ONE WAY AND TWO WAY SLAB

SLAB:

    Slab is a horizontal Structural element, which 

is constructed to create flat and useful surface such as floors, roofs, etc.

ONE WAY SLAB:

   One way slab is a slab, which is supported by parallel walls or beams on the two opposite sides to carry the load along one direction.

   The ratio of longer span to shorter span is

 greater than two.

Ly/Lx > 2

Ly = Longer span

Lx = Shorter span

Advantages:

  # Easy to design

  # Quantity of steel is less

  # Construction of cost is less

Disadvantages:

  #A One way slab in which the Reinforcement provide one direction so that the maximum load cannot be withstand.

  

Example,

    Longer span,Ly = 8m

    Shorter span,Lx = 3m

    

   ly/lx = 8/3 = 2.6 ( Hence One way slab)

    

TWO WAY SLAB:

   Two way slab is a slab, which is supported by beams for all the four sides to carry the load both direction.

 

    The ratio of longer span to shorter span is

 equal or less than two.

Ly/Lx < 2

Ly = Longer span

Lx = Shorter span

Advantages:

  #A Two way slab in which the load is transferred in both direction so that the maximum load can be withstand

without deflection.

  #The beauty of the room increases.

Disadvantages:  

  #The slab design is more complex 

  #Quantity of steel is more

  #The construction cost is high.

Example,

 Longer span,Ly = 4m

 Shorter span,Lx = 2m

Ly/Lx = 4/2 = 2 (Hence Two way slab)

Difference Between One way slab and Two way slab:

SI	ONE WAY SLAB	TWO WAY SLAB
1	Ly/Lx > 2	Ly/Lx < 2
2.	Reinforcement provide only for Shorter Direction	Reinforcement provide for both direction
3.	One side bending	Both sides bending
4.	Loads are carried out one direction	Loads are carried out the both direction
5.	This slab design is easy	This slab design is more complex
6.	This slab quantity of steel is less	This slab quantity of steel is more
7.	The construction cost is less	The construction cost is more