C60/75 vs C70/85

C70/85 and C60/75 are about equally stiff. Their densities are about the same. Per unit mass they are about equally stiff (15.94 and 16.75 MJ/kg). Strength: f_ck = 60 MPa for C60/75, f_ck = 70 MPa for C70/85.

C60/75 EN 1992-1-1 C70/85 EN 1992-1-1

Side by side

ratio = C70/85 / C60/75 · log scale

Property	C60/75	C70/85	Unit	Ratio
E Young's modulus	39	41	GPa	1.05×
G Shear modulus	16.25	17.08	GPa	1.05×
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	60	70	MPa	1.17×
f_ck,cube Characteristic cube strength	75	85	MPa	1.13×
f_cm Mean cylinder strength	68	78	MPa	1.15×
f_ctm Mean tensile strength	4.4	4.6	MPa	1.05×
f_ctk,0.05 Tensile strength, 5 % fractile	3.1	3.2	MPa	1.03×
f_ctk,0.95 Tensile strength, 95 % fractile	5.7	6	MPa	1.05×
ε_c1 Strain at peak stress	2.6	2.7	‰	1.04×
ε_cu1 Ultimate strain	3	2.8	‰	0.933×
ε_c2 Strain at peak, parabola–rectangle	2.3	2.4	‰	1.04×
ε_cu2 Ultimate strain, parabola–rectangle	2.9	2.7	‰	0.931×
n Exponent, parabola–rectangle	1.6	1.45	–	0.906×
ε_c3 Strain at peak, bilinear	1.9	2	‰	1.05×
ε_cu3 Ultimate strain, bilinear	2.9	2.7	‰	0.931×
E/ρ Specific stiffness E/ρ · derived	15.94	16.75	MJ/kg	1.05×
c₀ Bar wave speed √(E/ρ) · derived	3992	4093	m/s	1.03×
f/ρ Specific strength f/ρ · derived	24.52	28.6	kJ/kg	1.17×

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.