Application of Fibreglass Reinforced Plastic Bars for reinforcing road pavements

The road surface is dependent on the influence of climatic conditions or mechanical factors. The destruction of road pavements, tunnels, dams, bridges and other infrastructure facilities is caused by climate change, as well as influence of its negative impact. As a rule, this applies to climatic zones, where significant temperature changes are common even considered normal.

In addition, referring to the results of studies, in most cases critical damage to the reinforced concrete structures in use occurs due to the negative effect of chloride corrosion. The structure is highly exposed to aggressive environmental influences of various natures. Chemical reagents, salts, chlorides, as well as other substances contained in the composition of technological products negatively affect the useful life of the reinforcing bars activating chemical reactions destroying the structure.

By reinforcing the road pavement with a fibreglass frame, you increase the resistance of its pavement to deformation, which automatically extends its useful life. Owing to this kind of pavement, the inter-repair period is increased which significantly reduces the costs of the company serving these infrastructure facilities.

Referring to the above advantages of polymer reinforcing bars, it can be concluded that the use of reinforcing bars of such composition positively affects the quality of work, durability of use and reduction in the costs for repairing the road. But these are not the only positive factors. In addition, when using fibreglass reinforced plastic bars, there is a significant decrease in sagging of the road, as well as its wheel tracking due to regular increased loads.

Special reinforcement technology allows strengthening not only the roadbed itself, but also the pads located under it, which even more significantly increases the useful life of the road and saves the costs for repair works.

According to statistics, the United States annually allocate about $100 billion for renewal of bridges damaged by winter climatic factors and anti-icing reagents. American engineers, having faced with the problem of corrosive destruction of bridges, as well as their rapid “ageing”, made a big step towards the development of bridge construction industry in the 1970s by replacing steel reinforcing bars with fibreglass reinforced plastic bars. And this served as a perfect solution to the problem. The motor-road bridge reinforced with glass and concrete was built for the first time in 1986 in Germany according to engineering developments. This was the first step to research and statistical works in the field of construction of bridges using fibreglass reinforced plastic bars. Today, Canada takes a leading position in the market using the frame made of fibreglass reinforced plastic bars. Finally, it found its wide application in the bridge construction industry. Development of provisions, rules and standards of Canadian engineers laid the foundation for the practice of using this kind of reinforcing bars and became very indicative foreign experience in using fibreglass reinforced plastic bars for transport infrastructure facilities.

Our country’s experience related to the use of fibreglass reinforced plastic bars in the road industry is much smaller than the rest. But it may be surely stated that progressive steps towards the great popularity of fibreglass reinforced plastic bars among representatives of various industries of our country are made daily.

Fibreglass reinforced plastic bars are excellent solutions to the problems of frame corrosion in conditions with a sharp climate change, significant changes in temperature conditions or large amounts of precipitation. Also, the use of fibreglass reinforced plastic bars is relevant during a period of intensive increase in traffic, as well as loads on the roadbed. There is no doubt that every year the development of countries and their infrastructures, international relations, passenger and freight transportation only contributes to an increase in the negative impact on the infrastructure objects.

Summarizing the above, we may conclude the following:

• Multicomponent materials in composition of the frames are the best raw materials for the construction of infrastructure objects (roads, tunnels, bridges, dams, parking lots, concrete dividers, curbs and stairs).
• Fibreglass reinforced plastic bars are highly resistant to corrosive reactions, cracks, shears, roadbed deformation, fracture of concrete, which ensures the maximum useful life of road surfaces.

Historical Reference:

Construction of the first glued bridge made of wood dates back to 1975. The construction was based on a project developed under the acute supervision of the Department of Bridges and Tunnels of Khabarovsk Polytechnic Institute. The bridge was 9 meters long and equipped with cross-section beams with a size of 20×60 centimetres. The wood beams were reinforced with 4 stressed bunches of fibreglass reinforced plastic bars with a diameter of 4 millimetres.

In the same way, 1981 is famous for another significant event in the history of the development of bridge construction industry – the construction of a bridge over the Shkotovka River using fibreglass reinforced plastic frame.

The design consisted of six steel I-beams No. 45 pre-stressed with ties of 12 bunches of the reinforcing bars of cross section of 6 mm, where a reinforced concrete monolithic slab served as a union. The bridge length reached 12 meter.

The next bridge was built only 8 years later using reinforcing bars made of glass and plastic – this was the bridge built in 1989 in Khabarovsk Territory. Its length was 15 meters and it consisted of five I-beams. It was protected from corrosion by four bundles with 24 bunches of the reinforcing bars made of fibreglass with a cross section of 6 mm per each bundle. Beam reinforcement remains unchanged.

The use of new technologies in fibreglass reinforcement of road structures became more active only at the beginning of the 21st century and is closely connected with the territory of the former USSR. Today’s economic prerequisites for the use of composite fibreglass reinforcement and its reasonable, advantageous characteristics contribute to the popularization of this type of road pavement reinforcement in all countries of the world.