How to make a solution of concrete proportion. How to prepare concrete: requirements for materials, proportions and calculation of the composition. Required strength of foundation concrete
Read also
Concrete is the main material that ensures the strength of the house. The construction of the foundation, walls, floors, gender requires a concrete solution. With private construction, it is unprofitable to order small portions of concrete, large-scale volumes are needed by large construction. The interval of the use of material is small, it is necessary to spend it quickly. You can easily make concrete with your own hands. Consider how to cook concrete at home.
Warming and cooling of concrete can cause cracks and cracks, and that it does not occur, you must cover ballast with an old newspaper and sand bags and cement and keep them always wet. This is an informative article, in case of doubt, contact a specialist.
Self-adhesive concrete - mixing procedure. Self-adhesive concrete is a liquid mixture suitable for accommodating in structures with overloaded reinforcement without vibration. The self-adhesive design of concrete should provide a good balance between deformability and stability. The article presents an experimental procedure for the design of self-compensating concrete mixtures. In addition, the strength of compression aged 7, 28 and 90 days was also determined, and the results were included here.
Despite the fact that the cooking process is simple, to withstand a number of features, while maintaining the quality of the solution, quite difficult. Concrete - Mix binder and fillers. The main components are:
- cement;
- sand;
- fillers.
Classic variant - cement-sandy solution. The sphere of its use is quite narrow, the strength is low, but as protective layer From sending buildings, comes perfectly.
Self-adhesive concrete, which flows under its own weight and does not require any external vibrations for the seal, revolutionized the placement of concrete. Such a concrete must have a relatively low yield value to provide high fluidity, moderate viscosity to resist segregation and bleeding, and must maintain its homogeneity during transportation, placement and curing to ensure adequate structural characteristics and long-term durability.
Direct selection of proportions
Adding a large volume of powdered material or modifying impurity viscosity can exclude segregation. Powdered materials that can be added are bats, silicon dioxide, lime powder, glass filler and quartzite filler.
Requirements for components
Modern production of materials allows you to combine special additives in the solution, plasticizers that give concrete exceptional characteristics. The composition includes a knitting component, sand, crushed stone, additives, water. Let us dwell on every detail.
The main and the only binding ingredient in the solution is cement. To obtain an excellent result, Portland cement is best suited. His differences are in the increased content of calcium silicate, which provides a strong compound of components. Other types of mineral powder are used, it all depends on the goals and tasks. More suitable - M500, permissible to use M400, but the design will be less durable, which will not affect the duration of operation.
This document describes the procedure specifically designed to achieve self-adhesive concrete. In addition, presented durable characteristics From the point of view of compressive strength for 7 days, 28 days and 90 days. An ordinary portland cement was used. His physical properties Led in the table.
Physical properties of volatile ash
The physical and chemical properties of the volatile ashes are shown in Table 2 and Table 3, respectively. Chemical properties Fucking ash. Locally affordable natural sand with a maximum size of 75 mm was used as a fine aggregate with a specific weight, the fineness module and the specific weight specified in Table 4, and rubble with a maximum size of 16 mm with a specific weight, the subtlety module and the specific weight as indicated in the table 4 was used as a major aggregate. Table 4 shows the physical properties of large and small aggregates.
Mineral element Be sure to use in a dry, bully form. It is not eliminated by deprived, a lumpy type of powder. Bad storage conditions of an important component contribute to the loss of a significant part technical characteristics.
Modern marking includes an indicator denoted by the letter "D", the number near which shows the number of extraneous impurities in the cement. The maximum amount corresponds to 20%.
Physical properties of rough and small units
Self-adhesive concrete is characterized by the ability to fill, transmitting the ability and resistance to segregation. To date, no method has been found, which characterizes all the relevant aspects of working capacity, and, therefore, each mix was tested by more than one test method for various parameters of working capacity.
Recommended limits for different properties
When lifting the caution cone filled with concrete, concrete flows. The average diameter of the concrete circle is a measure to fill concrete. It measures the time spent in seconds from the moment when the cone rises until the horizontal flow reaches a diameter of 500 mm. The funnel is filled with approximately 12 liters of concrete and the time required to flow through the device is measured.
Sand
Sand fractions that are part of the solution are of 1.5 to 5 mm. An excellent result gives a matching fractions, the maximum discrepancy is within 2 mm. The content of impurities in the bulk element is unacceptable: dirt, dust, garbage. To make sure the purity of the sand, you need to sift it. Perfect option — river sand, with a suitable size of fractions, without clay impurities.
Selection of water when preparing a concrete mix
If concrete shows segregation, the flow time will increase significantly. The height of the concrete at the end of the horizontal section is expressed as the proportion from the residue in a vertical section. This is a sign of passing the ability. The specified condition is the ratio between the heights of the concrete at each end or the blocking coefficient, which must be. The procedure adopted in the study is such.
Productivity and compressive strength
The content of the fine filler was maintained constant at 40% by volume in the concrete and the content of the superplasticizer at 14% of the powder content, that is, cement and volatile ash. The proportions of mixing for different mixtures are shown in the table. Table 7 presents the results of tests for workability carried out to achieve self-adhesive concrete. The content of the superplasticizer was taken as 0, 76 and 80, respectively. In addition, the content of the superplasticizer was maintained permanent at 14% of the powder content.
Crusheden
It is the aggregate that gives the cement solution necessary strength. Perfect fragmented rock: Gravel, crushed stone. The best result of the strength gives the aggregate of different sizes: large and small. Different size Provides the density of fitting components to each other, not allowing the formation of voids.
At the same time, test equipment should be reliable, easily tolerated and inexpensive. One operator must perform a test procedure, and test results must be interpreted with minimal learning. One of the main applications of these test methods would be a testing of conformity in sites and at concrete factories, if self-adventure concrete was manufactured in large quantities.
You want to implement the foundation plan of the wall of fence or plan the floor laying under flooring or strengthening the plate that has no surface throat yet. And you need to provide a modest amount of concrete. What are the components of this material and proportion.
The purity of rubble is very important. In order not to allow pollution, the aggregate on the ground is located on a pre-laying tarpaulin, film.
Water
At first glance, the simple component - water should not contain acidic, alkaline connections. Application of lake river water unacceptable. Durable concrete solution is capable of making transparent, clean water.
All in order of magnitude and weight. That is, it begins on the amount of gravel or rubble, which is the biggest, up to the water with a smaller weight. It has weight, not volume, because specific gravity It differs for individual materials, and there are emptiness for example, in a pile of rubble, which does not exist in water. A very simple method that allows you to avoid memorizing different numbers and kilograms. All "Increasing the coherence of one material also doubles its weight that needs to be considered." Thus, you can mix any final amount as you need and repeat if necessary, using the same arguments.
Additives
Depending on the natural conditions Building, engineering tasks, lime, plasticizers, auxiliary and reinforcing substances are added to the solution. They contribute to the improvement of adhesion, give elasticity, reduce the percentage of cracking.
Proper material ratio
Consumption rates for obtaining 1 m cubic meters. concrete. The construction goal determines the correct composition of the solution. For example, a durable solution is required for the foundation of the building with the presence of large fractions. However, before the fill of the main mass be sure to endure technical properties The surface of the base, applying the simple composition of the solution. The composition includes cement and sand. According to the consistency, it is much less likely than the composition for the foundation.
Preparation of concrete mix
Do you think that it is easy to prepare a suitable cement mixture? You need cement for a number of projects - to install basements or fences, to fill the sidewalk or to correct defect in one of the bases of your home. If you make a design that requires a concrete or solution, you need to know how to mix cement that binds materials together.
Brands and proportions of concrete
Here's how to mix cement. Materials: Cement. This is clean cement mix. You will need to buy enough sand and aggregates in accordance with the amount of cement in the correct proportions. Before mixing, it is always advisable to read the manufacturer's label to find the best mixture and sand ratio to get the necessary quantities for the project you do. This is definitely the cheapest way to get a good combination of concrete or solution, but this is a physical work that will take time and energy.
The structure and percentage ratio of components in concrete is kept according to construction standards, taking into account the density of all components. It is better to measure the portions of the components better, it is important to follow equal number Set of materials.
The amount of water depends on the desired consistency of the solution. It is important to remember, a lot of water will reduce the strength, little water - poorly reflected in the state of concrete. The correct ratio of water to the mineral powder is in proportion to 5 to 10. The amount of water is 50% of the weight of the powder.
If the project is great, it is the cheapest route, but prepare the muscles! The main formula for the mixing ratio is 1 part of the cement, 1 part of the sand, 1 part of the stone and 1 part crushed, the amount of water being added so that the mixture is not too wet and not too dry - in the form of a cake mixture. Some products indicate the amount of water that should be used on the bag in the rear package.
Materials: concrete and solution. The decision on the type of mixture is necessary and fundamentally relative to your project. These two mixtures contain sand and aggregates, all you need to do is mix the dry contents of concrete with water and lime if you want to get a solution or gravel if you want to get concrete. Make sure you buy a solution for work requiring solution and concrete for work requiring cement - in almost all cases they are not interchangeable.
The percentage of components, according to the chassis brands mineral substanceNext (cement / sand / aggregate):
- M300 - 1: 2.4: 4.3;
- M 400 - 1: 1.6: 3.2;
- M 500 - 1: 1.4: 2.9.
The presence of additives into the percentage is not included, their number affects the purpose and condition of application.By paying attention to the quality of the components, the correctness of proportions, cooking technology, get exactly the brand of the binder that is necessary.
Ask an expert in the store help you get right proportions For your project. This is a machine that is ideal for small and medium workplaces, especially to fill jobs. Keep in mind that to fill the private road or pool, mostly for large jobs, it is advisable to rent a concrete truck. Safety. Usually preparations contain limestone, which is a dangerous material. Be sure to work in the ventilated room. Avoid touching dry mixtures with hands.
Marking of concrete and cement
During the mixing process, wear gloves and mask. Now you know how to mix cement. If you are planning to do it yourself, be sure to read the manufacturer's label to make sure you use right materials and proportions for the mixture.
Cooking process
How to make concrete with your own hands? How to knead it? From need quantity The solution will be selected by the method of kneading. There are two options: manual and mechanical.
Manual way
How to cook concrete at home, if the costs of concrete mixture are not included in construction plans? There is an old bath, shovel, you can take advantage of your own hands. Large volume this method is not suitable, it is indispensable for small. Two ways of making a solution are known:
Try using cement premix. . Stone masonry is nothing but the assembly of various cemented materials is binding, which is a solution. Useful materials are much and vary depending on the areas and goals to which the work is intended.
Rough unprocessed raw stones can be used roughly or cut according to accurate geometric shapeAnd can also be used to assemble calibrated or "modulated" materials. In the monolithic concrete, you can also build a storage room or make a small repair.
- First. Sand, cement is mixed in a dry form, after water, the remaining components are added. Materials are distributed evenly, but the procedure for adding water is worth paying special attention. There is a chance that some of the dry components can remain at the bottom, not to fall into the solution, violating the percentage ratio. Carefully, but not long, mix the components, do not push the concrete. On the external characteristics The solution similar little things will not appear, for technical characteristics it is not small, but the risk of losing strength.
- Second. The required amount of water is measured, cement, sand, aggregate and additives are added. The second method is better combined with a small amount of concrete. Boldly need to use it yourself.
The use of concrete mixer. Provide a construction concrete with a concrete mixer will work quickly, efficiently. The device is divided into gravitational and mechanical. The device is set at a distance of 40 meters from the place where concrete will need. A small distance will make it possible to make a high-quality solution, deliver it to the construction site faster before it starts to stick. Betting mixes are different.
Video preparation of concrete mix
The solution is a binder, which serves to store various materials, such as stones, bricks, plates, marble, etc. It consists of a mixture of fine sand and hydraulic cement or lime or mixture of equal parts of these two elements. Usually used doses: 30 kg of cement or lime per 100 liters of sand.
Concrete is a mixture of three elements:. - coarse materials, such as gravel, sandstone, stones, stones; sand;. - binding material. Concrete having good quality should be durable and waterproof. These properties depend on its compactness, cement or limestone content, the ability of gluing and the correct dosage of the granules used in the composition. As a rule, the following proportions are observed: 30 kg of cement for 40 liters of sand and 90 liters of gravel.
Production procedure Next:
- Include the machine, pour part of the water (10 -15% leave) and put cement into it (if we leave part of the water, we leave the amount of binding powder in equal proportions).
- Gradually add sand. The mixing process takes 3-4 minutes. In order to avoid lumps, the mineral powder is connected to the sand, after water is added.
- In ready cement mortar We attach the necessary reinforcing components.
- We put crushed stone last. If necessary, add liquid - water is mixed with the powder and in the form poured into a virtually finished solution.
The cost of concrete mixer does not justify its one-time use. If there is no need for continuous use, it is better to rent a device.
Common mistakes
The main errors are allowed in the selection of components for the solution:
- It is not necessary to reduce the amount of binding element, it can lead to loss of strength, lowering frost resistance, increase in moisture permeability. An increase in the amount threatens with an increase.
- The content in the sand of clay contributes to the formation of cracks, despite the plasticity of the solution.
- A large amount of water leads to the formation of pores affecting strength.
- Poor mixing of dry substances leads to a decrease in the strength of the material.
- The compound of water with the binding component leads to the formation of lumps.
Output
What to cook concrete at home, considered. If you independently use the right materials, comply with the ratio of components, it will work out to make a durable, high-quality concrete of the desired brand.
Do not forget to moisturize the surface of the frozen concrete in the first days until it gains strength.