C80/95 vs C90/105

C90/105 and C80/95 are about equally stiff. Their densities are about the same. Per unit mass they are about equally stiff (17.16 and 17.98 MJ/kg). Strength: f_ck = 80 MPa for C80/95, f_ck = 90 MPa for C90/105.

C80/95 EN 1992-1-1 C90/105 EN 1992-1-1

Side by side

ratio = C90/105 / C80/95 · log scale

Property	C80/95	C90/105	Unit	Ratio
E Young's modulus	42	44	GPa	1.05×
G Shear modulus	17.5	18.33	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	80	90	MPa	1.12×
f_ck,cube Characteristic cube strength	95	105	MPa	1.11×
f_cm Mean cylinder strength	88	98	MPa	1.11×
f_ctm Mean tensile strength	4.8	5	MPa	1.04×
f_ctk,0.05 Tensile strength, 5 % fractile	3.4	3.5	MPa	1.03×
f_ctk,0.95 Tensile strength, 95 % fractile	6.3	6.6	MPa	1.05×
ε_c1 Strain at peak stress	2.8	2.8	‰	1×
ε_cu1 Ultimate strain	2.8	2.8	‰	1×
ε_c2 Strain at peak, parabola–rectangle	2.5	2.6	‰	1.04×
ε_cu2 Ultimate strain, parabola–rectangle	2.6	2.6	‰	1×
n Exponent, parabola–rectangle	1.4	1.4	–	1×
ε_c3 Strain at peak, bilinear	2.2	2.3	‰	1.05×
ε_cu3 Ultimate strain, bilinear	2.6	2.6	‰	1×
E/ρ Specific stiffness E/ρ · derived	17.16	17.98	MJ/kg	1.05×
c₀ Bar wave speed √(E/ρ) · derived	4143	4240	m/s	1.02×
f/ρ Specific strength f/ρ · derived	32.69	36.78	kJ/kg	1.12×

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.