With reference to
"Building with the Site-Cast Concrete System" (July 1972, page 324), please explain the use of a continuous reinforcing bar for seven or more stories.
The photograph in the lower right-hand corner of page 326 shows the feet of a man who is guiding a reinforcing bar into a metal tube that is located vertically in the end of a wall panel. The tubes in each panel below and above are positioned in line, so that if a stone were dropped into the tube in the top panel it would go through the wall panels all the way to the ground floor. A reinforcing bar long enough (in the case of a six-story building, about 51 feet) to extend from the roof to the ground floor is lowered through the tubes by the same crane that erected the building. At the ground floor the lower end of this bar is welded to a mating bar extending from the foundation. The bottom wall-panel corners have been boxed out to permit access to bar ends for welding. Nonshrink grout is used to fill the remaining void in the tube, being introduced into the tube at the top end.