Experimental investigation on durability of prefabricated rollable asphalt: Creep and fatigue performance evaluation

Rollpave, a thin prefabricated rollable asphalt layer produced in a factory and rolled on a reel for laying on the existing surface, has attracted attention in the pavement industry due to its rapid treatment capabilities. However, the long-term durability of Rollpave needs further evaluation before considering widespread use. This study aims to assess the durability of Rollpave by evaluating the fatigue and creep performance of its modified bitumen and asphalt mixture. The results highlight that the creep stiffness of modified bitumen at −12°C is half of the corresponding value of virgin bitumen, and lowering the temperature to −18°C increases its creep stiffness to 78.44 MPa. At the same time, it is still 20 MPa less than virgin bitumen. Besides, it is showed the fatigue life of modified bitumen is 23 times greater than the corresponding value of virgin bitumen at 20°C and strain levels of 5 %, and modified bitumen has better stress relaxation ability leading to damage endurance. Additionally, it is observed that the flexural stiffness of the Rollpave mixture drops by only 23 % after 600,000 cycles under 400 µɛ repeated loading. Furthermore, it is indicated that although the creep performance of Rollpave is sensitive to stress and temperature, it has a noticeable recovery ability and rutting resistance, with the average value of non-recoverable creep compliance and percent recovery at stress level of 3.2 kPa at 64°C being 0.213 kPa−1 and 54 %. The asphalt dynamic creep test results of the Rollpave mixture also indicated nearly 20,000 µɛ of cumulative permanent strain at 50°C in the 9000th loading cycle.