The composite slab is made of a combination of concrete and profiled steel decking. For these two materials to work together a good bond between them is required they must not slip against each other this bond is created using shear studs.
What is Composite Slab?
In this type of slab, a concrete floor with permanent metal formwork at the soffit is attached to a steel beam by means of welded shear studs. Steel beams are generally located every two and a half meters apart so no propping underneath is required.
In the figure, the concrete and the steelwork are together with a standard US beam underneath and a slab on top. These two materials can resist loading applied to the floor.
The simple definition of the composite slab:
Profiled Steel decking and the in-situ reinforced concrete at the top combined to create a composite slab.
Types of the composite slab:
Generally, there are three types of composite slabs.
- Re-entrant and trapezoidal decking.
- Re-entrant decking.
- Trapezoidal decking.
Formula for calculating concrete slab:
Volume of concrete=L x W x H
- L= Length of slab
- W= Breath of slab
- H= Thickness of slab
Calculate the volume of the slab Example:
Floor Slab layout plan
- L= 11.5
Volume of concrete in slab= L x B x H
= 11.5 X 7.92 X O.15
= 13.662 CUM
Find the volume of the slab in the table.
|Calculation of volume of concrete in roof slab
|Roof slab Concrete
What are the composite slab reinforcement details?
In the figure, you can watch the reinforcement detail as also discussed below.
- Metal Deck sheet: first of all install the metal decking to increase the roof’s tensile strength and ductility. Known as bottom reinforcement.
- Shear Stud: studs connect the metal deck to ensure effective composite action.
- Reinforcements: Used to reduce the chance of cracking and improve the resilience of the composite slab to moments of bending, which includes mesh or steel bars.
- Cement concrete: Over the reinforcement, a protective coating of concrete is placed to prevent corrosion and ensure longevity.
How to design the composite slabs?
Designing the composite slab is simple. First, use the steel decking at the bottom and use the studs to connect the decking. After connecting the decking place, the reinforcement of the welded wire mesh. At last place the concrete slab on the top. To know the details, watch the tutorial.
How to calculate the load of the composite slabs?
The combination of metal decking and the concrete slab is able to resist loading applied to the floor. If this flour is loaded it will deflect like this with the bottom going into tension and the top into compression.
Concrete is used at the top because it is strong in compression and steel is used at the bottom because it is good intention as a result the floor has a good load-bearing capacity. With this design, it is possible to design a more efficient structure.
Types of construction loads:
During Concreting: In order to prevent local damages and manage concrete discharge, construction loads such as personnel, concrete, formwork, equipment, and impact forces must be carefully taken into account.
After Concreting: It is necessary to consult the structural designer for heavy loads, including equipment, fire protection bags, and debris skips, and to give additional weight exceeding 1.5 KN/m² due to thought.
What are the advantages and disadvantages of the composite slab?
The usage of the composite slab has advantages but also it has several disadvantages. However, it is worth remembering that the disadvantages depend on the projects. Keep reading to know.
|Combination of the two materials can create a stronger structure.
|More expensive due to the use of highly raw materials.
|The weight is lighter than the rational materials.
|Repairing the composite slab is difficult.
|It can be molded into a variety of shapes.
|It is time-consuming and complex to design.
|In applications where the structure will be exposed to hostile environments, specific composite materials can be useful in avoiding corrosion.
|Needed skilled workers for proper installation.
|Offers versatility and flexibility in construction.
|May Not be durable.
What are the Applications of the Composite slab?
Due to their versatility, the composite slab is used highly depending on the design and material.
- Use in commercial and residential buildings.
- Commonly used in multistory buildings as a floor system.
- Flexible in construction and adaptable to various architectural layouts and designs.
- Favorable in constructions where fire safety is an essential factor in the design process.
Frequently Asked Questions:
Q. What is the thickness of the composite slab?
Typically, the thickness of the composite slab is between 3.5” to 7.5”.
Q. How thick are composite deck tiles?
Interlocking Composite Decking Tiles:
- Tile Length: 605mm
- Tile Width: 305mm
- Tile Thickness: 25mm
- Tiles per box: 5.
Q. What is the purpose of composite construction?
Nowadays, composite construction is widely utilized because it enhances the structural performance of steelwork.
The composite slab is usable due to its versatility. The positive aspects of composites are numerous. Strength, lightweight, corrosion resistance, adaptability in design, and durability are important ones. The composite slab has longer-term advantages than short-term disadvantages, even with careful design and expert work necessary.