This document discusses the design of flat plate slabs. Flat plates are concrete slabs that are carried directly by columns without beams or girders. They are commonly used for spans up to 25 feet and loads up to 100 pounds per square foot. The load is directly transferred to the columns, making punching shear at the column connections critical. Proper reinforcement detailing is required between the slab and columns. Moment determination and shear design are important steps in the flat plate slab design process. Advantages include simplified formwork and reduced story height, while limitations include increased thickness and weight.

1. PRESTRESS CONCRETE DESIGN
SESSIONAL (CE-416)
WELCOME TO THE PRESENTATION
ON FLAT PLATE
(SLAB DESIGN)……
YEASIR MASUD
ID NO: 10.01.03.052

2. What Is FLATE PLATES
FLATE PLATES:
Flat Plates are concrete slabs
which are carried directly by
columns, without the use of
beams or girders..
Uses :
Commonly used where spans
are not large (20 to 25 ft).
& also loads not particularly
heavy (60 to 100 Psf)

3. DIFFERENCE BETWEEN
TWO WAY & FLAT PLATE
TWO WAY SLAB:
Slabs are resting on T-Beams.
Slab load transfer to the beams and then in to the
columns.
FLAT PLATE SLAB :
load is directly transferred to the columns
the shear is very critical at the area of
connection of slab with column (called punching
shear).

4. LITTLE CONFUSION REGARDING
FLAT PLATE & FLAT SLAB!!!!!!!!!!!!!
The flat plat is a slab of uniform thickness while in flat
slab there is thickened slab region in the vicinity of the
column that includes either drop panel or column
capitals.
Figure: Drop Panel & Column Head

5. ENSURE THAT:


Reinforcement bars
should be properly
detailed between the
columns and slabs.
Punching shear checks
are critical & vertical
shear reinforcement
should be detailed
accordingly.

6. Analysis (Moment Determination):
1.
A method of frame analysis such as
moment distribution, or stiffness
method or a Computer.
2. A simplified method using the
moment & shear co-efficient Table.

7. STEPS OF FLAT PLATE SLAB DESIGN
DETERMINE THICKNESS
DEAD & LIVE LOAD CALCULATION
MOMENT CALCULATION BY USING
TABLS & CO-EFFICIENTS
REINFORCEMENT DESIGN
SHEAR CHECK

10. Figure: Design Moment &
Shears for flat plate floor
interior Panel C.
(a): Moments
(b): Shears

11. 
Another Important Aspect regarding flat
plate design is punching shear at the
columns which require supplementary
shear reinforcement, & transfer of
unbalanced moments to the column which
may require additional flexural bars in the
negative bending region of the column
strip

13. 
ADVANTAGES:

The simplified Formwork.
Reducing the Story Height which makes it Economical.
There are no beams to obstruct light & circulation of air.
Less danger of concrete spalling & exposing reinforcement.

LIMITATIONS:





Loads due to higher thickness of plate elements as required to control
deflection
Stiffness & weight consideration in earthquake areas