C16/20 vs C55/67

C55/67 is 1.3 times as stiff as C16/20. Their densities are about the same. Per unit mass C55/67 is 1.3 times as stiff. Strength: f_ck = 16 MPa for C16/20, f_ck = 55 MPa for C55/67.

Side by side

ratio = C55/67 / C16/20 · log scale
Property C16/20 C55/67UnitRatio¼×1×4×
E Young's modulus 29 38 GPa 1.31×
G Shear modulus 12.08 15.83 GPa 1.31×
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 16 55 MPa 3.44×
f_ck,cube Characteristic cube strength 20 67 MPa 3.35×
f_cm Mean cylinder strength 24 63 MPa 2.62×
f_ctm Mean tensile strength 1.9 4.2 MPa 2.21×
f_ctk,0.05 Tensile strength, 5 % fractile 1.3 3 MPa 2.31×
f_ctk,0.95 Tensile strength, 95 % fractile 2.5 5.5 MPa 2.2×
ε_c1 Strain at peak stress 1.9 2.5 ‰ 1.32×
ε_cu1 Ultimate strain 3.5 3.2 ‰ 0.914×
ε_c2 Strain at peak, parabola–rectangle 2 2.2 ‰ 1.1×
ε_cu2 Ultimate strain, parabola–rectangle 3.5 3.1 ‰ 0.886×
n Exponent, parabola–rectangle 2 1.75 – 0.875×
ε_c3 Strain at peak, bilinear 1.75 1.8 ‰ 1.03×
ε_cu3 Ultimate strain, bilinear 3.5 3.1 ‰ 0.886×
E/ρ Specific stiffness E/ρ · derived 11.85 15.53 MJ/kg 1.31×
c₀ Bar wave speed √(E/ρ) · derived 3442 3940 m/s 1.14×
f/ρ Specific strength f/ρ · derived 6.538 22.47 kJ/kg 3.44×

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.