C70/85 vs C80/95

C80/95 and C70/85 are about equally stiff. Their densities are about the same. Per unit mass they are about equally stiff (16.75 and 17.16 MJ/kg). Strength: f_ck = 70 MPa for C70/85, f_ck = 80 MPa for C80/95.

C70/85 EN 1992-1-1 C80/95 EN 1992-1-1

Side by side

ratio = C80/95 / C70/85 · log scale

Property	C70/85	C80/95	Unit	Ratio
E Young's modulus	41	42	GPa	1.02×
G Shear modulus	17.08	17.5	GPa	1.02×
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	70	80	MPa	1.14×
f_ck,cube Characteristic cube strength	85	95	MPa	1.12×
f_cm Mean cylinder strength	78	88	MPa	1.13×
f_ctm Mean tensile strength	4.6	4.8	MPa	1.04×
f_ctk,0.05 Tensile strength, 5 % fractile	3.2	3.4	MPa	1.06×
f_ctk,0.95 Tensile strength, 95 % fractile	6	6.3	MPa	1.05×
ε_c1 Strain at peak stress	2.7	2.8	‰	1.04×
ε_cu1 Ultimate strain	2.8	2.8	‰	1×
ε_c2 Strain at peak, parabola–rectangle	2.4	2.5	‰	1.04×
ε_cu2 Ultimate strain, parabola–rectangle	2.7	2.6	‰	0.963×
n Exponent, parabola–rectangle	1.45	1.4	–	0.966×
ε_c3 Strain at peak, bilinear	2	2.2	‰	1.1×
ε_cu3 Ultimate strain, bilinear	2.7	2.6	‰	0.963×
E/ρ Specific stiffness E/ρ · derived	16.75	17.16	MJ/kg	1.02×
c₀ Bar wave speed √(E/ρ) · derived	4093	4143	m/s	1.01×
f/ρ Specific strength f/ρ · derived	28.6	32.69	kJ/kg	1.14×

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.