Innovation in concrete production: it's interesting

Gusevsky Andrey Anatolyevich

Innovative Technologies: Translucent Concrete

Plain and frame-reinforced concrete, over the past hundred years has been and remains the main building material in the whole world. The volume of its production is twice the amount of all other manufactured materials, including such super-popular as plastic, brick and ceramic tile.

Concrete dominates for the simple reason that often there are simply no other alternatives to it. Therefore, any innovative ideas regarding this material do not go unnoticed by scientists and builders.

New aggregate for lightweight concrete

Basically, innovative activity in relation to concrete, concerns the development of its new types, reinforcement for it, additives. In addition, specialists are also working on the creation of new structures and technologies that will maximize the protection or restoration of concrete.

Everything can be built from concrete

So:

• Today, our research institute has already developed concrete with such frost resistance and water resistance that the issue of reducing the performance of structures and coatings can be said to be removed from the agenda.
• Particular attention is paid to the creation of concrete based on self-expanding cements. They provide concrete structures with crack resistance, and the same water resistance, which is so important for structures with a long length, or exposed to aggressive environments.
• And such concrete has already begun to be used today in the construction of industrial facilities. But in civil engineering, the greatest interest is riveted on the creation of ultralight concrete mixes with high strength characteristics.
• The institute mentioned above already receives light heat-efficient concrete with the M600 brand, which will allow them to be used in any climatic zone of the country. Glassy aggregate made of siliceous rocks is used as a filler in such concrete.

In large-scale construction, it should replace aggregates from easily expanded clay (expanded clay, agloporite). But why didn’t they please us?

Arguments of Researchers

Firstly, there are not enough resources in our country for the manufacture of expanded clay in the required volume, since the reserves of easily expanded clay, which are already not too many, are rapidly depleted. And deposits of siliceous rocks can hardly be exhausted in the next hundred years. But this is not, of course, the most important thing. After all, if the new filler did not have advantages over the old, then there would be nothing to talk about. The reason lies elsewhere.

In Russia, they began building from expanded clay concrete 50 years ago, and in principle, you can still continue, since we have about two hundred factories producing this aggregate in the amount of 16 million. cubic meters per year. There are a lot of developments in this area, but the production realities are far from them. Expanded clay with a density of 400 kg / m3, or concrete based on it with a density of 800 kg / m3, is not produced too much.

So:

• Expanded perlite has always been considered the most promising lightweight concrete aggregate. But again: raw materials, production base, and some technological difficulties, do not give reason to consider this material promising. Therefore, the issue of finding alternative aggregate options for concrete remains relevant.
• Researchers always focus on the possibilities of expanding the raw material base - especially with regard to structural concrete. Most of all they are interested in closed-cell gravel-like fillers, whose solid phase is almost one hundred percent in an amorphous (glassy) state.
• The reason for this is the certainty that vitreous aggregates with increased strength characteristics will make it possible to obtain concrete that is effective from the point of view of mechanics and heat engineering - and not only heat-insulating, but also structural. This will make it possible to implement the most rational design solutions for building envelopes for different climatic conditions.

Anyway, the creation of lightweight concrete with increased strength properties will allow us to return again from three-layer wall structures to single-layer ones. At the same time, a thickness of 40-50 cm will be enough to provide maximum wall resistance to heat transfer.

Self-cleaning concrete

Another innovation was the creation of concrete with higher aesthetic qualities - that is, the surface of which does not require finishing. This is the so-called self-cleaning concrete.

Just one supplement solves a lot.

This was achieved by adding titanium dioxide to the concrete - a substance with a whitening effect, which until then was only a food additive. It is added to food for the same purpose - to achieve a whitening effect.

• Now, to get white concrete, you do not need to use expensive white cement.
• Titanium dioxide also successfully whitens ordinary gray cement, as a result of which, decorative concrete can be obtained with a slight increase in price. And it's not just the aesthetics of the material.
• Titanium dioxide also acts as a catalyst, which, under the influence of ultraviolet radiation, triggers the decomposition reaction of many harmful substances and bacteria that accumulate on the outer surfaces of any structures.
• For this reason, such concrete is also called photocatalytic.

• The ability of building structures to self-cleaning, plays a huge role in ecology. And in general, it will save not only on the decoration of buildings, but also eliminate the need for periodic cleaning of facades.
• Moreover, most of the large buildings with interesting modern architecture are built today from concrete. In Sweden, for example, a project has been launched to develop not only different grades of self-cleaning concrete, but also the creation of other building materials that can be coated with catalytic compounds.
• Such opportunities appeared due to the development of nanotechnology. What do they have to do with titanium dioxide? It's simple - not just its powder, but nanoparticles are used as a catalyst. And the smaller they are, the more actively its properties are manifested.

By the way! In Japan, a similar technology has long been used in the manufacture of ceramic tiles and facade panels.

Facade photoceramics

The Swedes consider it necessary to significantly advance research in the field of the use of photocatalysts, and plan to establish serial production of such materials. After all, the catalyst contained in them or on them will clean not only the surface of the structure itself, but also the air around it.

Concrete tunnels, through which the flow of cars constantly moves, need this especially. The EU has allocated a tidy sum for these studies - more than $ 2 billion. So, Europe also has high hopes for these technologies.

Translucent concrete

Innovative developments in the field of construction also include technologies for creating translucent materials.Concrete, which, it turns out, can also transmit light, has not been ignored.

What is the reason for the optical effect

The absence of a large filler contributes to this phenomenon (there is only granite or marble chips), and the presence of fiberglass:

• It is added no more than 5% of the total volume of concrete, which allows you to maintain all its basic qualities: from strength to water resistance.
• In fact, fiberglass here acts as a reinforcing fiber, and keeps the product from deformation.
• Why do we need such metamorphoses, and even such expensive ones? But the fact is that this material has huge potential in the field of design.
• The blocks are not completely transparent, they only transmit chiaroscuro, and when the lighting changes, they change the pattern.

What can I say - it's better to see once!

Note! The degree of transparency of concrete does not depend on its thickness, but on the amount of optical fibers in it. In appearance, a product made of such concrete can be compared with valuable varieties of natural polished stone, which made it possible to use it in interior design.

Today, translucent concrete is also produced in Russia. There are several options for its execution.

These are four basic colors:

• dark grey,
• light gray
• white (marbled)
• yellow-brown (under sandstone).

But when performing concrete on order, it can be tinted in any color. The pattern and structure of the material can also vary depending on the wishes of the customer.

Today, not only interior partitions and facade slabs are made of translucent concrete, but also countertops, bar and reception desks, small architectural forms (benches, fences) - and even lamps.

Conclusion

Developers today pay attention to such a direction as recycling concrete - that is, its recycling. At first it was a question of the fact that as a result of deep processing it was possible to obtain a binder, which could be suitable even for the production of low-quality concrete.

Reinforced concrete crushing before sending for recycling

But today, the same NIIZHB is already working on how to obtain high strength concrete from such a binder. By the way, his leadership in the Ministry of Construction made a proposal on the adoption of a concrete technology development program. After all, concrete is the material of the century - and it is unlikely that anything will change in the near future.