How to make concrete
Concrete is one of the most used materials in the construction area, both domestically and industrially. However, it is a compound product, so it is important to take into account the amount of each ingredient to achieve a mixture that suits the needs of the project.
The history of construction would not be the same without concrete, also called concrete. This material has its origin in the first buildings with clay materials, since it became necessary to prepare a mixture with lime or clay to join the different pieces and thus build walls. However, although they are still used to make cement, the truth is that these binders were quite weak, so they easily succumbed to atmospheric conditions.
For this reason, in Ancient Egypt, limestone rocks were used with gypsum and water to create the homogeneous pastes that allowed great architectural monuments to be covered, such as the Pyramid of Cheops, which is more than 4,000 years old.
Materials and proportions to prepare concrete
If you do not know how concrete is made, it is important that you first know the materials that are needed. It is necessary to clarify at this point that the density of the concrete varies according to the proportions of the ingredients used, therefore, it is essential to define the use before preparing the mix .
In general, the concrete must have one part of cement, two of sand and three of gravel, which is known as concrete of proportions 1 m3 1:2:3. As for the amount of water, it depends on the work to be done, but it is possible that a proportion equal to that of cement will suffice. For occasional DIY jobs, such as covering a hole in the wall, a firm mixture that carries little water is used, but for formwork in large constructions, it is necessary to add more water to facilitate the settling of the material in corrugated steel structures and at the same time reduce the weight of the reinforced concrete.
However, it must be taken into account that while the plasticity of the concrete increases, the water also decreases the final resistance of the concrete, therefore, it is not recommended to add a lot of water to the mix, unless it is a structure with a good metal reinforcement.
On the other hand, the components of the concrete can define the quality of the construction. In most cases, Portland cement is used as the main binder, a product made up of portions of lime and clay heated to high temperatures, which is very resistant, durable and economical, making it suitable for large-scale projects. However, currently there are additives specially designed to change the properties of concrete, such as setting time , consistency, among others, thus speeding up processes. The amount of these products depends on the proportions of the concrete.
Steps to prepare concrete at home
The dosage of homemade concrete is the same as for engineering works, but the preparation varies, mainly because of the proportions. In large constructions, an industrial concrete mixer is used, because it is necessary to mix considerable amounts of material. For its part, in homes, the concrete is generally mixed manually, using a spatula and a bucket in minor jobs, but if it is a larger quantity, it is more practical to do it on a wide and flat surface. Let’s see below the step by step to make concrete at home directly on the ground.
- Define proportions
The first step is to define the quantity of each material that we are going to use to make the concrete. You can use a scale for this, but it is also possible to calculate the proportions if you have several cubes of the same size. If this is the case, you should fill one bucket of regular Portland cement, two buckets of sand, and three buckets of gravel, taking care that they all have the same volume of material. It is good to clarify that the amounts do not have to be exact, but they do have to be as close as possible to obtain a good result.
- Craft a cone, heap, or volcano
If you are wondering how to make concrete for flooring or any type of construction, you should know that an important part is mixing the aggregate ingredients and the binder while they are still dry. In this sense, it is best to make a pile on a smooth and flat floor. The idea is to empty the buckets, but gradually, for example, add a little sand, some cement and gravel for concrete, always at the top of the pile so that the material spreads. In this way, you must add the interspersed materials until you form a conical volcano-shaped pile.
- Mix the dry materials
With the help of a construction shovel, you have to make a second pile next to the first, moving the materials from one place to another, always trying to drop the content on top of the volcano. You will notice that the materials begin to mix until they acquire a more neutral tone. Experts recommend doing this procedure 3 times, so you should return the pile to the starting position and then make the second volcano again with the same material.
- Add water and mix
This is the most important step when making concrete by hand, since if we add too much water the consistency will be very liquid, but if we add too little it can be heavy and difficult to use. For this reason, it is necessary to place the water progressively, because the necessary amount depends on the aggregates; sometimes the sand comes wet , therefore the mix will require less liquid.
You just have to make a hole in the center of the pile and proceed to put a little water. It is advisable to wait for the materials to absorb this first amount of liquid and then check if it is necessary to moisten a little more. The idea is to transfer the dry ingredients from the edges of the volcano to the center, where you have added the water, and then stir with the tip of the shovel. It is important to mix everything well before adding more water.
Finally, it only remains to point out the importance of preparing the right amount of mix according to need, in order to use all the prepared concrete and thus not lose the materials.
