Concrete is an amazing material. It is used not only for the construction of foundations of buildings, but also for the installation of walls and roofs. But this does not limit the scope of its application. Concrete can also be used to produce piece items, such as paving slabs, balusters, vases, and even countertops for living rooms and kitchens.
Today there are many ways to prepare concrete and this allows you to raise this material to almost a step, equated to such natural materials as granite or marble.
Although according to its external data, it is not particularly aesthetic as natural stones, but you can confidently say what it is made of.
If you decide to give up buying concrete and decide to make it yourself, then you need to observe the exact proportions of the materials to be mixed. Only in this case will your finished mixture have high strength and durability.
The whole process of concrete preparation quite simple, although you need to take into account a number of special points that will determine its quality and suitability in the future. Depending on the purpose of use, the method of its preparation will also change.
There are two main options for making concrete with your own hands: In the first case, mix all the ingredients dry, and then just pour water.
In the second case, you pour cement, aggregate and sand into the poured water.
We ordered sand and crushed stone on the pesokischeben website. ru
With dry mixing, all materials seem to be evenly distributed, but after adding water and manual mixing there is no exact guarantee that the entire volume will get wet quickly and efficiently. As a result, it turns out that a dry layer remains at the bottom, and as a result, this will lead to a violation of proportions.
If you mix the solution thoroughly and for a very long time, it will take a long time, and as a result, the solution will begin to set, and this will directly affect its strength. When all the components of the solution are added to the water, the cement will mix for a long time and will not be able to adhere well enough to the filler. The second option is slightly better than the first when mixing small quantities of concrete.
The most famous proportions of concrete are 1: 3: 6 parts of cement, aggregate and sand, also 0.5-1 part of water, depending on the required fluidity of the solution.
Adhering to these proportions, a concrete solution that is not very convenient for mixing may turn out.
When adding proportions, a bucket or other container is taken and filled (high-quality compaction is not needed) with sand, aggregate and cement in turn and weighed. Using elementary calculations, convert all buckets into a percentage to each other.
When mixing all proportions of concrete, the best way is to use special concrete mixers .Only thanks to such machines, it is possible to quickly and sufficiently high-quality mix the components of the concrete mixture and deliver them to the place of consumption before the mixture thickens.
Of course, the old manual method can be used, but it is not particularly suitable for large volumes of mixture. With this method of mixing, there is no way to control the entire process and add ingredients according to the desired recipe.
The composition of concrete is a mixture of a solution of cement and filler. The main ingredients are: cement, sand, filler (crushed stone, gravel, pebbles, slag, etc.).
However, in recent years, modern technologies have assumed special additives - plasticizers. Their purpose is to impart unique properties to concrete.
The main and main characteristic of concrete is strength (expressed in mega pascal).
Concrete by its strength is usually subdivided into grades. According to state standards in the CIS countries, concrete classes are marked as B7.
5 - B80. The number in the brand name means pressure in MPa.
The most common type of concrete is a mixture of cement and coarse sand. This concrete is used for the basement under the main foundation. Usually, such concrete is made directly at the bottom of the formwork under the main foundation.
When mixing the mixture, you need to add a small amount of water in order for the solution to acquire a density like wet soil. The strength of this concrete is low, but it perfectly protects the main foundation from subsidence and abundant moisture. To obtain the most durable concrete, it is necessary to use a variety of crushed stone with different fractions from 2 to 35 mm.
The quality of concrete will depend on the purity of all its components. Therefore, before proceeding with the preparation of the solution, it is worth considering each incoming component separately.
Cement is the main and main ingredient of the concrete mix, which binds all the components together. Most often used for the preparation of concrete - Portland cement (perfect for working at low temperatures). It is distinguished by a high content of calcium silicates (about 80%), which is why adhesion and gluing of materials improves.
Other types of cement are widely used depending on the task.
Today, cement grade 500 is used for construction.
M400 can also be used, only this will directly affect the durability and strength of the same foundation. For work in warm or hot weather, the use of slag Portland cement is ideal. In the standard marking of cement, in addition to indicating the strength, it is customary to indicate foreign impurities (letter "D").
For example, concrete grade M500-D0 or M500-D20, this is concrete with impurities from 0 to 20%.
When buying cement, it must be dry and free-flowing.
In unfavorable conditions, cement quickly picks up moisture from the air and loses its basic qualities. Therefore, it is recommended to buy the required volume of cement a maximum of 2 weeks before its application or directly in a couple of days.
When purchasing, be sure to check the integrity of the packaging and the presence of marking.
To prepare concrete with your own hands, you also need sand. Sand suitable for mixing a concrete mixture must necessarily have a fraction of 1.
5 to 5 mm, an ideal option would be a uniform size (1- 2 mm). When choosing sand, it should not contain various foreign impurities. Construction debris, plant residues, as well as various foreign inclusions, which decay and rot over time, will dramatically reduce the quality and strength of concrete. To clean the sand, it is passed through a special sieve with small cells.
For making concrete with your own hands, river sand is ideal, although it is more expensive than ravine sand, but it has the right grain size.
For places where there are stone quarries nearby, artificial heavy sand is used as an option. When it is washed and sifted, the size of its grains will be somewhat better than even river sand. But when using it, the concrete mixture will turn out to be much heavier, and this is important if it will be used to install screeds over interfloor floors.
The strength of concrete directly depends on filling with gravel or crushed stone. However, expanded clay is also often used.
It is strong enough, but lightweight.
When preparing a mixture, the size of gravel and crushed stone should not exceed 35 mm, larger pieces are most often used in production, but this is rare.
As with river sand, it is desirable that crushed stone or gravel contain as little foreign inclusions, dust or clay sediments as possible on their surface. It should be noted that the greater the roughness on the edges of the particles, the better the adhesion will be. For self-mixing of the proportions of concrete, an aggregate is chosen, the particles of which have several sizes, or coarse gravel is mixed with fine or medium.
This is done so that the particles fit snugly together and prevent the formation of large voids. In the worst case, all voids will be filled with mortar, and this can affect both the quality of concrete and the consumption of the mortar itself.
During preparation concrete mix the key and important point is the choice of water. Of course, there is no question of using any specific water. However, it must be free of any impurities (acid, alkali) and always clean.
The use of river and lake water, in which there are numerous foreign inclusions, is unacceptable.The main rule when choosing water for mortar: the water we drink is ideal for making good and durable concrete. By following this rule, you can calculate the strength and durability of your concrete without damage or destruction.
During repair and construction, craftsmen add a little slaked lime to the concrete. This is done to make the mortar more "convenient" for laying.
This slightly facilitates the process of leveling the surface of the concrete screed or the desired section of the porch, drainage. Whether or not to resort to adding lime, the master decides, depending on the required composition. Currently, it is customary to use ready-made slaked lime, which is sold in special hardware stores and is called fluff.
Modern technologies allow to give a concrete solution a large fluidity or viscosity due to special additives - plasticizers. It is they who change the properties of the solution in the right direction.
The use of plasticizers can increase or decrease the amount of water used to prepare the concrete solution. Plasticizers are usually not used for pouring the foundation, however, they can help if the reinforcement is compacted or the foundation is of a rather complex shape. However, a more fluid concrete will fill all the voids and branches formed much faster and better, and this will improve the result and speed up the whole process.
Posted By: Work Style |13, Nov 2020
Posted By: Work Style |12, Nov 2020
Posted By: Work Style |09, Nov 2020
Posted By: Work Style |08, Nov 2020
Posted By: Work Style |01, Nov 2020