location each panel includes reinforcing steel bars in the horizontal circumferential direction 3 and the vertical directions 4 as illustrated reinforcing steel bars 3 and 4 are spaced 18 inches apart to form two rectilinear parallel grids of reinforcement spaced apart over the elevation of the panel additional reinforcement bars may be used adjacent the edges of the panel two vertically extending conduits 5 are embedded to allow placement of threaded bars 15 in the vertical direction to facilitate the staggered arrangement of the panels and the alignment of the conduits 5 from row to row of panels the conduits are spaced apart by one half of the panels width and are located at one quarter of the panels width from each vertical edge threaded lifting inserts 6 are provided to facilitate lifting and handling of the panels projecting keys 8 and recessed keyways 7 help align and secure the panels in the desired staggered arrangement during erection the vertical edges of each panel include a fabricated connection system consisting of projecting plates 9 aligned one with each bar 3 vertical plates 10 and anchorage bars 11 the projecting plates 9 are welded to the vertically extending plate 10 at each edge of the panel while this.