CONVENTIONAL SLAB AND ITS TYPES

Conventional Slab

The slab which is supported on beams and columns is called conventional slab.In conventional slab the thickness of the slab is small whereas the depth of the beam is large and load is transferred to beams and then to columns.It required more formwork when compared with flat slab.The thickness of conventional slab is 4 inches or 10 cm.Normally conventional concrete slabs are in square shape and have a length of 4 m. Reinforcement is provided in conventional slab and the bars which are set in horizontal are called main reinforcement bars and the bars which are set in vertical direction are called distribution bars.These types of slab are generally used in high rise buildings.

There are two types of Conventional slabs based on length and breadth, they are:

1. One-way slab
2. Two-way slab

1. One-way Slab

One way slab is supported by beam on the two opposite sides to carry the load along one direction.In one way slab the ratio of longer span (l) to shorter span (b) is equal or greater than 2.

 i.e Longer span (l)/ Shorter span (b) ≥ 2. 

In this type of slab the main reinforcement bar will be provided in the shorter span where as the distribution bars will be provided in the longer span for the load distribution.

2. Two-way Slab

Two way slab is 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.

i.e Longer span (l)/ Shorter span (b)﹤2. 

In this type of slab the length and breadth of the slab are more than 4 m.To resist the formation of stresses distribution bars are provided at both the ends in two way slab.

Difference Between One Way Slab And Two Way Slab

• In one-way slab, the slab are supported by beams on the two opposite sides whereas in two-way slab, the slab are supported on all four sides.

• In one-way slab, the loads are carried along one directions whereas in two-way slab, the load are carried along both directions.

• In one-way slab, the ratio of Longer span to shorter span is equal or greater than 2. (i.e i/b ≥ 2 ) whereas in two-way slab, the ratio of i/b is less than 2. (i.e i/b﹤ 2 )