Identification of Cracks

ANS 1 A) This crack will be formed due to the flexural failure of beam . The flexural strength known as modulus of rupture , band strenth , fracture strength on on the jack ,is amaterial property defined as the stress in a material just before it yield in a flexural test . The flexural stength represent the highest stress experienced with in the material at its mmovement of rupture its is measured inn terms of stress . to overcome this type of failure main steel is provided at the bottom / top of the beam . The damage are repairable , to repaire damaged beams , locate a local welder or metal shop and request angle iron , cut and drilled to the length of the beam being repaired . remove any pipes , wires etc . currently goining through the beam .be sure to turn off the water , power etc .mount the angle iron on the jack and temporary post . get the angle iron in place and slowly raise the jack until the angle iron is wedged up against the damaged beam .

B ) This crack are formed due to the mistake done in the construction and honeycombing in concreting . To avoid crack in concrete , avoid using high slump concrete . concrete of moderate slump result in less cracking . high slump concrete can ponly be used if it is control by concrete admixture or designed such that segregation and bleeding of concrete is controlled . concrete adsmixtures such as water reducers or super plastcizer can be used toincrease slump while reducing addation of water content . Air entertained concrete can also be produce to increase slump espicall when concrete to be subjected to freeze and thaw cycle . As mentioned previously , poor concrete consolidation is usually the top causes of honeycombing , along with poorvariation.

C ) The cracks are formed due the beam coloum joint failure . in the strong column weak beam design . Beam are expected to form palastic hinges at their end and develope flexurakl overstrength beyond the design strength . the high internal forces develop at plastic hinge causes critical bond condition in the longititudnal reinforcing bars passinmg through the joint and also impose high shear demand in the joint core .

ANS 2 ) A) This crack will be formed due to the flexural failure of col.umn . columns have the most important role in all structure members of a building . according to the base civil engineer concept , column failure wants to be occurring after beams and other components damage. Performance of existing building in earthquake indicte that the beams are less vuleeralble to damage during earthquake and their damage appears to be less critical to performance .

B) This crack will be performed due to the shear failure of A column . lateral loads in astructure are carrying by vertcal elements such as coloumn and shear wall . when there are also shear walls , columns carry these lateral loads . lateral loads are generated by wind , earthquak loads are retaing wall .

C) This crack are formed due to the short column failure . In short coloum failure due to yielding and we define this phenomena as crushing . short columns are classified based upon slender ratio of the effective length and least laterial dimension . short column will fail because only of direct compressive streess occured that short column will usuaaly fail due to direct compression or crushing.