Introduction
Flanged section is more economical, efficient than rectangular section, so whenever it is possible for rectangular section to be replaced by flanged section. A section is considered as flanged if there is no relative motion between the flange & web or casting is done monolithically. Incase there is relative motion between flange and web then it is not called flanged section. In construction side, beam and slab are casting simultaneously for that reason.
Example of Flanged Section,
If monolithic construction of slab and beam is done & slab is in compression region, design beam as flanged section, but if slab is in tension region design the beam as rectangular section.
Effective Depth of Flanged Section
If width of flange is excessive then the part of the flange only provides compressive force and is termed as effective width (bf) of the flange, Which is computed as follows:
a) ISOLATED BEAM-FLANGED SECTION
Where,
For Example,
b) BEAM FLOOR SECTION
FOR T- SECTION
FOR L-SECTION
Problem :
- Calculate the effective width of flange for a Isolated T-beam spanning over simply supported effective span of 8m, section details are as follows & all values are in mm.
Solution,
2. Calculate the effective flange width of continuous beam over effective span of 30m. Section details are as follows.
Solution:
