Abstract
The microstructural evolution and hydration behaviors of cement composites incorporating three natural fibers (abaca, hemp, and jute) were investigated in this study. Mercury intrusion porosimetry was used to assess the microstructural changes, focusing on the pore-size distribution and total porosity. Additionally, the hydration characteristics were analyzed using setting time measurements and isothermal calorimetry to track the heat flow and reaction kinetics during cement hydration. Although the fibers tended to delay the initial stages of cement hydration, their internal curing effect ultimately led to a higher long-term compressive strength and a denser microstructure. Consequently, the use of these natural fibers in cement composites can enhance their durability and promote sustainable construction materials.