PURPOSE: To keep repaired effect of recoated face for a long time, by filling recessions and providing a coarse net by use of solidifying agent and fixing pins and further, striking reinforcing anchor pins after boring.

CONSTITUTION: Epoxy filler is applied in joints and spots left out to make even the rugged surface. Next, a coarse net 1 made of polyester fiber is laid down by making use of a solidifying agent 2 such as polyester putty, cement mortar, etc., and fixing pins 3. Next, sheath 5-screws 6 as reinforcing anchor pins for deaeration are striken to reach the concrete body 4. After that, acryl resin lithin finish paint is applied on the surface. The front end of the sheath 5 is expanded in the body 4 and the treatment layer is fixed in the body 4 for reinforcement. When water retains around the body 4, the water is discharged from the notch of sheath 5, drain holes of sheath 5 opened if necessary, hollow parts of screw 6, etc., to the outside.