Compare / C25/30 vs C12/15
C25/30 vs C12/15
EN 1992-1-1:2004 · Concrete
25 MPa cylinder, 30 MPa cube characteristic strength at 28 days; Ecm 31 GPa.
EN 1992-1-1:2004 · Concrete
12 MPa cylinder, 15 MPa cube characteristic strength at 28 days; Ecm 27 GPa.
Mechanical
| Property | Condition | C25/30 | C12/15 | Difference |
|---|---|---|---|---|
| Secant modulus of elasticity Ecm | 28 days | 31 000MPa2 | 27 000MPa2 | −13 % |
| Poisson's ratio ν | uncracked | 0.21 | 0.21 | same |
| Characteristic cylinder strength fck | 28 days | 25MPa3 | 12MPa3 | −52 % |
| Characteristic cube strength fck,cube | 28 days | 30MPa3 | 15MPa3 | −50 % |
| Mean compressive strength fcm | 28 days | 33MPa3 | 20MPa3 | −39 % |
| Mean axial tensile strength fctm | 28 days | 2.6MPa2 | 1.6MPa2 | −38 % |
| Characteristic tensile strength (5 % fractile) fctk,0.05 | 28 days | 1.8MPa2 | 1.1MPa2 | −39 % |
| Characteristic tensile strength (95 % fractile) fctk,0.95 | 28 days | 3.3MPa2 | 2MPa2 | −39 % |
| Strain at peak stress εc1 | — | 2.1‰2 | 1.8‰2 | −14 % |
| 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 | C25/30 | C12/15 | 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 | C25/30 | C12/15 | Difference |
|---|---|---|---|---|
| Unit weight γ | reinforced, normal percentage of reinforcement | 25kN/m³1 | 25kN/m³1 | same |
Thermal
| Property | Condition | C25/30 | C12/15 | Difference |
|---|---|---|---|---|
| Coefficient of thermal expansion α | — | 10×10⁻⁶ /K1 | 10×10⁻⁶ /K1 | same |
Fire
| Property | Condition | C25/30 | C12/15 | 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 C12/15 relative to C25/30; for ranges the lower bound is compared.