C25/30 vs C60/75

C60/75 is 1.3 times as stiff as C25/30. Their densities are about the same. Per unit mass C60/75 is 1.3 times as stiff. Strength: f_ck = 25 MPa for C25/30, f_ck = 60 MPa for C60/75.

C25/30 EN 1992-1-1 C60/75 EN 1992-1-1

Side by side

ratio = C60/75 / C25/30 · log scale

Property	C25/30	C60/75	Unit	Ratio
E Young's modulus	31	39	GPa	1.26×
G Shear modulus	12.92	16.25	GPa	1.26×
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	25	60	MPa	2.4×
f_ck,cube Characteristic cube strength	30	75	MPa	2.5×
f_cm Mean cylinder strength	33	68	MPa	2.06×
f_ctm Mean tensile strength	2.6	4.4	MPa	1.69×
f_ctk,0.05 Tensile strength, 5 % fractile	1.8	3.1	MPa	1.72×
f_ctk,0.95 Tensile strength, 95 % fractile	3.3	5.7	MPa	1.73×
ε_c1 Strain at peak stress	2.1	2.6	‰	1.24×
ε_cu1 Ultimate strain	3.5	3	‰	0.857×
ε_c2 Strain at peak, parabola–rectangle	2	2.3	‰	1.15×
ε_cu2 Ultimate strain, parabola–rectangle	3.5	2.9	‰	0.829×
n Exponent, parabola–rectangle	2	1.6	–	0.8×
ε_c3 Strain at peak, bilinear	1.75	1.9	‰	1.09×
ε_cu3 Ultimate strain, bilinear	3.5	2.9	‰	0.829×
E/ρ Specific stiffness E/ρ · derived	12.67	15.94	MJ/kg	1.26×
c₀ Bar wave speed √(E/ρ) · derived	3559	3992	m/s	1.12×
f/ρ Specific strength f/ρ · derived	10.22	24.52	kJ/kg	2.4×

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.