What are the three types of slab?

Generally, slab on grade is classified into three types:
  • Slab on ground.
  • Stiffened raft slab.
  • Waffle raft slab.

What is flat slab roof?

Concrete slab flat roofs

A concrete slab flat roof is normally made up of a structural layer of concrete finished with a smooth screed onto which a water proof layer such as a membrane is laid. The roof should incorporate insulation and usually a vapour control layer to protect from interstitial condensation.

What is slab and its types?

A slab is a structural element that is made of concrete, which is used to create flat horizontal surfaces such as floors, roofing floors and roofs. A slab is usually several inches thick typically between 100 and 500 mm thick and is supported by beams, columns, walls or floor.

Where flat plate slab is used?

Flat slabs are mostly used in large industrial structures, parking garages, ramps, warehouse, high rise buildings and hotels. 2. They are also used where uses of beams are not required.

What are flat slabs?

A flat slab is a two-way reinforced concrete slab that usually does not have beams and girders, and the loads are transferred directly to the supporting concrete columns. The flat plate is a two-way reinforced concrete framing system utilizing a slab of uniform thickness, the simplest of structural shapes.

What is the thickness of flat slab?

125 mm
The minimum thickness of the slab shall be 125 mm.

What is the maximum span of flat slab?

Flat slab span is mostly ranging from 7-12m and still economical. For the minimum thickness you can refer to ACI 318M-11 table9. 5(a) where for the flat slab you have an element with both ends continuous so 7500/28= 270mm.

What are components of flat slab?

Major components of flat slab are capital/head, drop panel, columns strip and middle strips.

What is a two-way flat slab?

Two-way slabs are slabs that are supported on four sides. In two-way slabs, the load will be carried in both directions, thus main reinforcement is provided in both directions for two-way slabs. The slabs are considered as spanning two-way when the longer to shorter span length is less than a ratio of two.

What is a slab roof?

A roof slab models a single face of a roof. Roof slab objects also differ from roof objects in that each roof slab is a separate entity with no direct connection to other entities.

What is the difference between solid slab and flat slab?

1- In models with flat slab system, slab thickness is variable from (18 cm = span/27.78) to (30 cm = span/16.67). 2- In models with solid slab system, slab thickness is constant and equal 20 cm (span/25). 1- In models with flat slab system, there are no beams.

Are flat concrete roofs good?

Flat concrete roofs are generally low maintenance, meaning they are easy to clean and aren’t too difficult to access. Like any other roofing, debris and dirt can pile up over time. However, roofers can easily remove these from the surface without damaging the roof itself.

What are the disadvantages of a flat roof?

The biggest drawback of flat roofs is the drainage or lack thereof. Sure, flat roofs do have a slight slope that drains the water, but not nearly as efficiently as a pitched roof. The rainwater tends to remain on the roof and form a puddle, which can lead to possible leaks or material damage.

What is the advantage of flat slab?

Flat Slabs are considered suitable for most of the construction and for asymmetrical column layouts like floors with curved shapes and ramps etc. The advantages of applying flat slabs are many like depth solution, flat soffit and flexibility in design layout.

What is the maximum span for flat slab?

For a live load of 50 PSF or less, flat slabs are cost-effective for span lengths between 30 and 35 feet. The economical range is 25 to 35 feet for a live load of 100 PSF. The impact of the column dimensions for a flat slab are similar to that described for a flat plate system.

What are the components of flat slab?

Major components of flat slab are capital/head, drop panel, columns strip and middle strips.

Is flat slab expensive?

Flat slab structure is more economical than that of conventional slab structure. The cost of flat slab structure is reduced by 15.8% compared to conventional slab structures.

Can flat slab be precast?

Precast flat slabs are cast in a 1200mm wide stressing bed allowing the manufacture of units up to a maximum of this width. A 75mm thick insitu concrete topping is cast over on site to produce a composite, versatile flooring solution.

What is 2way slab?

The two-way slab is a slab which is generally supported on all sides of walls or beams, and whose length to breadth ratio is less than two and it twists or bends in both direction while transferring the loads to the walls or beams.

What are the disadvantages of flat slab?

Disadvantages of Flat Slab
  • It has span limitations. …
  • They are not suitable for masonry partition of brittle nature.
  • It uses drop panels that may interfere with oversized mechanical ducting.
  • They have middle strip deflection, which may be critical.
  • They have more thickness as compared to typical RCC Slabs.

Do flat slabs have beams?

A flat slab is a two-way reinforced concrete slab that usually does not have beams and girders, and the loads are transferred directly to the supporting concrete columns.

Why drop panels are used in flat slabs?

Drop panels increase the shear strength of the flat slab floor (i.e it resists shear). Drop panels increase the flat slab’s negative moment capacity. Drop panels reduce deflection by stiffening the flat slabs.