Why Do We Provide Doubly Reinforced Beam?
In This today The Civil Experiences article We Briefly explain What has doubly reinforced beam is, Why we provide doubly reinforced beam is provided (adopted) and the Necessity of the Doubly Reinforced Section
Beam
The beam can be defined as a structural element that transfers structural load and resists bending. Its mode of deflection is primarily by bending.
Concrete Beam
If Concrete plays a role in making a beam then it’s called a Concrete beam
Reinforced Concrete beam
If Concrete and reinforcement play a role in making a beam then it’s called a Reinforced Concrete beam or RCC beam
Types of Reinforced Beam
By Using of reinforcement position Reinforced Beam are further divided into two types of beam
Also Read: Types of Beam Mechanics
- Singly Reinforced Beam
- Doubly Reinforced Beam
What is Doubly Reinforced Beam?
What is the necessity of doubly R.C. Beam?
- To increase the depth of the beam
- To use a higher grade of concrete, to improve M.R.
- To provide reinforcements in the compression zone of the beam, to increase M.R.
Also Read: What is Hidden Beam and why used?
Doubly R.C. Beam DEFINITION
Necessity of Doubly Reinforced Section
- when it is not possible or dimensions (breadth x depth) of the beam are restricted to increase the depth of beam due to architectural purpose
- To get more headway in the rooms
- When the beam is subjected to reversal of stresses
- When subjected to an external load may cause tension on both faces of the member
- When subjected to sudden load like in case of earthquakes
- For pre-cast beams
- When subjected to eccentric loading
The Civil Experiences always keeps updating our Articles/posts with the latest civil engineering news, Structural Engineering Career tips, exam papers, Answer links Jobs & Information. So, Don’t forget to bookmark the Civil Experiences website and Please share this link with your friends to help them.
Follow Us
LinkedIn | Google News | Telegram | Facebook | Twitter | YouTube | Quora
Difference between singly and doubly reinforced beam
Singly R.C. beam
|
Doubly R.C. beam
|
 |
 Ast = Area of steel in tension zone
Asc = Area of steel in compression zone
|
|
In the tension zone, Ast is provided |
In the tension zone, Ast is provided |
|
|
In the compression zone, Acs is provided |
|
In the compression zone, 2 – 10 Φ anchor bars are provided. The anchor bars are not designed to carry any compressive force |
In the compression zone, Asc is provided to resist compressive force |
|
When Mu < Mu lim, the beam is designed as a singly R.C. beam |
When Mu > Mu lim, the beam is designed as a doubly R.C. beam |
|
Its M.R. is less |
Its M.R. is more |
|
Ductility is less |
Ductility is more due to Asc in the compression zone |
|
Not suitable where there are chances of a reversal of stresses |
Suitable where there are chances of a reversal of stress ( for example During earth quack ) |
