A solid and dependable foundation must be built, and selecting the proper concrete mix is essential. The final product’s strength and durability can be greatly affected by the ratios of cement, sand, and gravel in your concrete mix. M400 and M500 are the two concrete grades most frequently used for foundations. These grades, which relate to the concrete’s compressive strength, are appropriate for various kinds of building projects.
Using a concrete mixer is a practical solution for many builders, as mixing concrete by hand can be difficult and time-consuming. To get the right consistency and strength, precise ingredient measurement is still necessary—even when using a concrete mixer. This procedure can be made simpler and more accurate by measuring the components with buckets.
We’ll take you step-by-step through the process of selecting the proper concrete mixer bucket ratios in this guide, especially for M400 and M500 grades. We’ll go through the suggested proportions of cement, sand, and gravel as well as offer helpful advice to make sure your mix is reliable and of the highest caliber. Knowing these fundamentals will enable you to lay a foundation that will last for years, regardless of your experience level as a builder or your level of DIY enthusiasm.
- Technology for making concrete mix
- Main components
- Cement
- Crushed stone
- Sand
- Water
- Auxiliary substances
- Proportions in buckets – recipe and stages of work
- Proportions for the foundation
- Video on the topic
- Mixing concrete with a concrete mixer
- Mixing concrete m300. Proportions.
- Recipe for concrete M400 | Eyes of the seruna, handles of the deluna
- CORRECT MIXING OF CONCRETE. ORDER OF FILLING MATERIALS INTO A CONCRETE MIXER!
Technology for making concrete mix
The most common tool used for mixing concrete is an automated concrete mixer (concrete mixers). Compact and less expensive tools, such as shovels and construction mixers, can be used for small volumes of material. A mixture made in a concrete mixer is found to be more robust than one made by hand.
- Calculation of proportions and selection of components.
- Preparation of fillers (sifting, washing, drying).
- Step-by-step loading of components into a concrete mixer, taking into account their density.
- Adding water with special components.
- Mixing concrete in a concrete mixer.
- Unloading the mixture ready for use.
- Cleaning the concrete mixer and other equipment.
The concrete’s constituent parts can also be used to clean the mixer. Before loading a new batch, builders use water mixed with fine filler to remove the leftover mixture.
Using a concrete mixer to prepare concrete for a foundation requires precise measurement in order to achieve the required strength, particularly for grades like M400 and M500. Measure the ingredients into buckets to make the process easier and guarantee consistency. A typical mix for M400 might be one bucket of cement to 2.5 buckets of sand and 4.5 buckets of gravel; however, M500 would need to slightly modify these ratios in order to retain strength. This technique guarantees your foundation is strong and complies with building codes, in addition to simplifying the mixing process.
Main components
The primary ingredients of construction concrete are water, Portland cement, sand, and crushed stone. Extra additives help to advance technology or enhance the concrete’s performance characteristics.
The proper order of components must be followed when mixing concrete: coarse filler (crushed stone) should come first, followed by fine filler (sand), and finally cement. Only after the dry ingredients have been thoroughly mixed is water with additional special additives added.
Cement
The primary binding ingredient in concrete is cement, specifically Portland cement. It creates the material’s matrix, which rebalances the load across the coarse and fine reinforcing filler particles. Furthermore, some of the physical properties are provided by cement.
Aluminates, aluminoferrites, belite (modified dicalcium silicate), and alite (tricalcium silicate) are all found in cement. The cement’s short-term strength (during the first four weeks of use) is determined by the alite phase, which accounts for 50–70% of the cement mass.
Concrete and cement become stronger over time with belit. It makes up 15–30% of Portland cement. The remaining elements guarantee that the material sets quickly when it comes into contact with water.
The minimum compressive strength of the material (measured in kilograms per square centimeter) is matched with the cement grade (ranging from M200 to M600). It may exceed or be equal to the concrete’s computed grade.
In addition to the brand, you should consider the cement’s freshness and structure when making a purchase. It is important to select a material that does not form lumps in your hands and was produced less than three months ago in order to guarantee the strength of the foundation.
Crushed stone
One of the main fillers in the mixture is crushed stone. It supplies the majority of the material’s strength properties when combined with the matrix. In building, crushed stone is used, such as granite or gravel.
- Granite crushed stone chips (up to 5 mm) are used in the “washed concrete” technology, granite particles of 5-10 mm are used in floor slabs (to fill voids). Fractions of 5-20 mm, 20-40 mm (for industrial buildings), 40-70 mm (for massive building structures) can be used for the foundation.
- Gravel crushed stone of small fractions (3-10 mm and 5-20 mm) is used in construction and finishing works. Larger gravel (20-40 mm) is used for road repair and reinforcement of concrete that does not bear a high load. For reinforcement of the foundation, especially for a massive structure, crushed stone of a large fraction – 40-70 mm is used.
Residential buildings are built using fractions of 20 to 70 mm in size of granite and gravel.
Sand
Sand fills in the spaces between large fillers, strengthens concrete further, and uses less cement mortar. The purity and fraction of fine aggregate are highly regarded. There should be no debris or clay in the sand. Sand from rivers or quarries that has been purified is used in construction.
- fine (up to 1.6 mm);
- small (1.6-2 mm);
- medium (1.9-2.5 mm);
- large (2.5-5 mm).
When preparing concrete in a concrete mixer, medium and large fractions of sand with particle sizes ranging from 2 to 3.5 mm are typically utilized. Some builders only allow the fine fraction to be used, meaning that sand with particle sizes ranging from 1 to 5 mm can be used.
Water
During construction, water serves as a binder to guarantee that the cement sets and that the concrete is highly fluid. Only clean water may be used to prepare the mixture because chemical additives, fatty impurities, mineral salts, and clay slow down the hardening process and decrease the strength of concrete.
Use of industrial, drinking, and settled rainwater is permitted. Water from natural sources (rivers and other bodies of water) should have an acid-base index (pH) of at least 4, a maximum of 5.6 g/l of salt, and a maximum of 2.7 g/l of sulfates.
It is not appropriate to produce concrete using waste water or swamp areas.
Auxiliary substances
Functional purposes are used to categorize additional additives:
- plasticizers increase the fluidity of the material and simplify the work of builders before the setting begins, and slaked lime simplifies the laying of concrete;
- reinforcing additives (for example, polypropylene fibers) increase the strength of the foundation and its resistance to operation in special climatic conditions;
- water-reducing and colmatating components increase the water resistance of the material;
- Gas-forming and air-entraining additives increase the proportion of the gas phase in concrete and the frost resistance of the mixture;
- modifiers for accelerated hardening of the mixture allow to neutralize the influence of low temperature, high humidity and excess water in the solution.
Concrete delivery and long-term work require the addition of ingredients that slow down the setting process.
Proportions in buckets – recipe and stages of work
The mass proportion of components is used to determine the foundation or finishing cost. For low strength concrete (M200), the mass ratio of cement, sand, and crushed stone is 1:3:5, and for medium strength concrete (M350), it is 1:1.6:2.7.
Nonetheless, using volumetric ratios directly during construction is more practical. A 10-liter bucket is a common unit of measurement for parts.
The necessary strength of the concrete mixture determines the proportions of water, cement, and fillers. Concrete class (e.g., B25) is specified in modern construction documentation instead of brand. It has the following relationship to the strength indicator:
- M100 corresponds to B7.5;
- M150 — B12.5;
- M200 — B15;
- M250 — B20;
- M300 — B22.5;
- M350 — B25;
- M400 — B30;
- M450 — B35.
Used a concrete mixer with buckets of concrete in the proper proportions
Concrete class | Amount of cement, in buckets | Amount of crushed stone, in buckets | Amount of sand, in buckets |
B12.5 | 10 | 50 | 32 |
B15 | 42 | 25 | |
B20 | 34 | 19 | |
B22.5 | 32 | 17 | |
B25 | 24 | 14 | |
B30 | 24 | 11 | |
B35 | 22 | 10 |
For cement grades with a medium strength, this ratio is provided. Use of a high-strength binder results in a reduction in its ratio. The proportions of the components are calculated based on their bulk densities: 15 kg for cement, 17.5 kg for crushed stone, and 19 kg for sand per bucket.
To prepare the mixture, add 0.6–1.15 volumes of water to each volume of cement. The strength of the brand has an inverse relationship with the volume of water.
- Calculate the required amount of components and prepare cement, fillers and water with a reserve. To ensure the strength of the material, sand is pre-sifted, and crushed stone is washed and dried. The filler should be dried on a tarpaulin or other covering, because.. otherwise it may become contaminated with clay.
- Install the concrete mixer on a flat area or a specially formed platform. Lubricate the walls of the device with a mixture of water, cement and sand to reduce the adhesion of concrete. If it is not possible to treat the mixer, then the proportion of sand and cement for the first batch of concrete should be increased (10% is enough).
- Turn on the concrete mixer and start loading fillers. For large devices, it is recommended to add water and pour in about half of the dry components. Then gradually pour the rest of the cement, crushed stone and sand into the hole of the device. About a minute is maintained between additives. For small concrete mixers, a different sequence can be recommended: first, sand, cement and a small amount of gravel are loaded, the mass is thoroughly mixed and diluted with water. After re-mixing, the remaining crushed stone is poured in.
- Plasticizers and other modifying additives are added after other ingredients. At home, liquid soap or dishwashing detergent (2 tbsp) will help increase the plasticity of concrete.l.). If water is added after dry components, the plasticizer can be pre-dissolved in it.
- When using a concrete mixer with forced mixing, the time the concrete stays in the device should not be more than 1-2 minutes. If a gravity mixer is used, the mixing time will be 1-2.5 minutes. Mixing time is calculated for the final mixture with a full load of components.
- To check the readiness of the concrete, you need to tilt the mixer container slightly, pour out a little mortar and make 4-5 notches on it with a shovel. A high-quality mixture remains smooth, but retains peaks between the notches. If the generated ridges fall, then the spilled solution must be loaded back into the tank. The readiness of concrete is also determined by its consistency. The most optimal is a dense curd-like solution, which remains plastic enough for molding.
- The finished mixture is unloaded into prepared buckets or a wheelbarrow. It should be used as quickly as possible. If the solution has hardened, it cannot be diluted with water or stirred manually: this sharply reduces the strength characteristics.
- After use, you need to wash the walls of the concrete mixer. To do this, you need to take 5-7 liters of clean water and a little sand. The drained water with fine filler can be used to prepare the next batch of concrete.
Before doing the final mixing, some builders prepare a trial batch of material. This enables you to prevent both excessive compaction, which makes working with the solution difficult, and concrete cracking caused by high humidity.
The proportional discrepancy could be caused by the cement brand, the "slide" set, the concrete mixer’s features, the ratios of sand and crushed stone, etc.
Proportions for the foundation
The amount of concrete needed for the foundation (measured in kilograms or buckets) will depend on how strong it needs to be. It depends on a number of variables, including the building’s height and intended use.
In the construction of single-story buildings, for instance, combinations of grades M200 and M250 may be employed. Concrete of grade no lower than M300 is needed to create intricate structures and taller buildings. Combinations of grades M400 and M500 are employed in the construction of high-rise structures that place a significant load on the foundation, as well as critical and hazardous structures.
Concrete with low strength (M100, M150) is utilized for both interior design and road construction. If you pour it into a building’s foundation, it may quickly crack.
In a concrete mixer, the foundation’s mass and volume proportion
Concrete grade | Material class | Volume ratio of cement, crushed stone and sand | Mass ratio of cement, crushed stone and sand | Purpose of the brand |
M200 | B15 | 1:4.2:2.5 | 1:4.8:2.8 | Manufacturing of low-load foundations of various types (in individual construction), creation of platforms, paths, stairs, floor screeds, etc. |
M250 | B20 | 1:3.4:1.9 | 1:3.9:2.1 | Casting of strip, monolithic, pile-and-groove and other foundations, retaining walls and low-load floors |
M300 | B22.5 | 1:3.2:1.7 | 1:3.7:1.9 | Manufacturing of monolithic and strip foundations |
M350 | B25 | 1:2.4:1.4 | 1:2.7:1.6 | Casting of foundations for monolithic buildings, manufacturing of floors and load-bearing walls |
M400 | B30 | 1:2.4:1.1 | 1:2.7:1.2 | Construction of basements in monolithic buildings, swimming pool bowls |
Concrete Type | Cement (buckets) | Sand (buckets) | Gravel (buckets) | Water (buckets) |
M400 | 1 | 2 | 3 | 0.5 |
M500 | 1 | 2.5 | 4 | 0.5 |
To guarantee the stability and longevity of your building, it is essential to select the appropriate concrete proportions for your foundation. It’s crucial to precisely measure the ingredients using buckets when using a concrete mixer. To attain the required strength and consistency, the cement, sand, and gravel ratios for M400 and M500 grades must be carefully balanced.
One bucket of cement, two buckets of sand, and four buckets of gravel is the typical ratio for M400 concrete. This blend guarantees a strong base appropriate for the majority of commercial and residential structures. However, M500 concrete calls for a slightly different proportion, typically one bucket of cement, one and a half sand buckets, and three buckets of gravel. This mixture offers more strength, making it perfect for heavy-duty constructions.
To get a workable consistency, don’t forget to add the appropriate amount of water—typically about half the cement’s volume. Make sure all ingredients are well combined by giving it a good stir. You can get a trustworthy concrete mix for your foundation needs by using accurate measurements and mixing methods.
You can make sure that your foundation is durable and robust by paying attention to these ratios and mixing techniques. Achieving the proper proportions is essential for any construction project, no matter how big or small. Have fun constructing!