Identification of Cracks

FAILURES AT JOINTS:

In general the failures occur due to low stability,strength and inadequate durability.

1^ST QUESTION Fig:a

In the figure the failure occur at the edge of the beam and the failure occur only for the beam this typwe of failure occur due to moment in the beams in the opposite direction.

It will not repaced or repaired because the failure is with the reinforcement.

FIG:b

In the given figure the failure is observed at the top and bottom of the beam at the beam and column junction.

This failure due to inadequate strength.

This may be adjusted because the failure is observed at the concrete but not the reinforcement.

FIG:c

In the figure the complete structure is observed to have cracks soo the failure is not only at the junction but also at different points.0

This mode of failure may seen in the situations like earthquacks.

This is not replaced because the bound between the concrete and the steel may lost internally.

2^ND QUESTION:

FIG:a

In the given fig the failure occuer mostely at the right top corner of the beam at the junction of the beam and column.

As we can see in the failure the reinforcement was bend towards LHS of the structure soo we can conform that this failure occur due the heavy loading at the left side of the structure.

It can not replaced because the failure damaged the bond between the materials and structure got deformed.

FIG:b

In the given figure it is clearly seen that the crack is diagonal to the beam so in  most of the case the diagonal cracks are occur due to inadequate strength,stability,durability.

In this type of failure ew can not repalace the exesting beam before removing the excess load if possible.

Or els using nondistructive method we can strengthen the structure.

FIG:c

In this figure the structural member got distructed completely and there is no chance of repaing the structure.

This type of structure failure mostely occur due to earthquack or less moment resistance