How to make concrete with their hands

Concrete solution is an essential component in the construction of foundations, and its quality depends on the durability of the whole structure.It is not always possible to order ready-mix, and therefore it is desirable to know how to make concrete with their hands.It is important not only to comply with the proportions, but to correctly choose the components, or the strength of the solution is not high enough.

concrete specifications

strength

concrete solution is a mixture of cement, sand, aggregate and water in certain proportions, which vary depending on the purpose of concrete and cement brand.If necessary, plasticizers are added to the solution.The most important characteristic of concrete - is its compressive strength, measured in MPa (Mega Pascals).It is for this indicator, the concrete is divided into classes.But concrete mark indicates the amount of cement in the composition of the solution.

concrete class	Average strength of this class, kg / cm	nearest grade of concrete
in 5	65	M 75
V 7.5	98	M 100
In 10	131	M 150
In 12,5	164	M 150
15	196	M 200
In 20	262	M 250
In 25	327	M 350
In 30	393	M 400
In 35	458	M 450
In 40	524	M 550
In 45	589	M 600
50	655	M 600
In 55	720	M 700
In 60	786	M 800

Concrete brand M100 and M150 (B7.5 and V12,5) is most often used as a layer under the basic foundation for screeds, concrete paths.Concrete M200-M350 the most in demand: it is used in the construction of foundations for the production of screeds, concrete stairs, pavings.Solutions of higher grades are mainly used in the construction industry.

Plasticity

important characteristic of concrete is its plasticity.The plastically solution, the better it fills the formwork construction.At low mobility of concrete in the foundation screed or remain unfilled portions, which leads to the gradual destruction of the concrete slab.For standard designs used concrete plasticity P-2 or P-3, it is recommended to use the P-4 and above solution for a complex form and shuttering in remote places.

Waterproof and frost

Water resistance depends on the amount of cement and in solution.The higher the grade, the more stable concrete moisture.frost resistance of concrete is achieved by the addition of the plasticizer.Please note that these solutions very quickly seize;if properly calculated amount of the mixture or its use at low temperatures, concrete will turn into a monolithic lump directly into the container.

Components concrete

Cement

Cement Cement performs communication function for all other components of the concrete mix and of its quality is directly related to the strength of the concrete.In a particular construction of the most demanded cement brand M400 and M500.When buying cement should be aware that it will lose its quality during prolonged or improper storage.A month after the production of cement binding properties drop by 10% in six months - 50%, in a year it is generally not recommended to use.But even the fresh cement would be unsuitable for use, if the pull dampness, therefore it must necessarily be stored in a dry place.

Sand

Sand Sand is the second most important component of a concrete solution.In rare cases, it is replaced with slag, the standard is always the concrete is mixed with sand.It is best to use a coarse river sand without various impurities.If in the presence of only the usual fine sand, it should not be a clay, earth or mud, which reduces the adhesion of the solution with the filler.Before kneading the sand is sifted sure to remove all unnecessary.

Filler

best aggregate for concrete solution considered rubble sizes from 5 to 35 mm.rubble is often replaced with gravel, a little less - expanded clay.It is important that the filler surface is rough, then its adhesion to cement will be as strong.To seal the mixture must be taken aggregate of various fractions.Like sand, aggregate should be clean, so it should be emptied and compacted to the prepared area or spread out on the canvas.

Additives

To give concrete frost resistance, water resistance and other useful properties of the used plasticizers.They provide grasping solution at low temperatures, increase its plasticity, or, conversely, give viscosity.They must be used only if it is really necessary, and should strictly adhere to the instructions for their use and to comply with the proportions.

If you want a thin screed or screed on an unstable base, a concrete solution admixed reinforcing fibers.They are made of polyvinyl chloride and polypropylene, have little strength, but excellent help to avoid cracking of the concrete.The standard foundations and screeds reinforcing agents are not needed.

proportions solution

to yourself to make a qualitative concrete, you need to know in what proportions to mix the components.The most frequently used cement ratio, sand and gravel as 1: 3: 6;water while taking less than half the total weight of dry ingredients.Add the water all at once is not recommended, as several portions, so it is easier to control the density of the solution.Humidity of sand also has its value - the larger it is, the less water is required.Measure out all the ingredients you need one capacity, such as a bucket.When using containers of different sizes to achieve the desired proportions will not work.

When mixing should take into account the purpose of the solution.To support a screed do lean concrete without the addition of crushed stone, for concrete paths and pavings using gravel medium and fine fraction, for the foundation under the house srednefraktsionny gravel and high-quality cement.Find out the exact ratio of concrete of different brands will help the table.

Manual mode mixing concrete

Mixing concrete solution is performed manually or in a mixer.If you want to fill in a large area, the first method does not work, because it would take too much time and physical effort.If the solution should be a bit easier to knead his hands.

Step 1. Preparation

To prepare the solution will need a low wide container, such as a large metal trough Podbornoe shovel, bucket and conventional hoe.

Step 2. Dry mixing

The capacity of cement poured a bucket, then 3 bucketssifted sand and 5 buckets of rubble.Dry ingredients are thoroughly mixed hoe.The proportions may be different, depending on the desired grade solution.

Step 3. Add water

If all the ingredients are mixed evenly, you can add water.First, poured 7-8 liters and begin actively interfere with the contents of the hoe.This process will require effort, but you need to stir very well.It is desirable to raise the lower layer and carry a hoe in the corners where they can stay dry lumps.If the solution is very thick and extends over a hoe, you need to pour a little water.Properly prepared concrete ramps up slowly with a shovel, not separate.

There is another option of mixing: in the first container is poured water, and then pour the cement.On 2 buckets of water necessary to cement 2 buckets.Thoroughly mixed with the cement, water and sand were added 4 buckets.Again, good to prevent uniformity.The final pour the rubble of 8 buckets and stirred again.Which way is better, there is no single opinion, it is worth to try both and determine for themselves the most optimal.

Mixing in a concrete mixer

set no more than 40 meters away from the work area, preferably close to the sand and gravel.This will make it easier to do the work and process of delivering a solution quickly.Now you're ready to batch:

• the mixer pour a little less water than you need;
• fall asleep necessary amount of cement;
• sand is added and stirred for about 3 minutes;
• pour, if necessary, plasticizers, and other additives;
• last pour gravel and stirred for 10 minutes.
  

  concrete mixer Production in

If the resulting concrete is too thick, in the remaining water add a little cement, mix well and pour into the mixer.Stir the solution for more than 10 minutes is not recommended, otherwise the cement starts to set.Ready concrete is poured directly on the ground or in the car, if the concrete mixer is located.It is advisable to pour the entire solution at once, but if it does not work, part of the mass is left in the mixer is enabled.Use it to be as soon as possible.

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