C20/25 vs C50/60

C50/60 is 1.2 times as stiff as C20/25. Their densities are about the same. Per unit mass C50/60 is 1.2 times as stiff. Strength: f_ck = 20 MPa for C20/25, f_ck = 50 MPa for C50/60.

Side by side

ratio = C50/60 / C20/25 · log scale
Property C20/25 C50/60UnitRatio¼×1×4×
E Young's modulus 30 37 GPa 1.23×
G Shear modulus 12.5 15.42 GPa 1.23×
ν Poisson's ratio 0.2 0.2 – 1×
ρ Density 2447 2447 kg/m³ 1×
γ Weight density 24 24 kN/m³ 1×
α Coefficient of thermal expansion 10 10 10⁻⁶/K 1×
f_ck Characteristic cylinder strength 20 50 MPa 2.5×
f_ck,cube Characteristic cube strength 25 60 MPa 2.4×
f_cm Mean cylinder strength 28 58 MPa 2.07×
f_ctm Mean tensile strength 2.2 4.1 MPa 1.86×
f_ctk,0.05 Tensile strength, 5 % fractile 1.5 2.9 MPa 1.93×
f_ctk,0.95 Tensile strength, 95 % fractile 2.9 5.3 MPa 1.83×
ε_c1 Strain at peak stress 2 2.45 ‰ 1.22×
ε_cu1 Ultimate strain 3.5 3.5 ‰ 1×
ε_c2 Strain at peak, parabola–rectangle 2 2 ‰ 1×
ε_cu2 Ultimate strain, parabola–rectangle 3.5 3.5 ‰ 1×
n Exponent, parabola–rectangle 2 2 – 1×
ε_c3 Strain at peak, bilinear 1.75 1.75 ‰ 1×
ε_cu3 Ultimate strain, bilinear 3.5 3.5 ‰ 1×
E/ρ Specific stiffness E/ρ · derived 12.26 15.12 MJ/kg 1.23×
c₀ Bar wave speed √(E/ρ) · derived 3501 3888 m/s 1.11×
f/ρ Specific strength f/ρ · derived 8.172 20.43 kJ/kg 2.5×

Values at the first thickness band or product form of each material (EN 1992-1-1; EN 1992-1-1). A minimum and a characteristic value are not the same kind of number — read the ratio as a guide. Each material's page lists every band and every source.