Design And Advantages Of Bubble Deck Slab System In Construction

Advantages of Bubble Deck Slab System

Discuss about the Punching Shear Behaviour Of the Bubbled Reinforced.

There are several stages for the structural design in the construction project. In the first step the selection of the material and the method of implementation is done. In the second phase the engineering calculations, surveying and sketching is done. Review of the result and getting approved by the authorities is done on the third stage(Teja et al., 2012). Compilation of these stages can be done properly if the method and design of the structure is relevant. In case of structural design checking of some element is needed before sending it for approval. These elements include the column, the material, different typesof beams and slabs and their material. In this case the common material is timber,steel and concrete. The weights of the slabs are higher than any other elements of the building as the slabs are made of concrete. Therefore the new design of the slab is focused on the invention of the light weight slab which will be sustainable in use and will deliver the same working performance.

The solution was invented in the Europe at 1990 which allowed the weight of the concrete slab to reduce its weight and enlarge the reinforce(Midkiff, 2013).. Presently this system has become popular and is accepted by the world. This method is known as Bubble Deck slab system where plastic void slabs are used to carry the load capacity, making the slab lighter in weight compared to the conventional slabs. This weight reducing technique of the slabs have certain advantages and is appreciated by the experts in the construction engineering (Midkiff, 2013).

In Bubble Deck slab system the concrete is taken off from the non-critical zone and the removed concrete is replaced by the plastic bubbles, maintaining the same load capacity like the solid concrete slab. The use of this kind of slabs are happening since 1990s and their applications were made to create hollow core slab, light blocks(Lai, 2010).

This report discusses the design of theBubble Deck from the different perspective. The viewpoints are based on structural performance, sustainability and maintain the cost effectiveness. The comparison will be done between the new plastic slab and the conventional solid slab on the basis of these viewpoints.

There are many articles which describes the advantages of using Bubble Deck slabs in then construction (Hashemi et al., 2017). Therefore, this literature review will discuss the usefulness of using the Bubble Deck technique in the construction on the basis of the structural performance of the plastic bubbles used in the slab, sustainability, time taken to complete the construction and the cost.

Structural Performance

The production of the concrete contributes 5%-10% of the CO₂ which is produced by human activities. In order to reduce the emission of the greenhouse gas the decreasing practice of producing concrete can be proposed. The inventors of the Bubble Deck has proved the ecological advantage of using this new slab system(Fidjestol and Thorstensen, 2012). It has more than 50% beneficial than the convenient slab system. The other sustainable factors that bubble deck contributes are the usage of primary raw materials and less quantity of concrete granule and the use of recycled plastic bubbles which do not stick on the concrete slab(BubbleDeckInternational, 2008).There are many attempts has been made to compare this new kind of slab system with another kind of conventional solid concrete slabs from the ecological aspects. In this case it has been found out that increasing the acceptance from the ecological aspects depends on the four things(Arets, 2001):

• Searching the best material for the building span.
• Searching for the optimal contractual combination like concrete material,cost effectiveness and reinforcement of the steel.
• Use of sustainable material for the construction.
• Modification and improvement goals and the objectives for the constructions.

Therefore, it can be said that the use of bubble deck in the construction project is sustainable from different ways.

The significant amount of concrete has been removed from the slab through the use of biaxial slab since 2013(Arslan&Arslan, 2017). This modification does not affect the effectiveness of the biaxial slab. In the conventional slab the concrete depth is compressed in a certain portion which implies that the concrete between the surfacesthe bubbles plays the important role in maintaining the working principal(Midkiff, 2013). This make the effectiveness of the bubble deck system similar with the conventional concrete slab system.

There is no significant difference between the working principal of bubble deck and the solid slab system(BubbleDeckInternational, 2008). The only difference is the shell or the outer surface in the solid slab which works as compression zone and in the stress diagram works as steel. The value of the bending moments are same in both the slabs. In case of flexibility, both the slab system is responding the same as per the research by the experts in India(Teja et al., 2012).

The comparison of bending moments between buddle deck and the solid slab system:

Table 1 (SD and BBD-Bending Moment)(Teja et al., 2012)

It is needed to be mentioned that shear capacity in case of bubble deck slab is factored by 0.6of a shear capacity of a solid concrete slab. The result has been achieved through the practical researches conducted by Bubble Deck International Company in the United Kingdom since 2008, which proves that the shear stress is dependent on the concrete mass. The results of these experiments prove that the range of shear capacity is in the range of (72%-91%) of shear capacity of the solid slab(BubbleDeckInternational, 2008).

Sustainability

The strength of concrete is needed to be checked before the experiment of the punching share. The checking of strength of concrete is done for checking the strength and the need of extra reinforcement, if it is not then the amount of steel reinforcement is needed to be checked.

• In the first step the checking of the reaction of the column is done by finding the value of V The value of V_t is modified for taking account of transfer of the moment.

The column is the internal column in this research model so, here. The shear is calculated by using the following equation

• The second step includes finding the maximum shear

• At 1.5d from the column face the shear stress is located. In the third step critical section’s shear stress is checked

 (a and b= rectangular column’s plain dimension,

=perimeter multiplier=1.5 if

: use of link reinforcement

: Shear reinforcement need not to be used.)

Cost and timeframe of construction:

One of the most important factor of the project management is to finish the project in time and in a cost effective manner (Yang et al.,2016). The report published in the 2014 shows that the use of bubble deck slab system in the construction can save the time of construction by 30%. Regardless the size and complexity of the project(Churakov, 2014).

Another report stated that the use of bubble deck slab can reduce the cost of the project by 2.5% to 10% of overall cost of the construction. According to some Iraqi researchers the cost of the raw materials can also be saved using this bubble deck technique in the construction (Hirapara& Patel, 2017). The bubble deck is used to make slabs which can be made of concrete, sand and gravel, the reduction of the cost can be up to 28% and this leads to a significant reduction in the cost and also shorten the time span of compilation of the project(Ahmed, 2009).

1. Material:

Voided biaxial concrete slab is composed of HDPE bubbles, concrete and the two layering of the steel.

The concrete used in Bubble deck slab is made of normal Portland cement mixed with water, sand and gravels. The maximum size to aggregate is 20mm. In the lab tests it has been proved that concrete compressive strength which is achieved in the bubble deck is same as the solid slabs. In case of semi pro cast technique of making bubble deck slabs the concrete is poured in the casting yard. The side shutters, the steel mesh and the bubbles are needed to be checked before casting concrete for the panel. To remove the air voids from the mixture the needle vibrator is used(Sarkisian et al., 2013).

Steel reinforcement for the Bubble deck is shown in the below table:

Table 2 (Reinforcement Specification of the Steel) (Lai, 2010)

Cost and Timeframe of Construction

In the plastic sphere the steel mesh is positioned for only once. Using diagonal bars and steel reinforcement are the best method for looking up for bubbles in the place(Lai, 2010.

HDPE bubbles are made from recycled high density polythene which works as a hallow sphere. The diameter of the plastic bubbles can be in various sizes, dependent on the size of the constructions. The table below shows the characteristics of bubble deck size:

The bubbles in the Bubble Deck slabs is recyclable and this special property of the slabs has made it sustainable for the green cities.

The main thing after discussing all the elements of the bubble deck, is to check the sustainability, structural performance and economic aspects of using the bubble deck as a sample (Ali & Kumar,2017). The material required is included below table and comparison is made with the solid concrete slab.

According to the literature review in this review and the result of this report, it can be said that the bubble deck slabs behave like solid concrete slab in the construction project (Shetkar&Hanche, 2015). Though there are some differences between the conventional concrete slabs and the bubble deck slabs in terms of structural performances such as loading capacity and the shear capacity. The bubbldedeck slab is said to be sustainable as fewer materials like concrete are needed in this system, this leads to the sustainability in the ecology like reducing the emission of CO₂(Teja et al., 2012)_. The bubble deck system is also cost effective and it reduces the time of implementation which is beneficial for the project.

It can be said from the discussion that the concrete quantity in the bibbledeck slabs id much lesser than the conventional solid concrete slabs(Teja et al., 2012). The percentage of concrete and the steel is 25% and 70% less respectively in the bubble deckslabs, compared with the conventional solid slabs (Jamal & Jolly, 2017). Merging the material cost with the labor cost and the other expenses, the cost in the bubble deck system is 60% less than the use of other types of slabs.In the bubble deck slabs punching shear is lower than the flat concrete slab because the flat slab depends on the sustainability of the depth of the concrete(Teja et al., 2012). The high density polythene used in the bubble deck sab promotes the green as the bubbles can be made from plastics wastes...

The bubble deck slabs are lighter than the solid concrete slabs. The lighter weight leads to the advancement of the construction designs (Subramanian, Bhuvaneshwari&Jabez, 2017). In case of using bubble deck slabs in the building, the cost of the material and the number of workers required for the construction are reduced. The time taken to complete the construction using Bubble Deck is also comparatively faster than solid slabs(Teja et al., 2012). All these positive factors using the bubble deck affect positively in the management technique. On the other hand, using the bubble deck technique needs more skilled engineer labors and technicians as there is the importance of controlling the location of the bubble column zone and steel reinforcement (Fatma&Chandrakar, 2018). In case of using the bubble deck technique the international quality standards such as ISO, ACI, AS, ASTM and BS must be followed (John & Varghese, 2015). In this context it can be mentioned that the Bubble Deck International Company provides excel sheets mentioning load and quantities of the material for controlling the project. The discussion indicates that the use of bubble deck slabs in the construction will be helpful for the green cities in various parts of the world and it will be ecologically sustainable(BubbleDeckInternational, 2014).

Conclusions:

It can be concluded from the discussion, methodology and the literature review that it is more convenient to use the bubble deck slabs in the constructions for maintaining the sustainability and for the future green cities in different parts of the world. The report has found that structural properties of the bubble deck slab and the flat concrete slab is same. The flat slab has shear capacity more than 20% than the voided slab. To dissolve this problem the use of carbon fiber sheet is done on the place of sheer stress. In case of sustainability the bubble deck slabs reduces the emission of the CO₂ as it requires less concrete and other raw material, production of which causes carbon emission.

Bubble deck has also reduced the cost of constructions as it needs less raw materials and the use of bubble deck reduces the time of the construction, which indirectly reduces the labor cost. It can be concluded from the above discussion that the use of bubble deck will help to build the green cities maintaining the sustainability.

• AHMED, Q. W. 2009. PUNCHING SHEAR BEHAVIOR OF BUBBLED REINFORCED CONCRETE SLABS.
• ARETS, M. 2001. Milieuvergelijkingen van draagconstructies ('Environmental comparison of bearing structures'). Master thesis, Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Building Engineering, The Netherlands.
• BUBBLEDECKINTERNATIONAL 2008. BubbleDeck Design Guide. 1st.
• BUBBLEDECKINTERNATIONAL 2014. Bubbledeck Span Guide. 4.
• CHURAKOV, A. 2014. Biaxial hollow slab with innovative types of voids. Construction of Unique Buildings & Structures, 6, 70-88.
• FIDJESTOL, P. & THORSTENSEN, R. T. 2012. IMPROVING SUSTAINABILITY OF CONCRETE CONSTRUCTION–THE ROLE OF HIGH STRENGTH AND HIGH PERFORMANCE CONCRETE.
• HARDING, P. 2004. BubbleDeck–Advanced structure engineering. BubbleDeck article, 4-7.
• KYNGCONSULTING 2008. BubbleDeck Design Guide for compliance with BCA using AS3600 and EC2. BubbleDeck®.
• LAI, T. 2010. Structural behavior of BubbleDeck® slabs and their application to lightweight bridge decks. Massachusetts Institute of Technology.
• MIDKIFF, C. J. 2013. Plastic voided slab systems: applications and design. Kansas State University.
• SARKISIAN, M., LONG, E., SHOOK, D. & HU, L. Innovation in Sustainable Engineering Design: Sustainable Form-Inclusion System (SFIS). Structures Congress 2013: Bridging Your Passion with Your Profession, 2013. ASCE, 2745-2754.
• TEJA, P. P., KUMAR, P. V., ANUSHA, S., MOUNIKA, C. & SAHA, P. Structural behavior of bubble deck slab. Advances in Engineering, Science and Management (ICAESM), 2012 International Conference on, 2012. IEEE, 383-388.
• Shetkar, A., & Hanche, N. (2015). An experimental study on BubbleDeck slab system with elliptical balls. Proceeding of NCRIET-2015 and Indian J. Sci, 12(1), 021-027.
• Fatma, N., & Chandrakar, V. (2018). To study Comparison between Conventional Slab and Bubble Deck Slab. Technology, 5(1).
• Hirapara, A., & Patel, A. P. D. (2017). ANALYSIS OF LIGHT WEIGHT FORMERS IN CONCRETE SLABS USING VOIDS. Development, 4(4).
• Jamal, J., & Jolly, J. (2017). A study on structural behaviour of bubble deck slab using spherical and elliptical balls.
• John, R., & Varghese, J. (2015). A study on behavior of bubble deck slab using ansys. SET–International Journal of Innovative Science, Engineering and Technology, 2(11).
• Ali, S., & Kumar, M. (2017). ANALYTICAL STUDY OF CONVENTIONAL SLAB AND BUBBLE DECK SLAB UNDER VARIOUS SUPPORT AND LOADING CONDITIONS USING ANSYS WORKBENCH 14.0.
• Subramanian, K., Bhuvaneshwari, P., & Jabez, N. A. (2017). Flexural Behaviour of Biaxial Slabs Voided with Spherical HDPP Void Formers. Iranian Journal of Science and Technology, Transactions of Civil Engineering, 41(4), 373-381.
• Hashemi, S. S., Sadeghi, K., Vaghefi, M., & Siadat, S. A. (2017). Evaluation of ductility of RC structures constructed with bubble deck system. International Journal of Civil Engineering, 1-14.
• Yang, K. H., Kwak, M. K., Yun, S. H., & Park, S. T. (2016, February). Flexural behavior of hollow deck-plate slabs with simplified construction procedure. In Advanced Materials and Structural Engineering: Proceedings of the International Conference on Advanced Materials and Engineering Structural Technology (ICAMEST 2015), April 25-26, 2015, Qingdao, China(p. 399). CRC Press.
• Arslan, M. H., & Arslan, H. D. (2017, August). New Trends on Green Buildings: Investigation of the Feasibility of Using Plastic Members in RC Buildings with SWs. In IOP Conference Series: Earth and Environmental Science(Vol. 83, No. 1, p. 012022). IOP Publishing.