The influences of chemical treatment on recycled rejected fiber cement used as fillers in the fiber cement products

Fiber cement products (FC) are globally used in the constructions of houses and commercial buildings. The recycling of rejected FC as fillers is an important way to contribute to a sustainable material flow. However, several negative effects regarding the extremely high water content from the FC forming (Hatschek process) and the limited reuse of rejected FC instead of natural fillers can be explained by the negative influences on setting and hardening behaviors of FC. Both mentioned inferiors significantly decrease the cement hydration mechanism, leading to remarkable reductions of set and hardened performances of FC. Hence, chemical treatment (CT) was applied to drive the hydration kinetic, and the properties achieved were characterized via the relevance of higher heat of hydration. Moreover, scanning electron microscope (SEM) was used to reveal the favorable effects of appropriate chemical and mineral additives through the microstructures of treated reject-FC.