The point of Contraflexure is a point whese Bending Moment changes its sign (BM is zero).
2.) GRADE OF CONCRETE & MIX PROPORTION:
C:S:A
1.) M-75 1:4:8
2.) M-10 1:3:6
3.) M-15 1:2:4
4.) M-20 1:1-5 :3
5.) M-25 1:1:2 3.
Notes:- C:S:A° C-- Cement, S---Sand,
A--- Aggregate
3) MINIMUM CLEAR COVER:
As per IS Code 456:2000
a} Footing = 40mm
b} Column = 50 mm
c} Slab & stairs = 15 mm
d} Beam = 25 mm
4.) DENSITY
i} R.C.C = 2500 kg/m³
ii} Steel - 7850 kg/m³
iii} Brick = 1600 - 1920 kg/m³
iv} PCC= 2400 kg/m³
v} Cement = 1440 kg/m³
