What is the difference between concrete and cement?


People are often heard using the words concrete and cement interchangeably, but they are in fact two completely different substances.

So, what are these materials? And why are they so often confused?

Where, and in what way, are they used?

What exactly is cement?

Cement, like flour, is an ingredient.

It is, to be more specific, a key component of concrete.

However, cement isn’t a naturally occurring organic material like stone.

Instead, it is manufactured by the chemical combination of different elements.

These include limestone, calcium, silicon, aluminium, iron and a number of different minerals.

They are heated to a temperature of around 1,482 Celsius.

This ultra-hot state causes the ingredients to create ‘clinkers’; small spheres, which resemble marbles, that are then crushed and ground into a fine powder.

Gypsum is then added, which creates a product that has a similar consistency to flour.

What is cement used for?

Cement plays a key part in all our lives.

It acts as a binder that sets, then hardens, and adheres to other materials to join them together.

It’s seldom used on its own, but binds sand and aggregate for construction purposes.

Cement that’s mixed with finer aggregates produces mortar for masonry.

If it’s mixed with sand, or gravel, it produces concrete.

After water, it’s the most widely used resource on the planet.

In fact, cement is a vital ingredient in so many construction processes that without it, much of our modern life wouldn’t be possible.

What exactly is concrete?

Concrete is a mixture of 60 to 75 per cent crushed stones or slag, which are called aggregates; sand, water, and cement.

The cement usually constitutes somewhere between 10 to 15 per cent of the mixture.

When aggregate is mixed with cement, and then water is added, the combination forms a workable paste or slurry that can easily be poured or moulded into shape.

As it’s being laid, chemical reactions in the mix create a hard matrix.

This binds the materials together, giving the substance an incredibly hard, stone-like finish that makes it suitable for a wide variety of construction purposes.

The aggregates for concrete must be carefully chosen.

The type and size included in the mix depends on the thickness of the concrete required, and the purpose it will be used for. 

Thin building sections might require small coarse aggregates, while large-scale civil engineering projects often use larger aggregates.

A dam, for instance, might use aggregates with a size up to 150mm.

The character of the concrete is determined by the quality of the paste.

Its strength, in turn, depends on the ratio of water to cement.

That ratio is determined by the weight of the mixing water divided by the weight of the cement.

To create high-quality cement, you lower the ratio of water from the mix, without losing the workability of the paste.

Generally speaking, using less water produces a higher quality concrete, providing that the concrete is properly laid, consolidated, and cured.

What are the uses of concrete?

If cement is one of the most used resources on the planet, then concrete is one of the most used products.

In fact, it’s the most commonly used man-made material in the world and is a vital construction material for buildings, bridges, roads and dams.

It has countless structural applications such as drains, pipe and kerbs. Put simply, civil engineering could not exist without it.

What are the advantages of concrete?

Whatever its application, concrete has proven its durability over time.

It’s renowned for its strength, and can be adapted to meet the needs of a specific project by altering the water ratio.

Incredibly, concrete strengthens year on year.

That is because of the ability of its components to form bonds with surrounding moisture particles.

It resists erosion, fire, rotting, rust, and other weathering with very little maintenance needed.

This means it has a much longer lifespan than many other materials.

It reflects heat, rather than absorbing it like asphalt, which helps to keep buildings cool.

It also reduces the need for an air conditioning system, in turn saving energy.

This combination of strength, durability and versatility makes concrete the perfect material for a wide range of uses.

It’s cement that make concrete adaptable, and it’s concrete that makes construction possible.

Goodmix Concrete provides high-quality, mixed concrete for a wide range of construction projects across the North West.

Why not get in touch with our friendly team to discuss yours?