Concrete is a unique product used not only in the construction industry for the construction of buildings, but simply for the production of various products. What? For example, balusters, paving slabs, vases, countertops and so on. At the moment, modern technologies allow the production of concrete, which can easily compete with such natural materials as marble or granite. Yes, concrete is not as aesthetically pleasing, but it does not have a radiation background, which is undoubtedly good!
Buy or not?
Yes, now it's easy and simple to go to the hardware store and purchase this material, but if you decide to abandon this idea, then what? You are most likely interested in the question of how to make concrete yourself. You should immediately understand that when creating a material, you will need to adhere to certain rules and norms, otherwise the quality of the product will not please you at all. Interested in how to make concrete yourself? This is not easy, but first you need to understand the definition and characteristics of this material.
What is concrete?
This is a cement mixture in which fillers are included and the main ingredients are water, sand, cement and filler(crushed stone, gravel, pebbles, etc.). Plasticizers can be used as an additive, adding various unique qualities to the finished product.
Product Features
Not everyone can make concrete correctly, especially if you have not previously familiarized yourself with the characteristics of this material. The main characteristic of raw materials is compressive strength. This indicator is measured in megapascals. Products are distributed by brands depending on the strength values. According to GOST, classes are designated in this way - B7, 5-B80. Their main differences depend on the type of cement used, sand, fraction, type of crushed stone. The number in the class name indicates the pressure that the material is able to withstand in many cases. Getting a durable product is not easy, so you need to know in advance how to make concrete with the properties you need and what proportions you need to meet.
The simplest option
There are many different ways to prepare this material. You can make concrete at home from a mixture of coarse sand and ordinary cement mortar. Such a product is ideal for laying the foundation substrate, it also protects the base of the building from subsidence and excessive moisture. If you need a more durable type, then you need to add crushed stone with different fractions, for example, 2-3 millimeters and 30-35 millimeters. In addition, the quality of the material directly depends on the purity of the starting products.
What exactly will be required materials and tools in the work?
Understanding how to make concrete with your own hands,you will need to worry in advance about the tools and raw materials base. You will not be able to create a good mixture without crushed stone, cement and sand. For comfortable work, you will also need to prepare:
- Shovel.
- Building level.
- Concrete mixer.
- Container.
- Metal buckets for each ingredient.
More about the choice of cement
How to make concrete, you roughly understand, now we will delve into the topic. The first required ingredient is cement. It is he who binds all the components into a single whole. Usually in practice, cement grade 500 is used, in some cases grade 400, however, if you take the second type, then the strength of the object will be reduced.
A little advice: buy cement immediately before its use, as the product begins to lose its useful qualities during long-term storage. How much properties are lost?
The ratio is something like this:
- Storage over a month - subtract ten percent strength.
- Storage more than two months - subtract twenty percent of the strength.
- Storage for more than six months - subtract up to fifty percent of the strength.
- Storage more than a year - the material is not usable.
Cement must be dry, free-flowing. Don't save money by buying a damp, discounted, or even unlabelled product - it could negatively impact your safety in the future.
Choose sand
The next necessary product is sand. To prepare good concrete, you will need to take sand with a fraction of 1.5 to 5 millimeters, without impurities and with a uniform size and a run-up of no more than two millimeters. Impurities will adversely affect the strength of the material in the future, so pay special attention to the purity of the sand. According to GOST, the purchased sand must comply with the first class. What does this mean? The fact that the composition of the product of impurities and particles is not more than a percent, and the filtration rate is 5-7 m / day. The first class includes river and sea sand. In its composition, unlike career, it has a small fraction and pure. Is it possible to check the quality of the sand? Yes, it is easy and even possible to do it at home. Take a handful of sand and pour it into a jar of water, shake it up and wait a day. If the product is good, then the water above the settled sand will be clear or slightly cloudy. If so, feel free to use the material to make concrete mortar.
What about rubble?
It is also an important ingredient in concrete production and should not be replaced by pebbles. Why? Pebbles have a slippery surface that will not properly bind the concrete solution. Here the crushed stone is distinguished by roughness and notches, and this contributes to good adhesion. It is worth putting into practice a product with a particle size of 5 to 35 millimeters. Larger types are rarely used in production. The material must contain a small percentage of dust or clay components.
What kind of water should I take?
Water is an important element of concrete. It is necessary to use only clean water, without bleach, silt and oils. The amount of liquid should not be more than twenty percent of the mass of cement. This indicator is considered the best for binding. If you pour more water, then cavities will form inside the concrete, which means its strength will fall.
A word of advice: if the water is drinkable, then it can be used to make concrete.
Supplements or not?
It is allowed to add various plasticizers, reinforcing mixtures, lime to the composition. Lime, for example, is added to improve the leveling of the surface, but there is also a downside - lime can harm the normal bond between cement and aggregate, which means that the strength of the product will be weak. Plasticizers are added to the composition to give the solution fluidity or, conversely, viscosity. When adding a plasticizer, remember that, depending on the type of additive, more or less water will be required.
Flowable concrete is used to form foundations of complex shape, it quickly and reliably fills all holes and recesses. To give the solution other properties, various auxiliary elements are used.
If you are preparing concrete for a thin screed, then you need to add reinforcing components to the composition: polypropylene or polyvinyl chloride fiber. Such a component will not allow the concrete to spread.
What should be the ratio of materials for making concrete at home?
Toto make concrete correctly, the proportions of the components must be taken into account without fail. Let us first consider the ratios using cement grade 400 as an example (see table).
| Grade of produced concrete | Composition, kg (C:Sch:P) |
| 100 | 1:7:4, 6 |
| 150 | 1: 5, 7:3, 5 |
| 200 | 1:4, 8:2, 8 |
| 250 | 1:3, 9:2, 1 |
| 300 | 1:3, 7:1, 9 |
| 400 | 1:2, 7:1, 2 |
| 450 | 1:2, 5:1, 1 |
If we take cement grade 500, the table will look like this.
| Grade of produced concrete | Composition, kg (C:Sch:P) |
| 100 | 1:8, 1:5, 8 |
| 150 | 1:6, 6:4, 5 |
| 200 | 1:5, 6:3, 5 |
| 250 | 1:4, 5:2, 6 |
| 300 | 1:4, 3:2, 4 |
| 400 | 1:3, 2:1, 6 |
| 450 | 1:2, 9:1, 4 |
Now you know how to make concrete with your own hands and avoid unpleasant consequences. ATThe tables show the optimal proportions that guarantee good density and normal binding qualities.
How is the product mixed?
There is only one way to make concrete at home:
- Water is poured into the apparatus, then cement is added, and then crushed stone and sand are added to the resulting solution. The concrete mixer should be located close to the place of pouring, so that the concrete does not have time to seize or delaminate before it is poured.
- The second option involves adding all the components at once in the right proportions, in addition to water. All mixtures are mixed and only then water is poured, its amount is regulated depending on the fluidity of the material you require.
The second way is considered the most rational way of cooking, because there you are guaranteed to get an evenly mixed product. All options require a concrete mixer.
Can I make mortar by hand?
Kneading concrete with a shovel and hands is not recommended. This process is very laborious, you will get tired and take breaks, and they are undesirable during kneading. Why? All this leads to a drop in the strength characteristics of the product itself. In addition, it is unrealistic to manually mix concrete to standard indicators.
How is concrete mixed with a concrete mixer?
A unit with a motor power of 0.5 to 1 kW and a tank volume of 200 liters is suitable for you. This is enough for the job. Standard kneading is done like this:
- The required amount of water is poured into the mixer, leave about 15% of the liquid in reserve.
- Start putting cement inside and don't add 15% again.
- Add sand, the composition should be mixed for a couple of minutes so that the components are evenly distributed.
- Now add the additives you need to get the specific properties of the concrete.
- Pour crushed stone or other aggregate inside.
- Now add the rest of the water and cement.
In fact, the process is simple and takes about ten minutes. Do not mix the product for too long, otherwise the cement will begin to set. How to make concrete with your own hands, you figured it out, now it’s worth mentioning the pouring of the product separately.
Pour the concrete mass
This process also plays an important role. For example, you want to make floors, the concrete is already mixed, but it will need to be poured correctly, otherwise you will not get positive results.
To do everything right, you will need to distribute, compact the mixture and make sure that there are no bubbles in the solution. Vibration does an excellent job with these tasks, you only need to use special tools in the work. They allow you to level the surface, compact the concrete, which means that your floor will be perfect! No special tools? It doesn't matter, you can try to do everything manually. For vibration, you can use a sledgehammer, with which blows will be applied to the formwork,bars. During the filling process, it will be necessary to release air from the mixture without fail. This is done using a pointed rebar, which pierces the solution to the full depth.
Everything is done simply: pour one layer of concrete, level, pierce, and only then pour the next layer. As a result, you will get a tightly compacted, even concrete layer. The top layer will need to be leveled, this is done in several passes over a couple of hours. In order for the concrete to completely harden, dry, you will need to cover it with a film. This will protect the product from external influences, drying will be uniform.
By the way, it will take exactly 36 hours to be able to walk on it. Full drying occurs over a couple of weeks, everything directly depends on the thickness of the layer. Once the concrete is completely dry, you can continue to work on it. Maximum strength characteristics are achieved after 1-1.5 years.
Now you know how to make concrete in the country, in the house, at the construction site and so on. Follow the recommendations, strictly calculate the proportions of products. And then you will succeed, even if there was no experience before!
