Mixing your own concrete is all very well and good if you know what you are doing, but more often than not, little attention is paid when mixing your own concrete at home, so what is a concrete mix, and how can it critically jeopardize the strength and durability of your concrete.
Today we will be looking into concrete mix ratios and the effect they have on concrete strength and durability.
What Is A Concrete Mix Exactly?
In its, simplest form concrete is a mixture of fine aggerates, water, sand, and cement.
Concrete when first mixed is called plastic and only becomes a solid mass once the concrete has cured, or hardened.
The ratio of chemical compositions and the proportions of the components used in the mixture will determine whether the concrete in its hardened state, will be appropriate for which the concrete will be used.
In other words, when we talk about a concrete mix, we normally are referring to the strength or MPa of the concrete, as well as the slump of the concrete ( How runny the mixture will be )
What Is In A Concrete Mix?
Any typical concrete mix will consist of 4 ingredients. The ingredients ratio will vary depending on the purpose it is intended for.
To a point, the more cement in the concrete mix the stronger it will be.
In all cases, smaller aggregate mixtures require more water and cement than other mixtures with larger size aggregates.
What Is A Concrete Mix ingredients?
- Water
- A mixture of fine and coarse aggregates
- Sand
- Cement
This chart shows typical concrete mix ratios in weight and the strength ( MPa = Megapascals ) that your concrete will be.
The outcome of your concrete greatly depends on both the chemical bonds between the aggregates and the cement paste working as the moisture is expelled ( Bleeds ) and evaporates.
Just like many types of glue, adding too much water will have an adverse effect on your concrete and will make the overall MPa ( Strength ) of your concrete weaker. Having said this, concrete needs to be workable, and adding a little water to help workability is often needed.
For any ratio mix of concrete, maximizing the bond of aggregates will only occur when the water content is at its minimum, and all of the air has been expelled from the concrete.
What To Mix Concrete In
Mixing your own concrete at home is common, and if you’re. going to be undertaking a concrete job at home you may be asking yourself what to mix concrete in?
Ultimately if you are pouring a larger size project you will want to order ready mix through your nearest ready mix concrete supplier.
By far the most common DIY concrete mix container is the wheelbarrow, however, if you are fortunate to have access to a concrete mixer this is ideal.
the wheelbarrow is convenient for many reasons and is commonly found in most people’s homes.
Not only does the wheelbarrow offer a nice slick surface to slide your shovel against when turning and mixing your cement, aggregates, sand, and water, the wheelbarrow is perfect for relocating your concrete mix, and it is easy to pour or shovel the concrete out from.
If you do not have access to a wheelbarrow there are many other options available to you such as…
What To Mix Concrete In
3: Old Bath Or Tub
4: Hole Dug In-Ground Lined With Plastic Or Tarpaulin
DIY Concrete Mix Ratios
Planning your own DIY concrete project should be a fun and stress-free venture, and over my years in the concrete industry, I have seen many at-home DIY concrete disasters and most of this is just due to bad planning or being given the wrong advice from the get-go.
In my experience concrete should be made for its intended purpose, and as the old saying goes…Concrete is only as good as its base.
This saying has been around for a long time, and for good reason. You can make good hard concrete, and have the nicest finish on it, but if it is sitting in soft or moist ground, chances are your concrete is critically disadvantaged and cracks or moisture spots may start to present themselves sooner rather than later.
So what mixes are correct for what type of concrete job?
Here is the most common ratio for mixing concrete at home.
DIY Concrete Mix Ratio Chart
Compression
Strength
2500 psi ( 17.2 MPa )
3000 psi ( 20.6 MPa )
3500 psi ( 24.1 MPa )
4000 psi ( 27.5 MPa )
4500 psi ( 31.0 MPa )
Mixing Ratio
Cement - Stone - Sand
1 – 2 – 4
1 – 3 – 3
1 – 2 – 5
1 – 2 – 3
1 – 2 – 2
Most Commonly
Used For
Small Slabs, Fence Posts, Mowing Strips
Footings, Walls, House floors
Patios, Walkways, Dairy Sheds, Lanes
Driveways, Curb & Channel, Exterior Slabs
Heavy Commercial Floors & Slabs
Mixing Your Own Concrete Mix
When about to start mixing your own concrete there are a few things to keep in mind to get the best result possible.
For instance, you should always make sure your measurements are exactly the same for every mix, as this will ensure the concrete will dry the same color, and minimize any variations.
Here are a few tips to help when mixing your own concrete mix.
- Always use a bucket or measuring device to get your quantities exactly the same. Buckets are perfect as they are great for pouring, and you can scrape the top to get the exact same amount every time.
- Add water to your mix from a bucket slowly, this way you can take note of how much should be in each mix… Note: add small amounts of water at first to minimize overwatering. There is a fine line between just right and too much.
- Mix your concrete on an old piece of plastic or opened-out cardboard boxes… this makes for an easy clean-up and stops stains or damage on the ground or floor.
- Cement dust can stick on moist walls or surfaces as they dry, take care on windy days.
- A wet cloth and bucket of water on standby are always advised.
- Always mix your concrete well and when you think you have mixed it well enough, mix a little more to be sure. The texture should not be runny and not too hard or dry where it can not be molded, you will know when you start placing the concrete if it needs to be wetter or dryer.
- DON’T ADD WATER AND CEMENT FIRST! Always add your gravel and sand first, and add the cement last, this will reduce big clumps of cement forming and you will achieve a faster mix time.
- Old clothes are always best, and the less concrete you can get on them the better, washing machines hate concrete dust.
- Try to mix your concrete in the most convenient place where you will be placing your concrete.
- As mentioned earlier, a wheelbarrow is ideal for mixing your concrete in and is perfect for moving around and pouring.
- Ideally, if you have a concrete mixer on hand, I would suggest using this.
Happy Mixing!
I hope this has given you a better understanding of how to mix your concrete and what strength your concrete should be mixed at.
If you have any questions please do leave them in the comments section below.
