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[logeshcivil]

Dear Vikram
Thank you for your response.


Is there any other options available for decreasing the deflection of the long span beam.

Thank you

[vikram.jeet]

60 feet span beam

Section of 230x600 mm is grossly less from deflection as well as design oint of view - fear shear stress check may dictate increase of section.

If a T beam ,  take advantage of flanges in deflection  check , better model slabs also as plate elements. Deflection and support moments may reduce in complete model .

Other option is to make composite section of rcc 230x 600mm Plus 100x 200mm ISMB 200 , two nos one 100mm below top and other one 100mm above bottom can be composited/ fused in rcc work and advantage can be taken in design and deflection check.

[vikram.jeet]

Further to add to above post regarding composite section :

ISMB 200 steel girders be provided one row of WEB holes at its mid depth  minimum 25mm dia  at certain intervals for concrete flow . links can be inserted thru holes to make section monolithic.
Or other wise  use 2 nos ISMB 150 , section 80x150 , it may give u a gap of 100mm in mid depth of rcc beam. But all depend on how much additional strength needed from steel combo sections.

[pvgraju]

Dear Sir,

Providing pre camber to beam will also reduce total deflection.

Regards,

P.V.Gavarraju.

[vikram.jeet]

Yes cambering is must in such long span beam as age old practice at site  and mention of same be given thru notes.

[logeshcivil]

Dear sirs
Thank you for your suggestions.

Pre cambering is not possible since the structure is already completed.
Skilled labor is not available for using composite structures an also the client is not keen on providing steel beams.

[vikram.jeet]

But steel beams are hidden in rcc beam and will provide you much needed MOI for deflection limit fulfilment as also share strength.