Development and evaluation of high-temperature resistant bituminous composites: A study on the performance of expanded perlite and polytetrafluoroethylene in asphalt mixtures

Studies on the mechanical properties of asphalt mixtures at high temperatures revealed that materials enhancing asphalt mixture properties at high temperatures couldn't maintain the necessary properties at low and medium temperatures. Thus, this research addresses this issue. The new bituminous composite product introduced in this study contains superior materials.to enhance asphalt mixture properties at high temperatures across various aspects. Expanded perlite filler, expanded nano perlite, and polytetrafluoroethylene polymer are excellent materials that can create the mentioned conditions, so the samples made were subjected to microstructural studies, conventional tests, and sharp tests. The results showed that the bitumen composite, due to its cohesion, stability, uniform particle distribution, and wavy layered structure, has transformed the bitumen and turned it into a hard and resistant sample against high-temperature failures. The bitumen composite in the MSCR test had better performance in reducing Jnr and increasing the percentage of R return, and also the results of the DSR test showed that the bitumen composite can even meet the requirements of Superpave at 76 degrees Celsius, while studying the rheological behavior of the bitumen composite at medium and low temperatures showed that this composite has a suitable resistance against fatigue cracks and thermal cracks.