Study on durability property and environmental benefit of modified asphalt containing high-volume lithium slag under different aging conditions

The recent growth in the production of new energy vehicles and smart devices resulted in the great amount of lithium slag (LS), whose traditional landfilling disposal method posed a severe challenge to the environmental concerns and heavy burden to the land resources. And the large quantity of active nano-oxides in LS provided the prospect for its application in asphalt pavement. In this study, five kinds of lithium slag modified asphalt (LSMA) were prepared to investigate the durability performance and environmental benefit. Rolling thin film oven (RTFO) test, pressurized aging vessel (PAV) test and ultraviolet (UV) aging test were applied in all samples to simulate the aging conditions. The fourier transform infrared (FTIR) test, multiple stress creep recovery (MSCR) test, temperature sweep (TS) test and linear amplitude sweep (LAS) test were conducted to evaluate the impact of anti-aging performance. The carbon emissions were assessed and compared between traditional landfilling disposal and application of LSMA. The chemical results revealed that active chemical components of LS exerted limited influence on the fundamental structure of virgin binder, facilitated the formation of network and contributed to positive functional groups. And the rheological tests indicated that LSMA enhanced the stress sensitivity, aging durability and fatigue failure cycles when compared to virgin binder. The recommended powder-binder ratio of LS was in the range from 0.8 to 1.0, which achieved desirable durability and rheological performance. The environmental assessment showed that the utilization of LS1.0 in asphalt pavements reduced lifecycle carbon emissions by approximately 62.41% when compared to traditional landfill disposal. The findings provided a sustainable solution for high-volume industrial solid waste valorization and low-carbon infrastructure development.