PURPOSE: To improve a resistance to slip and a working property by mixing inorg. based particles to a slurry-like cement based material to be solidified, subjecting a surface to a blast finishing after solidifying by an impact force of the order by which the cement based material to be solidified is shaved but the inorg. based particles are not shaved and exposing the inorg. based particles on the surface.

CONSTITUTION: (a) The colored inorg. based particles 4 each having several mm to several cm grain size is mixed at need to the slurry-like cement based material to be solidified incorporated at need with an aggregate, a coloring material, a blowing material, etc., in a mixing ratio of an order at which a cement slurry 3 is cured to form a concrete plate-like body 1 containing the inorg. based particles 4. (b) Then, the surface is blasted. The cement part 3 is shaved by blasting which the inorg. based particles 4 are remained. A finished figure is shown in (c), the surface becomes scrubbed finish-like, and a surface work treatment is executed without necessitating any treatment at a site of construction.