How to Choose the Right Concrete Mix for Your Project

It could be said that concrete is the foundation of construction (see what we did there?). Aside from being used as a literal foundation for most builds, concrete is used for so many parts of a project. Why? Because it's a versatile material. The different concrete mix types mean it can be used for a wide scope of things, from literal foundations to pillars or flooring. So, how do you know which concrete design mix is the right one for your project?

Choosing the right mix for your project is crucial for the stability, durability, safety and required finish of your project.

Each mix type has different strengths and qualities. These are defined by their grades. So, to choose the right concrete, you need to understand the different grades. But, don't worry, this is something we can help you with when ordering your concrete with us.

At 2 Brothers Concrete & Pumping, we live and breathe concrete. With a combined 25 years in the industry, we are experts on the subject (as you would expect). Our team knows everything there is to know about concrete types and will be able to reel off the best concrete for your commercial or domestic project within seconds of knowing what you are doing.

In this blog, we explain what the different options are, their applications and how you choose which one is right for your project.

Understanding Concrete Mix Ratios and Strength Grades

As you likely know, concrete is made up of four ingredients: cement, sand, aggregates and water. By changing the ratio of each of these ingredients, you change the characteristics of the final product.

On top of this, you can change the aggregate used, also adapting the outcome of the concrete made.

Ratios of ingredients in concrete determine its strength, durability and workability.

So, if you are looking for higher-strength concrete, your concrete ratio will include more cement than water. Meanwhile, if you are looking for something with a lower strength, you would choose a concrete mix type with higher aggregate content and a lower cement ratio.

The concrete is graded. The grades are basically shorthand for the ratio of ingredients, its strength and load-bearing capacity.

The grades range from C10 (lower strength) to over C35 (higher strength). Typically, anything over a C35 grade will be used in specific circumstances where projects have very specific strength and durability requirements.

Concrete Mix Types and Their Applications

As with most materials, there are a number of concrete mix types to choose from. Usually, your choice will be dictated by the project and what is needed from the concrete – how strong it needs to be, how workable it is, and its durability.

Standard Mixes for Common Projects

There are a number of standard design mixes that are commonly used in commercial and domestic projects.

C10-C20 mixes are the lowest-graded concrete mix types. They are predominantly aggregate, with a ratio of cement to sand to aggregate of 1:4:6.

With a load capacity of between 10 MPa and 20 MPA (very small), these grades are better used for non-load-bearing applications like pathways, garden walls, or levelling layers because the concrete would crumble under too much pressure.

The next common grade up is C25 to C30. Slightly stronger than the above grades, these concrete mix types use less aggregate and a slightly larger amount of sand.

Typical ratios for these grades of concrete will look like 1:1.5:3.

The load-bearing capacity of these, therefore, is higher, ranging from 25 MPa to 30 MPa. So, they are used where more weight will be put on the structure, such as in bridges, flooring slabs where there will be heavy machinery or high foot traffic and reinforced concrete beams.

High-Strength Concrete for Heavy-Duty Applications

For more heavy-duty industrial applications, the grades go from C35.

C35 concrete or above is comprised of a more coarse aggregate and requires less of it to create a more dense final product.

Typically, the ratio of ingredients will be along the lines of 1:1:2. On top of this, it will have lower water content.

As you would expect, with a denser material and higher grade, the load-bearing capacity of these grades will be higher at 35 MPa and above.

These concrete mix types are used where heavy loads are expected, be it equipment and machinery or foot traffic. So, they are commonly used for commercial foundations, industrial floors, car park flooring, structural beams, and columns.

Specialised Mixes

Finally, there are a number of specialised concrete mixes.

These aren't as frequently required but offer specific characteristics for their specific uses.

• Self-levelling concrete – as the name suggests, the concrete levels out by itself as it's being poured. It is ideal for creating smooth, even surfaces on floors and for projects with large surface areas.
• Waterproof concrete – concrete that repels water and is typically used for basement walls, retaining walls, and any application exposed to moisture.
• Decorative concrete (e.g., exposed aggregate, coloured concrete) – added decorative elements for a more visually appealing look. This is perfect for driveways, patios, or surfaces that need to look good as well as be strong.

Factors to Consider When Choosing a Concrete Mix

So, now you know the difference between concrete mix types, how do you choose them?

There are several factors you need to consider when selecting a concrete design mix:

• Project type and load-bearing requirements – what are you working on, and where will the concrete be? What will the load bearing needs be? Will it have a lot of foot traffic or none at all?
• Environmental exposure and durability – will it be exposed to water or moisture? Will it experience the freeze-thaw cycle during winter? Or will it be exposed to chemicals?
• Finish and aesthetic requirements – will the concrete be seen? If so, can it look industrial, or should it have a more visually appealing style to it?

If your concrete will need to be able to withstand moisture or water, common sense says you will need a specialised mix of waterproof concrete.

Meanwhile, if you are using concrete for a garden path, driveway or patio, you might want to look into decorative concrete.

The strength and placement of concrete will determine what grade of concrete you need. Something incredibly strong will need a C35 or higher, but typical home DIY projects can often get away with C10-C30.

We recommend discussing your project and concrete needs with experts before ordering so you can be sure you are choosing the right concrete mix type.

Get the Right Concrete Mix Type with 2 Brothers

Getting the right concrete mix type for your project is imperative. If it's wrong, it can delay construction or worse, crumble part way through or once in use.

So, it is important you understand the different grades of concrete and what you need to think about when ordering the material.

At 2 Brothers Concrete & Pumping, we take the time to understand what you are doing and why you need concrete before completing your order. We use our years of industry knowledge to help ensure you are ordering the right mix.

If you aren't sure which type of concrete you need, we can work with you to figure it out, making the process quick and painless. Plus, we will probably throw in a few jokes to keep the conversation entertaining.

We provide a mix-on-site service, so if your specifications change or we arrive on-site and decide another concrete type would be better, we can amend the mixture there and then.

Plus, our volumetric trucks also mean that we will only mix the exact amount you need, meaning you only pay for what you lay.

And don't worry if your project site is in a difficult-to-reach area. We have a fleet of line and boom pumps, which are able to pump the concrete to the area.

So, if you need concrete for your commercial or domestic project, get in touch with the experts at 2 Brothers Concrete & Pumping. Call us on 01489 552737 or complete our online contact form, and we will be in touch with you soon.