Introduction of Slab Construction
The concrete slab is a horizontal surface of a residential building or commercial building, factory, flat, etc.
The thickness of the steel-reinforced slab is near about 100-500mm. These types of slabs are used for ceiling and floor purposes. Less thin slabs are used to construct exterior paving.
Sometimes in a domestic or commercial building, a thick concrete slab is constructed directly into the subsoil. These types of slabs are generally classified as ground-bearing slabs.
What Is Slab Construction?
Slab construction has some following processes. Those are-
- Prepare Formwork
- Preparation of Slab Bedding
- Reinforcement Instalment
- Pour, Compact, and Concrete Finish
- Curing of Concrete & Remove the Formwork
Formwork is the frame for the concrete slab, and it’s necessary to check the measurements according to the building plan to set up the formwork correctly.
Formwork needs correct placement to withstand the considerable load of concrete, leakage, and other necessary requirements. The height of the formwork must be at the top of the concrete slab to finish the surface in line with the top of the formwork.
Preparation of Slab Bedding
- It’s very important to set out the slab bedding properly because the whole slab rests upon it in the primary condition.
- The road surface is suitable for the base of the slab bedding.
Reinforcement prevents the slab from cracking, buckling, and caving. It totally carries the tensile strength of the structure.
Pour, Compact, and Concrete Finish
This is good to use ready-mix concrete, but all the time, we can’t use ready-mix concrete. After the concrete is poured, it needs to vibration for compaction.
Curing of Concrete & Remove the Formwork
The curing of the concrete slab with water is near about seven days. If we use spray curing, then we must spray two times a day.
After 24 hours of concrete being poured the formwork can be removed totally, but we avoid heavy load to seven days.
Also Read: What is Soft Flooring | Types of Soft Flooring | Advantages & Disadvantages of Soft Flooring | Use of Soft Flooring | Maintenance of Soft Flooring
Types of Slab Design
Types of slab design are available-
- Ground Bearing Slab
- Suspended Slab
- Unreinforced Slab
- Mud Slab
- One Way Slab
- Two Way Slab
Ground Bearing Slab
Ground-bearing slabs are mainly used in residential or commercial buildings for floor purposes. These types of slabs are also known as “on-ground” or “slab-on-ground“.
For this type of slab is necessary to construct according to the condition of the soil because some dynamic grounds create cracking. The ground-bearing slab needs proper curing to gain adequate strength.
When the corrugated slab is designed, the concrete is poured into a steel tray. This improves the strength of the slab and prevents it to bend from its own weight.
In the case of the ribbed slab, it gains more strength in one direction. This is achieved with concrete beams bearing load between piers or columns, and thinner, integral ribs in the perpendicular direction.
The waffle slab provides adequate strength in both directions using a matrix segment beneath the slab.
The unreinforced slab is also known as a plain slab. Here reinforcement is not used; that’s why the entire load of the slab is carried by concrete.
The load must be within the limit of the flexural strength of concrete to prevent cracks.
Mud slabs are thinner than suspended slabs or ground-bearing slabs; it’s also known as rat slabs. The mud slab does not contain reinforcement that’s why it is economical and easy to construct.
Sometimes coarse aggregate is used in place of mud.
One Way Slab
The one-way slab has moment-resisting reinforcement only in a shorter direction. In this type of slab, the longer direction will be negligible. A one-way reinforced slab may be stronger than a two-way non-reinforced slab because it depends on the type of load.
To construct a one-way slab one factor is affecting, those-
- Load Calculation
- Bending moment Calculation
- The effective depth of flexure
- Main Steel
- Effective Steel
- Deflection Checking
- Development length Checking
- Shear Checking
Two Way Slab
The two-way slab has moment-resisting reinforcement in both directions, i.e. longer & shorter directions. These types of slabs can carry a heavy load, vibration, etc.
To construct a two-way slab, the main thing is to note that lx: ly< 2, where lx is the shorter span, and ly is the longer span.
What Is Floor Slab?
The floor slab is acting as a floor constructed of concrete, which is one of the most important building components. Floor slabs formed a floor of a basement of a building, or act as a roof.
This is constructed in the site by steel reinforcement or set out readymade prefabricated materials. Those floors which are made with timber or other materials is not referred to as floor slab.
Sometimes floor slabs are supported with beams, and then it’s constructed on the roof of a building then it’s termed roof slabs.
Also Read: First Angle Projection & Third Angle Projection Symbol (Orthographic Projection)
Types of Floor Slab
The first type is slab is a flat concrete slab that is generally 100mm thick. It’s supported by two sides or more sides of the concrete beam or steel beam.
The second type of slab is also a flat concrete slab supported with a steel ribbed. The steel provides temporary and permanent support for concrete, a steel ceiling is observed from the downside of the slab.
A waffle slab is the third type of slab. In this type, the concrete is poured over a series of plastic; it results in an egg crate style. The thickness of this type of slab is 500mm or more.
An in situ concrete slabs over a beam and block with steel reinforcement is the other type. The final type of floor slab is a pre-cast concrete slab.
Concrete Slabs Thickness
The minimum thickness of the concrete slab totally depends on the type of slab-like way or two-way, the span of the slab, and the design load.
The minimum thickness of the concrete slab is near about 4 inches but not less than that according to standard code, but the slab thickness entirely depends on the design load and the span of the slab.
On the other hand, concrete mix grade is also very important to the thickness of the slab. Basically, the actual thickness of the slab is to find out the design of the slab and by the Bar Bending Schedule (BBS).
Prefabricated Concrete Slabs
Prefabricated concrete slabs are constructed in a factory and transported to the site, and they are ready to use. This slab is made through a pre-stressed or post-stressed procedure.
The precast slab has more advantages because it is constructed with a more controlled environment than a regular slab.
The slabs are made by pouring concrete into a mold under highly supervised conditions. Concrete precast slabs are also used in industrial and institutional buildings.
Benefits of Precast Slab
- Concrete slabs offer a wide variety of benefits, from initial design to long-standing structure and design.
- Precast concrete slabs are made in a controlled environment that’s why concrete which is used to construct is extremely good; for this reason, cracking is not generally developed.
- Temperature and weather effects don’t impact this type of slab.
- The precast concrete slab is enough strong and durable, so using this instead of a concrete slab is stronger and more stable.
- This slab resists both tensile and compressive strength.
- This slab is good in thermal resistance.
Also Read: Piling for Foundation | Use of Pile Foundation | Characteristics of Pile Foundation
Concrete Floor Slab
The floor slab is a reinforced concrete slab whose thickness is near about 5-6cm. Sometimes it can be 7 cm, depending on the cover of the reinforcement. This is also called a plate slab.
Sometimes the floor slab is precast, and it’s constructed in a highly controlled environment, so it resists flexural tension. The thickness of this precast slab is 12cm or 30cm. It totally depends on the span and loading of the slab.
What Is Slab?
A concrete slab is a common structural element of modern buildings, consisting of a flat, horizontal surface made of cast concrete.
Steel-reinforced slabs, typically between 100 and 500 mm thick, are most often used to construct floors and ceilings, while thinner mud slabs may be used for exterior paving.
Slab Construction Definition
A molded layer of plain or reinforced concrete, flat, horizontal (or nearly so), usually of uniform but sometimes of variable thickness, and supported by beams, columns, walls, other frameworks, or on the ground
The depth of the slab depends on the bending moment and deflection criterion.
For obtaining a modification factor, the percentage of steel for the slab can be assumed from 0.2 to 0.5%.
The effective depth d of two-way slabs can also be assumed using cl. 24.1,IS 456 provided short span is <3.5m and loading class is <3.5KN/m.
How to Build a Concrete Slab?
Step 1: Build the Concrete Slab Frame.
Step 2: Dig Out the Area.
Step 3: Add the Gravel.
Step 4: Mix the Concrete.
Step 5: Pour the Concrete Pad.
Step 6: Screed the Concrete.
Step 7: Finish the Concrete Pad.
What Is Floor Slab?
A floor slab (also called plate slab or filigree slab) is a reinforced concrete slab with a minimum thickness of 5–6 cm.
The floor slab is made into a solid and monolithic reinforced concrete floor by using mix-in-situ concrete that is poured at the construction site.
Types of Floor Slabs
- One Way Slab
- Joist Slab (Ribbed)
- Two Way Slabs
- Flat Slabs
- Flat Plates
- Waffle Slabs
- Hollow Core Slab
- Hardy Slab
- Bubble Deck Slab
- Composite Slabs
- Precast Slabs
Concrete Slabs Thickness
Standard concrete floor slab thickness in residential construction is 4 inches. 5 to 6 inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. To prepare the base, cut the ground level to the proper depth to allow for the slab thickness.
Minimum Concrete Thickness
The minimum recommended thickness is 25 to 50 mm (1 to 2 in.) for a fully bonded concrete overlay placed on a base slab that is practically free of cracks and in which the concrete is sound, clean, and of good quality. The use of welded wire fabric reinforcement is usually not warranted under these conditions.
Prefabricated Concrete Slabs
Precast concrete slabs can be a helpful addition to any construction project. Precast concrete has an advantage over traditionally made slabs because it is poured in a controlled environment. The slabs are made by pouring standard concrete into a mold under highly supervised conditions.
A slab foundation is made of concrete that is typically 4″ to 6″ thick in the center. The concrete slab is often placed on a layer of sand for drainage or to act as a cushion. Houses built on a slab lack crawlspaces, and there is no space under the floor.
Flat Slab Construction
The flat slab construction is a reinforced concrete slab supported by the concrete columns directly without the support of the beams. So, we can say that a flat slab is a one-sided or two-sided system with a sheer load targeting the square slab or supporting columns.
30×30 Metal Building with Slab Cost
Using an average cost of $8 per square feet gives an approximate cost of $7,200.
Concrete Slab Construction
Concrete blocks are placed together to create a slab in a technique known as hard slab. Once these blocks are stacked in place, a formwork is arranged around it and reinforcement is placed in between blocks. Concrete is then poured around the blocks. This technique is most often used in hot climates.
Slab Construction Cost
A concrete slab costs between $4.34 and $7.73 per square foot, with an average cost of $6.60 per square foot. The national average cost of a concrete slab is $6.60 per square foot for materials and labor. Most homeowners can expect to pay between $4.34 and $7.73 per square foot for concrete installation.
Pt Slab Construction
Post-tensioned (PT) slabs are typically flat slabs, band beam and slabs or ribbed slabs. PT slabs offer the thinnest slab type, as concrete is worked to its strengths, mostly being kept in compression. Longer spans can be achieved due to prestress, which can also be used to counteract deflections.
Slab Construction Ceramics
The slab building technique starts with smooth slabs of clay that are formed around moulds or shaped and cut by hand. The slabs are then layered. This technique is used to make more angular shapes that can’t be created on a wheel.
Slab Construction Clay
The slab building technique involves rolling out clay to an even thickness – usually 1 cm – then cutting shapes, folding, bending, manipulating and joining together to form a finished object. Slab objects are left to dry EVENLY before bisque firing for at least 7 days – turning regularly.
Concrete Slab Construction Methods
On-site concrete slabs are built on the building site using formwork – a type of boxing into which the wet concrete is poured. If the slab is to be reinforced, the rebars, or metal bars, are positioned within the formwork before the concrete is poured in.
What Type of Gravel Under Concrete Slab?
Most concrete contractors want a mix of coarse and fine aggregate to create a compactable base that is going to be safe for settlement and drainage. Crusher run (a mix of crushed stone and stone dust) and #57 coarse aggregate are two of the best base materials for concrete slabs.
What Are the 3 Types of Slab Foundations?
3 Types of Concrete Foundations – Slab on Grade, T-Shaped, Frost Protected – Concrete Network.
What Is Slab Construction in Ceramics?
Slab Construction – A construction technique in which clay is rolled into thin sheets and manipulated into shapes. Slip – Suspension of clay in water, used as a “glue” or for decorating. Wedging – The process by which air pockets are forced out of the clay and the clay is mixed.
Function of Slab
To provide a flat surface. To act as sound, heat and fire insulator. It provides a covering shelter or working flat surface in buildings. Its primary function is to transfer the load by bending in one or two directions.
Types of Slabs in Construction
- One-Way Flat Slab.
- Two-Way Flat Slab.
- Kitchen Slab.
- Sun Shade Slab.
- Sunken Slab.
- Cable Suspension Slab
- Pre-Tension Slab.
Difference Between Slab and Beam
The main difference between flat slab & conventional slab-beam system is that the one is directly supported on the column while another system has a beam for support. The load is transferred directly from slab to column in the flat slab.
Materials Used in Slab Construction
Slabs are most commonly made of concrete because of its mass and stiffness which can be used to reduce the floor’s deflections and vibrations, and achieve the necessary fire protection and thermal storage.
How Many Types of Slab?
There are 16 different types of concrete slabs used in construction projects. Flat slabs are some of the most common types used in commercial construction projects. Consider a flat slab for a parking lot or a floor with or without drop columns.
What Is Floor Slab?
1 : a paving slab. 2 : the slab forming the floor of a usually reinforced-concrete structure.
What to Put on Concrete Floor?
To sum it up – carpet, engineered hardwood, laminate, or vinyl flooring are all great options to install over a concrete substrate that can last for years when properly maintained.
What Is Ground Floor Slab?
Ground-bearing slabs, also known as “on-ground” or “slab-on-grade”, are commonly used for ground floors on domestic and some commercial applications. It is an economical and quick construction method for sites that have non-reactive soil and little slope.
Floor Slab Construction
The concrete slab construction process includes the preparation of formwork, compaction of a slab bed, placement of reinforcement, pouring, compacting, finishing the concrete, removing formwork and curing the concrete slab.
Slab in Construction
A concrete slab is a structural feature, usually of constant thickness, that can be used as a floor or a roof. A slab-on-ground is supported on the subsoil and is usually reinforced with reinforcing bars or welded wire mesh.
Concrete Slab Material List
- 2-in x 4-in Board (Actual: 1-1/2-in x 3-1/2-in)
- Concrete Mix.
- Concrete Cure & Seal.
- Landscape Stakes.
Concrete Slabs Thickness
Standard concrete floor slab thickness in residential construction is 4 inches. Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. To prepare the base, cut the ground level to the proper depth to allow for the slab thickness.
Slab Thickness in Mm
In general, 6 inch (150mm) slab thickness is considered for residential and commercial buildings with reinforcement details as per design. Methods used for finding slab thickness varies for different types of slabs. For example, one-way slab thickness calculation is different and easier from that of two-way slab.
Maximum Slab Thickness
Maximum slab thickness for office building:– using some basic thumb rules, regulation and guideline as per ACI code and IS code 456:2000, for concrete floor, maximum concrete slab thickness for office building is kept 10 inch (250mm), providing maximum concrete grade M10 to M20 and mesh bar should be embedded in …
Concrete Slab Thickness Mm
The thickness of concrete floor slabs supported directly on the ground shall be not less than 31/2 inches (89 mm).
Precast Concrete Slab Cost
Precast concrete slab costs $20 – $30 per square foot. In contrast, when concrete is poured and cured at a specific construction site, it is called “cast-in-place concrete.” As you might imagine, cast-in-place concrete is required for unique, non-standard shapes and sizes.
Concrete Floor Slab
A concrete slab floor provides a simple way to add thermal mass to a design. Concrete slabs can be onground, suspended, or a mix of both. Concrete slabs need to be appropriately insulated to suit the climate. They can be insulated both underneath and on the edges.
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