Civil Engineering - Concrete Technology - Discussion

How can say that construction joints are provided where B.M &S.F are small?

Because both are inversely proportional to each other.

I think Construction joints are not provided they are formed, as the construction of the whole structure can't be done in a single stretch (the place where fresh Concreting is done on the previously casted member forms a construction joint).

What is SF?

@Shishpal : You’re right, at some points, bending moment (BM) is minimum (often zero), But at those same points, shear force (SF) is maximum, like supports of a simply supported beam.

So, we do not provide construction joints exactly at points of minimum BM if SF is high, we must find a balance between both i.e. moderate values. In the beam, at L/3 from the support, both BM and SF have moderate values, hence the best compromise location for the construction joint. Engineers should carefully select joint locations based on B.M. And S.F. Diagrams.

How is it so that at 18 m apart in huge structures? Is it not a very big space?

What is construction joint?

Construction joints are provided where the bending moment is Zero and also to have a continuity of work in the next day.

Construction joints are provided at the position where the bending moment is minimum. Usually provided at 1/3 from the support in site.

Yes, you are Correct @Rakshith.

SF means shear force.