The bubble deck slab is a method of construction that is known for its diverse applications. It replaces concrete in axial points with balls or similar materials and strengthens the building. It is a unique method and decreases the structural weight of concrete slabs by fifty per cent. Read on to learn about what it is, its types and applications.
What Is a Bubble Deck Slab?
A bubble deck slab utilises steel and hollow plastic balls (known as bubbles) to decrease the concrete slab weight in a building. The centre part of the slab that is made of concrete is replaced by balls, thus reducing the weight of the slab by fifty per cent.
The bubble deck slab is a type of slab that has an upper hand in terms of rapid construction, reduced environmental impact, sustainability, and decreased cost. This technique is used in different types of building construction, including hospitals, schools, offices, and schools.
Types of Bubble Deck Slabs
There are different types of bubble deck slabs that are used in the construction process. Some of them are explained below:
Semi-Precast Slabs
It is a combination of unconstructed and constructed elements. The precast concrete layer has a thickness of 60 mm which is brought to site, with the bubbles, and reinforcement steel bars being unattached.
Above the precast layer, the bubble is supported by a temporary stand and further supported by interconnected steel. The bubbles and steel are then locked into place and the remaining concrete is poured. This method is useful when the design needs to be customised on site.
Reinforcement Modules
These modules contain a pre-assembled steel mesh and bubbles organised in place. They are placed after bringing them to the site and are connected with extra reinforcement. The concrete is then poured.
They generally follow a traditional style of construction in which standard modules or layouts of bubbles and reinforcement are required. The bubble deck can be utilised in tight construction spaces. To increase the storage efficiency, they can also be stacked upon one another.
Finished Slabs
The finished planks are modules that are completely shop-fabricated and include plastic spheres, mesh reinforcement, and concrete. The entire process happens in a different place, i.e, in factory settings and is delivered to the construction site as a fully formed slab. This model works better for shorter spans and restricted construction schedules.
Advantages of Bubble Deck Slabs
The applications and utilisation of bubble deck slabs are vast, and some of the applications are listed below:
Reduction in Concrete
Bubble deck slabs replace the axial concrete, hence reducing the concrete weight and making the structure lighter by thirty to fifty per cent. The eliminated volume is used by HDPE bubbles, thus decreasing the dead load of the structure.
Increased Strength
The mixture of concrete and high-density polyethene (HDPE) spheres will decrease the slab weight. This increases strength, decreases deflections, and leverages flexural strength, thus providing stiffness, shear force, and larger spans with decreased design loads to spread the weight through columns.
Architectural Design
Bubble deck slabs increase the architectural freedom of designers and can also be utilised in non-rectilinear plan forms. This allows enhancement of aesthetic values without restricting creative design.
Reduced Cost Due to the reduced amount of concrete and lower transportation charges (due to lightweight), bubble deck slabs are generally cost-effective.
Materials and Specifications Used in Bubble Deck Slab
Bubble deck slab is an innovative method that includes hollow plastic spheres within concrete slabs to decrease the weight and material. Its common components are listed below:
Concrete:
The concrete grade that is used in bubble deck slabs is M20 or higher. The maximum aggregate size should be 20 mm. The type of concrete used for the slab can also be used in joint filling.
Reinforcement Steel:
The reinforcement steel that is used for the bubble deck slab is Fe-500 or higher grades than this. They are placed or arranged as two meshes to support vertical or lateral loads.
Plastic Spheres:
Polypropylene or high-density polyethene materials (HDPE) are used. The size and diameter range from 180 to 380 mm.
All these structural materials work as a group to create a strong yet lightweight structure that can reduce the structural dead load.
Installation of Bubble Deck Slab
The installation process of bubble deck slabs is listed below:
- The panels reach the site and are lifted to the specific floor with the help of specialised equipment.
- Once the panels reach the specific floor, they are laid perpendicular, that is, ninety degrees in angle, on the temporary prop runners.
- After ball placement, the concrete is poured into the gaps in the balls.
- Right after pouring the cement, the concrete is cleaned using high-pressure water to remove dust and keep it tidy.
- If the connections are not uniform, then add fluids or a thin silicon layer to adjust it.
The installation process of a bubble deck requires specific alterations and processes according to the usage and project needs.
Conclusion
Bubble deck slab is a versatile engineering method that helps to decrease the weight of the building. This is possible by replacing concrete with plastic balls. This plays a crucial role in construction and provides strength to the building. These bubble deck slabs have several advantages compared to conventional methods such as energy efficiency, reduced cost of transportation, fireproof, explosion safety, and earthquake safety. It is important to understand the structure and installation method to use them in your building.
FAQs
A bubble deck slab is a patented integrated method that links steel, air, and concrete in a two-way structural slab. Hollow plastic balls are used to reduce concrete and are held using reinforced steel.
The slab depth ranges from 200-500 mm. The diameter of the bubbles depends on the depth of the slab and can range from 180mm, 270mm, 360mm, 315mm to 225mm.
The critical reason for the minimum usage of bubble deck slabs in India is their high initial cost. Compared to conventional concrete, it is costly and is often not used in India due to this reason.