Question { CCCL, 27604 }

why breadth of beam is shorter than (or equal to )its depth?

Answer

While Counter acting the External Action like Bending
Momnent and Deflections
The depth of beam governs ie the Strength of Beam depends
Square (Mu/bd^2) Times in Resisting Bending rather than
width
The depth of beam governsin case Deflection Cubic (bd^3/12
for Rectangular Sections) Times
In All practal cases Bending Moment and Deflections are
Dominant
But in Case of Shear Force if you keep wider beams the
resisting capacity is more
Conclusion
In case of Members with large Spans provide Depth of Beam
More (Usally 2 times the Width)
In Case of Smaller Spans with Point Loads Provide Wider
Beams

Question { Prism Cement, 45735 }

What is the thumb rule for calculating the number of chairs in slab?

Answer

As per IS:2502-1963 Clause 7.4.2
SL&s - In slabs, whether double or multiple, layers of
reinforcement are provided, the distances between the
layers may be maintained by the method illustrated in Fig.9
The Code does not Specify the Exact Spacing of the Chairs
but in Practal the Spacers are provided based on the
Spacing and Dia of Main Reinforcement it is 1 Chair per Sqm