Enhanced fly ash use in concrete: Ex-ante LCA on an emerging electro-mass separation technology

Abstract

A new treatment process for Class F fly ashes is being developed, using a proprietary technology to separate the fly ash into several fractions based on their particle size, with the ultra-fine fly ashes being used to act as a substitute for silica fume in Ultra-High-Performance Concrete. The goal of this study is to assess the potential future environmental impact of using this technology when it becomes available on an industrial scale and to compare these results to that of the direct use of Class F fly ashes in concrete by performing an ex-ante life cycle assessment. This involves theoretically upscaling the technology from a pilot to an industrial scale and taking into account potential changes to the foreground and background data by the time the technology reaches the industrial scale. The preliminary results indicate that an additional environmental benefit can be gained when fly ashes are separated before use.