What are the over reinforced section and under reinforced section?

In an over reinforced section the percentage of steel provided is greater than the balanced section. So the actual neutral axis shift downward i.e., n>nc [Fig. 2.6(d)]. In this section, stress in concrete reaches its permissible value while steel is not fully stressed.

What is under reinforcement and over reinforcement?

Reinforced concrete beam sections in which the steel reaches yield strain at loads lower than the load at which the concrete reaches failure strain are called under-reinforced sections. Every singly reinforced beam should be designed as under-reinforced sections because this section gives enough warning before failure.

What is the effect of over reinforcement?

For over-reinforced helically confined HSC beams, increasing the concrete compressive strength decreases the yield deflection slightly and decreases significantly the ultimate deflection.

What is a over reinforced section?

Reinforced concrete beam sections in which the failure strain in concrete is reached earlier than the yield strain of steel is reached, are called over-reinforced beam sections.

What is meant by an under reinforced section?

Concept: a) If the depth of actual neutral axis (n) is lesser than the depth of critical neutral axis (nc) then the section is called as under reinforced section and in this case the steel in the tensile zone attains its maximum stress earlier than the concrete in compressive zone.

What is singly reinforced section?

The beam that is longitudinally reinforced only in tension zone, it is known as singly reinforced beam. In Such beams, the ultimate bending moment and the tension due to bending are carried by the reinforcement, while the compression is carried by the concrete.

What is simply reinforced & doubly reinforced sections in detail?

A Singly reinforced beam holds a steel bar in the tension zone, but in doubly reinforced beams, steel bars are given in both zones, tension, and compression. In singly reinforced beam compression, stress resists by the concrete, while in doubly reinforced beam compression steel, counters the compression stress.

What is meant by over reinforced section?

What is the deficiency of designing over reinforced sections?

Over Reinforced Section Section fail in compression is called the over-reinforced condition. This is simply a failure of the concrete. As we know, there are no warnings when concrete fails as it is a brittle failure. Therefore, the designer shall keep in mind to avoid failures of this nature.

What is balanced section?

Balanced section is the section in which the stress acting in concrete and that applied in steel section will attain permissible value simultaneously. This means that the tension produced in the steel reaches their yield strain value at the same time, when the concrete attains the failure strain value in bending.

What type of failure occurs in an over reinforced section?

The primary failure (occurs first) in an over reinforced beam is compression failure, as the crushing of concrete occurs before yielding of the tension reinforcement.