In the construction of the underground station, super workable concrete was used for filling concrete into 63 steel tubular columns, in which "push up concrete" method was applied for 49 steel square tubular columns. As a result, quality of concrete changed after pushing into columns compared with that measured before pushing. Flow decreased about 10 %, amount of coarse aggegate increased 12 〜 15 %, and compressive strength decreased about 1 %. In addition we could control the filling of concrete into steel tubular columns by monitoring with a micro video camera.
