What do you mean by a doubly reinforced section?

In which situation doubly reinforced beams used?

when our demand is more than capacity then designer prefers to choose doubly reinforced beam .for example your maximum moment is greater than nominal momentthen doubly reinforced beam is used.

What is the difference of singly reinforced beam from doubly reinforced beam?

Singly reinforced beams have reinforcing only on the tension face. Doubly reinforced beams have reinforcing on the tension and compression face. Doubly reinforced beams can increase section capacity, but are primarily used to increase the ductility of the concrete beam. In certain codes, if the concrete section is controlled by the concrete failing in compression before the tension steel rebar yields (called a compression-controlled or brittle section), the calculated section capacity must be reduced to account for the brittle and sudden/unpredictable nature of a compression controlled (also called a brittle) failure. In order to make the section controlled by the yielding of the tension reinforcement (called a tension-controlled or ductile section), the ductility must be increased. This can be accomplished by adding steel in the compression zone, which gives strength to the compression area, thereby delaying the failure of the concrete. Enough compression steel can cause the section to switch from a brittle mode-of-failure to a ductile mode-of-failure, thereby permitting the designer to not decrease the section capacity from its calculated value. When identifying a doubly- reinforced beam, be sure that the steel in the compression area is meant to be for strength. Oftentimes, all faces of a beam will have some reinforcing for temperature/shrinkage protection and to tie the stirrups to. Steel that is only there for temp/shrinkage or to facilitate tying the rebar will usually be small and not much of it. In buildings, they will be often #3 bars @ 12" centers. In bridges, they may be #4 bars. These small bars should not be counted as compression-zone reinforcing. Look for bars in the compression zone that are of similar size to the main tension reinforcing.

If the neutral axis of a reinforced section is above the critical section what is the section called?

Under Reinforced Section

When designing a double-reinforced beam why is it necessary to provide extra reinforcement on the tension side as well as compression reinforcement?

A doubly reinforced beam is provided reinforcement in compression side also as to take care of extra load due to big section and to take care of tension in compression side ie compressive stresses so the section is safe.

What is the difference between the singly reinforced beam and doubly reinforced beam?

A singly reinforced beam only has steel reinforcement on the tension side (along the bottom of the cross section) where as a doubly reinforced beam has steel reinforcement on both the tension and compression sides, ie. the top and bottom of the cross section.

Doubly reinforced concrete vs singly reinforced?

Doubly reinforced concrete and singly reinforced concrete are two types of reinforced concrete structures that differ in the way reinforcement is provided to resist tensile forces. Singly Reinforced Concrete: Singly reinforced concrete refers to a structural element (such as a beam or a slab) where reinforcement is provided only on one side to resist tensile forces. Typically, steel reinforcement in the form of bars or meshes is embedded in the concrete in the tension zone, where the concrete is subjected to tensile stresses. The reinforcement helps to carry the tensile forces, while the concrete primarily resists compressive forces. Singly reinforced concrete is commonly used in many structural applications. Doubly Reinforced Concrete: Doubly reinforced concrete refers to a structural element where reinforcement is provided on both sides to resist tensile forces in different zones. In addition to the primary reinforcement on the tension side, secondary reinforcement is also provided on the compression side to increase the structural strength and control the development of cracks. The secondary reinforcement helps balance the tensile and compressive forces, improving the overall performance and load-carrying capacity of the element. Doubly reinforced concrete is often used in situations where higher strength and resistance to cracking are required, such as in deep beams or heavily loaded structural members. The decision to use singly or doubly reinforced concrete depends on factors such as the structural requirements, loads, span lengths, and design considerations. Doubly reinforced concrete is typically employed in situations where the loads are higher or where there is a need to control deflection or cracking to a greater extent. It provides enhanced strength and ductility to the structural element. However, it also requires careful design and detailing to ensure proper placement and spacing of the reinforcement on both sides. It's important to note that the design and implementation of reinforced concrete structures should always be carried out by qualified structural engineers who consider the specific project requirements, local building codes, and safety factors.

What does evenly and doubly even mean?

A number is even if it is divisible by 2. It is doubly even if it is divisible by 4.

What is the name of a tapered cylinder with different diameters each end?

Bi-truncated conic section, or doubly-truncated conic section

How is Reinforced concrete made?

Reinforced concrete is made by placing steel bars in the tension zone of the beam x-section.

What is the difference Between under reinforced section and over reinforced section?

When the maximum stresses in steel and concrete simultaniously reaches allowable value the section is called balanced section when the %of steel in a section is less than that required for a balanced section it is under reinforced section when the %of steel in a section is more than that required for a balanced section it is over reinforced sectionover reinforcement is as per section design I.e Ast1+Ast2>Ast Ast1+Ast2

A sentence for the word doubly?

Use the word 'doubly' in a sentence:All these questions are hard, but this one was doubly hard.

Why it is undesirable to design over reinforced sections?

There are two basic reasons 1. In over reinforced section failure happens due to concrete which is sudden without any type of warning like bending or deflection.... 2. Steel is one of the most costly material used in construction work so from the economical view it is also undesirable to provide over reinforced section...