If slabs may be supported by columns only, in this case, two-way action will prevail. If the ratio of long side / short side > 2 it is considered as one-way slab, and if longer side to shorter side ratio < 2 then it is considered as a two-way slab.
How can we identify one way slab and two way slab?
If L/b the ratio is greater than or equal 2 or then it is considered a one-way slab. If L/b the ratio is less than 2 then it is considered a two-way slab. In one-way slab, the load is carried in one direction perpendicular to the supporting beam. In two-way slab, the load is carried in both directions.
How is one way slab calculated?
What is a one-way slab? When a rectangular slab is supported on all four sides, but the ratio of the longer side, L, to the shorter side, S, is 2 or more, L/S ≥ 2.0, then, the slab will act as a one-way slab, with bending primarily occurring in the short direction.
How is two way slab calculated?
If the longer span of the slab is ly and the shorter span is lx, then for a two-way slab, ly/lx is less than 2. If the ratio is greater than 2, it is identified as a one-way slab. The two-way slabs distribute the loads in both directions. Hence, the reinforcement is provided along shorter and longer sides of the slabs.
Where is one way slab and two way slab used?
Difference Between One Way Slab And Two Way Slab:
| One Way Slab | Two Way Slab |
|---|---|
| The slabs are supported by the beams on the two opposite sides. | The slabs are supported on all the four sides. |
| The loads are carried along one direction. | The loads are carried along with both directions. |
What is a two way 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 is LX in slab?
Lx- Length of shorter side of slab( Shorter span) Ly- Length of longer side of slab( Longer span)
How is reinforcement calculated in two way slab?
- A slab supported on four adjacent beams with a ratio of longer span to shorter span less than two that carry the load by flexure in both perpendicular directions refers to a two way slab.
- Nos of Bars = Total length/ spacing + 1.
- Inclined Length D.
- Inclined Length D.
Which is better one way or two way slab?
The one-way slab is economical up to a span of 3.6 meters. Whereas the two-way slab is economical for the panel sizes up to 6m × 6m. In one-way slab quantity of steel is less. In two-way slab quantity of steel is more as compared to the one-way slab.
Where is two way slab used?
In two way slab, the ratio of longer span (l) to shorter span (b) is less than 2. In two way slabs, the load will be carried in both the directions. So, the main reinforcement is provided in both directions for two way slabs. Example: These types of slabs are used in constructing floors of a multi-storeyed building.
How do I make a two way concrete slab?
Procedures of Two Way Slab Design by Direct Design Method
- Determine slab type and layout.
- Choose slab thickness that should be adequate for avoiding excessive deflections and satisfy shear at the interior and exterior columns.
- Choose design method (direct design method in this case)
Where is one way slab used?
One-way Ribbed Slab (with beams)system is used for the office buildings (low rise), parking structures, and warehouses.
How many types of two way slab are there?
Types of Two Way Slab:
Two Way Flat Plates Slab. Two Way Flat Slabs. Two Way Waffle Plate Slab.
What is a cantilever slab?
Abstract. The concrete deck slabs of girder bridges are usually projected transversely beyond the outermost girders. These projections, which are provided for reasons of economy and aesthetics, are referred to in this book as cantilever slabs or cantilever overhangs.
What is a one way concrete slab?
A one-way slab is supported on two opposite sides, so structural action is only ever in one direction. Total load is carried in the direction perpendicular to the supporting beam. Main reinforcement is provided in only one direction. Nominal distribution reinforcement is provided in cross direction.
What is crank bar in slab?
Cranked bars / Bent up bars are provided on top of the reinforcement to resist negative bending moment/Hogging at the supports of the slab. To resist the shear force at the supports. To reduce the risk of a brittle failure of slab-column connection.
How is slab reinforcement calculated?
Firstly, you need to calculate the area of your concrete slab. To do this simply multiply the length of the slab by the width. Now that you have your area calculation, you need to divide the area by 12.5. This will give you the number of steel mesh sheets required to reinforce your concrete slab.
How do you calculate reinforcement in slab?
Steel Quantity Calculation
(Cutting length) main bar: formula = (l) + (2 x ld) + (1 x 0.42d) – (2 x 1d), where l = clear span of the slab, ld = development length which is 40 d (where d is diameter of bar), 0.42d = inclined length (bend length), 1d = 45° bends (d is diameter of bar) first calculate the length of “d“.
Which is best slab?
The best cement for slab used in construction is OPC- 53 (Ordinary Portland cement grade 53) and PPC (Portland pozzolana cement) brand of UltraTech Cement, ACC Cement, Ambuja Cement, Sagar cement, Dalmia Cement, Shri cement, Birla cement, etc. These cement brands offer & good deals.
What is the minimum depth of two way slab?
Moreover, the minimum thickness of any two way slab without interior beams should not be less than the following: For slabs without drop panel 125 mm. For slabs with drop panel 100 mm.
How far can a two way slab span?
Economic Span Range:
5-8m (Conventional RC) 6-10m ( Post-Tensioned)
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