How to design a doubly reinforced beam

This construction video demonstrates the solution method to a problem often found Civil Engineering Exam. The problem is associated with designing a doubly reinforced beam.

The details of the problem are given below :-

The problem relates to a simply supported rectangular beam across an operative span of 5 meter.

A simply supported beam belongs to a type of beam that contains pinned support at one end and roller support at the other end. Based on the applied load, it endures shearing and bending.

The beam bears a uniform distributed load (UDL) concerning 2000 kg/m along with its self weight. UDL refers to a distributed load having a constant value like 1kN/m.

Here, Sigmacbc = 70 Kg/cm2
SigmaSt = 1900 Kg/cm2
m = 13

The beam section should be designed for flexure only with working stress method.

The size of the beam is limited to 40 cm wide x 40 cm overall deep. Suppose, operative cover is 4 cm (it means cover from reinforcement center).

If required, the stress in compression reinforcement will be assumed as 1.5 m times the stress in adjoining concrete.

The value of m is taken as 13 for tension but for compression reinforcement the value should be 13 x 1.5 and it will be called doubly reinforcement.

Video Source: Tech Hindi India