Dispersed concrete — old new composite

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Dispersed concrete — old new composite
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In the 1970s, research and testing were carried out in Moscow on the development of modified concrete and, at the same time, improving the ecology at plants for concrete products and reinforced concrete structures of The Moscow Capital Construction Department (Mosstroikomitet). After a thorough study of foreign experience in using metal and glass shavings for reinforced products, a material was discovered and tested, which does not react with cement alkalis and does not cause corrosion in products, and most importantly, it is durable in a severe Russian climate. Domestic experience in using dispersed concrete for reinforced concrete products was implemented at the construction of a bridge in Germany — 30 years later.

Since 1980, the contributor has been carrying out prospecting work on the replacement of steel reinforcement in reinforced concrete products at enterprises of Mosstroikomitet in order to increase products’ basic performance in the field of improving the production ecology by reducing welding workshops. In 1986, a technology of dispersed concrete with the use of basalt fiber was successfully and efficiently introduced by the contributor at Spetsstroybeton No. 17 concrete plant at Glavmospromstroymaterial (The Moscow Directorate of Construction Materials And Structural Elements Industry) of The Moscow Capital Construction Department, with more than 500 pieces of driving-in prefabricated piles with a length of 6 to 17 meters being manufactured, as well as at Krasnopresnenskii DSK No.1 reinforced concrete structure plant at Glavmosstroy of The Moscow Capital Construction Department in manufacture of three-layer external wall panels, roof slabs, bulkheads, decks, etc., which were also produced in an amount of over 500 pieces.

In all products, metal fittings were applied only for lifting points. For the production of a concrete mixture, a standard basalt fiber, which was manufactured with a standard technology at P. O. Mosasbotermosteklo in the city of Zheleznodorozhny in the Moscow region, was used for heat-insulation materials. The uniqueness of this technology lies in the fact that a well-known material that has been used in the production for decades was applied in the manufacture of products.

The last 30 years of a successful and trouble-free operation of these products have confirmed the durability under the conditions of Russia's frosty climate, with frequent temperature changes — and a very high potential of the new building material. The economic profit of replacing reinforced concrete with a new dispersed concrete technology amounts to 30-40% of the cost of products made according to traditional technologies.

It is worth noting that the raw materials base of basalt in Russia and Ukraine is huge and amounts to more than 2.5 billion cubic meters. The explored reserves of basalt leave no doubt about prospects of using natural basalt, a unique and universal domestic building material of the future. Basalt successfully replaces steel fittings, having decades of proven ideal fire, heat and sound insulation. Concrete products made of basalt fiber show high rates of abrasiveness, durability, impact strength, wear-resistance, tensile strength in bending, cavitation resistance, etc.

Thirty years of experience in the development, implementation, and operation of metal-free technology in Moscow allows for the conclusion that basalt as a building material has expanded beyond laboratories and that its full-scale production application is on the agenda. This will result in the settlement of several production problems, the main of which is the modernization of domestic construction industry. Costs will be reduced while terms of the accident-free operation of buildings and structures are extended several times.

The package of basalt positive properties, simple technology, absence of reinforcement shops and harmful for people and the environment welding production, as well as the availability and low cost of raw materials — all these qualities hold great potential in the near future for the rapid development of the industry of dispersed technology for the manufacture of prefabricated and monolithic building constructions and structures of high strength, reliability, and durability.

The basalt fiber produced in Russia is a commercially viable export product that meets all requirements of German DIN standards for entire Germany’s complex of construction industry using Russian basalt. The article by German magazine Concrete & Steel-Concrete Construction reports on the construction of a pedestrian and bicycle bridge made of carbon fibers (Carbonbeton) in 2015 in the German city of Albstadt-Ebingen in Baden-Württemberg. When replacing a typical steel reinforcement with carbon fibers, the durability, wear-resistance, and reliability of the structure were improved, since the resulting carbon concrete has a high density and impact strength. The article gives the highest guarantees and immense prospects for this “world’s first” bridge.

However, it should be added that operation conditions in Germany differ significantly from the climate in Russia, therefore, more frost-resistant and chemically stable basalt fiber was successfully used in Moscow 30 years ago. Apart from that, basalt has another very important advantage — it is one of the most abundant minerals in nature, with the raw material base of basalt in Russia being enormous. To make a choice between basalt or carbon fiber for concrete production, joint tests of samples should be conducted in laboratories, with the calculation of a comparative economic benefit, testing for frost-resistance, salt-resistance, waterproofness, abrasiveness...                                   

It should be noted that even in a very voluminous (770 pages) and chockfull book by D.Sc., V.G. Batrakov (The Concrete and Reinforced Concrete Research Institute of Moscow) titled “Modified Concretes” published in 1998, there are no data on the development and application of the above-mentioned unique composite technology for the new generation of concrete. In the 1990s, a destructive and gangsterlike “privatization” of all Russian enterprises was launched with massive fake bankruptcies and hostile takeovers. As a result, the unique technology of basalt fiber application, as well as many other domestic inventions were buried.

D.Sc., A.B. Trinker