Concrete block with porous surface

TLDR: In this paper, a concrete block is formed by providing a thin layer of a gelled aqueous layer of natural polysaccharide on the bottom of a form, spraying sawdust on the thin layer, placing concrete thereon, releasing the form after hardening the concrete, and washing the exposed surface to remove the easily peelable sawdust.

Abstract: PROBLEM TO BE SOLVED: To provide a concrete block with porous surface for construction of a slope face of a river bulkhead or road, which has a soft touch harmonized with the nature without white reflection of concrete, is easily covered with moss to impart a habitat for small animals, and never deteriorates the strength of the concrete body SOLUTION: This surface porous concrete block comprises a porous layer on the exposed surface of a concrete block and a sawdust inclusion layer having sawdust penetrated into a concrete layer on the lower surface of the porous layer This concrete block is formed by providing a thin layer of a gelled aqueous layer of natural polysaccharide on the bottom of a form, spraying sawdust on the thin layer of the gelled aqueous layer, placing concrete thereon, releasing the form after hardening the concrete, and washing the exposed surface to remove the easily peelable sawdust