Strain-hardening ettringite-based composite with polypropylene fiber reinforced ladle slag: durability under combined chloride and sulfate attack

Ladle slag, an industrial waste from steel manufacturing processes, is an interesting raw material for sustainable inorganic binders. In earlier work, we have developed an ettringitebased binder (LSG) from the hydration between ladle slag and gypsum. In addition, polypropylene (PP) fiber was employed to attain a strain-hardening cementitious composite from LSG. To investigate the durability of PP fiber reinforced LSG, the composite was exposed to a combined chloride and sulfate environment under freeze-thaw cycling. The compressive and flexural behavior of PP fiber reinforced LSG after up to 180 freeze-thaw cycles was experimentally characterized. The experimental results confirm the durability of LSG under Na2SO4-NaCl environment. Furthermore, the PP fibers generally enhance the mechanical properties and durability of the reinforced composite. Since there is a lack of study on the durability of ettringite-based binders from industrial wastes under harsh environments, this experimental study reveals the feasibility of using fiber reinforced ettringite-based composite as an alternative construction material.