Common Concrete Strengths & Their Uses

Concrete is an exceptionally versatile building material. And, beyond the benefits of its affordability, easy installation and quick setting, it can also be blended to best suit the specific needs of the task at hand.

Different concrete strengths can be blended, in order to provide the construction project with the best-fit material.

This could be anything from a concrete that’s designed for heavy duty wear, or a blend that’s made to achieve a sleek, smooth and even finish.

So, to help you understand the most common concrete strengths and grades, and identify the right strength for the job that you’re working on, we’ve created a simple guide to concrete types.

C8 (GEN 0) Concrete

C8 / GEN 0 concrete is relatively lean, or ‘weak wet’. Because of its comparatively low strength, this concrete mix is mainly used to provide a firm base, in applications when no structural strength is needed.

Strength (Newtons): 8N (28 day strength)

Common construction use: C8 concrete is very versatile, and a popular general purpose mix. As such, it’s commonly used for housing or other non-structural projects.

Best used for:

• Bedding 8N
• Mass and cavity fill
• Kerb backing
• Blinding

C10 (GEN 1) Concrete

C10 / GEN 1 concrete is a slightly stronger mixture, with a greater level of flexibility. However, it is still not durable enough to be used in outdoor fixtures (unless it is completely covered or encased).

Strength (Newtons): 10N (28 day strength)

Common construction use: Thanks to its flexibility and light weight, C10 concrete is commonly used in general purpose housing projects.

Best used for:

• Foundations for a pad, conservatory or wall
• Domestic foundations (built in DC-1 soil that are unreinforced)
• Drainage works (at 10N)
• Filling trenches
• Some agricultural uses
• Cavity and mass fill
• Kerbing and haunching
• Unreinforced strip footings
• Oversite (below suspended floors or binding house floors)
• Mass concrete (in non structural applications, where DC-1 non-aggressive ground exists)

C15 (GEN 2) Concrete

C15 / GEN 2 concrete is, primarily, designed for house floors and domestic projects that don’t have any embedded metal. Thanks to its strength, it can be used in both commercial and for domestic site projects.

Also, take note that this concrete mix can be used outside, but it must be encased or fully covered.

Strength (Newtons): 15N (28 day strength)

Common construction use: C15 concrete is widely used across house and internal flooring projects, where carpets, tiles or other types of covering will be added on top.

Best used for:

• Floors without embedded metal
• Unreinforced and reinforced strip footings (for small walls)
• Foundation filling for trenches
• Foundations for walls, sheds and conservatories
• Paving for steps and paths
• Blinding
• Unreinforced mass concrete fills

C25 (ST2) Concrete

C25 concrete has a low-medium concentration of cement, which means that it has a relatively medium level of strength. As such, it can be used in projects that require more structural strength and durability.

Strength (Newtons): 25N (28 day strength)

Common construction use: C25 concrete is an extremely versatile mix. It is widely used in domestic and commercial projects, typically for house foundations and building extensions.

Best used for:

• Bases for extensions, either for houses or patios
• Un-reinforced strip footings
• Fence post footings
• Un-reinforced foundations
• General groundwork
• Mass concrete and trench fills
• House floor blinding and pad foundations
• Kerbs
• Unreinforced house floors
• Drainage and filling (around manholes or trenches)
• Mass concrete (for non aggressive, non structural DC-1 ground)
• Some agricultural uses

C40 (ST5) Concrete

C40 concrete has a very high strength level. As such, it is a great fit for agricultural, commercial and domestic projects.

Strength (Newtons): 40N (28 day strength)

Common construction use: The strength of C40 concrete can easily withstand light trolley or foot traffic. This means it is a popular material for structural and support beams, roadworks and agricultural projects.

Best used for:

• Structural applications
• Industrial applications
• Floor slabs (for garages or houses, which are partially or completely reinforced, and either suspended over sub-floor voids or ground bearing)
• HGV parks
• Agricultural equipment stores
• Foundations for traffic sign posts, planted lighting columns and posts for environmental barriers

At iMix Concrete, our team of concrete mixing specialists can provide you with all of the concrete grades listed above.

As domestic and commercial concrete suppliers, we supply durable, high quality and affordable concrete, across London and the surrounding areas.

iMix Concrete has a long-standing reputation for our efficient, accurate and professional service. So, if your upcoming project requires any of these concrete strengths, don’t hesitate to get in touch.