Concrete, mortar, and plaster products are familiar for all of us, but not many know what is a common ingredient to all of them. That ingredient is cement, which is present in many construction products used these days.
So what is cement made out of? To answer, I’ve gathered some data on this article to get a better view on how it’s made and what is it made out of.
There is also a cement vs concrete article on this site to better answer the uses of cement in the concrete mix. These are often used as a synonym, but concrete and cement are different from each other, cement being one of the ingredients concrete is a combination of.
How is cement made
Cement has a long history and it’s been used since ancient times so naturally, the recipe has changed a little during times. For convenience, let’s just make this about modern products.
Modern cement is made of limestone and clay or limestone and shale, it’s called Portland cement. There are other kinds of cement, but this is the most widely used one. There are also many different types of Portland cement that include fly ash, silica, etc. that helps the cement to have different properties.
Portland cement is hydraulic cement. It means that it needs water to cure. There is also non-hydraulic cement which doesn’t need water but carbon dioxide (CO2). It needs dry conditions to harden so it’s not that popular.
How to make cement
So how to make cement from limestone and clay? I’ve read that it’s made by grinding and burning the before-made ingredients until they become the grey powder we’re more familiar with.
So we can say that on paper Portland cement formula seems quite simple.
When the cement ingredients that are ground and burned are introduced to water, it will make the paste that will with fine and rough aggregates cure into the concrete. Now, this was a very simplified process without any chemistry involved as I don’t want to fake knowledge in that, I’m more interested in use and basics.
How is cement made step by step
Cement manufacturing isn’t a simple factory process as there is other work involved as well. This is overly simplified as I’m no expert and overly copying makes no sense. It’s here just to help those whore curious about the general process.
Step 1: Getting the raw materials. Limestone and clay for example, both have to be mined in open quarries.
Step 2: The mined materials would have to be crushed now. First to to bigger pieces, then to smaller ones, etc.
Step 3: Grinding and burning in the cement kiln. Now when the ground clay and limestone are placed in the 2700°F kiln, it will slowly turn into cement clinker. This is the burning process of cement
Step 4: The cement clinker is further ground to fine cement.
If you want to study it more, I recommend making a search about it. There was a lot of information about making cement available and if you’re interested, I recommend diving into it.
When was cement invented
As stated before, cement and concrete have been around for thousands of years. The Portland cement that is widely used today was patented in 1824 so modern cement is soon 200 years old.
For ancient uses, you can check things like Pantheon from Rome. For modern concrete structures, there are all kinds of examples that are better left for finding as beauty is in the eye of the beholder.
Romans are not the inventors of concrete either as Egyptians are known to have used cement as well. And before that other kind of clay and fiber building has been used as building coatings.
So it’s quite reasonable to say that cement is old and I guess that it will be present far into future as well.
Now let’s look deeper at the Portland cement. Without going to chemistry, there are still different Portland cement types that have different qualities. For us, builders, that matters.
American Society for Testing and Materials (ASTM) has categorized Portland cement types into 5 different types. The first is ordinary, the second is modified, the third is high-early-strength, the fourth is low-heat and the fifth is sulfate-resistant.
This doesn’t include things like colored cement and masonry cements. Or the others that are left out here as material list isn’t my agenda here.
Like you can see from the categories, the different types of cement have different qualities. That means they are better at different conditions and if you’re planning on using cement products, it’s good to see what’s available. Like cement with pigments.
If you’re wondering about Portland cement price, it will depend on the location, but all cement should be quite close to each other in price. Concrete cost isn’t that high so Portland cement will be around $50 to $70 for 1000lb. The smaller bags and different sellers might ask for more, but you should get it cheap by asking around.
Finally, about Portland cement vs cement of other kinds, it can be said that while Portland is the most common cement, the other ones can bring special qualities to the table.
Different types of cement mixes
There is multiple uses for cement in the construction industry and for that there are multiple types of cement mix available.
Concrete mix is something most are aware of. Made with cement, sand, rough aggregates, and water it’s one of the most used building materials in the world. It’s highly durable and strong building material four roads, driveways, houses, etc.
Then there is mortar mix where sand, cement and water is combined for adhering things like bricks together. Another common use cement product.
Then there are plaster and render mixes that have cement introduced to them. Plaster can be used indoors and outdoors and rendering mixes like stucco is mainly for outdoor use.
You should have now a bigger picture of what is cement made of and what kind of process making it is. I wanted to have a general idea of how it’s made and what the process is like.
As you can see, cement is a common factor in many forms of building. Masonry, concrete work, plastering, rendering, and many forms of decoration all rely on cement products.
It’s used as outdoor building panels and in between ceramic tiles as a grout and also as glue under them. The list goes on.