Evaluation of aging behaviors of asphalt with different thermochromic powders: Fid-Bau Portal

Evaluation of aging behaviors of asphalt with different thermochromic powders

Zhang, Henglong / Chen, Zihao / Li, Lu / Zhu, Chongzheng

Highlights•The PG of asphalt could be extended after addition of a certain type and amount of thermochromic powder.•Thermochromic powders could improve anti-aging performance of asphalt after all of three aging patterns.•Asphalt with 6% red thermochromic powder displayed the best anti-aging performance.

AbstractAs an innovative road material, thermochromic asphalt binder plays a significant role in keeping the surface temperature of pavement within relatively reasonable range. The objective of this paper was to evaluate physical, rheological and aging performance of asphalts with different types (i.e., black, blue and red color) and amounts (i.e., 4% and 6%) of thermochromic powder. The conventional physical tests were conducted. Dynamic shear rheometer (DSR) and bending beam rheometer (BBR) were used to measure rheological properties of binders. Thin film oven test (TFOT), pressure aging vessel (PAV) test and ultraviolet (UV) radiation vessel were adopted to simulate short-term, long-term thermal oxidation and photo oxidation aging of binders, respectively. The results showed the introduction of thermochromic powders could improve high-temperature stability of asphalt by increasing its softening point, viscosity, complex modulus while decreasing penetration and phase angle. Under the same powder content, the ranking of high-temperature stability of asphalt was red group>black group>blue group in general. The performance grade (PG) of asphalt was extended as well after addition of a certain type and amount of thermochromic powder and asphalt with 6% black thermochromic powder represented the better PG than others. In comparison with blank sample, asphalts with thermochromic powder exhibited superior aging resistance after all of three aging patterns by rheological aging indices evaluation. Besides, asphalt with 6% red thermochromic powder displayed the best anti-aging performance among binders.