Eurocode 2 Concrete Grades & Strength Classes (EN 1992-1-1)
Determine concrete characteristics as per Eurocode 1992-1-1.
What is Eurocode Concrete Strength?
Eurocode concrete strength is defined in EN 1992-1-1 (Eurocode 2), the European standard (Eurocode Standards) design code for the design of concrete structures. In Eurocode 2, concrete strength classes are listed with the notation/pattern Cx/y, where x is the characteristic compressive strength measured on a 150 mm diameter by 300 mm high cylinder, and y is the characteristic compressive strength measured on a 150 mm cube. Both of these compressive strengths are measured at 28 days after casting the concrete. The compressive strength is the force (pressure) that the concrete can resist before it cracks or fails, measured in MPa (megapascals).
Eurocode Concrete Strength Designations
| Concrete Grade | Characteristic Cylinder Compressive Strength fck(MPa) | Characteristic Cube Compressive Strength fck,cube (MPa) | Approximate Elastic Modulus Ecm (MPa) | Mean Cylinder Compressive Strength fcm (MPa) | Approximate Mean Tensile Strength fctm (MPa) |
|---|---|---|---|---|---|
| C8/10 | 8 | 10 | 27000 | 16 | 1.2 |
| C12/15 | 12 | 15 | 27000 | 20 | 1.57 |
| C16/20 | 16 | 20 | 28600 | 24 | 1.9 |
| C20/25 | 20 | 25 | 30000 | 28 | 2.21 |
| C25/30 | 25 | 30 | 31500 | 33 | 2.56 |
| C30/37 | 30 | 37 | 32800 | 38 | 2.9 |
| C35/45 | 35 | 45 | 34100 | 43 | 3.21 |
| C40/50 | 40 | 50 | 35200 | 48 | 3.51 |
| C45/55 | 45 | 55 | 36300 | 53 | 3.8 |
| C50/60 | 50 | 60 | 37300 | 58 | 4.07 |
| C55/67 | 55 | 67 | 38200 | 63 | 4.21 |
| C60/75 | 60 | 75 | 39100 | 68 | 4.35 |
| C70/85 | 70 | 85 | 40700 | 78 | 4.61 |
| C80/95 | 80 | 95 | 42200 | 88 | 4.84 |
| C90/105 | 90 | 105 | 43600 | 98 | 5.04 |
| C100/115 | 100 | 115 | 45000 | 108 | 5.2 |
Eurocode Concrete Design Strengths
What is Eurocode Concrete Design Strength?
The design strengths of concrete listed in Eurocode 2 are used by structural engineers in structural calculations. These reduced strength values account for material variability, construction quality, and long-term effects of concrete, such as creep, shrinkage, exposure to environmental conditions, and sustained loads over time. Design strengths are derived from the characteristic strengths by applying partial safety factors and, where applicable, coefficient reduction values defined in EN 1992-1-1 or the relevant Eurocode National Annex of a country.
| Concrete Grade | Design Compressive Strength fcd (MPa) (αcc=1.00) | Design Compressive Strength fcd (MPa) (αcc=0.85) | Design Tensile Strength fctd (MPa) (αct=1.00) |
|---|---|---|---|
| C8/10 | ≈5.33 | ≈4.53 | ≈0.57 |
| C12/15 | 8 | 6.8 | 0.73 |
| C16/20 | 10.67 | 9.07 | 0.89 |
| C20/25 | 13.33 | 11.33 | 1.03 |
| C25/30 | 16.67 | 14.17 | 1.2 |
| C30/37 | 20 | 17 | 1.35 |
| C35/45 | 23.33 | 19.83 | 1.5 |
| C40/50 | 26.67 | 22.67 | 1.64 |
| C45/55 | 30 | 25.5 | 1.77 |
| C50/60 | 33.33 | 28.33 | 1.9 |
| C55/67 | 36.67 | 31.17 | 1.97 |
| C60/75 | 40 | 34 | 2.03 |
| C70/85 | 46.67 | 39.67 | 2.15 |
| C80/95 | 53.33 | 45.33 | 2.26 |
| C90/105 | 60 | 51 | 2.35 |
| C100/115 | ≈66.67 | ≈56.67 | ≈2.45 |
References
- As defined in EN 1992-1-1:2004, Eurocode 2: Design of concretestructures – Part 1-1: General rules and rules for buildings
- Concrete properties and associated design values are defined inClause 3.1
- Values have been cross-referenced and rounded where reasonable.
- Users should verify values with their concrete supplier forproject-specific data.
What Type of Eurocode Concrete Strengths Are Used Where?
Typically, concrete grades are used in different types of projects, such as:
- C12/15 to C25/30: Residential buildings, sidewalks, and light-duty pavements.
- C30/37 to C40/50: Commercial buildings, parking structures, and medium-duty pavements.
- C45/55 to C60/75: High-rise buildings, bridges, and heavy-duty pavements.
- C70/85 and above: Specialized structures such as dams, nuclear power plants, and high-performance applications.
The following table breaks down where you might see concrete classes typically used.
| Concrete Grade | Typical Uses |
|---|---|
| C8/10 | Non-structural use cases, small footings or landscaping |
| C12/15 | Light-duty slabs, pavements, pathways or minor foundations |
| C16/20 | Residential ground slabs, simple garden retaining walls, low-rise structures |
| C20/25 | Residential floor slabs, driveways, small structural walls, low-rise buildings |
| C25/30 | Medium-rise residential buildings, structural slabs, columns, beams |
| C30/37 | High-quality residential and commercial buildings, standard for high-rise floor slabs, columns |
| C35/45 | High-rise buildings, parking structures, bridges with moderate loading |
| C40/50 | High-rise towers, heavy-duty structural elements, bridge decks, industrial floors |
| C45/55 | Very high-rise buildings, heavily loaded beams/columns, high-performance infrastructure |
| C50/60 | High-strength applications in high-rise cores, large bridges, precast elements |
| C55/67 | Specialized structural elements, post-tensioned slabs, high-rise cores, industrial structures |
| C60/75 | High-performance/high-strength concrete, long-span bridges, tall towers |
| C70/85 | Ultra-high-strength elements, special infrastructure (offshore, bridges, high-rise cores) |
| C80/95 | Specialized high-strength applications, mega-structures, high-rise super-columns |
| C90/105 | Ultra-high-strength elements for super-tall buildings, high-performance bridges, niche engineering structures |
| C100/115 | Rare, extreme high-strength applications, specialty mega-structures, advanced construction |
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