This document discusses the behavior of composite slabs with profiled steel decking. It presents information on: 1) Composite slabs that use profiled steel sheets as permanent formwork and tensile reinforcement, allowing for 30% reduced concrete and lower structural weight. 2) The profiled steel decking used which is thin-walled, cold-formed sheets meeting ASTM and IS standards with a galvanized coating. 3) Three slabs - plain concrete, bar reinforced, and steel fiber reinforced - were tested for negative bending capacity, with the fiber reinforced slab showing over a 2.5x increase in load capacity compared to plain concrete.

1. BEHAVIOUR OF COMPOSITE SLABS
WITH PROFILED STEEL DECKING
PRESENTED BY
SHEIK FARHAN(271298)
SANDIPAN SINHA(271316)
MANIVEL S(271324)
KARTHIKEYAN V(271342)

2. INTRODUCTION
• The composite slabs have now become a
common form of construction of floor
decks in major buildings.
• In composite slabs, the profile sheet is
used as permanent formwork and as
tensile reinforcement.
• In this composite slab, there is 30% saving
in concrete material, resulting in reduced
structural weight.
• It favours fast and easy construction and
also it proves to be economical

4. Profiled Deck steel
• Thin-walled cold-formed profiled steel decks
• Quality steel sheets conforming to ASTM A653
(2008) and IS 1079 (1994)
• A galvanized surface coating with an average
thickness of 0.0254 mm is finished on each face
of the steel deck
• Yield strength of sheet = 250 N/sq.mm
As per EN 1993-1-1, 3.2.6.
• Shape= Trapezoidal type sheeting
• Embossments= Oval and concave

5. Size of sheeting = 1.8mx0.830m
Thickeness = 1.1mm
(a min. of 0.7 mm ie recommended)

6. Thickness of slab
• Based on the satisfactory performance of floors
that had previously been constructed in a wide
range of countries, EN 1994-1-1 specifies the
following minimum slab thicknesses that should
be used in design:
• Where the slab acts compositely with a beam, or
is used as a diaphragm:
o the overall depth of the slab h ≥ 90 mm; and
o the thickness of concrete above the top of the
ribs of the sheeting hc ≥ 50 mm.

7. Where the slab does not act compositely with a
beam, or has no other stabilising function:
o the overall depth of the slab h ≥ 80 mm; and
o the thickness of concrete above the top of the
ribs of the sheeting hc ≥ 40 mm.

8. • Here the depth of deck alone is 52mm and so
40mm to 50mm is the minimum thickness of
concrete above deck sheet.
• Hence over all slab thickness will be 110mm.
• This is much less than conventional rcc slab
• As per Euro code 4 (part 2) a slab thickness of
110mm will have a fire resistance of 90 minutes

9. LIVETIME EXAMPLE
Site: Coimbatore
Type: Two way steel bridge
Span: 20m

10. TEST CRITERIA
• Three slabs with different reinforcement
conditions are to be tested for negative bending.
• Negative bending is very essential in deck slab
design as it is laid as continuous slab at site.
• Usually positive bending tests will be carried out
and they give least importance to negative
bending.

11. • Here in deck slab, the deck sheet is at the
bottom and hence during negative bending, it
will be subjected to compression and top flange
to tension.
• 1st slab - Plain concrete with no reinforcement
• 2nd slab - Concrete with bar reinforcement
• 3rd slab - Concrete with steel macro fibre
reinforcement

12. Properties of Fibre
S.no Fibre Properties
Steel Fibre
1.
Length (mm)
30
2.
Shape
Wavy
3.
Size/Diameter (mm)
0.5
4.
Aspect Ratio
60
5.
Density (Kg/cubic m)
7850
6.
Youngs Modulus
210 GPa
7.
Tensile strength
532 MPa

13. • As per Euro code 4 (Part 2) the dosage of steel
macro fibres is 20kg/m3 to 30 kg/m3 for
increasing the flexural strength and crack control
• Here, we have chosen 20kg/m3
• Also beyond 30kg/m3, increase in fibre content
does not have any effect in the strength of
composite slabs

14. TEST SETUP

15. END SLIP

16. TEST RESULT
TYPE OF SLAB
ULTIMATE LOAD
PCC
1.183
RCC
3.55
FIBRE REINFORCED
4.1

17. LOAD DEFLECTION GRAPH FOR PCC

18. LOAD DEFLECTION GRAPH FOR RCC

19. LOAD DEFLECTION GRAPH FOR FIBRE
REINFORCED CONCRETE

20. CONCLUSION
• The use of fibres in the composite slab
increased its load carrying capacity to nearly
2.5 times of the capacity of plain concrete
composite slab.
• Also the fibres played an important role in
crack control.

21. Code books & Refernces
1. For steel sheet properties - ASTM & IS codes
2. For Composite slab design and experiment
inference - Euro code 4 (Part 1)
3. ASCE portal
LITERATURE:
1. Composite Slab behaviour and strength
analysis, Part I: Calculation procedure, Byton j.
Daniels and Michel Crisinel.
2. The use of profiled steel sheeting in Floor
Construction, H.D. Wright, H.R. Evans and
P.W.Harding, University College, South Wales, UK

22. THANK YOU