What Is Concrete Made Of? - Explained By Converge

April 21, 2022

What concrete is made of

Concrete is a mix between cement, aggregates, and water. Many people think concrete and cement are the same thing, but cement is actually one of the ingredients that make concrete. Concrete is made of three different ingredients. Concrete mixture contains aggregates, water, and Portland cement. The cement and the water bind the materials together and hardens the concrete mix.


Portland cement

Portland cement was invented and patented in 1824 by the Englishman Joseph Aspdin. Portland cement is used as a binding material in concrete and is a mix between limestone and shale or limestone and clay. Before it blends with water, it is a fine powder. When adding water, a chemical reaction occurs and together with aggregates, the setting of the concrete and the curing of the concrete starts.



Aggregates are things such as gravel, sand, or crushed stone. The purpose of the aggregates is to stuff the concrete and provide strength. They are divided into different types. For example, gravel is a rough one, and sand is a fine one.


Read more: What are the differences between cement and concrete?


How concrete is made

So, how is concrete made? The process of making concrete starts with Portland cement and ends with the curing. There are many different steps in the process, and here are some of them:


-   The proportioning of the ingredients.

-   The mixing of the ingredients.

-   The hydration of the concrete.

-   The placement process.

-   The curing of the concrete.


We will now explain these steps further below.


The proportioning of the ingredients

All ingredients must be perfectly proportioned for the concrete mix to be strong and workable. The chemical reaction between the different components happens differently depending on the amount of each ingredient that has been added in relation to each other.


The mixing of the ingredients

The mixing is when all the ingredients, water, Portland cement, and aggregate are mixed. It is very important to mix properly.


The hydration of the concrete

Hydration is an exothermic process in the making of concrete. It happens when the water and the cement are reacting with each other. This starts directly after the mixing process is done, which is also when the concrete starts to build its strength.


The placement process

When the hydration has started, it is very important to place the concrete. This is because it hardens fast, and the placement can’t be done if the hydration process has gone too far. The placement process determines how strong and durable the concrete will become when it is finished.


You can use many different techniques when placing concrete. The ideal technique varies depending on, for example, the type of concrete mix or what you will build with the concrete.


The curing of the concrete

Concrete curing is when the water and the cement bind together and build strength. The curing is dependent on the concrete staying damp as well as the temperature. If you pour concrete in cold weather, the concrete will cure slower, or if it's too cold, it will stop curing completely. If you, on the other hand, let the concrete cure in a temperature that is too hot, it will cure too fast, and you risk cracking.


Reading tips: Concrete cube test, concrete slump test, what concrete slabs are and what concrete maturity is.


What you want from a concrete mix


-   That it is cost-effective. How good, strong, and durable the concrete becomes depends much on the ratio between cement and water. Therefore, to keep the costs down, you should try to minimize the need for these ingredients. 


-   That the mix is easy to work with. This helps the whole process and saves time for the people in the industry. If the workflow can proceed as planned and not be delayed due to the concrete mix, everyone will be satisfied.


-   The proportions of the ingredients in the mix are adjusted to fit its purpose. Depending on what the concrete is to be used for, the mix needs to achieve different characteristics when hardened. This can, for example, be that it can handle frozen temperatures or extra durability.


Frequently asked questions


What are the ingredients of concrete?

Concrete consists of 3 different ingredients. These are water, Portland cement and aggregates.


Is it a long process to make concrete?

Yes, it is! It all starts with finding the right proportions of the ingredients in the mix. Thereafter, you need to mix it properly, let the hydration start, place it, and then let it cure. It is a long process but it gives you strong and durable concrete of high quality if you do all the steps correctly.


What are aggregates in a concrete mix?

Aggregates can, for example, be gravel, sand, or crushed stone. They can be divided into different types. Gravel is seen as a rough one, and sand is considered a fine aggregate when speaking of ingredients in a concrete mix.


Is Portland cement important when making concrete?

Yes, Portland cement is, along with water, the most important ingredient in a concrete mix. Mainly because the water and the cement start to react to each other, creating strong concrete when the mix has hardened.

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