Quick Answer: What Is The Slab Method 2

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 2way slab?

Where is 2 way slab used?

In two-way slab, the load is carried in both directions. The deflected shape of the one-way slab is cylindrical. Whereas the deflected shape of the two-way slab is a dish or saucer-like shape. Whereas two-way slabs are used in constructive floors of the Multistorey building.

How do you calculate the number of bars in a slab?

The quantity is done in two steps.

(Calculation of Bars No’s) First, calculate the number of bars required (main and distribution both). FORMULA = (Total length – Clear cover)/center to center spacing + 1. Main bar = (5000 – (25+25))/100 + 1.
(Cutting length) MAIN BAR: FORMULA = (L) + (2 x Ld) + (1 x 0.42D) – (2 x 1d)

Where is one way slab and two way slab used?

Whereas two-way slabs are used in constructive floors of the Multistorey building. 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. Main Reinforcement is in provide short span due to banding.

What is the maximum height of column?

The maximum height of a column is 24 m. Columns height from 20 m to 24 m can be manufactured as one piece (uncut), and composite.

Why we use extra bar in slab?

Extra Bars:- The extra bar is provided at the bottom of Cranked bars to maintain the framework of the slab. The length of Extra bar is L/4. Deduct the cover for finding length of bar.

How do you calculate slab load?

Slab Load Calculation = 0.150 x 1 x 2400 = 360 kg which is equivalent to 3.53 kN.

How much steel is RCC slab?

Thumb rule for Steel required for RCC slab is 80 kgs/m3, then quantity of steel required for 100 sq ft ( 0.944 m3) rcc slab is equal to = 80 × 0.944 = 75.5 Kgs.

How is two way slab calculated?

If the longer span of the slab is l_y and the shorter span is l_x, then for a two-way slab, l_y/l_x 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.

What size rebar would be used on a 4 slab?

If you want to make a driveway or patio, you should use a #3 rebar which is 3/8 inch in diameter. If you are constructing walls, piers or columns, I recommend the use of a small piece of reinforcement. I use a 5 inch rebar for building footings.

Why do we use two way slab?

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.

What is the minimum depth of two way slab?

For slabs without drop panel 125 mm. For slabs with drop panel 100 mm.

How do I create a two way slab in Excel?

How to use the sheet for design of two way slab

Grade of concrete ƒck =
Grade of Steel ƒy =
Concrete cover =
Clear Short Span Lx=
Clear Long Span Ly =
Width of Supporting Beam =
Assume the Thickness of Slab =
Dia. of Reinforcement Bar=

How do I create a slab manually?

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.Or, the following thumb rules can be used:

One way slab d=(L/22) to (L/28).
Two way simply supported slab d=(L/20) to (L/30)
Two way restrained slab d=(L/30) to (L/32)

How do I calculate how much steel I need for a slab?

Steel Quantity Calculation D = (thickness) – 2 (clear cover at top, bottom) – diameter of the bar, = 150 – 2(25) -12, d = 88 mm ans, by putting values: cutting length = 2000 + (2 x 40 x 12) + (1 x 0.42 x 88) – (2 x 1 x 12), cutting length = 2000 + 960 + 36.96 – 24, =2972.96 mm ~ 2973 mm or 2.973 m.

How far can a concrete slab span without support?

How far can you cantilever a concrete slab? Cantilevers are usually limited to a span of about 25 to 35% of the back span and should be supported by a stiff support such as a beam or column. They should not be supported off another cantilever at right angles.

How is slab calculated?

How to calculate concrete:

Determine how thick you want the concrete.
Measure the length and width that you’d like to cover.
Multiply the length by the width to determine square footage.
Convert the thickness from inches to feet.
Multiply the thickness in feet by the square footage to determine cubic feet.

Which is better one way slab or two way slab?

In one way slab main bars are laid along the shorter span and temprature reinforcement or disribution bars along the long span. One way or two way are not designed that any type of them is better than the other but due to change of loading conditions with change of the length breadth ratio of the slab.

What are the types of two way slab?

There are mainly three types of designs for two-way slab.

Two-way solid slab (with beams) Two-way Solid Slabs on Beams.
Two-way Waffle Slab (with Beams) Two-way Waffle Slab (with Beams)
Two-way Waffle Slab (with Integral Beams) Cast in Situ Two-way Waffle Slab with Integral Beams.

What is flat slab construction where is it used?

Flat slabs are mostly used in large industrial structures, parking garages, ramps, warehouses, tall buildings, and hotels. They are used where the beam is not required. These slabs also used where the structures require less formwork.

What are the types of slabs?

Concrete Slab Types – Construction, Cost, and Applications

One-Way Slabs on Beams.
One-way joist slab (Ribbed slab)
Waffle Slab (Grid slab)
Flat Plates.
Flat Slabs.
Two-way Slabs on Beams.
Hollow core slab.
Hardy Slab.