Identification of Cracks

Question 1:

a) b) c)

What is the mode of failure or damage of the beams in the figure above? Are the damages repairable? Elaborate

Ans:

Failure:

• Overloading: When the structure is subjected to forces exceeding its design capacity.
• Material defects: Weaknesses or flaws in the materials used can lead to premature failure.
• Design errors: Mistakes in the structural design can compromise the integrity of the building.
• Construction flaws: Improper construction techniques or use of substandard materials can create vulnerabilities.
• Environmental factors: Earthquakes, floods, and other natural disasters can put immense stress on structures, leading to failure.

Based on above causes the structure will fails in different modes likely;

Failure modes in RCC Beam divided into two types

1. Flexural Failure (Bending Failure),
2. Shear Failure.

These Failures futher divided into different types;

Flexural failure is categorized into

• Tension failure,
• Compression Failure, and
• Balanced Failure.

Shear failure is categorized into

• Tension shear failure,and
• Compression Shear Failure.

a)

Mods of failure: Flexural failure at bottom of the beam

Cause:

• Overloading: When the structure is subjected to forces exceeding its design capacity. due to this condition flexural failure is occured.Damage have occurred at the beam column joint. The beam have undergone severe damage as compared to Column.

b)

Mods of failure: Honeycombimg in concrete at edges of structure.

Causes:

• High slump concrete, And
• Due to not using proper compacting techniques.

c)

Mods of failure: Joint Failure at Beam/Column Connections.

Causes:

• Due to not using proper compacting techniques.
• Due to short column weak beam.

Question 2:

a)b) c)

Ans:

a)

Mods of failure: Failure of column due to Compression

Cause:

• high compressive load acting on the column

Due to this the column will fail without undergoing any lateral deformation. The concrete gets crushed and the steel will yield and then column failure occurs.

b)

Mods of failure: Shear Failure

Cause:

• In the absence of shear walls in a structure/ building

the lateral loads will be completely carried by the columns. Lateral loads can be in the form of wind, earthquake loads etc.

c)

Mods of failure: Short Column failure

Cause:

• short column is subjected to compressive stresses

Thus it fails due to crushing. Should have designed by considering design factors.