Fourier Transform Infrared Spectroscopy as a Fingerprint for Reacted and Activated Rubber Modified Bitumen

Fourier Transform Infrared Spectroscopy (FTIR) has emerged as a powerful tool for evaluating the performance of asphalt binders. Its ability to analyze both the chemical composition and molecular structure of materials provides essential insights into the changes that occur during the bitumen modification process. A key area of application is the investigation of shared components in bitumen modified with rubber. Recently, the modification of crumb rubber bitumen has shifted from the wet process to the dry process, which involves pre-activation of the crumb rubber surface, resulting in what is known as Reacted and Activated Rubber (RAR). Since the modification process entails both physical and chemical interactions between the components, analyzing these interactions is crucial, and FTIR emerges as a viable tool for this purpose. This study focused on analyzing crumb rubber modified bitumen with varying rubber content, examining the chemical changes and correlating them with performance-related parameters. The findings indicate that FTIR can be effectively used as a fingerprint tool for crumb rubber modified bitumen. It also suggests that the modification process, particularly when using RAR, is more of a physical process than a chemical one.