Notations & Symbols

a

depth of equivalent stress block

As

area of tension reinforcement

Ask

area of skin reinforcement per unit height in one side face

b

width of compression face of member

c

distance from extreme compression fiber to neutral axis

d

distance from extreme compression fiber to centroid of tension reinforcement

dc

thickness of concrete cover measured from extreme tension fiber to center of bar or wire

Ec

modulus of elasticity of concrete

Es

modulus of elasticity of steel

f’c

specified compressive stress of concrete

fs

calculated stress in reinforcement at service loads

fy

specified yield strength of steel

h

overall thickness of member

Ig

moment of inertia of gross concrete section above centroidal axis, neglecting reinforcement

Ise

moment of inertia of reinforcement about centroidal axis of member cross-section

Mn

nominal moment

Mu

factored moment at section

B1

factor defined in Section 5.10.2.7.3

3c

strain in concrete (maximum = 0.003)

3s

strain in steel below yield point

3y

strain in steel at yield point

p

ratio of tension reinforcement

pb

balanced steel ratio

phi

strength reduction factor