The steel provided in the beam is such that both concrete and steel reach the limiting values of strain simultaneously.

• Balanced section

• Under reinforced section

• Over reinforced section

The steel provided in the beam is such that steel reach the limiting values of strain prior to concrete. This results in yielding of the steel and the steel could yield till it attains the ultimate strain at which point it breaks.

• Balanced section

• Under reinforced section

• Over reinforced section

The steel provided in the beam is such that concrete reach the limiting values of strain prior to steel. This results in breaking in concrete and since now there is no concrete present to take the compression, the beam fails suddenly.

• Balanced section

• Under reinforced section

• Over reinforced section

The additional margin that we get under this section helps in prevention of a sudden failure and provide the necessary warning to the inhabitants of the building.

• Balanced section

• Under reinforced section

• Over reinforced section

One in which the main reinforcement is provided only in the tension zone

• Singly reinforced beam

• Doubly reinforced beam

• T beam

Here, the ultimate bending moment is less than the limiting bending moment.

• Singly reinforced beam

• Doubly reinforced beam

• T beam

Occasionally, beams are restricted by space or aesthetic requirements to such extent the compression concrete should be reinforced with steel to carry compression.

• Singly reinforced beam

• Doubly reinforced beam

• T beam

Reinforced concrete floor usually consist of slabs and beams, which are placed or monolithic poured. In this effect, the beam will have an extra width at the top (that is under compression) called flanges.

• Singly reinforced beam

• Doubly reinforced beam

• T beam

A reinforcement used to resist shear and diagonal tension stresses in a concrete structural member

• Stirrups

• Ties

• Purlins

Very dangerous especially if it happens before flexure failure because they can occur without warning

• Shear failure

• Bending failure