Concrete is a construction material that comprises a mixture of both fine and coarse materials such as aggregates, water, and Portland cement. The cement binds the elements together to form a paste that will solidify and harden over time through a chemical reaction called hydration. The solid product that resembles a rock mass is called the concrete. Looking at the process of how concrete is formed, we can say that concrete, on the initial stage of the mixing process, is plastic and malleable. But when it hardens, it becomes strong and durable, and that makes it great building material for houses, buildings, driveways, and roads. 

If you’re planning to do some construction or renovation in your home, backyard, or building, concrete is an inevitable ingredient in your building project. You can buy a bag of concrete mix in your local hardware store, or you can make your do-it-yourself concrete mix. To create your concrete pre-mixed, you need to purchase cement and combine it with other materials such as water, sand, gravel, or other forms of aggregates. You can also make your limestone cement. Regardless if this do-it-yourself project is new to you, creating your concrete is an easy task provided that you have the proper tools and materials. 

Before we start creating your own concrete powder, let’s go over some definitions first: 

  • Cement is a pulverized limestone, oyster, freshwater seashells that undergo a heating process to remove the CO2. This acts as a binder as it adheres to other materials like aggregates and water. 
  • Concrete, as mentioned above, is a combination of cement, water, and aggregates such as sand or gravel that hardens over time. 
  • Mortar is a mixture of water, cement, sand, and lime that acts like a paste that binds building block materials that dry over time. 

Now let’s make your concrete powder. If you don’t want to buy a ready-mixed bag of cement, you can also make your own by using a limestone. 

How to make limestone cement

  1. Buy or look for limestone in your backyard. You can tell if the stone you find is limestone if it crackles or cracks when you soak it in vinegar. If you cannot find one in your property, then buying online, in a hardware store, or any home and gardening centers are your next option. 

2. Using a sledgehammer, crush the limestone into 3-inch pieces. Some companies use mechanical crushers or hammer mills to convenience since they are mass-producing materials. But if you will just use the materials in your home repair, then a sledgehammer will do the job for you. 

3. Preheat your kiln and put your limestone there under 2,700 Fahrenheit (1482.2 C). Wait for 3 to four hours before switching the heat off. You can use a high-temperature kiln thermometer to check the temperature of the kiln. Since the kiln is emitting harmful gas, don’t forget to wear your goggles and respirator for protection.  

4. Remove the limestone out of the kiln. Let it cool for one to two hours. Use a fan to speed up the cooling process. Once it cools, disintegrate the pieces of each limestone. Make sure to wear thick gloves when crumbling up the limestones. 

5. Place the limestones to a wheelbarrow, then using a shovel, break up the limestone into smaller pieces until it looks like fine dust. 

How to make a concrete powder out of limestone cement

Now that we have our DIY cement, it’s time to make our concrete powder. 

  1. Get your all-purpose sand, either coarse of fine, from a hardware store or online. If you have a spare of sands in your backyard, you can use that. Combine two parts of the sand to one part of cement. You can mix the two using a wheelbarrow and a shovel, but if you have access to a concrete mixer, that will work better. If you are trying to mix, more than 80 lbs (36.28 k), it is advisable to use a concrete mixer for accuracy and efficiency. Make sure to follow the 2:1 ratio when adding materials. 
  1. Add four parts of your aggregates such as gravel or crushed brick to the mixture. In this case, you should follow the ratio of 4:1 – 4 parts of gravel for every one part of the cement mixture. These aggregate materials play a vital role in holding the concrete together once it dries. If you prefer a smoother finish, you can opt for smaller or finer pieces of gravel. Continue mixing until everything is well incorporated. 

Once all the dry materials are properly mixed, you can now add some water to make your concrete, or you can simply set aside these dry materials for future use. This is now your do-it-yourself concrete powder.