagation, samples are given a rest period of 2 h at 10 degrees C to promote healing before retesting them. Two different analysis approaches appealing to linear elastic fracture mechanics and viscoelastic fracture mechanics are compared. In order to perform analysis based on viscoelastic fracture mechanics, the elastic-viscoelastic correspondence principle is used. The amount of healing after the rest period is quantified using various healing indices based on the recovery of stiffness, peak load, fracture toughness, fracture energy, and J-integral. From the analysis performed on bitumen and mastic samples, the study illustrates that the quantum of healing is different when comparing different healing indices. While the stiffness-based healing index demonstrated the healing ability of bitumen, other healing indices used in the study confirmed the higher healing potential of mastic. The healing based on critical value of J-integral shows a distinct difference in the healing of bitumen and mastic. The study emphasizes that the quantification of healing capacity when using different healing indices should be closely linked to its measured conditions. (C) 2021 American Society of Civil Engineers.