Identification of Cracks

Identification of Cracks

Question 1 : What is the mode of failure or damage of the beams in the figure above? Are the damages repairable? Elaborate

a)

in this picture the mode of failure is dispaching of concrete from the rebars and production of cracks from bottom to the top of beam due to the high tention produces at the bottom of beam.its also have a another mode of failure that is fluxerual failure due to stress revrsal cause by earth complications. in the case of acting the laod or stress on the structure it takes compression at top and tension at bottom .so.. in this case it fails at bottom so it has provided no efficient reinforcement at bottom. if the provided reinforcement will be satisfied and it will be repairable the damages through the yeilding the reinforcement by the local welderrs then it will not repeated.

b)

in this picture it looks seperated beam from the column at its joining place, and the cracks are developed overall element.

the mode failure for this structure is called beam pullout failure due to insufficient of rebars and developement length at the joints.the beam dispached from the column due to acting the horizontal load when the time earthquake occures. the damge is not been repairable because of providing developement length of rebar at joints is very difficult. when the case of providing reinforement bars should be careful ,if any mistake is happend, it may not repairable after counstruction.

c)

this picture looks developed overall cracks across the structure,at the joining section of beam and column , some cracks are produced at the botoom of slab.

this type of failure mode is called plastic hinge failure,the damage occurs at the joints only .this may occures due to cyclic lateral loading and stress act reversal at the joints,the slab also getting risk due to taking tention .it can be passible to repair by giving strength from external appliences by attaching strongly concrete or cement.

Question 2 : What is the mode of failure or damage of the beams in the figure above? Are the damages repairable? Elaborate

a)

this looks damaged at the bottom of joints location,this damage cause at the ccolumn only , in this case here walls also not available may be its parking lot at the ground floor.

this mode of failure is Soft storey failure, Technically Plastic hinge formation.

Due to absence of Infill walls at the Ground floor, The plastic hinge forms at the Top of ground storey columns during Lateral movement.

Based on the development of crush of concrete, it can either be repairable or Non-repairable..

b)

this failure picture looks Concrete detached from the column,its loks in shape of diagonally.the Longitudinal rebars are stable.shear rebars are not provide sufficiently.

It's a mode of Pure Shear failure.Inadequate shear reinforcement compels concrete takes all the shear stresses.

c)

in this case here the column looks completely failure at its top.the wodden piels have been keep to give support.

this type mode of failure is known as Short Column failure.An additional slab or a Beam connected to a Column in mid-height leads to this effect.This leads to failure especially if the connection is unintentional and not accounted in design.The failure given in the picture is not at all repairable.