The terms mortar, cement and concrete are often used interchangeably amongst those outside of the industry. But the three are actually completely different.
Put simply, the differences are as follows: mortar is a mixture of cement and sand, cement is a fine binding powder that’s always combined with other materials, and concrete is a combination of cement, gravel, and sand.
If you’re wondering what all the differences are between mortar, cement, and concrete, the following article will break them down in detail, as well as answer some of the most frequently asked questions regarding these materials.
Mortar is a building material that’s made up of cement and fine sands, as well as water. Lime (a sedimentary mineral mostly made up of calcium carbonate) is also added to enhance the product’s durability.
Adding water to the mixture will activate the cement, causing it to harden (or cure).
So, cement is an ingredient within mortar- but what’s the difference between mortar and concrete?
While concrete is a complete building material used for foundations and other masonry structures, mortar is used more as a glue to hold bricks and other masonry materials together.
You’ll most commonly find mortar as a dry, pre-mixed form sold in bags, so that all you need to add is water. Sometimes it’s mixed on site, though, either with a cement mixer or manually, using a shovel (or a hoe) and a wheelbarrow.
A similar product to mortar is grout, which is essentially a form of mortar without the addition of lime. Grout also has a higher amount of water than mortar, meaning it’s used not as a binding material, but simply to fill gaps.
Cement is purely a binder, similar to how flour would be used to bake. It holds all the other materials together, and these other materials (like mortar or concrete) are required; you’d never use cement on its own.
So, not only is cement completely different from concrete and mortar, but it’s an essential component within concrete and mortar. The primary ingredients present in cement include calcium, limestone, iron, silicon, and aluminum.
The mixture of ingredients is heated in large kilns to roughly 2,700 degrees Fahrenheit (or 1,482 degrees Celsius), which results in a product referred to as ‘clinkers’, which look somewhat like marbles.
The clinkers are ground down into a powder, and at this stage gypsum is added, and the substance becomes cement. It’s the addition of water that makes cement harden, due to the chemical process involved.
There are multiple types of cement, but the most common types include high alumina cement, acid resistant cement, hydrophobic cement, and sulfate resistant cement.
High alumina cement is used for structures built in regions with high temperatures, and acid resistant cement is employed for chemical-proof structures.
Hydrophobic cement is used for regions with temperatures below freezing, and sulfate resistant cement is used for structures likely to be regularly exposed to sulfate.
As we’ve established, the difference between concrete and cement is that cement is an ingredient found within concrete. Concrete is a complete building material, and is used for foundation walls, patios, concrete slabs, and other masonry structures.
It begins as a dry mixture which consists of cement, sand, and gravel (or equivalent). When water is added, the cement is activated, and the mix is bound together to become a product as hard as rock.
Metal reinforcements are often added to concrete structures in order to increase their strength, as well as to lessen the effects of cracks. Concrete is most often found ready-made in bags, meaning all you have to do to use it is add water.
These are most suited for smaller scale projects.
For larger projects, ready-mix cement would either be delivered via truck, or the builders would acquire bags of cement, which they would then mix with gravel and sand.
What is Lime in the Context of Building Materials?
Lime is found in cement, and as cement is found in mortar there will always be some lime within said product- but extra lime is also added to the mixture of mortar for increased durability.
The difference between mortar and grout, as well as the higher water content in the latter, is that grout doesn’t contain lime. This is because it’s used to fill gaps, rather than as a binding material, so the extra durability isn’t required.
But what actually is lime? Limestone is a sedimentary mineral composed mostly of calcite, otherwise known as calcium carbonate. Limestone is burnt at high temperatures to produce lime, which is a calcium oxide.
When water is added to the lime, this creates slaked lime, which is a calcium hydroxide.
When first mixed lime putty is malleable, but once it’s absorbed enough carbon dioxide it will strengthen and revert back to calcium limestone.
What Makes Concrete Crack?
Concrete goes through very small changes (roughly in the 500 millionths) when it dries. It’s this shrinkage that results in cracks in the concrete. Metal rebar is often installed in concrete pavements so that the cracks will appear in a straight, neat line at the joints.
Conclusion: The Difference Between Mortar, Cement and Concrete
So, yes- there are huge differences between mortar, cement, and concrete. Cement is a substance made up of raw materials, and is the ingredient found in both mortar and concrete that activates the hardening of said products.
Concrete is a complete building material most often used as the foundation of a structure, while mortar is used to bind bricks and other masonry materials together.
It’s important to learn all the key differences between building materials when you’re first getting into building. Certain structures will require different materials than others, whether it be mortar, concrete, cement, or all three- and often it’ll be all three.