 Open Access
 Total Downloads : 11
 Authors : G. Sugila Devi, K. Banupriya, N. Rohini, V. Thesingarajan, R. Premadasan
 Paper ID : IJERTCONV3IS11010
 Volume & Issue : NCNTCE – 2015 (Volume 3 – Issue 11)
 Published (First Online): 30072018
 ISSN (Online) : 22780181
 Publisher Name : IJERT
 License: This work is licensed under a Creative Commons Attribution 4.0 International License
Design of Steel – Concrete Composite Construction in Floor System
G. Sugila Devi1, K. Banupriya2, N. Rohini3, V. Thesingarajan4, R. Premadasan5
1Head of the Department, Civil engineering,
2,3,4,5 Final Year Civil Engineering.
Nadar Saraswathi College of Engineering and Technology, Theni
AbstractThis paper presents the structural behavior of composite concrete slabs with trapezoidal type profiled steel decking by experimental and theoretical studies. The slab is created by composite interaction between the concrete and steel deck with embossments to improve their shear bond characteristics .However, it fails under longitudinal shear bond due to the complicated phenomenon of shear behavior. Therefore, an experimental fullsize tests has been carried out to investigate the shear bond strength under bending test in accordance to Eurocode 4 – Part 1.1. specimens are split into two sets of one specimens each in which all sets are tested for different shear span lengths under static and cyclic loadings on simply supported slabs. The longitudinal shear bond strength between the concrete and steel deck is evaluated analytically and compare the above results with the conventional concrete.
KeywordsComposite slab, profiled steel deck, longitudinal shear bond stress, shear span length, partial shear connection method.
I. INTRODUCTION
A composite slab with profiled steel decking has proved over the years to be one of the simpler, faster, lighter, and economical constructions in steelframed building systems. The system is well accepted by the construction industry due to the many advantage s over other types of floor systems. Coldformed thinwalled profiled steel decking sheets with embossments on top flanges and webs are widely used in many composite slab constructions. Profiled steel deck performs two major functions that act as a permanent formwork during the concrete casting and also as tensile reinforcement after the concrete has hardened. The only additional nominal light mesh reinforcement bars that needs to be provided is to take care of shrinkage and temperature, usually in the form of welded wire fabric.
Composite slab reinforced with profiled steel decking sheet means there is a provision in the system for positive mechanical interlock between the interface of the concrete and the steel deck by means of embossments.
The profiled decking sheet must provide the resistance to vertical separation and horizontal slippage between the contact surface of the concrete and the decking sheet. It also permits transfer of shear stresses from the concrete slab to the steel deck. The horizontal slippage
between the concrete and the steel deck will exist due to the longitudinal shear stress when the shear force of the shear connectors reaches its ultimate strength.
Several fullsize experimental tests have been proposed by past researchers to account for complex phenomenon of shear bond behavior between the steel deckconcrete interactions in composite slabs.
Fig 1.

Marimuthu and Seetharaman (2007) carried out 18 tests to investigate primarily the shear bond behavior of the embossed composite deck slab using trapezoidal profiled steel decking under simulated imposed loads and to evaluate the mk values. The longitudinal shear strength of the composite slab calculated using mk method is verified with the results obtained by partial shear connection method in Euro code 4 Part 1.1 and is differed by about 26% in the average.

Mohammed (2010) carried out an experimental work to study the fresh and hardened properties of concrete containing crumb rubber as replacement to fine aggregate. The strength of composite slab lies within the bond between the concrete and the profiled steel sheeting; therefore, the use of lighter in weight and more ductile concrete such as CRC to toping the steel sheeting could produce a new composite slab system. Two sets of slabs, each set comprising three CRC composite slabs and one conventional concrete slab, have been tested with two shear spans. It is found that the shear bond capacity obtained by mk method was slightly higher compared
to the value obtained by partial shear connection method of the Euro code 4 Part 1.1.
The review of literature shows that the strength of longitudinal shear bond achieved depends on many factors, among which include the shape of steel deck profile, type and frequency of embossments, thickness of steel decking, arrangement of load, length of shear span, slenderness of the slab, and type of end anchorage. However, an accurate determination of strength for a new steel deck profile type is possible only by fullsize testing.
Fig 2.
2 MATERIALS
The following materials are using in composite construction. These materials are to be tested and their results are followed below.,

COMPARISON OF TEST RESULTS

SIEVE ANALYSIS: Fineness modulus is an empirical factor obtained by adding the cumulative percentages of aggregate retained on each of the standard sieves ranging from 80 mm to 150 micron and dividing this sum by 100. Generally sand having fineness modulus more than 3.2 is not used for making good concrete.TABLE 1
Sieve size
weight retained in gm
Percentage of weight retained
Cumulative percentage of weight retained
4.75mm
30
3
0
2.36 mm
160
16
3.0
1.18 mm
214
21.4
24.4
600 micron
282
28.2
52.6
300 micron
294
29.4
82
150 micron
19
1.9
83.9
* Sieve analysis of river sand
Fineness modulus= Sum of cumulative percentage of weight retained/100 = 245.6/100
Fineness modulus = 2.456
TABLE 2
Sieve size
weight retained in gm
Percentage of weight retained
Cumulative percentage of weight retained
4.75mm
28
2.8
2.8
2.36 mm
63
6.3
9.1
1.18 mm
32
3.2
12.3
600 micron
272
27.2
39.5
300 micron
455
45.5
85
150 micron
60
6
94
* Sieve analysis of Msand
Fineness modulus= Sum of cumulative percentage of weight retained/100 = 242.7/100
Fineness modulus = 2.427

SPECIFIC GRAVITY OF CEMENT: To determine the specific gravity is normally defined as the ratio between the weight of a given volume of material and weight of an equal volume of water. To determine the specific gravity of cement, kerosene which does not recent with cement is used.
Specific gravity of cement = 3.15

SPECIFIC GRAVITY OF RIVER SAND Specific gravity of river sand = 2.60
Fig: 3 Specific gravity of River sand

SPECIFIC GRAVITY OF MSAND
Specific gravity of quarry dust = 2.4
Fig: 4 Specific gravity of Msand

INITIAL AD FINAL SETTING TIME OF CEMENT

INITIAL SETTING TIME OF CEMENT: Initial setting time is that time period between the time water is added to cement and time at which 1 mm square section needle fails to penetrate the cement paste, placed in the Vicats mould 5 mm to 7 mm from the bottom of the mould.
Percentage of water added = 0.85 x consistency of cement
= 0.85 x 31 = 26.35
\
TABLE 3
TABLE 4
Sl. No
Time in minutes
Penetration from the bottom
1
10
0
2
15
1
3
20
2
4
25
2
5
30
3
6
45
4
7
60
4
*Final setting time of cement The final setting time of the cement is 10 hours


WORKABILITY TEST
Slump test is used to determine the workability of fresh concrete. Slump test as per IS: 1199 1959 is followed.

Slump is a measurement of concrete's workability, or fluidity.

It's an indirect measurement of concrete consistency or stiffness.

The dimensions are:

Sl. no
Time in minutes
Weight of cement in gm
Percentage of water added
Volume of water added in ml
Penetration from bottom in mm
1
0
400
26.35
105
0
2
5
400
26.35
105
0
3
10
400
26.35
105
0
4
15
400
26.35
105
1
5
20
400
26.35
105
2
6
25
400
26.35
105
4
7
30
400
26.35
105
6
Sl. no
Time in minutes
Weight of cement in gm
Percentage of water added
Volume of water added in ml
Penetration from bottom in mm
1
0
400
26.35
105
0
2
5
400
26.35
105
0
3
10
400
26.35
105
0
4
15
400
26.35
105
1
5
20
400
26.35
105
2
6
25
400
26.35
105
4
7
30
400
26.35
105
6
Top Diameter – 10cm Bottom Diameter – 20cm Height – 30cm
TABLE 5
* Initial setting time of cement Initial setting time of cement is 30 minutes.

FINAL SETTING TIME OF CEMENT
Sl. No
Water Cement ratio
Weight of cement in gm
Volume of water added in ml
Slump value in mm
Degree of Workability
1
0.35
2550
1020
17
True
2
0.40
2550
1147.5
33
True
3
0.45
2550
1275
58
True
4
0.50
2550
1402.5
84
Shear
5
0.55
2550
1530
111
Collapse
Sl. No
Water Cement ratio
Weight of cement in gm
Volume of water added in ml
Slump value in mm
Degree of Workability
1
0.35
2550
1020
17
True
2
0.40
2550
1147.5
33
True
3
0.45
2550
1275
58
True
4
0.50
2550
1402.5
84
Shear
5
0.55
2550
1530
111
Collapse
* Slump value of concrete for river sand concrete with out
Super plasticizer
Final setting time is that time period between the time water is added to cement and the time at which 1 mm needle makes an impression on the paste in the mould but 5 mm attachment does not make any impression
TABLE 6
Sl. No
Water Cement ratio
Weight of cement in gm
Volume of water added in ml
Slump value in mm
Remarks
1
0.20
2550
510
28
True
2
0.25
2550
625
57
True
3
0.30
2550
765
86
Shear
4
0.35
2550
892.5
105
Collapse
5
0.40
2550
1020
128
Collapse
Sl. No
Water Cement ratio
Weight of cement in gm
Volume of water added in ml
Slump value in mm
Remarks
1
0.20
2550
510
28
True
2
0.25
2550
625
57
True
3
0.30
2550
765
86
Shear
4
0.35
2550
892.5
105
Collapse
5
0.40
2550
1020
128
Collapse
*For M sand
140
120
100
80
60
40
20
0
MSAND
RIVER SAND
140
120
100
80
60
40
20
0
MSAND
RIVER SAND
0.35 0.4
0.35 0.4


PROFILED STEEL DECKING PROPERTIES
Thinwalled coldformed profiled steel decks used to build the slab specimens are made of structural quality steel sheets conforming to IS 1079 (1994). galvanized surface coating with an average thickness of 0.0254 mm is finished on each face of the steel deck. The total specimens are carried out with 0.8mm thickness (20 gauge) which have a cross sectional area (Ap) of 839 mm2, a yield strength (fyp) of 250 N/mm2, and second moment of inertia (Ip) of 0.364
Ã—106 mm4.
Fig 5.

CONCRETE PROPERTIES
Concrete used for the specimen is of normal weight, Designed for compressive strength 25.984 N/mm2. Concrete compressive strength is determined from concrete cubes 150 mm Ã— 150 mm Ã— 150mm size according to IS 456 (2000) procedures. Three cubes are tested on the same day as the slab test to determine the concrete compressive strength. Course aggregate size used in the concrete is 20mm down. Concrete proportion used in the mixture is 1:1.42:3.09 (cement/ fine aggregate/course aggregate).
Mix proportioning: The determination of relative quantity of materials like cement, fine aggregate, coarse aggregate and water is called the mix design of concrete M 20. For more
structural work the concrete is designed to give compressive strength of 20 Mpa. Design adopted in this investigation as per Indian standard specifications is 1:1.5:3(M 20).M20 grade concrete has been designed according to IS 4562000 and the mix proportion is shown in Table 1 & 2,
Table 2.2.3.1 Mix proportion for river sand
Description
Cemen t (kg/m3)
Fine Aggre gate (kg/m3)
Coarse Aggre gate (kg/m3)
Water (kg/m3)
W/C
RS
CS
325
2336
1162
186
0.45
Table 2.2.3.2 Mix proportion for msand
Des crip tion
Cemen t (kg/m3
)
Fine Aggre gate (kg/m3
)
Coarse Aggre gate (kg/m3
)
Water (kg/m3
)
Super Plasti zer (kg/m
3)
W/ C
rat io
RS CS
320
2291
1216
960
1.6
0.3
Fig 6.

PROPERTIES OF SLAB SPECIMAN
Composite slab specimens are constructed with 150 mm nominal depth 930mm width (b) and 1500mm span the thickness of the concrete above the flange is 50 mm while depth of the profiled steel deck is 0.098 mm. All composite slab specimens are cast with full support on the plain surface concrete flooring in the Composite Testing Laboratory. Steeldecking surface is well cleaned before casting of the concrete. All slabs are constructed utilizing M20 grade of concrete obtained from a hand mixing method. Concrete test cylinders and concrete cubes are made at intervals while concrete is being placed according to IS 456 (2000) and cured in the same manner as the slab specimens.

DETERMINATION OF THEORETICAL LOAD CARRYING CAPACITY
RCC Slab
Ultimate Moment of resistance = 0.138 fck bd2
= 0.138 x 20 x 1500 x 512
= 7.178 kNm/m
For slab of span L and four point loading of W/4 with simply supported end condition, the Maximum B.M is = 3WL/20
Equating the Ultimate moment of resistance and the maximum BM and multiplying with the factor of safety, we get the theoretical ultimate load as 31.90 kN.

STEEL AND CONCRETE COMPOSITE SLAB ULTIMATE MOMENT OF RESISTANCE
The theory behind the calculation of ultimate moment of resistance is.
N.A within sheeting,
Ncf = bhc x 0.36 x fck
= 73x300x0.36×20 = 157.680kN
MpRd = Ncf (dp 0.42hc)
= 157.680x (0.098(0.42×0.073))
= 107.12 kNm/m
Equating this with the maximum BM as explained for RCC the theoretical ultimate load obtained is
107.121 = (3wl)/20
W = (107.121×20)/3×1500
W = 1.5×47.186 = 70.78kN

SERVICEABILITY LIMIT STATES

For simply supported composite beams the most critical serviceability Limit State is usually deflection.

The effect of vibration, cracking of concrete, etc. should also be checked under serviceability criteria.

In exposed condition, it is preferred to design to obtain full slab in compression to avoid cracking in the shear connector region.


STRESS AND DEFLECTION SERVICE

Elastic analysis is employed to check the serviceability performance of composite beam.

Concrete area is converted into equivalent steel area by applying modular ratio m = (Es/Ec).

Analysis is done in terms of equivalent steel section.

It is assumed that full interaction exists between steel beam and concrete slab.

Effect of reinforcement in compression, the concrete in tension and the concrete between ribs of profiled sheeting are ignored.


ADVANTAGES

Effective utilisation of steel and concrete.

More economical steel section (in terms of depth and weight) is adequate in composite construction when compared with conventional noncomposite construction.

Enhanced headroom due to reduction in construction depth

Less deflection than steel beams.

Efficient arrangement to cover large column free space.

Amenable to fasttrack construction.

Encased steel beam sections have improved fire resistance and corrosion.



CONCLUSION
An experimental investigation carried out on reinforced concrete with & without profile sheets and shear connectors has been studied in this project work.
Based on the results of study, the following conclusions are drawn
TABLE 7
Slab Mark 
Load carrying capacity (kN) 

Theoretical 
Experimental 

RS 
31.90 
35.5 
* For conventional concrete slab
TABLE 8
Slab Mark 
Load carrying capacity (kN) 

Theoretical 
Experimental 

CS 
70.78 
160 
* For composite concrete slab
REFERENCE
[1]. Investigating the Behavior of Composite Floors (Steel Beams and Concrete Slabs) under Mans Rhythmical Movement Journal of Civil Engineering Research 2014, [2]. Seismic behavior analysis of steelconcrete composite Frame structure systemsworld conference on earthquake engineering. [3]. Limit analysis of steelconcrete composite Structures with slipcivil and environmental engineering reports. [4]. Design of composite slabs with profiled steel decking: a comparison between experimental and analytical studies. [5]. Comparative Study on Structural Parameter of R.C.C and Composite Building Civil and Environmental Research ISSN 22245790 (Paper) ISSN 22250514.