C35 vs C40

C40 is 1.1 times as stiff as C35. Their densities are about the same. Per unit mass they are about equally stiff (27.66 and 29.17 MJ/kg). Strength: f_m,k = 35 MPa for C35, f_m,k = 40 MPa for C40.

C35 EN 338:2016 C40 EN 338:2016

Side by side

ratio = C40 / C35 · log scale

Property	C35	C40	Unit	Ratio
E₁ Modulus, direction 1	13	14	GPa	1.08×
E₂ Modulus, direction 2	0.43	0.47	GPa	1.09×
E₃ Modulus, direction 3	0.43	0.47	GPa	1.09×
G₁₂ Shear modulus 1-2	0.81	0.88	GPa	1.09×
G₁₃ Shear modulus 1-3	0.81	0.88	GPa	1.09×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	8.7	9.4	GPa	1.08×
ρ Density	470	480	kg/m³	1.02×
ρ_k Density, characteristic (5 % fractile)	390	400	kg/m³	1.03×
f_m,k Bending strength	35	40	MPa	1.14×
f_t,0,k Tension parallel to grain	22.5	26	MPa	1.16×
f_t,90,k Tension perpendicular to grain	0.4	0.4	MPa	1×
f_c,0,k Compression parallel to grain	25	27	MPa	1.08×
f_c,90,k Compression perpendicular to grain	2.7	2.8	MPa	1.04×
f_v,k Shear strength	4	4	MPa	1×
E/ρ Specific stiffness E/ρ · derived	27.66	29.17	MJ/kg	1.05×
c₀ Bar wave speed √(E/ρ) · derived	5259	5401	m/s	1.03×
f/ρ Specific strength f/ρ · derived	74.47	83.33	kJ/kg	1.12×

Values at the first thickness band or product form of each material (EN 338:2016; EN 338:2016). 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.