Method for retrofitting reinforced concrete column using multi-layered steel plates, and retrofitting structure of reinforced concrete column using the same

A method for retrofitting an already-formed reinforced concrete column using multi-layered steel plates, comprising the steps of:

• pressing one single-piece first reinforcing plate on the already-formed reinforced concrete column where the one single-piece first reinforcing plate is equipped to directly contact with an outer surface of the already-formed reinforced concrete column and to wrap around a whole circumference of the already-formed reinforced concrete column;
• tightly bonding an edge surface of the one single-piece first reinforcing plate with the other opposite edge surface of the same one single-piece first reinforcing plate by a first welding process for connecting the one single-piece first reinforcing plate on the already-formed reinforced concrete column so as to consolidate the one single-piece first reinforcing plate;
• pressing a second reinforcing plate on the one single-piece first reinforcing plate where the second reinforcing plate is equipped to directly contact with and to wrap an outer surface of the one single-piece first reinforcing plate;
• and
• tightly bonding an edge surface of the second reinforcing plate with the other opposite edge surface of the same second reinforcing plate by a second welding process for connecting the second reinforcing plate on the one single-piece first reinforcing plate so as to consolidate the second reinforcing plate,
• wherein, at least double-layered or more reinforcing plates are compressed on the outer surface of the already-formed reinforced concrete column in sequence, and the first and second reinforcing plates are made from steel plates.