Advancing eco-friendly SBS-modified asphalt with sustainable solutions: performance, mechanisms, and risk assessment

• Advancing Eco-friendly SBS-modified asphalt with sustainable solutions. • Multidisciplinary assessment addressing environmental, health, and performance trade-offs. • ACP and EG reduce the environmental and health risks of SBS-modified asphalt. • ACP and EG enhance high-temperature performance but impair adhesion and low-temperature performance. • 3 % ACP offers the best balance of environmental and health risk control and binder performance. Asphalt materials are significant sources of hazardous air pollutants, particularly volatile organic compounds and polycyclic aromatic hydrocarbons. These emissions contribute to secondary air pollution, including ozone and secondary organic aerosols, posing health risks through inhalation and skin exposure. To advance sustainable and health-conscious pavement technologies, this study aims to develop eco-friendly styrene–butadiene–styrene modified asphalt with sustainable solutions, focusing on performance, mechanisms, and the environmental and health risk assessment of bio-based activated carbon powder (ACP) and expanded graphite (EG) modifications through a multidisciplinary approach that integrates environmental science, toxicology, chemistry, surface physics, and rheology. Results indicated that both additives significantly reduced organic emissions and potential secondary pollutants, minimizing odor nuisance and human exposure risks. However, although both ACP and EG improved high-temperature resistance, they adversely affected low-temperature performance and adhesion. Overall, 3 % ACP provided the best balance of environmental, health, and performance outcomes, making it a recommended option for practical applications.