If you’ve ever watched a concrete mixer truck spinning away at a building site and wondered what’s actually in that giant drum, you’re in the right place. Today we’re answering a common question we get from curious customers: does ready mix concrete need sand?
The short answer is: absolutely yes! Sand is a crucial ingredient in ready mix concrete. But there’s much more to the story, and understanding the ‘why’ behind it can help you appreciate why your concrete mix designs turn out the way they do for all sorts of construction projects.
Let’s dive into the wonderful world of concrete and uncover why sand is so important to what we do here at Express Concrete, from our batching plants straight to your concrete delivery.
What Actually Goes into Ready Mix Concrete?
Before we get stuck into the sand question, let’s quickly break down what ready mix actually contains:
- Cement – This is the binding agent that holds everything together
- Water – Activates the cement and makes the mixture workable
- Aggregates – These include:
- Coarse aggregates (gravel or crushed stone)
- Fine aggregates (sand)
- Additives (sometimes) – Special ingredients that might change how the concrete behaves
Together, these ingredients create the strong, durable material we use for everything from garden paths to massive skyscrapers.
Why Sand is Essential in Ready Mix Concrete
Sand isn’t just a filler material in concrete—it’s absolutely essential! Here’s why:
Filling the Gaps
Imagine building a wall with just large stones. No matter how carefully you place them, you’ll end up with gaps and spaces between them. That’s exactly what happens with the larger aggregates (gravel) in concrete.
Sand particles are much smaller, so they fill those tiny spaces between the larger stones. This creates a denser, stronger concrete with fewer weak points.
Creating a Smooth Finish
Have you ever seen concrete that has a really rough, bumpy surface? That might be because it didn’t have enough sand. Sand helps give concrete that smoother, more workable texture that’s easier to finish.
Without enough sand, concrete would be rough, porous, and difficult to work with. It would be nearly impossible to create those smooth driveways, patios, and footpaths we rely on every day.
Strengthening the Mix
You might think that bigger, harder stones would make concrete stronger, but that’s only part of the picture. The fine particles of sand combine with cement to create a “mortar” that binds everything together.
According to research from the University of Cambridge, the proper proportion of sand in concrete can increase its compressive strength by up to 40% compared to mixes with insufficient sand content.
How Much Sand Goes into Ready Mix Concrete?
The exact amount of sand in ready mix concrete varies depending on what the concrete will be used for, but typically:
| Concrete Type | Sand Content (% by volume) | Common Uses |
|---|---|---|
| Standard Mix | 25-30% | Driveways, footpaths, general construction |
| High-Strength | 20-25% | Structural elements, commercial buildings |
| Decorative | 30-35% | Patios, decorative features, coloured concrete |
| Flowing/Self-levelling | 35-40% | Indoor flooring, complex forms |
As you can see, sand typically makes up about a quarter to a third of the total volume of ready mix concrete. That’s a lot of sand!
What Kind of Sand is Used in Ready Mix Concrete?
Not just any sand from the beach will do! The sand used in quality ready mix concrete, like ours at Express Concrete, must have specific characteristics:
Clean and Washed
The sand needs to be free from contaminants like salt, clay, or organic matter. These impurities can weaken concrete and cause problems later on.
Properly Graded
“Graded” means the sand contains particles of different sizes within a specific range. This mixture of particle sizes helps create stronger concrete.
Sharp and Angular
The best concrete sand has sharp, angular particles rather than smooth, rounded ones. These jagged edges lock together better and create stronger bonds with the cement paste.
According to the British Geological Survey, construction sand is one of the most extracted materials in the UK, with millions of tonnes used annually just for concrete production.
What Happens If You Don’t Use Enough Sand?
Skimping on sand might seem like a way to save money, but it leads to serious problems:
- Weak Concrete – Without enough sand, concrete won’t achieve its designed strength
- Honeycombing – You’ll get those ugly little holes and gaps throughout the concrete
- Poor Workability – The mix will be difficult to pour and finish
- Increased Shrinkage – More cracking as the concrete dries and cures
- Reduced Durability – The finished concrete won’t stand up to weather and wear
At Express Concrete, we carefully measure all our ingredients to ensure your ready mix concrete performs exactly as expected for your construction projects. That’s part of our commitment to quality.
Can You Use Too Much Sand?
Yes, absolutely! Too much sand creates its own problems in your concrete mix:
- The concrete becomes weaker because there’s not enough cement to bind all the sand
- The mix becomes very stiff and difficult to work with
- The finished concrete may be more prone to surface dusting and wear
- It might cause issues when using a concrete pump during delivery
Getting the balance right is crucial, which is why professional ready mix suppliers like us carefully control our mix designs at our batching plants.
Ready Mix vs. Site-Mixed Concrete: The Sand Advantage
One of the big advantages of using ready mix from a supplier like Express Concrete instead of mixing on site is consistent, precise proportioning of materials—including sand.
When concrete is mixed on site, it’s common for proportions to vary from batch to batch. Sometimes there’s too much sand, sometimes too little. This inconsistency can lead to sections of concrete with different strengths and appearances, which can be a nightmare for construction projects of any size.
With ready mix concrete, computer-controlled batching plants ensure the perfect amount of sand goes into every single load, giving you consistent results every time. Plus, our concrete delivery service means you get the perfect mix right when you need it, ready to pour or pump.
Environmental Considerations of Sand in Concrete
It’s worth mentioning that sand is a natural resource, and there are environmental concerns about sand mining. The construction industry uses billions of tonnes of sand globally each year, which has led to increased focus on sustainable sourcing.
At Express Concrete, we’re committed to sourcing our sand responsibly from properly managed quarries that follow environmental guidelines. According to the UK Minerals Association, UK quarries must follow strict restoration plans that often leave sites in better ecological condition than before extraction began.
Some exciting research from the University of Bath is also exploring alternative materials that could partially replace sand in concrete, including recycled glass and certain industrial by-products.
Conclusion: Yes, Ready Mix Concrete Definitely Needs Sand!
To wrap things up, sand isn’t just an optional ingredient in your concrete mix—it’s absolutely essential for creating strong, workable, durable ready mix concrete that will stand the test of time for any construction projects you have on the go.
When you order from Express Concrete, you can be confident that our carefully controlled mix designs contain the perfect amount of high-quality sand for your specific project. From our modern batching plants to your site via our reliable concrete delivery service, we’ve got you sorted—whether you’re pouring directly or using a concrete pump.
If you have any questions about our concrete mixes or want to discuss your next project, get in touch with our friendly team today!
Frequently Asked Questions
Can I add more sand to ready mix concrete after it’s delivered?
No, you should never add additional materials to ready mix after delivery. The concrete mix has been carefully designed with precise proportions at our batching plants. Adding extra sand will weaken the concrete and may void any guarantees on the product. It could also cause problems if you’re using a concrete pump for placement.
How do you know if concrete has the right amount of sand?
Professional ready mix suppliers use precise measuring systems and quality control procedures to ensure correct proportions in all our mix designs. When mixed properly, concrete should be workable but not runny, with a consistent texture throughout. This is especially important for successful construction projects where strength and finish quality matter.
Is the sand in concrete the same as playground sand?
No, concrete sand is different from playground sand. Concrete sand is generally coarser and has angular particles, while playground sand is finer and has rounded particles for safety. The two types of sand serve very different purposes.
Does coloured concrete need sand?
Yes! Coloured concrete has the same basic ingredients as standard concrete, including sand. The colour comes from special pigments added to the mix. The sand content might be adjusted slightly to enhance the colour’s appearance.
How long does it take for ready mix concrete with sand to dry?
Ready mix concrete doesn’t technically “dry”—it cures through a chemical reaction. It usually takes 24-48 hours to harden enough to walk on, but continues to gain strength for up to 28 days. The sand content affects workability but doesn’t significantly change curing time.
Can beach sand be used in concrete?
Beach sand is generally not suitable for concrete because it contains salt and other impurities that can weaken concrete and cause reinforcement to rust. Construction sand is specially selected and processed for use in concrete.