Construction of cottages using Elstar technology

Recommendation points

• What is Elstar technology
• Filler ozonation
• Electrical processing
• Features and advantages of Elstar technology
• Equipment for the construction of walls “Elstar”

The article provides an analysis of the new technology for the construction of country houses “Elstar”. You will learn about the origins of this method, its advantages and disadvantages. The article will tell about the peculiarities of making Elstar walls, the cost of work and materials, as well as the processes that make the material unique.

The search for new technologies in order to reduce the cost of construction and the final cost per square meter leads, oddly enough, to the origins of housing construction. Proof of this is the “new” material arbolit or sawdust concrete. This technology is experiencing a new birth, gaining popularity among private developers on a limited budget, who constitute the vast majority of people who want to build a home..

Of course, the product in demand could not be ignored by engineers and innovators. As a result, a new Elstar technology was born, based on recipes from many years ago, but with the introduction of a scientific approach and modern processing tools..

What is Elstar technology

The raw materials for the walls are improvised material, wood waste, straw, reeds and even silage. Like wood concrete, it is crushed, soaked and mixed with cement mortar. The result is an effective combined material – insulated construction – which, moreover, has a decent appearance even without external finishing.

This method of erecting walls involves creating a monolithic building box, the elements of which – walls, corners, openings – are interconnected. Moreover, the bundle in this case is the maximum possible, since the entire structure consists of a solid element. The principle of erecting walls is the same as monolithic concreting – installation, filling and reinstallation of inventory formwork. The composition of the mixture has been known since the 18th century – chips, sawdust, cement mortar. It would seem, what’s new here?

The wood concrete has a problem that the supporters of sawdust concrete prefer not to discuss. This is the reactivity of the aggregate, i.e. wood inclusions. As you know, wood retains chemically active substances (in particular, sugar) in the fibers and lives, that is, reacts, until complete decay. With prolonged contact with water, inevitable oxidation occurs.

If we assume that this reaction occurs in a cement slurry, where an alkaline reaction dominates, then it turns out that the acid (from the sugars of the tree dissolved in water) quenches the alkali (cement). As a result, the reaction does not pass completely, but only by 40-60%, depending on the quality of the wood.

The originality and effectiveness of Elstar consists in two additional stages of preparation and conditioning of the mixture – ozonation and electrical treatment.

Filler ozonation

In the absence of additional equipment, the craftsmen simply soak the raw materials. This quenches some of the acid — only 15–20%. But the process of ozonation, that is, electrification of soaked wood, can give a qualitative effect. As a result, the oxidation reaction takes place by 50-60%.

Electrical processing

Formwork made of stainless steel – an electrode to which a current of 50 A / m is connected after laying the mixture² at a voltage of 80–120 V. In other words, the packed mixture is ozonized. As a result, water decomposes into oxygen and hydrogen. Oxygen extinguishes acid from wood, hydrogen evaporates. Ultimately, concrete hardening occurs without organic hindrances, which makes Elstar many times stronger than wood concrete.

Features and advantages of Elstar technology

The described technology, despite the fact that it requires the use of special equipment, brings sawdust concrete to perfection. At the same time, a phenomenal speed of box erection is achieved – 30-40 m³ per work shift. This becomes possible thanks to know-how that has not been previously used in construction in such a combination..

Coupling of material reactivity in two stages.This procedure is described in the previous chapter. Thanks to this, any, even stale wood waste becomes suitable..

Enhanced heating of the mixture.Electric current not only splits water, but also heats up the steel formwork. This speeds up the drying and hardening of the mixture. We can say that the material is steaming. As a result, the wall is ready for stripping within 30 minutes after starting the transformer. This is truly invaluable when working in the winter – the wall does not lose quality.

Installation of openings during the construction of walls.The strapping of door and window openings is installed directly into the formwork and covered with a mixture. This saves time on the installation of windows and doors. It should be noted that the low volumetric weight of the material (600-800 kg / m³) and monolithic construction, so you don’t have to worry about shrinkage.

The density of the surface allows nails to be driven in, while they hold securely (especially screw). This property eliminates the need for hammer drilling in outdoor applications. The porous material adheres perfectly to plasters and putties.

Equipment for the construction of walls “Elstar”

We can say that this is the “weak point” of the technology. Building a house with high-quality, durable and energy-efficient walls will not work at all without investment. In order to build a cottage box in 2-3 days, you need not only a set of units, but also specialists who can service them:

1. Generator with a capacity of 100 kW – for power supply of the facility.
2. Electricity converter – transformer for preparation of current for heating and ozonation.
3. Shotcrete machine – for placing the mixture in the formwork.
4. Formwork-electrodes – for mold mounting.
5. Crushing machine (disintegrator) – for aggregate preparation.
6. Ozonizer – for aggregate preparation.
7. Concrete mixer – for preparing the working mixture.
8. Vibrators, non-standard equipment, containers.
9. Trucks.

Some of these devices require professional knowledge, and formwork is a completely special product. Therefore, the authors of the technology (OJSC “Podolsk Chemical and Metallurgical Plant” and the Moscow road-building company “Megara”) offer to rent equipment and formwork together with the technical staff. At the same time, the main work that does not require qualifications – procurement, preparation, laying, etc. – can be performed by the customer on his own. This is especially true for large families where there are many free, hardworking hands..

Technical characteristics of Elstar walls

Index	Value
Density (volumetric weight)	600 – 800 kg / m3
Vapor permeability	0.48 mg / m2 hour? Pa
Thermal conductivity	0.07 W / m2 ° C
Compressive strength	3.1 MPa
Tensile strength	1.2 MPa
Fire safety class	1

As can be seen from the table, the new material is not inferior in thermal conductivity and vapor permeability to mineral wool, and in compressive strength – to aerated concrete. This gives every reason to believe that in our country, rich in forests (and therefore in wood waste), the future of economical and environmentally friendly construction lies with such materials..

Speaking about the price of the issue, it should be noted that the main items of expenditure are equipment rent, technicians’ salaries and electricity. The cost of wood filler is negligible in the overall estimate, and cement goes much less than for the same walls (300 mm) made of concrete. As a result, 1 m² a finished house without decoration and communications costs $ 50 e.