Identification of Cracks
1) a.
Observation:
- Beam concrete is spalled at the bottom and in beam-column joints location.
- Reinforcement is also visible in the picture.
Mode of failure:
- Beam column joint detailing is not done as per ductile design.
- Lateral force is not considered during the design of beam and it leads to crack formation at the junction.
- Based on the provided reinforcement moment of resistance not satisfied the design requirement of the beam.
Repairing techniques:
- Cracks can be repaired using some patching of cement mix.
- But inorder to avoid the further formation of cracks member is to be redesigned by considering the lateral forces and retrofitting technique is to be adopted.
1)b.
Observation:
- Crack formation in the column.
- No defects in the beam
Mode of failure:
- Weak column - strong beam concept is adopted.
- Inadequate design of column.
Repairing techniques:
- Redesign the column and use retrofitting technique to repair.
1)c.
Observation:
- Cracks are formed at the beam column joint.
- Cracks developed at the slab bottom also.
Mode of failure:
- Size of the beam is not flushed with the size of the column. one edge of the beam is flushed with the edge of the column whereas the other edge protruded.
- Spalling of concrete due to improper loading transfer mechanism from beam to column.
- Improper site execution of beam column joint junction.
2)a.
Observation:
- Spalling of concrete in the exterior column.
- Reinforcement is bent in the column.
Mode of failure:
- Exposure condition is not considered for external condition.
- under design for the loading conditions.
Repairing techniques:
- Redesign the column and retrofit.
2)b.
Observation:
- Spalling of concrete.
- Reinforcement is exposed and bent.
Mode of failure:
- Buckling failure of column
- Poor confinement.
Repairing techniques:
- Repairing is not possible in this case.
- Design the column with proper design assumptions and steel column can be added for a support.
2)c.
Observation:
- Beam column joint is fully damaged.
- Reinforcements are bent and exposed.
Mode of failure:
- Building seems to be deteriorated due to age of the building.
- Srength of the building is reduced.
Repairing techniques:
- Restore the building.