Identification of Cracks
What is the mode of failure or damage of the beams in the figure above? Would you characterize the case as damage or as a failure? Are the damages repairable? Elaborate
a)
Generally, there are two types of failures caused in beams 1-Shear failure 2-Flexural failure. In the above figure the damage is caused on beam near beam and column junction. Here Shear mode of failure occured. This type of failure occures at end of beams. Improper or negligiency during reinforcement can lead to this type of failure. Improper placement of plastic hinges also cause damage like this. Shear failures cracks can be prevented by can providing stirrups. Plastic hinges should be places accurately.
b)
This failure is due to improper strength and inadequate or insuffienct curing.Due to this duraility and abrasive resistance are affected and decreased. This damage can be reduced by plastering well . Can recovered by shotcreting on it again.
c)
This Damage is occuring at beam-column junction. This is governed by bond and shear failure mechanisms(brittle). Generally this junctions are most prone in failure of structure in earthquakes. This can repaired temporarily only.
2.What is the mode of failure or damage of the beams in the figure above? Would you characterize the case as damage or as a failure? Are the damages repairable? Elaborate
a)
This failure is caused due to buckling due excess bending moment on column near beam and colum juction.This occurs due to improper reinforcement and low strength .To avoid this all reinforecement bars in a single column should not be meeting at same point.
b)
This failure is caused due to influence of partial height infill increasing column shear force i.e short column effect-undesirable mode of deformation. The simple solution is to close the openings by building a wall of full height.
c)
This failure is caused at Beam-column joint. This failure is due to weak column and strong beam .Due to this crushing takes place .While constructing structures must always include strong column and weak beam.