The placement of rebar in slipform construction is a difficult task and must be planned very carefully. The need for careful planning of placement of rebar is because the beams of the jacking yokes are moving upward and the horizontal reinforcing steel is station­ary, the horizontal rebar must be threaded through the yokes, and the time between concrete pours is short. As a result, the reinforc­ing should be on the job well in advance to placement, for a short­age of rebar and a shutdown of the slipform could be very costly.