Identification of Cracks

1. a )

Observations

• Beam Crushed at the bottom of the Beam column Joint, Reinforcement exposed.
• There are no cracks on the upper side of the beam and the Slab Beam joint is undamaged.
• The failure is because of Stress reversal in the Frame.
• Concrete crushed due to lack of ductile reinforcement.

The damage is Unrepairable, Yielding of reinforcement cant be repaired

Can Provide External Support like Retrofitting as the column and Slab is Undamaged

1. b)

• Cracks are along the beam and Column.
• Beams are separated from the Column as cracks are covering the total depth of the beam.
• Pulled out Failure It might be Because of lack of development length.

Unrepairable cant provides development length in the existing structure.

1. c)

• Concrete crushed exactly at the beam-column joint.
• Cracks developed along the length of the beam.
• Beams totally separated from columns as cracks around the periphery.
• Cracks in the slab Show that stress reversal forces can’t get balanced by the flange action of the slab.

It seems like the reinforcement is undamaged so can be repaired using micro concrete.

2. a)

• Strong Beam Weak Column Frame, plastic hinge formed at top of the column.
• The soft story, as we can see no walls below the beam
• No cracks in the beam.

Unrepairable Failure, Yielding of reinforcement occurs as concrete damage.

2. b)

• Shear Failure of Column Diagonal Cracks Developed
• Reinforcement was exposed and Concrete totally damaged.
• Lack of shear reinforcement.

Due to Lack of shear reinforcement Longitudinal reinforcement buckled.
The damage is Unrepairable.

2. c)

• Column totally separated from beam & upper column.
• Plastic Hinge generated because of short column effect.
• Can see the intermediate slab.

Unrepairable Damage.