Whether you are looking for the right domestic or commercial concrete mix for your construction job, or are just curious about the different grades of concrete and would like to know more, read on to get an understanding of these different types of concrete and their uses, or get in contact today!
Understanding Grades of Concrete
Grades of concrete are defined by the strength and composition of the concrete, and the minimum strength the concrete should have following 28 days of initial construction. The grade of concrete is understood in measurements of MPa, where M stands for mix and the MPa denotes the overall strength.
Concrete mixes are defined in ascending numbers of 5, starting at 10, and show the compressive strength of the concrete after 28 days. For instance, C10 has the strength of 10 newtons, C15 has the strength of 15 newtons, C20 has 20 newtons strength and so on.
Different mixes (M) come in various mix proportions of the various ingredients of cement, sand and coarse aggregates. For instance, M20 comes in the respective ratio of 1:1:5:3. You can see other examples below in the table.
| Concrete Grade | Mix Ratio (cement : sand : aggregates) | Compressive Strength | |
| MPa (N/mm2) | psi | ||
| Grades of Concrete | |||
| M5 | 1 : 5 : 10 | 5 MPa | 725 psi |
| M7.5 | 1 : 4 : 8 | 7.5 MPa | 1087 psi |
| M10 | 1 : 3 : 6 | 10 MPa | 1450 psi |
| M15 | 1 : 2 : 4 | 15 MPa | 2175 psi |
| M20 | 1 : 1.5 : 3 | 20 MPa | 2900 psi |
| Standard Grade of Concrete | |||
| M25 | 1 : 1 : 2 | 25 MPa | 3625 psi |
| M30 | Design Mix | 30 MPa | 4350 psi |
| M35 | Design Mix | 35 MPa | 5075 psi |
| M40 | Design Mix | 40 MPa | 5800 psi |
| M45 | Design Mix | 45 MPa | 6525 psi |
| High Strength Concrete Grades | |||
| M50 | Design Mix | 50 MPa | 7250 psi |
| M55 | Design Mix | 55 MPa | 7975 psi |
| M60 | Design Mix | 60 MPa | 8700 psi |
| M65 | Design Mix | 65 MPa | 9425 psi |
| M70 | Design Mix | 70 MPa | 10150 psi |
Choosing the right concrete grade for the construction job:
So what can these grades be used for and which is best for the job at hand? Below is a list of a few of the initial concrete grades and what they are best used for.
C10
Used for: Patio slabs, pathways and non-structural work
Type: Domestic & commercial use
C15
Used for: Pavement kerbs and floor blinding
Type: Domestic & Commercial
C20
Used for: Domestic floors and foundations (where the weight of structure will be lighter). Also good for workshop bases, garages, driveways and internal floor slabs.
Type: Domestic
C25
Used for: Construction in all areas. Multi-purpose concrete mix, usually used for foundations.
Type: Domestic & Commercial
C30
Used for: Pathways and roadways (this is the lowest grade concrete mix that can be used for this purpose). More durable than the grades that have come before, and thus is much more weather-resistant and can take heavy road traffic.
Type: Commercial
C35
Used for: Commercial structures. This heavy concrete mix is usually used for creating external walls and slabs, as well as for structural piling.
Type: Commercial
C40
Used for: Commercial construction sites, creating foundations and beams for structural support and roads. The most durable in this list, C40 can withstand chemical corrosion also, so is frequently used on farms where slurry could corrode structures, or in septic tanks.
Type: Commercial
We hope you found this guide useful, and if you are interested in learning more, visit our blog for more information on the concrete types available to you.