With the placement of the machinery and forming of the building panels in progress, your next considerations are the placement and the weight-lifting capabilities of the crane. Check the weight-lifting chart of the crane for its maximum weight capacity. This dictates the number of panels you can safely lift at the operating distance. As with all crane operations, attempting to lift more than the rated capacity can cause the crane to turn over.
Attaching the spreader bar (fig. 8-16) to the curved formed panels is a critical step; failure to clamp the panel tightly can cause the panels to slip and fail with potential harm to personnel and damage to the panel. With guide ropes attached (fig. 8-17) and personnel manning these ropes, lift the panels for placement. When lifting, lift only as high as necessary, position two men at each free end to guide them in place, and remind crew members to keep their feet from under the ends of the arches. Never attempt lifting any sets of panels in high winds.
Place the first set of panels on the attaching angle of the foundation, and position them so there will be room for the end-wall panels. After positioning the first set of panels, clamp them to the angle, plumb with guide ropes, and secure the ropes to previously anchored stakes. Detach the spreader bar and continue to place the panel sets. Seam each set to standing panels before detaching the spreader bar.
After about 15 panels (three sets) are in place, measure the building length at both ends (just above forms) and at the center of the arch. This measurement will seldom be exactly 1 foot per panel (usually slightly more), but should be equal for each panel. Adjust the ends to equal the center measure. Panels are flexible enough to adjust slightly. Check these measurements periodically during building construction. Because exact building lengths are difficult to predict, the end wall attaching angle on the finishing end of the building should not be put in place until all of the panels are set.
After arches are in place, set the longest end-wall panel in the form, plumb, and clamp it in place. Work from the longest panel outward and be careful to maintain plumb.
When all of the building panels are welded to the attaching angle (fig. 8-18) at 12 inches on center, you are ready to place the concrete. When you are placing the concrete, remember it is extremely important that it be well-vibrated. This action may eliminate voids under all embedded items. As the concrete begins to set, slope the top exterior portion of the concrete cap about 5 inches (fig. 8-19) to allow water to drain away from the building. The elevation and type of the interior floor are not relevant as long as the finish of the interior floor is not higher than the top of the concrete cap.
The K-span building system is similar to other types of pre-engineered or prefabricated buildings in that windows, doors, and roll-up doors can be installed only when erection is completed. When insulation of the building is required, insulation boards (usually 4 by 8 feet) maybe of any semirigid material that can be bent to match the radius of the building. The insulation is installed using clips, as shown in figure 8-20.
When the integrity of the end-wall panels is continuous from ground to roof line, the end walls become self-supporting. The installation of windows (fig. 8-21) and aluminum doors (fig. 8-22) presents no problem because the integrity of the wall system is not interrupted. The installation of the overhead door (fig. 8-23) does present a problem in that it does interrupt the integrity of the wall system. This situation is quickly overcome by the easily installed and adjustable (height and width) doorframe package that supports both the door and end wall. This doorframe package is offered by the manufacturer.
Shown in figure 8-24 are the fundamental steps in constructing a K-span from start to finish.
There is another type of K-span building, actually referred to as a Super Span by the manufacturer, the ABM 240. Actual construction of the ABM 240 is the same as the ABM 120 (K-span). It can use heavier coil stock and is a larger version. Figure 8-25 is given to show the differences between the two.
Keep in mind that the information provided in this section on the K-span building is basic. During the actual construction of this building, you must consult the manufacturer's complete set of manuals.Continue Reading