The transformed area of compression steel is equal to:

Explanation:

For tension steel:

Modular ratio = m

Equivalent area = m._Ast

Stress in steel = σ_st

Stress in concrete = σ_st/m

For compression steel:

Modular ratio = 1.5 m

Equivalent area = 1.5 m A_sc

Considering deduction of concrete area (Asc) not available at steel location

Net area of compression steel considered = 1.5 m A_sc - A_sc

= (1.5m - 1) A_sc

Stress in concrete at the location of compression steel = σ'_c

Stress in compression steel = 1.5 mσ'c

Note:

Higher value of m (1.5 m) is due to the higher effect of creep considered in compression steel as compared to tension steel.