In Russia, composite materials are multi-component materials consisting of a plastic base (matrix) and a reinforcing charge. Its high strength, no corrosion and light weight make it an attractive alternative to a traditional steel product in construction.
Russia is currently experiencing a technology and production boom associated with composite construction.
For the first time, the issue of manufacturing non-metallic reinforcement from composite materials was raised in the mid-20th century. There were several reasons for this. The construction of structures based on reinforced concrete structures operated in aggressive environments has expanded, so the use of traditional steel reinforcement with its characteristic low corrosion resistance has become irrational. It was necessary to construct buildings with anti-magnetic and dielectric characteristics (medical centres, research institutes). The widespread use of steel in the future raised the question of the limited supply of deposits of iron and metals used for alloying.
Alkali-resistant glass fibre with a diameter of 10-15 microns was used as the main material for the manufacture of composite reinforcement in the 1960s, and synthetic resins of the epoxy or polyester type were used to form it into a monolithic core. National researchers organized a trial production of this reinforcement with the aim of a more detailed study of its physical and mechanical properties. Therefore, it was revealed that the alkali-resistant glass fibre composite reinforcement with a diameter of 5 millimetres has the following technical characteristics.
Long-term resistance under normal temperature and humidity conditions is: 65%. Unfortunately, at that time it was not possible to organize large-scale production of composite reinforcement in the USSR, however, this material was used for the construction of several structures:
Between 1969-1979 - The experimental sections of power lines with fibreglass concrete crossings were put into operation in Moscow, Stavropol, Batumi and Grodno.
In 1976 - in the towns of Rogachev and Cherven two sliding warehouses were built, inclined elements of arches, in which they are reinforced with fiberglass rods with a diameter of 6 mm.
In 1975 - in the USSR, the first glued timber bridge in the world was built with composite reinforcement with a diameter of 4 mm, designed according to the project of specialists from Khabarovsk Polytechnic Institute.
In 1981 - a bridge was built over the river with fiberglass reinforcement on Primorsky territory. Shkotovka.
In 1989 - a bridge was put into operation on the territory of Khabarovsk, for the reinforcement of beams of which steel and composite reinforcement was used.
According to the results of a survey of bridges built in the period from 1975 to 1989 as experimental structures, during the years of operation, the prestressing effect of the glass fibre reinforcement remained unchanged.
After a long break, research on the development of non-metallic composite reinforcement was resumed in 2000. Thanks to the joint efforts of NIIZHB, the "Research Center MATI" of the Federal State Unitary Enterprise and the "Yaroslavl Composite Plant" LLC, two pilot industrial plants for the production of composite accessories based on the principle of pultrusion and filterless technology were developed and put into operation. To date, the above-described method of manufacturing reinforcement from composite materials has been selected as the most promising.
The advantages of using lightweight, durable composite materials in the aerospace industry subsequently became the basis for their wider use in all industrial fields. As far as the production of non-metallic FRP reinforcements is concerned, this topic started to be seriously considered by American specialists only since the mid-1960s. However, it is worth noting that due to the high cost of composite reinforcement, it did not receive commercial distribution until the late 1970s.
In the United States, Marshall-Vega Inc. was responsible for the development of FRP rebar. In the 80s and 90s, non-metallic composite reinforcement was used mainly in the following industries.
The practical application of fiberglass reinforcement in South America comes down to the construction of a warehouse in British Columbia (1998).
In Canada, FRP rebar has been used for several road bridge demonstration projects. In the second half of the 90's, 4 road bridges were put into operation here, using composite reinforcement (Manitoba Bridge, Saint-François Bridge, etc.). Today Canada is a leader in the use of FRP rebar in the construction of the bridge deck.
As for Europe, Germany was the first country to pay attention to composite construction armature. In 1986, a road bridge was built here, for reinforcement of which FRP prestressed fittings were used. The European program of research of fiber composites and technology of non-metallic reinforcement was headed by EUROCRETE. The use of composite rebar has also become the most widespread in developed countries in Asia and the East. Thus, by the mid 90s of the 20th century in Japan there were more than 100 commercial facilities, concrete structures of which were reinforced with FRP rebars. Today, the largest consumer of composite reinforcement is China: here this building material is used in the construction of most new constructions - from industrial buildings to bridges and subways.