Question

Which one of the following is correct in respect of the material efficiency of RCC flexural elements in rectangular beam, T-beam and two-way slab?

• A. All the three sections are equally efficient
• B. T-beam section is most uneconomical
• C. Two-way slab is most economical
• D. The efficiency of rectangular section lies between that of T-beam and two-way slab sections

Answer 1

The correct option is D The efficiency of rectangular section lies between that of T-beam and two-way slab sections

(d) In two way slab material efficiency is very high as moment redistribution occurs both in lateral and longitudinal directions, so MOR of section increases. Mostly in T- beams the neutral axis lies within the web. The concrete below neutral axis does not take any stress. Thus lot of material below remains unused. Hence material efficiency of rectangular beam is less than
that of two way slab but more than that of T-beam.