Formwork for Concrete Structures by R.L.Peurifoy and G.D- By EasyEngineering.net

Downloaded From : www.EasyEngineering.net
Patented Forms for Concrete Floor Systems 373
This company also manufactures extra long forms for faster concrete
forming and custom forms for special shapes. The custom forms
can be formed into almost any shape. Because the forms are light in
weight, they are particularly suited for application with flying forms
where entire floor sections may be moved from floor to floor in a
complete grid format.
Corrugated-Steel Forms
Corrugated-steel sheets are frequently used as forms for concrete
floor and roof slabs supported by steel joists, steel beams, and precast
concrete joists. The sheets are available in several gauges, widths, and
lengths to fit different requirements.
The sheets are laid directly on the supporting joists or beams with
ww.EasyEngineering.n
the corrugations perpendicular to the supports. Side laps should be
one-half of a corrugation, and end laps should be at least 3 in., made
over supporting joists or beams. The sheets are fastened to the supports
with special clips or spot welds. The edges of adjacent sheets
are fastened together with steel clips.
The depth of a concrete slab is measured from the top of the surface
to the centroid of the corrugated sheet. The span is the distance from
center to center between the supporting members. The maximum safe
span will depend on the total load per unit of area, including the weight
of the section, the concrete and live loads, and the moment of inertia
and section modulus for the section under consideration.
Cellular-Steel Floor Systems
Cellular-steel panels are frequently used for the forms and structural
units of floor systems. This system offers a number of advantages,
including light weight, the elimination of shores and forms for concrete,
rapid construction, and abundant raceways for utility services.
Thus, the forming system combines the structural slab and electrical
functions within the normal depth of the floor slab.
Each cellular unit has three cells which may be used for telephone,
power, and computer cables. Cellular units are available in 24- and
36-in. widths, as illustrated in Figure 12-11. The panels are manufactured
from rolled-steel shapes and plates that are electrically welded
together in various types. Openings in the cells provide routing for
wire cables through the floor slab into the room area.
The panels are prefabricated by the manufacturer to fit any given
floor condition and shipped to the project ready for installation without
additional fabrication. If storage is necessary, the cellular units
may be stacked on wood blocking clear off the ground and tilted longitudinally
to ensure against the entrapment of water. All deck bundles
have labels or handwritten information clearly visible to identify
the material and erection location.
Downloaded From : www.EasyEngineering.net