PURPOSE: To enhance strength and workability by installing a high tensile wire inside a precast board formed with high strength mortar or the like, and what is more, installing a plurality of ribs and fine projected and recessed parts inside a form.
CONSTITUTION: A high tension wire 2 made of stainless steel fiber or the like inside a precast board 1 so as to enhance tensile strength and reduce the width of cracks dramatically. Then, the wire 2 is dispersively mixed in high strength mortar or prestressed, thereby enhancing bending strength. In case when ribs 3 are placed inside a form, the thickness of the ribs 3 is used as a reinforcement covering, thereby securing a specified thickness of concrete from the surface of a concrete structure to the reinforcements. Furthermore, when fine uneven parts 4 are installed on the inner surface of the precast board 1, the surface area will be increased so that the integrality with the cast concrete may be enhanced. This construction makes it possible to inhibit the generation of cracks and enhance durability and its appearance, and what is more, to facilitate reinforcement work as well.
SHINODA YOSHIO
HARA NATSUO
IMANISHI HIDEKIMI