Alkali-Activated Materials are Promising Alternatives for Reducing Roadway Emissions

Planned substantial road infrastructure investments emphasize the need for alternative materials that can reduce economic and environmental costs. Alkali-activated materials are one such alternative. These inorganic binders can be produced with fewer CO₂ emissions than asphalt and concrete binders while offering comparable mechanical properties. Alkali-activated materials also develop strength more rapidly, facilitating rapid construction and large-scale repair and maintenance operations.

Existing studies suggest that alkali-activated materials would produce fewer CO₂ emissions than conventional cement. However, work to date has not considered availability of the precursors needed to produce alkali-activated materials. Limited availability of raw materials could result in significant additional emissions from transporting materials long distances to market. Researchers at the Georgia Institute of Technology analyzed published life cycle assessment literature to understand whether alkali-activated materials can achieve the same mechanical performance as Portland cement with lower CO₂ emissions, considering the local availability of raw materials. This policy brief summarizes the findings from that analysis and provides policy implications.