Abstract: Disclosed is an improved granular material used for forming construction materials such as concrete and mortar. The grain material comprises a main material of fly ash or slug powder and reinforcing fibers. The reinforcing fibers are mixed with the main material together with a binder to form a grain body such that the reinforcing fibers project outward from the surface of the grain body. The reinforcing fibers mixed in this fashion permit increasing the bonding strength between the grain and the binder such as cement so as to improve the mechanical strength of the resultant construction material.