Bonding, rheological, and physiochemical characteristics of reclaimed asphalt rejuvenated by crumb rubber modified binder

Rejuvenating the reclaimed asphalt pavement by crumb rubber modified binder for recycling in new pavements arouses a great interest as a sustainable paving technology that uses waste to recycle waste and hinders resource depletion. By investigating rheological and adhesion/cohesion characteristics of the asphalt binder, this study aims to divine optimal dosages of reclaimed asphalt and crumb rubber that enhance the overall performance of the binder without undermining any feature. Thirty binders produced from two types of virgin binder, two sources of reclaimed asphalt, three dosages of reclaimed asphalt, and two dosages of crumb rubber were prepared and tested. Bonding, rheological, and physiochemical characteristics of binders were investigated using pull-off test, dynamic shear rheometer, and Fourier transformed infrared spectroscopy. The results show that mixing reclaimed asphalt with rubberized asphalt greatly enhances the cohesion strength, rutting resistance, creep resistance, and colloid homogeneity. However, certain reclaimed asphalt and crumb rubber dosages undermine the fatigue cracking resistance. The physiochemical investigation revealed that the crumb rubber chains intensively swell and disintegrate simultaneously during mixing with virgin binder and further mixing with reclaimed asphalt. Through correlation analysis, it was emphasized that the improvement of cohesion strength and rheological characteristics is ascribed to the physiochemical changes caused by crumb rubber interaction and reclaimed asphalt addition. [Display omitted]