MATH: Reinforced Concrete Design 02

p. 276 CHAPTER 9
p= 0.85(28)275 [1-1-2(2.059)0.85(28)]
p= 0.0078
pmin= 1.4fy=1.4275
pmin= 0.0051
pmax=0.75 pb
pmax=0.750.85(28)(0.85)(600)275(600+275)= 0.037
Use p= 0.0078
As= pbd
As=0.0078(3000)(577)=13502 mm2
π4 (28)2N = 13502
N = 21.9 say 22
Along short direction:
Mu = 293.6(4.7)(1.2)(1.2/2)
Mu = 993.54 kN-m
Mu = Ru b d2
993.54 x 106 = 0.90 Ru (4700)(577)2
Ru = 0.7055 MPa
p= 0.85f'cfy [1-1-2Ru0.85f'c]
p= 0.85(28)275 [1-1-2(0.7055)0.85(28)]
p = 0.0026 [