Investigation on performance and durability of bone glue and crumb rubber compound modified asphalt and its mixture

Rubberized asphalt has excellent environmental protection and road property, but its storage stability needs improvement. Existing studies have found that the compound modification of bone glue (BG) and crumb rubber (CR) can effectively raise the separation of CR in asphalt, along with outstanding comprehensive properties. Therefore, this paper explores the micro mechanism, aging performance, and engineering characteristics of bone glue and crumb rubber compound modified asphalt (BCCMA). First, the adhesion of BCCMA was evaluated by a static drop test, and a scanning electron microscope test revealed its microscopic surface morphology. Second, three aging indices using rheological tests were developed to evaluate the aging resistance ability of the BCCMA. Lastly, the road performance of the bone glue and crumb rubber compound modified asphalt mixture (BCCMAM) was investigated. The results indicate that the surface energy of BCCMA (15% BG and 20% CR) increased by 52.39% compared to the neat asphalt. BG can improve asphalt's aging resistance, and the BCCMA with a BG content of 10% has the lowest aging sensitivity. BG promotes the dispersion uniformity of CR in neat asphalt, making the low-temperature crack resistance, high-temperature stability, and water stability of BCCMAM better than rubberized asphalt mixture.