Table of Contents
- 1 What is the direct design method?
- 2 Which of these methods is used for designing of two way slabs?
- 3 What are requirements needed for designing slab by direct design method?
- 4 What is a 2 way slab?
- 5 What is slab design?
- 6 What is one way slab and two way slab?
- 7 What is the direct design method (DDM)?
- 8 What is the ACI 318-11 code for slab design?
What is the direct design method?
The direct design method is an analytical approach by which the required area of reinforcement for short reinforced concrete columns or shear walls is determined directly without using an interaction diagram.
Which of these methods is used for designing of two way slabs?
Coefficient Method: In the American Concrete Institute in 1963 to design two-way slabs carried by steel beams, deep beam, or walls this method was provided. This method employs tables of moment coefficients for different slab edge conditions and these conditions are based on the elastic analysis.
What are the two methods specified by the code for the design of two way slabs?
Minimum thickness for two way slab construction designed as per methods provided by ACI 318-11 Code namely, direct design method and equivalent frame method. The minimum thickness of slab is specified by ACI 318-11, section 9.5.
What is one-way slab design?
One-way slab is a type of concrete slab in which loads are transferred in one direction to the supporting beams and columns. Therefore, the bending occurs in only one direction. The procedure of designing a one-way slab is similar to that of a rectangular beam. Slabs are used to provide flat, useful surfaces.
What are requirements needed for designing slab by direct design method?
Solution: Check if the slab system satisfies all the limitations for Direct Design Method.
- There must be a minimum of three continuous spans in each direction.
- The panels must be rectangular, with the ratio of the longer to shorter spans within a panel not greater than 2.
What is a 2 way slab?
Two way slab is a slab supported by beams on all the four sides and the loads are carried by the supports along with both directions, it is known as 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.
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 1 way slab and 2 way slab?
Difference between One Way Slab and Two way slab:
| One Way Slab | Two Way Slab |
|---|---|
| Slabs are supported by the beams on the two opposite sides | Slabs are supported by beams on all the four sides. |
What is slab design?
A slab is a structural element, made of concrete, that is used to create flat horizontal surfaces such as floors, roof decks and ceilings. A slab is generally several inches thick and supported by beams,columns, walls, or the ground.
What is one way slab and two way slab?
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. |
How to design a two way 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 interior and exterior columns. Choose design method (direct design method in this case) Calculate positive and negative moments in the slab
What is the direct design method for a slab panel?
The direct design method, which could have been named the direct analysis method because it determines or prescribes moments for different parts of the slab panel without the need to conduct structural analysis, is explained in the following sections.
What is the direct design method (DDM)?
For the Direct Design Method moments are found using a simplified procedure similar to analyzing a One-Way Slab . The following conditions must be met to use the DDM: Panels must be rectangular in shape with a ratio of the long side to the short side of no more than 2 (this ensures that the slab acts as a two-way slab).
What is the ACI 318-11 code for slab design?
ACI 318-11 Code provides two methods for two way slab design one of which is direct design method. Direct design method, that could have been named the direct analysis method because it determines or prescribes moments for different parts of the slab panel without the need to conduct structural analysis, is explained in the following sections.