Identification of Cracks
1.
a)
1. Concrete is crushed and reinforcement is visible
2. Beam top portion looks good and safe, because of the slab flange
3. The cracks start from bottom to top
4. Rebar yielding occurs in bottom
5. It is a flexural failure due to a reversal of stress during earthquake
6. During this failure top support experiences compression and bottom support experiences tension
7. Top compression is safe because of slab
8. Reinforcement got yielded, so it cannot be repaired.
b)
1. Cracks along beam and column edge
2. Concrete is not crushed severely
3. Beam looks away from column
4. Its beam pullout failure due to insufficient development length in reinforcement of joints
5. The horizontal movement of the structure makes this condition worse
6. Detached the beam from column during earthquake
7. Providing anchorage length between concrete is diificult
8. It is not repairable
c)
1. Cracks are at the joints of the beam and column
2. Slabs are also developed cracks along the beam width direction
3. It is a platsic hinge failure
4. It occurs mainly in the joint zone first
5. Slab has handled the tension part and cracked with its flange condition
6. The joint can be strengthened
2.
a)
1. Concrete got damaged at the top of the column
2. Beam is safe
3. Location of column looks at the edge of building
4. No walls are present so it is the ground floor for parking area
5. It is soft storey failure, plastic hinge formation
6. Due to no walls, the plastic hinge forms at the top of the column at the ground storey of the building during lateral movement
7. It can neither be repairable or non repairable
b)
1. Concrete completely damged diagonally
2. Longitudinal reinforcement are not damged but visible
3. Shear reinfrocement spacing looks wider
4. Its a pure shear failure
5. Shear stresses attacked the concrete completely
6. It is not repairable
c)
1. Column completely failed at the top
2. There are two slabs connected to the column
3. Wooden piles must be a temporary support to avoid entire collapse
4. It is short column failure
5. An additional slab or beam connected lead to this effect
6. It is not repairable