Clay concrete - material features. composition and

Far from everyone knows about this material, so it usually raises a lot of questions from beginning builders. However, in fact, everything is very simple - the hero of this article is better known as adobe (a mixture of clay and straw). In this article we will look at what clay is and its application.

Material Features

It would seem that clay as a building material turned out to be a long time in the past, but with the development of ecological construction, it has recently been actively used again. The fact is that finely ground clay is a good astringent and preservative.

If you dilute it with water and add a filler to the solution, for example, vegetable fibers or sawdust, you can get an excellent and eco-friendly thermal insulation material. For example, such a mixture is often used to fill hollow slag- and claydite-concrete blocks, or as a warming plaster.

Also, gypsum, lime or even cement are sometimes added to the mix, which makes the clay concrete more durable. This allows it to be used as a carrier material in the construction of green houses.

The bulk density of the material depends on the ratio of ingredients. The best indicator is considered to be 550-600 kg per cubic meter.

There is an opinion that such material is rotting, and is also flammable, as it contains straw or sawdust. However, this is just speculation, since the cutting of plant stalks and sawdust in a clay liquid solution swells up and is well enveloped in clay, which not only binds them securely, but also preserves them.

As for fire hazard, the filler begins to fester only when exposed to an open flame, for example, a gas flame, within a few minutes. As a result, the fire safety of the material is even higher than that of some of the more traditional materials used in construction.

Virtues

The increasing popularity of the material due to the following advantages:

• Promote the formation of a human-friendly microclimate. Clay способна поглощать и выделять влагу быстрее и гораздо в большем объеме, чем традиционные стройматериалы. Причем, это не отражается на прочности материала.
• Accumulates heat. Due to this property, the material can create comfortable conditions in the home even in the conditions of large daily temperature differences.
• ReusabilityFor this, the material just needs to be soaked in water.
• Ideal for do-it-yourself home building. The material does not require the use of construction equipment and expensive equipment. The technology of working with it is available even for inexperienced builders.
• Clay защищает древесину и прочие органические материалы от гниения. If you treat it with wooden walls, then they will not hit any fungus or insects.
• Clay очищает воздухabsorbing pollutants.
• Low material cost. Due to this, building with the use of clay is not only environmentally friendly, but also economical.

Note! In the manufacture of lightweight material with a density of less than 500-600 kg per cubic meter, the material must be dried. Otherwise, the straw will remain wet for a long time and begins to rot over time.

disadvantages

Of course, along with the advantages, mud concrete has some drawbacks:

• The strength is less than 600 kg per cubic meter, with the result that nails and dowels do not hold in it. Plastering is possible only with the use of reinforcement.
• When the solution dries, significant shrinkage occurs.

Preparation of material

Composition and proportions

For the preparation of durable and "warm" material using the following components:

Preparation of the solution

It is possible to prepare solution in a usual concrete mixer.

The instruction is as follows:

• Before proceeding to the preparation of the solution, you need to prepare a straw fiber. Its length should not exceed the thickness of the material. For example, if the solution is to be used for pouring into concrete formwork with a thickness of 20 cm, then the fiber length should also be no more than 20 cm.
• Then water is added to the mixer and lime is poured into it. The contents are thoroughly mixed.
• Then straw fiber is filled in for concrete and sawdust.
• After disintegration of the filler, gypsum is added.
• Finally, finely ground clay is added with constant stirring.

Mineral fillers

In many ways, the characteristics of the material depend on the filler. Therefore, experts recommend using different mineral porous fillers instead of straw fibers to improve their thermophysical properties.

For example, for these purposes it is great:

• Foam;
• Керемзит;
• Puma;
• Вспученный перлит;
• Volcanic tuff.

I must say that the correct ratio of mineral aggregates will completely solve the problem of shrinkage.

If we compare clay concrete based on mineral aggregate with clay fiber concrete, then the vapor permeability coefficient of the first one is several times higher, which reduces the likelihood of condensation in the wall.

Now let's take a closer look at the above types of placeholders.

Керемзит

It is an inexpensive and easy filler, made in the form of granules. Its feature is good strength, despite the fact that the density is 250-800 kg / m3.

Expanded clay is produced by firing low-melting clay at temperatures up to 1200 degrees Celsius. As a result of the release of a gaseous substance inside the granules, the clay is expanded. As a result, claydite has a porous structure, substituting a frozen foam, but the shell gives the granules high strength.

Foam

Foam является искусственным материалом, напоминающим пемзу, с плотностью 100—700 кг на метр кубический. Процесс его изготовления заключается во вспучивании молотого стекла, которое смешивается с небольшим количеством известняка, древесного угля или другими материалами, которые способны выделять газ при размягчении стекла.

Вспученный перлит

Expanded perlite is also made by burning volcanic glassy rocks. Water in the firing process at a temperature of 1000 degrees Celsius evaporates, and perlite is increased to 20 times.

The bulk density of perlite is 60 kg per cubic meter, and the coefficient of thermal conductivity is 0.045 W / m K.

Volcanic tuff

Volcanic tuff refers to rocks formed as a result of the solidification of the products of a volcanic eruption — pumice, ash, etc., which were subsequently cemented and compacted.

Puma

This material is a porous volcanic glass formed in the process of solidification of medium and acid lavas emitting gas. Pumice density is in the range of 500-750 kg per cubic meter.

Tip! The clay solution can be poured into the formwork, as usual concrete, or to make blocks for building walls from it. When pouring the mixture must be sealed.

Lightweight Bricks

Among organic fillers, in addition to straw and sawdust, cork chips are often used. The advantages of this material include low bulk density. As for the drawbacks, this aggregate is rather expensive, besides, the compressive strength of the cork is significantly lower than expanded clay.

I must say that in the building stores you can find dry mixes that contain the following components:

• Ground clay;
• Cork;
• Straw fiber;
• Minor amount of pulp.

This mixture is most often used as heat insulation in the construction of walls or plaster. Before use, the mixture is diluted in water.

The density of the clay concrete is 300–450 kg per cubic meter. Heat conductivity coefficient - 0.07–0.08 W / m K.

Conclusion

Recently, clay has been increasingly used in various areas of construction and for different purposes, since it has many advantages. The only thing is to get really high-quality material, you need to properly prepare the clay concrete with your own hands, choosing the right components for it.

From the video in this article, you can get more information on this topic.