Analytical Study on Behaviour of Different Shapes In Voided ...

IJARSCT ISSN (Online) 2581-9429

International Journal of Advanced Research in Science, Communication and Technology (IJARSCT)

Volume 5, Issue 2, May 2021

Copyright to IJARSCT DOI: 10.48175/568 627 www.ijarsct.co.in

Impact Factor: 4.819

Analytical Study on Behaviour of Different Shapes

In Voided Slabs and Voided Beams Srivani M1 and D. K. Ramadevi2

PG Scholar, Department Of Civil Engineering1

Professor, Department of Civil Engineering2

Kumaraguru College of Technology, Coimbatore, India

Abstract: Slab is hugest member that consumes concrete and once load performing on the slab is large

or clear span between columns is additional, the slab thickness is increasing. It ends up in consumption

of additional material like concrete and steel due to that, self-weight of slab is enhanced. To avoid these

disadvantages numerous studies are carried out and researchers counsel voided slab system[1]. To scale

back the concrete in center of the slab, hollow recycled plastic balls are employed. High density

polythene (HDPE) hollow balls replace the ineffective concrete within the center of the slab, therefore

decreasing the dead weight and increasing the potency of the floor. The benefits are less energy

consumption each in production, transport and carrying out, less emission exhaust gases from

production and transport, particularly CO2[2]. The aim of this paper is to debate concerning the

comparison of typical slab and voided slab and additionally, typical beam and voided beam by

manipulating in ANSYS software.

Keywords: Bubble deck, Total Deformation, Voids, High density polythene balls, ANSYS.

I. INTRODUCTION

Concrete has been used for several years and has competed in making large infrastructure as well as residential

projects. Voided beams are R.C.C beams that decrease the number of concrete with the assistance of voids. Hollow

core slab, is additionally called as voided slab. They are pre stressed concrete components that have a relentless cross

section. In buildings, slab is one in all vital support furthermore the largest member consuming concrete. Therefore by

manoeuvring high density polythene balls the consumption of concrete can be optimized. Void forms in the middle of a

slab eliminates 35% of a slabs self-weight removing constraints of high dead loads and short spans. Hollow cores are

factory made employing high tensile strength pre stressed strands or single wires which are embedded inside the

component. Bubble deck eliminates up to 35% of the structural concrete once plus the reduced ground thickness and

facade, smaller foundations and columns, construction fees could also be reduced by as heaps as 10%.On most tasks

this system gets obviate over 95% of highly-priced formwork as compared with typical concrete structures. Regardless

of project size, form or complexity; merely shore, area, and pour to quickly deploy concrete decks. Off-site producing,

fewer vehicle journeys and crane lifts additionally for easy installation of all integrate to limit operating risks,

additionally decreasing health & safety risks.

The objectives of this project are,

To study the sequel of voided beams and voided slabs and their properties.

To simulate the behaviour of voided beams and voided slabs in several shapes manipulating in ANSYS.

Reduced concrete usage – 1 weight unit recycled plastic replaces 100 weight unit of concrete.

Environmentally Green and Sustainable – reduced energy & carbon emission.

[3] Bubble-Deck is a biaxial technology that will increase span length and makes the depth of beams diluent by

reducing the self-weight whereas maintaining the performance of reinforced concrete beam. Bubble deck system is a

new construction technology using recycled spherical balls in slabs to scale back self-weight of the structure as a part of

the concrete is replaced by the bubbles. The utilisation of spherical balls/bubbles to fill the voids in the middle of a






beam eliminates 35% of beam self-weight compared to solid slab having same depth without affecting its deflection

behaviour & bending strength of beams.

II. LITERATURE REVIEW

[1] Slab is hugest member that consumes concrete and once load performing on the slab is large or clear span between

columns is additional, the slab thickness is increasing. It ends up in consuming additional material like as concrete and

steel because of that, self-weight of slab is enhanced. To avoid these disadvantages numerous studies are carried out

and researchers counsel voided slab system. During this study the design method for plastic voided slab is compared

with concrete solid flat slab through a design comparison of typical bays of 4.54 m by 4.54 m (15 feet by 15 feet), 6.05

m by 6.05 m (20 feet by 20 feet), 7.57 m by 7.57 m (25 feet by 25 feet) and 9.08 m by 9.08 m (30 feet by 30 feet) with

the constant thickness of 0.25 m (10 inch). The solid flat slab design method follows the provisions made in the ACI

318-11 and the plastic voided slab design process is modified from the Bubble Deck Design Guide for compliance with

BCA using AS3600 and Euro code 2. Also, the finite element analysis of the slab panels has been carried out by using

ANSYS Workbench 14.5 to find out the deformation. The obtained results of deformation ought to be checked for live

load and long-term deformation as per ACI 318-11.

[2] Concrete plays a serious role in the construction field. In building construction slab is one of the vital and important

structural member consuming concrete. Concrete slab use additional concrete than demand, therefore should be

optimized. Thus cut back the concrete in center of the slab by using hollow recycled plastic balls. High density

polythene (HDPE) hollow balls replace the ineffective concrete in the center of the slab, therefore decreasing the dead

weight and increasing the potency of the ground. Voids in the middle of a flat slab eliminate 35% of a slab’s self-

weight removing constraints of high dead loads and short spans. Combination of recycled plastic bubbles permits 50%

longer spans between columns without any beams. This provides a good vary of economy and construction benefits. In

this paper, Finite element analysis (FEA) was disbursed by using ANSYS software to review the structural behavior of

bubble deck slab with different arrangements of elliptical balls.

[3] In building constructions, the beam is a vital support to hold load of the slab. Bubble beam could be a methodology

of just about eliminating all concrete from the center of a Beam, that isn't performing any structural operation, thereby

dramatically reducing structural load. Bubble beam is a beam whose core is replaced with Spherical balls that may be

of assorted sizes and shapes. Sometimes the Bubble Deck system combines the advantages of works factory-made parts

in controlled conditions alongside on-the-spot completion. Numerous major advantages are lower total price, reduced

material use, increased structural potency, decreased construction time, and is a green technology. In this project, the

in-effective concrete within the Centre of the beam is replaced with High density polythene hollow spheres, using M35

grade of concrete no of beams with and without spherical bubbles were casted to match weight and flexural strength.

[4] A structural system of Tremendous importance in constructions are slabs or floor systems, it's known as two

dimensional slab structural parts, wherever the dimension is tiny compared with the opposite two basic dimensions.

Masses acting perpendicular slabs, to the flat principal, could also be from totally different shapes Y configurations

counting on the requirement that apply in the least times seeks to create them lighter however covering the best doable

distances and perpetually seeking to boost productivity and energy savings in construction. These systems cut back the

concrete in the center of the block by a lighter material to from cut back the burden own from the structure. However

nonetheless these mitigated as in slabs cut back the strength thence before exposure to shear forces and hearth. BD is a

biaxial technology that will increase span lengths and makes floors diluent by lowering the burden at a similar time as

keeping the performance of RC slabs. This paper provides a number of the reviews associated with bubble Deck slabs.

[5] Bubble deck block is a methodology of about eliminating all concrete from the center of a floor block, that isn't

performing any structural operation, thereby dramatically reducing structural dead weight. High density polythene

hollow spheres replace the in-effective concrete within the centre of the slab, therefore decreasing the dead weight and

increasing the potency of the ground. By introducing the gaps ends up in a 30 to 50% lighter block that reduces the

masses on the columns, walls and foundations, and in fact of the complete building. The benefits square measure less

energy consumption - each in production, transport and winding up, less emission - exhaust gases from production and






transport, particularly carbon gas .The aim of this paper is to debate regarding numerous properties of Bubble deck slab

supported the varied studies done abroad. Moment, deflection and stress distributions are verified using Finite element

method (FEM) in SAP2000.

[6] In buildings, slab is one amongst the necessary support similarly because the largest member consuming concrete.

So by utilising high density polythene balls the consumption of concrete are often optimized. The aim is to review the

utility of hollow plastic balls in a very RC slab. The slab specimen casted were of 3 sorts particularly, standard slab,

B.D.S of 50 mm diameter and B.D.S of 100 mm diameter having dimensions of 750 mm X 500 mm X 150 mm. The

testing of slab specimen was done on universal testing machine by giving one purpose line loading. Finite element

analysis on slab specimen is additionally done by manipulating in ANSYS WORKBENCH 16.0. From the results it are

often finished that Bubble deck slab of 50mm and 100mm diameter are often utilized in practice, because the deflection

values of the actual slabs range within the permissible limit as declared in IS Code.

[7] The target of this study is to perform the behavioural analysis of standard slab and bubble deck slab manipulating in

ANSYS WORKBENCH 14.0. This comparative study includes the study of traditional slab and slab with HDPE

spherical ball at center to make voids. High Density polythene (HDPE) empty sphere replaces the ineffective concrete

at neutral axis of the slab section, during this approach decreasing the dead weight. Merely supported finish conditions

are assumed for each slab underneath Static (UDL) masses. The analysis result showed the entire deflection, Von-mises

Stress of each block underneath uniformly distributed load for various finish conditions. This paper furthermore

displays a review on the properties and preferences of Bubble Deck section over standard slab.

[8] Biaxial voided block is a rising block system that reduces its self-weight up to 50% compared with the traditional

RC slab. It reduces each unidirectional and two-way (punching) shear capability for about 40%. Therefore, an efficient

approach of predicting the punching shear capability is investigated because the presence of voids alters the essential

failure section. Additionally, eight specimens were tested with the sphere and cuboid form of voids. Finally,

experimental results of existing study and test information collected from literature (33 specimens) were compared with

predictions by the relevant code provisions. Hence, the presence of voids is taken into account by modifying the

essential section looking on the void location. Further, solely the effective concrete space is taken into account to

predict the punching shear capability. Post modifications, the predictions by all 3 building standards result in

satisfactory results.

[9] Voided slab is employed in the construction of floor slabs, roof slabs and short, medium span block bridges. Voids

of circular form are less complicated for construction and therefore the stress concentration around these voids is

reduced critically than the other form. The conferred study deals with the experimentation general modification

behavior of the RC voided slab underneath unsymmetrical case of loading. The voided RC slab of dimensions 1.8 m x

1.04 m x 0.12 m having void diameters of 50mm was modelled and tested under eccentric loading. The slab was tested

as simply supported on span of 1.60 m. The main focus of projected work is that the comparative study of

experimentation on voided slab manipulating in ANSYS WORKBENCH 14.5.

[10] Slab is largest member that consumes concrete. If the load engaged on the slab is massive or clear span between

columns is a lot of, the thickness of slab will increase. It ends up in consume a lot of material like concrete and steel

because of which the self-weight of slab rises and to avoid these disadvantages voided block system is employed. RC

slab with plastic voids is a new and innovative style of construction. High density polythene (HDPE) hollow spheres

replace the ineffective concrete from the centre of the block and reduce the load. The benefits are less energy

consumption each in production and transport, less emission of exhaust gases from production and transport,

particularly CO2 and cut back the material, the load, lower the price and it's additionally a GREEN Technology. The

impact is to decrease the weight by the maximum of 15% in comparison to a solid slab of a similar bearing capability.

[11] Among the recent trend in buildings, voided slabs are extensively used as a result of the high reduction in their

self-weight up to 35%. 5 half-scale specimens were made-up. They contained 96 spherical voids distributed uniformly

throughout the slab space, 3 of them were braced with six embedded steel sheets, 3 sheets in each direction. The sheets

were orthogonally organized and intersected below the column stub. The variable of the study was the sheet thickness

(0.8 mm, 1.0 mm, and 1.2 mm). The specimens were subjected to a restrained intense load through the column up to






collapse. The check results disclosed that vital losses were recorded in the strength, stiffness, ductility, and energy

absorption of the voided slab while not with the sheets compared with the reference one.

III. FORMULATION

[1] Deflection due to Live Load: (ACI 318-11 Table 9.5 b) ∆L.L = ∆u max X L.L / (1.2 D.L + 1.6 L.L) ‹ (L/360)

Long-term Deflection: (ACI 318-11 9.5.2.5) ∆ (3D.L+ L.L) = ∆u max X (3D.L+ L.L)/ (1.2 D.L + 1.6 L.L) ‹ (L/180)

3.1 Benefits of BDS

According to representatives of technology in Brazil, several aids can be cited for BDT, such as

1. Elimination of beams - formwork economy, cheaper and quicker execution of masonry and facilities.

2. Reducing the amount of concrete - 3.5 kg of reusable plastic balls replacing 14.31kg concrete.

3. Carbon energy and emission reduction – because of the utilisation of reusable plastic, reducing the

consumption of raw materials.

4. Freedom in the projects - versatile layouts that adapt easily to curvilineal and irregular layouts.

5. Increasing gaps in either direction - slab affiliation on to the pillars with no beam through concrete in-situ.

6. Reduced own weight - 35% smaller, permitting reduction in the foundations.

7. Increased interior column strength - 50% and more than traditional structures.

IV. ANALYSIS

S. NO Name of material Property Value

1. Steel Modulus of Elasticity (E) 200000 MPa

Density (ρ) 7850 kg/m3

Poisson’s Ratio(µ) 0.3

2. Concrete Modulus of Elasticity (E) 22361MPa



3. HDPE balls Modulus of Elasticity (E) 1035 MPa



Table I: Material Properties

Figure 1: Reinforcement detail given for conventional slab






Figure 2: Four side fixed support given in slab

Figure 3: load given for conventional slab

Figure 4: Total deformation






Figure 5: Directional deformation in slab

Figure 6: Reinforcement given for voided slab

Figure 7: Four side fixed support given for voided slab






Figure 8: Load given for voided slab

Figure 9: Voids arrangement in main rod

Figure 10: Total deformation






Figure 11: Directional deformation in voided slab

V. RESULTS AND DISCUSSION

The deformations developed in the solid slab are relatively less than the bubble deck slab. The variations are shown

in table 2 whereas the stresses developed in the solid slab are relatively higher in case of solid slab. The moments

developed in XX direction (M11), in YY direction (M22), in XY direction (M12), the shear forces developed in XZ

direction (V13), in YZ direction (V23), the maximum stresses that are developed in the slab (SMAX), and the

deflections (U3).

Slab Load (KN) Deflection (mm) Weight (Kg)

Conventional slab 260 8.70 321

Voided slab 320 9.20 242

Table II: Comparison Of Conventional Slab And Voided Slab

VI. CONCLUSION

The market of construction floors in the building industry principally consists of massive concrete floors,

prefabricated filigree slab floors and hollow core slab floors. This case has not changed for more than 20 years.

However this innovative slab construction technology is proven to be more efficient than a traditional biaxial concrete

slab in a workplace floor system. The finite element models of the office slabs created for this study in ANSYS 2021

verify the prior analysis and experiments.

1. Bending stresses in the bubble deck slab are found to be 6.43% lesser than that of a solid slab.

2. Deflection of Bubble deck is 5.88% over the solid slab because of stiffness reduction due to the hollow

portion.

3. Shear resistance of bubble deck slab is 0.6 times the shear resistance of the solid slab of same thickness.

However required resistance can be achieved by providing vertical reinforcement.

4. Weight reduction is 35% compared to solid slab.

REFERENCES

[1] Y. J. Purushottam, P. Tambe, and Y. Hemantkumar, “Analytical study of solid flat slab and voided slab using

ANSYS,” Int. J. Mag. Eng. Technol. Manag. Res., vol. 3, no. 11, pp. 261–264, 2016.

[2] A. Mohan and A. Sukumaran, “Performance Analysis of Bubble Deck Slab Using Elliptical Balls,” Int. J. Eng.

Res. Technol., vol. 6, no. 06, pp. 2–5, 2018.

[3] S. K. Sabale, S. R. Sule, P. D. Utkhede, O. S. Phalke, and N. K. Gupta, “Experimental Study on Bubble Deck

Flat Slab,” vol. 8, no. 06, pp. 848–850, 2019.






[4] S. Konuri and T. V. S. Varalakshmi, “Review on bubble deck slabs technology and their applications,” Int. J.

Sci. Technol. Res., vol. 8, no. 10, pp. 427–432, 2019.

[5] P. Prabhu Teja, P. Vijay Kumar, S. Anusha, C. H. Mounika, and P. Saha, “Structural behavior of bubble deck

slab,” IEEE-International Conf. Adv. Eng. Sci. Manag. ICAESM-2012, no. March, pp. 383–388, 2012.

[6] M. Singh and B. Saini, “Analytical and experimental study of voided slab,” Lect. Notes Civ. Eng., vol. 21

LNCE, no. 08, pp. 438–448, 2019, doi: 10.1007/978-3-030-02707-0_50.

[7] S. Ali and M. Kumar, “Analytical Study of Conventional Slab and Bubble Deck Slab Under Various Support

and Loading Conditions Using Ansys Workbench 14 . 0,” Int. Res. J. Eng. Technol., vol. 4, no. 5, pp. 1467–

1472, 2017, [Online]. Available: https://www.irjet.net/archives/V4/i5/IRJET-V4I5288.pdf.

[8] Version of Record: https://www.sciencedirect.com/science/article/pii/S235201241930058X. 2019.

[9] I. Journal and D. In, “Comparative Study of Experimentation on Voided Slab,” no. 5, pp. 382–383.

[10] S. Kitture, N. Kabra, and H. A. | J. B. | S. Kate, “Experimental Study on Voided Biaxial Slab and its

Application,” Int. J. Trend Sci. Res. Dev., vol. Volume-2, no. Issue-1, pp. 1224–1228, 2017, doi:

10.31142/ijtsrd7153.

[11] T. S. Al-Gasham, J. M. Mhalhal, and H. A. Jabir, “Improving punching behavior of interior voided slab-

column connections using steel sheets,” Eng. Struct., vol. 199, no. May, p. 109614, 2019, doi:

10.1016/j.engstruct.2019.109614.

Analytical Study on Behaviour of Different Shapes In Voided ...

Documents

Transcript of Analytical Study on Behaviour of Different Shapes In Voided ...