Compare / C35/45 vs C20/25
C35/45 vs C20/25
EN 1992-1-1:2004 · Concrete
35 MPa cylinder, 45 MPa cube characteristic strength at 28 days; Ecm 34 GPa.
EN 1992-1-1:2004 · Concrete
20 MPa cylinder, 25 MPa cube characteristic strength at 28 days; Ecm 30 GPa.
Mechanical
| Property | Condition | C35/45 | C20/25 | Difference |
|---|---|---|---|---|
| Secant modulus of elasticity Ecm | 28 days | 34 000MPa2 | 30 000MPa2 | −12 % |
| Poisson's ratio ν | uncracked | 0.21 | 0.21 | same |
| Characteristic cylinder strength fck | 28 days | 35MPa3 | 20MPa3 | −43 % |
| Characteristic cube strength fck,cube | 28 days | 45MPa3 | 25MPa3 | −44 % |
| Mean compressive strength fcm | 28 days | 43MPa3 | 28MPa3 | −35 % |
| Mean axial tensile strength fctm | 28 days | 3.2MPa2 | 2.2MPa2 | −31 % |
| Characteristic tensile strength (5 % fractile) fctk,0.05 | 28 days | 2.2MPa2 | 1.5MPa2 | −32 % |
| Characteristic tensile strength (95 % fractile) fctk,0.95 | 28 days | 4.2MPa2 | 2.9MPa2 | −31 % |
| Strain at peak stress εc1 | — | 2.25‰2 | 2‰2 | −11 % |
| Ultimate strain (analysis curve) εcu1 | — | 3.5‰2 | 3.5‰2 | same |
| Strain at maximum stress (parabola-rectangle) εc2 | — | 2‰2 | 2‰2 | same |
| Ultimate strain (parabola-rectangle) εcu2 | — | 3.5‰2 | 3.5‰2 | same |
| Exponent of the parabola n | — | 22 | 22 | same |
| Strain at maximum stress (bilinear) εc3 | — | 1.75‰2 | 1.75‰2 | same |
| Ultimate strain (bilinear) εcu3 | — | 3.5‰2 | 3.5‰2 | same |
Design values
| Property | Condition | C35/45 | C20/25 | Difference |
|---|---|---|---|---|
| Long-term coefficient on compressive strength αcc | — | 11 | 11 | same |
| Partial factor for the material γc | persistent and transient design situations | 1.51 | 1.51 | same |
Physical
| Property | Condition | C35/45 | C20/25 | Difference |
|---|---|---|---|---|
| Unit weight γ | reinforced, normal percentage of reinforcement | 25kN/m³1 | 25kN/m³1 | same |
Thermal
| Property | Condition | C35/45 | C20/25 | Difference |
|---|---|---|---|---|
| Coefficient of thermal expansion α | — | 10×10⁻⁶ /K1 | 10×10⁻⁶ /K1 | same |
Fire
| Property | Condition | C35/45 | C20/25 | Difference |
|---|---|---|---|---|
| Compressive strength reduction in fire kc(θ) | at +20 °C · siliceous aggregate | 11 | 11 | same |
| at +100 °C · siliceous aggregate | 11 | 11 | same | |
| at +200 °C · siliceous aggregate | 0.951 | 0.951 | same | |
| at +300 °C · siliceous aggregate | 0.851 | 0.851 | same | |
| at +400 °C · siliceous aggregate | 0.751 | 0.751 | same | |
| at +500 °C · siliceous aggregate | 0.61 | 0.61 | same | |
| at +600 °C · siliceous aggregate | 0.451 | 0.451 | same | |
| at +700 °C · siliceous aggregate | 0.31 | 0.31 | same | |
| at +800 °C · siliceous aggregate | 0.151 | 0.151 | same | |
| at +900 °C · siliceous aggregate | 0.081 | 0.081 | same | |
| at +1000 °C · siliceous aggregate | 0.041 | 0.041 | same | |
| at +1100 °C · siliceous aggregate | 0.011 | 0.011 | same | |
| at +1200 °C · siliceous aggregate | 01 | 01 | ||
| at +20 °C · calcareous aggregate (≥ 80 % by weight) | 11 | 11 | same | |
| at +100 °C · calcareous aggregate (≥ 80 % by weight) | 11 | 11 | same | |
| at +200 °C · calcareous aggregate (≥ 80 % by weight) | 0.971 | 0.971 | same | |
| at +300 °C · calcareous aggregate (≥ 80 % by weight) | 0.911 | 0.911 | same | |
| at +400 °C · calcareous aggregate (≥ 80 % by weight) | 0.851 | 0.851 | same | |
| at +500 °C · calcareous aggregate (≥ 80 % by weight) | 0.741 | 0.741 | same | |
| at +600 °C · calcareous aggregate (≥ 80 % by weight) | 0.61 | 0.61 | same | |
| at +700 °C · calcareous aggregate (≥ 80 % by weight) | 0.431 | 0.431 | same | |
| at +800 °C · calcareous aggregate (≥ 80 % by weight) | 0.271 | 0.271 | same | |
| at +900 °C · calcareous aggregate (≥ 80 % by weight) | 0.151 | 0.151 | same | |
| at +1000 °C · calcareous aggregate (≥ 80 % by weight) | 0.061 | 0.061 | same | |
| at +1100 °C · calcareous aggregate (≥ 80 % by weight) | 0.021 | 0.021 | same | |
| at +1200 °C · calcareous aggregate (≥ 80 % by weight) | 01 | 01 |
Rows are matched by condition (thickness band, temperature, product form). A dash means the grade has no sourced value for that condition. Differences are C20/25 relative to C35/45; for ranges the lower bound is compared.