Answer is alpha1 and alpha2 are \"factors defining the equivalent rectangular st
ID: 1712525 • Letter: A
Question
Answer is
alpha1 and alpha2 are "factors defining the equivalent rectangular stress blocks of concrete under uniform compression and flexure, respectively; or permissible compressive and tensile stress coefficients respectively, at transfer of prestress"
5. You are given the following service load data for a column subjected to uniaxial bending: dead load, g = 380 kN dead-load moment, M, 38 kNm live load, q = 250 kN live-load moment, M,-44 kNnm. . Assuming =65 MPa and using N bars only, proportion a (preliminary) square sec- tion that is to be symmetrically reinforced with + 1.5%Explanation / Answer
Prestressed block dimensions and reinforcement details as shown above.
The assumptions here are the stress factors and compressor stress in steel got from IS 456 code book for concrete cross sectional dimensions should be provided far more than the obtained value from equations. So the provided area of steel more than required area hence the prestreed block will be safe. The moment includes in above calculation is total dead moment due to dead load and live moment due to live load hence the section can resist the moment very safely hence obtained.