Recycling Off-Specification Fly Ash for Producing Strain-Hardening Cementitious Composites

This paper investigates the viability and advantages of incorporating off-specification fly ash (OSFA) into the production of strain-hardening cementitious composites (SHCC). Influences of variables in mix design on key properties of SHCC were experimentally investigated. The underlying mechanisms were explored by means of analysis on hydration kinetics and hydration products. The results show SHCC mixture incorporating OSFA achieved high mechanical properties such as crack resistance, ductility, and controlled crack width, as well as economic benefits, lower carbon footprint and embodied energy, and low leachability of heavy metals. This research demonstrates a synergistic way to utilize OSFA and produce SHCC.