Identification of Cracks

What is the mode of failure or damage of the beams in the figure above? Would you characterize the case as damage or as a failure? Are the damages repairable? Elaborate.

1)

a)

We can clearly observe that the failure is at beam-column joint. The damage is more at the beam.

Beam-Column connection failure: This type of damage can be caused mainly due to the inadequate covering from the reinforcement to the beam. This inadequate reinforce can cause in loss in strength and stiffness and can even collapse.

This may also be due to the formation of the plastic hinge at the undesirable location. The plastic hinge must be connected at the end of beams but not at the connection of beam and column.

This can be prevented by providing proper covering at the beam-column joint.

b)

This damage may be due to the improper shotcrete of the plaster material. We can repair it by removing the extra and improper plaster material around the damaged part and shotcreting again properly.

c)

The damage in this picture is at beam-column joint due to the high shear forces.

This may cause loss of strength which hence causes the collapse of the building.

This damage can be temporarily repaired but can cause harm further.

2)

a)

The damage shown in the figure is the buckling of column. This occurs when the column couldn’t resist the buckling load acting in the column.

To avoid these type of failures we should take of the reinforcement bars such that they should not lap in a single column.

b)

This type of failure can be mostly observed during Earthquakes.

In this figure, the column is deformed due to the high shear forces acting on the column.

c)

This is a beam-column joint failure.

This may be caused due to the improper placement of the concrete in the reinforcement.

This is also mostly seen during earthquakes because of the movement of beams and columns in different diections.