BEHAVIOUR OF COMPOSITE SLAB BEAM WITHOUT SHEAR …€¦ · BEHAVIOUR OF COMPOSITE SLAB BEAM WITHOUT...

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International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 4, April 2018, pp. 1039–1048, Article ID: IJCIET_09_04_117

Available online at http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=9&IType=4

ISSN Print: 0976-6308 and ISSN Online: 0976-6316

© IAEME Publication Scopus Indexed

BEHAVIOUR OF COMPOSITE SLAB BEAM

WITHOUT SHEAR CONNECTOR

Alphonsa Antony

Assistant Professor,

Department of Civil Engineering,

Jeppiaar Engineering College, Chennai, India

Nivin Joy

Assistant Professor,

Department of Mechanical Engineering,

Sathyabama Institute of Science & Technology,

Chennai, India

ABSTRACT

The floor-to-floor height is considered as a significant aspect due to limited city

areas as the number of high-rise buildings increases. To reduce the floor-to-floor

height, a newly developed composite slab was proposed and experimentally explored.

This project deals with the study of behavior of composite slabs without shear

connector. The principal disadvantage of shear connector lies with the placement of the

transversal bottom slab reinforcement, which is often very difficult. In the proposed

composite beam the top flange of I-section takes the role of shear connector. The

behavior of composite slabs with different depths of I Section inside the slab is found

out by using two sections of steel. Based on the results Load Deflection curve was

plotted. CAD Modeling is done using Solidworks Software and Finite Element Analysis

is done using ABAQUS software.

Key words: Composite Slab, Shear Connector, I-Section, Load Deflection Curve, Finite

Element Analysis.

Cite this Article: Alphonsa Antony and Nivin Joy, Behaviour of Composite Slab Beam

Without Shear Connector, International Journal of Civil Engineering and Technology,

9(4), 2018, pp. 1039–1048.

http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=9&IType=4

1. INTRODUCTION

Around 1926 the use of steel–concrete composite construction began due to the increasing

demands of long span floors but with shallow floor depth. A large number of composite floor

sections were proposed and had been successfully used in the building construction industry.

The composite construction results in a shallower beam depth and consequently smaller floor-

Alphonsa Antony and Nivin Joy


to floor height. Reinforced concrete slab, hot-rolled steel beam, and shear connector are the

main components of a composite member. That is a composite member consist of a T -beam

formed by a reinforced concrete slab, a steel joist and mechanical shear connectors between

them. The ability to combine well the advantages of both steel and concrete results in the

popularity of this form of construction. When compared to the contribution of the slab and joist

separately composite beams exhibit enhanced strength and stiffness. The shear connectors

perform the horizontal shear resistance and vertical interlocking between slab made of concrete

and steel beams to generate a composite section that acts as a single unit. Composite members

are constructed keeping in mind that the structural steel shapes and the concrete act together to

resist axial compression and or bending. Different types of shear connectors are studs, channels,

stiffened angles, and flat bars. Through the steel deck studs are welded into the structural steel

framing in the building construction markets. A new composite section system was introduced

to the building construction industry in the late twentieth century which uses the cold-formed

steel beam as a substitute for the hot-rolled steel beam to provide a lighter weight of structural

system.

For framed buildings, bridges, and stadia, steel–concrete composite construction is a very

efficient structural method because of several well-established advantages that it provides

compared to other structural types. Structures are safe, robust, and economic due to the optimal

combination of the individual properties of structural steel and concrete. Because of the

increased speed of construction and flexibility that they offer, steel–concrete composite beams

are an ideal solution for building floors or bridge decks. In municipal buildings and bridge

structures due to the excellent performance in terms of higher loading capacities and larger

flexural stiffness. In the preliminary design phase more and more newly-built high-speed

railway bridges also give preference to composite beams just because of their excellent

mechanical and economic performance. Stiffness and high strength properties together with a

low weight, good corrosion resistance, enhanced fatigue life, low thermal expansion, low

machining cost are some of the interesting features of composite structures that impel their use

in different industrial devices.

2. EXPERIMENTAL PROCEDURE

2.1. Material Properties

A nominal mix was designed according to IS: 10262-1982 for M30 grade of concrete.

2.1. Test Specimen

A total of 6 full-scale composite slab specimens are built and tested in accordance with the

Eurocode 4 - Part 1.1 to determine (1) the structural behavior and (2) the load carrying capacity.

Experimental program includes flexural test on 2 sets of slab specimens subjected to varying I

sections. That is for 1 set ISMB 200 is used (PES1a, PES 1b, PES 1c) and for another set

ISMB300 is used (PES2a, PES 2b, PES 2c). For each set of 3 specimens, first specimen is made

up of inserting 80 mm of I section inside the concrete slab, second specimen is made up of

inserting 100 mm of I section inside the concrete slab and the third specimen is made up of

inserting 120 mm of I section inside the concrete slab.

Behaviour of Composite Slab Beam Without Shear Connector


2.2. Specimen Designation

Table 1 Specimen Designation

Specimen

Designatio

n

Description I Section

Used

Depth of

Insertion Drawing

PES 1a Partially Encased Slab 1a ISMB 200 80 mm

PES 1b Partially Encased Slab 1b ISMB 200 100 mm

PES 1c Partially Encased Slab 1c ISMB 200 120 mm

PES 2a Partially Encased Slab 2a ISMB 300 80 mm

PES 2b Partially Encased Slab 2b ISMB 300 100 mm

PES 2c Partially Encased Slab 2c ISMB 300 120 mm

2.1. Testing of Composite Slabs

The beams are tested under a one-point load by gradually increasing the load and the relevant

deflection is noted for each load case. 25kN load is increased gradually and corresponding

deflection is noted and finally, the collapse load is found out.

The slabs are placed on a loading frame in which the proving ring and the hydraulic jack

are also placed. A Hydraulic Jack capacity of 500 kN is used for load application. The dial

gauges are placed along the slab diagonally. In the testing setup three dial gauges are used. Dial

2 is placed in the center just beneath the point of load application. Dial 1 and Dial 3 are placed

on the opposite edges. Thus, when the load is applied gradually, the corresponding deflection

is also noted from the dial gauges.



Figure 1 Testing Setup of PES 1a

3. FINITE ELEMENT MODEL

A three-dimensional FE model was developed by using the general-purpose program ABAQUS

to investigate the bending behavior of composite slab partially encased with I section.

Geometric and material non-linear behaviors were considered in the model. The materials used

were concrete and I section. The compressive strength of the concrete was fck =30 MPa. The

modulus of elasticity for concrete, Ec, can be calculated based on ACI building code:

Ec = 57000 √fc

which results in Ec = 25.2 GPa. The modulus of elasticity for steel was Es = 200 GPa.

Concrete was modeled using 3D deformable solid 8-point elements (C3D8R). The 4-node

general-purpose shell element S4R with reduced integration was employed in steel beam

component. The steel reinforcement was simulated using stringers, which were defined using

3D truss elements (T3D2). The self-weight and test load were simulated using a two-step

loading process to more accurately represent the loading conditions. Dynamic analysis is

carried out. The self-weight was applied using ‘‘gravity load’’ while the test load was applied

as pressure load, which were solved using a general dynamic analysis. The boundary conditions

were pinned at all its four sides. A typical FE mesh is shown in Fig.2. The mesh shape is HEX.

Figure 2 Finite Element Model

4. TEST RESULTS AND DISCUSSION

4.1. General Observations and Failure Mode

For the beam PES 1a, PES 1b, PES 1cthe first crack appear near the internal support when the

load increased to 57%, 63%, 66% of peak load respectively. In case of PES 2a, PES 2b, PES

2c first crack occurs when the load is increased to 65 %, 71%,78% of peak load respectively.



The concrete slab near the midspan crushed and the bottom flange near the internal support

buckled at the ultimate failure state.

Figure 3 Failure pattern of PES1a Figure 4 Failure pattern of PES1b

Figure 5 Failure pattern of PES1c Figure 6 Failure pattern of PES2a

Figure 7 Failure pattern of PES2b Figure 8 Failure pattern of PES2c

4.2. Load Deflection Behaviour

The beams which are tested under two-point loading by gradually increasing the load will

deflect and the corresponding value of deflection is noted for the gradual increase in load.

Finally, the collapse load is found out. The ultimate load of PES1a, PES1b, PES1c, PES2a,

PES2b, PES2c is found to be 350kN, 275 kN,150 kN,475 kN,350 kN,175 kN respectively.

Figure 9 Load Deflection Behaviour of PES1a



Figure 10 Load Deflection Behaviour of PES1b

Figure 11 Load Deflection Behaviour of PES1c

Figure 12 Load Deflection Behaviour of PES2a

Figure 13 Load Deflection Behaviour of PES2b



Figure 14 Load Deflection Behaviour of PES2c

4.3. Analytical Results

For PES1a the failure first starts near the I section and then distribute to the bottom corner of

the composite slab. The displacement is maximum at the center and it gradually decreases as it

moves from the center. The stress is maximum near the top flange of ISMB 200 and surrounding

portion of it and will be minimum near the edges of the slab. The stress is maximum at the

center of ISMB 200. For PES1b the failure begins near the bottom corner of the partially

encased slab. The stress is maximum at the web of ISMB 200 and then to the top flange of the

I section.it will be minimum near the edges of the slab. For PES1c also the failure begins near

the bottom corner of the partially encased slab. The displacement is maximum near the web of

the I section and decreases gradually and minimum displacement is occurred near the corner.

The stress is maximum at the top flange of ISMB 200. For PES2a the failure begins just above

the top flange of the partially encased slab. The displacement is maximum at the center of the

composite slab and decreases gradually and minimum displacement is occurred near the corner.

The intensity of the stress will be less when compared to partially encased slab with 80 mm of

ISMB 200 inside. For PES2b the failure begins at the bottom corner of the partially encased

slab. The stress is maximum at the center of ISMB 300. The intensity will be less when

compared to PES 1b. For PES2c failure will be more at bottom corner. The stress is maximum

at the top flange of ISMB 300 and then to the web of the I section it will be minimum near the

edges of the slab.

Figure 14 Failure pattern in FE Model of PES1a Figure 15 Failure pattern in FE Model of PES1b

Figure 16 Failure pattern in FE Model of PES1c Figure 17 Failure pattern in FE Model of PES2a



Figure 18 Failure pattern in FE Model of PES2b Figure 19 Failure pattern in FE Model of PES2c

4.4. Comparison Between FE Model and Experimental Data

The Ultimate Load carrying capacity of PES 1a obtained from FE MODEL IS 420 kN and that

from the experimental data is 350 kN. Thus there is a difference of 70 kN between the analytical

and experimental data.In case of PES1b, PES1c, PES2a, PES2b PES2c there is a difference in

load carrying capacity of 55 Kn, 30kN, 95kN, 70kN, 35kN respectively between the analytical

and experimental data.

Figure 20 Comparison Between FE Model and Experimental Data of PES1a

Figure 21 Comparison Between FE Model and Experimental Data of PES1b

Figure 22 Comparison Between FE Model and Experimental Data of PES1c



Figure 23 Comparison Between FE Model and Experimental Data of PES2a

Figure 24 Comparison Between FE Model and Experimental Data of PES2b

Figure 25 Comparison Between FE Model and Experimental Data of PES2c

5. CONCLUSION

From the results it is found that, of all the 6 specimens, partially encased slab with 80 mm of

ISMB 300 inside the slab carries the most ultimate load of 475 kN compared to other composite

slab specimens. Hence it is inferred that the said slab can be preferred most. Compared to slabs

with ISMB 200 insertions, slabs with ISMB 300 insertions are able to carry more load. It is also

found that when applying point load, the amount of deflection is more at the center of the

composite slab.

REFERENCES

[1] Bengi Aykac, Ilker Kalkan, Sabahattin Aykac (2013), Yusuf Emre Egriboz, “Flexural

behavior of RC beams with regular square or circular web”, Engineering Structures, Vol.

No: 56, pp.2164-2174

[2] Cheng-Tzu Thomas Hsu, Sun Punurai, Wonsiri Punurai, Yazdan Majdi, (2014) “New

composite beams having cold-formed steel joists and concrete slab”, Engineering

Structures, Vol. No: 71, pp.187-200



[3] Eray Baran, Cem Topkaya, (2014) “Behavior of steel-concrete partially composite beams

with channel type shear connectors”, Journal of Constructional Steel Research, Vol. No: 97,

pp.69-78.

[4] Erica C. Fischer, Amit H. Varma, (2015) “Fire behavior of composite beams with simple

connections: Benchmarking of numerical models, Journal of Constructional Steel Research,

Vol. No: 111, pp.13-125.

[5] Hamdy M. Afefy, Khaled Sennah, Hamid Akhlagh-Nejat, (2016) “Experimental and

analytical investigations on the flexural behavior of CFRP-strengthened composite girders”

Journal of Constructional Steel Research, Vol. No: 120, pp.4-105.

[6] Huiyong Ban, Brian Uy, Sameera Wijesiri Pathirana, Ian Henderson, Olivia Mirza, Xinqun

Zhu (2015), “Time-dependent behaviour of composite beams with blind bolts under

sustained loads, Journal of Constructional Steel Research, Vol. No: 112, pp.10-207.

[7] Huiyong Ban, Mark A. Bradford (2013), “Flexural behaviour of composite beams with high

strength steel”, Engineering Structures, Vol. No: 56, pp.1130-1141

[8] Ilker Fatih Kara, Ashraf F. Ashour, Mehmet Alpaslan Körog˘lu (2015), “Flexural behavior

of hybrid FRP/steel reinforced concrete beams”, Composite Structures, Vol. No: 129,

pp.111-121

[9] Nguyen T.T, K.-H. Tan, I.W. Burgess (2015), “Behaviour of composite slab-beam systems

at elevated temperatures: Experimental and numerical investigation”, Engineering

Structures, Vol. No: 82, pp.199-213

[10] Safat Al-deen, Gianluca Ranzi, Zora Vrcelj (2011), “Shrinkage effects on the flexural

stiffness of composite beams with solid concrete slabs: An experimental study”,

Engineering Structures, Vol. No: 33, pp.1302-1315

[11] Shiming Chen, Toi Limazie, Jianyao Tan (2015), “Flexural Behaviour of Shallow

Composite Floor Beams with Innovative Shear Connector” Journal of Constructional Steel

Research, Vol. No: 106, pp.329-346

[12] Tolga Aksencer, Metin Aydogdu (2015), “Flapwise vibration of rotating composite beams”,

Composite Structures, Vol. No: 134, pp.672-679.

[13] Vasdravellis, Uy.B, Tan E.L. , Kirkland.B (2015), “Behaviour and design of composite

beams subjected to sagging bending and axial compression”, Journal Of Constructional

Steel Research, Vol. No: 110, pp.9-39

[14] Yuchen Jiang, Xiamin Hu, Wan Hong, Bolian Wang (2016), “Experimental study and

theoretical analysis of partially encased continuous composite beams”, Journal of

Constructional Steel Research, Vol. No: 117, pp.13-16.

[15] P. Sai Shraddha, C. Sudha and Dr. M. Lakshmipathy, Study on Ductility Behavior of

Different Types of Shear Connectors in Composite Structural Elements. International

Journal of Civil Engineering and Technology, 8(4), 2017, pp. 339–353

[16] Yunita Idris, Togay Ozbakkaloglu (2014), “Flexural behavior of FRP-HSC-steel composite

beams”, Thin Walled Structures, Vol. No: 80, pp.207-216.

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