Design principles and calculation method 1 Nominal axial strength NpLRa Npl,Rd= Aafy 1,0AcfckAsfsk 十 Ya Yc Ys Steel Rebars contribution Concrete contribution contribution Design principles and calculation method - I Nominal axial strength 𝑁𝑝𝑙,𝑅𝑑 𝑁𝑝𝑙,𝑅𝑑 = 𝐴𝑎𝑓𝑦 𝛾𝑎 + 1,0𝐴𝑐𝑓𝑐𝑘 𝛾𝑐 + 𝐴𝑠𝑓𝑠𝑘 𝛾𝑠 Steel contribution Concrete contribution Rebars contribution