One Way Slab Overview and Design Aspects
The one-way slab is a kind of slab type that comes under the slab classification. The other most popular slab type is the two-way slab. The load distribution of the slab is the factor that is considered to classify the slabs.
In simple terms, load distribution is in one direction in the one-way slab whereas the load distributes in both directions in the two-way slab.
Classification of Slab
The following figure indicates the two main slab types
The main criteria used to classify the slab is the span ratio which is the long-span to short-span ratio.
If [long span / short span] > 2
These slab types are classified as one-way slabs.
If [long span / short span] ≤ 2
Those slabs are classified as two-way slabs.
As indicated in the above figure, the load will be transferred in one direction when the slab is spanning in one direction.
Design of One-Way Slabs
Design is not as complicated as the two ways slab as the load transfer in one direction. A simplified method or computer analysis method could be used to calculate the bending moments.
A strip can be analyzed manually or by using a computer to find the bending moments. The same can be used to calculate the reinforcement requirement.
The deflection of the slab shall be checked in the short direction and there is no requirement of considering the other direction. The main reinforcement shall be provided in the shorter direction and minimum reinforcement may be provided in the longer span.
The same reinforcement detailing applicable for the two-way slab applies to the one-way slab panels.
Some of important facts about one-way slabs are as follows.
- Transfer load in one direction
- They are economical when span up to 3.5m. Beyond that it could not be economical.
- Categorized when long span to short span ration grader than 2.
- Reinforcement is provided in the shorter direction the bending rebar.
