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

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CHAPTER 11
Forms for Beams
and Floor Slabs
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Concrete Floor Slabs
There are many types of concrete floor slabs, including, but not limited
to, the following:
1. Concrete slabs supported by concrete beams
2. Concrete slabs of uniform thickness with no beams, designated
as flat slabs
3. Fiberglass dome forms for two-way concrete joist systems
4. Metal-pan and concrete-joist-type slabs
5. Cellular-steel floor systems
6. Corrugated-steel forms and reinforcement floor systems
7. Concrete slabs on steel floor lath
The forms used to support each of these slabs or floor systems
will depend on the type of slab, as described in the following
sections.
In previous chapters of this book, calculations are shown to
determine the minimum size and spacing of members for formwork.
For example, 2-in.-thick lumber was used for studs and wales
for wall forms. Formwork for floor slabs is somewhat different than
formwork for walls or columns. Slab forms are elevated; therefore,
they require some type of vertical support. Also, a full crew of
laborers will be working on the formwork; therefore, 2 × 4 the need
for safety is important. Thus, for constructability and safety it is
desirable to use 4 × 4 joists on 4 × 6 stringers for slab forms because
4-in.-thick members are easier for workers to walk on, and place,
than 2-in.-thick members. Also, the 4-in.-thick member will not
roll-over or fall sideways during installation compared to 2-in. thick
members.
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