Basalt, steel or fiberglass rebar.

What rebar type to choose?


Comparison of the steel and composite rebar properties

About rebar

What are the rebar types

There are two main types of rebar: steel rebar and composite (non-metal) rebar.

Unlike traditional steel rebar, composite rebar has many advantages, along with obvious disadvantages. In many cases, the use of composite reinforcement is more justified than the use of steel.

If we do not consider carbon fiber due to its high cost (from 40 USD/kg), then among the composite rebar types basalt is the most durable.


Steel Rebar

Steel rebar is the most commonly used reinforcement in construction. In civil and industrial construction, steel rebar of classes A1 (A240), A2 (A3300), A3 (A400), A4 (A600), A5 (A800) and A6 (A1000) are used. The first marking is the marking adopted according to the Soviet GOST, the new marking is indicated in brackets.


Composite Rebar

Fiber-reinforced plastic rebar, FRP rebar are rods made of basalt, glass, carbon, or aramid fibers, impregnated with a polymeric binder and cured.

The most common types in the construction industry are basalt composite rebar and fiberglass composite rebar.

Basalt rebar

Basalt rebar is made at the unique equipment from thousands of basalt fibers impregnated with a special composition based on epoxy resin, which heats up and polymerizes as it passes through the line. Unlike many manufacturers, we have ensured the absence of polymer cracking by deep modernization of production processes.

Basalt reinforcement has outstanding strength characteristics with tensile strength three times higher than that of steel reinforcement and one and a half times that of fiberglass reinforcement. However, due to the lower elastic modulus than steel reinforcement, composite reinforcement of any kind is not recommended for use in ceilings longer than 3 m.

Basalt rebar is a perfect product for application in places where the rods work at breaking, in places with the influence of aggressive media and temperature changes (industrial floors, foundations, road surfaces, reinforcement of coastlines, berths, etc.).

Beware of counterfeits. There are cases when unscrupulous manufacturers make only the outer shell of the rod from basalt fibers, and the core is made of fiberglass. In no case such a product can be called basalt reinforcement, since it is significantly inferior in its properties to the original composite.

Fiberglass rebar

Like basalt rebar, fiberglass rebar is made by the same principle, but out of glass roving.

Fiberglass composite rebar is inferior in its technical parameters to basalt rebar. Low rates are a consequence of the artificial material characteristics from which it is made, we mean glass.

You can find comparative characteristics of different rebar types in the table at the bottom of the page.

Steel rebar

Steel rebar is the most common reinforcing material in construction. It is made of both high-carbon and low-carbon steel (the more carbon, the harder and stronger the steel).

In terms of their tensile strength properties, steel reinforcement is significantly inferior to the properties of basalt reinforcement and can be easily replaced with it in certain areas of construction.

Correspondence table of steel and basalt rebar diameters  with equal strength steel replacement with basalt:

Steel rebar diameter, mm Basalt rebar diameter, mm
Ø6 Ø4
Ø8 Ø6
Ø12 Ø8
Ø14 Ø10
Ø16 Ø12
Ø18 Ø14

Replacement of steel rebar with composite

Construction is carried out in all sectors of the economy and this area of ​​life, like others, is in a constant innovation process, developing and mastering more and more efficient materials and technologies.

At the same time, it is in the construction industry where the highest demands on the strength and reliability of materials are made. These requirements are met by non-metallic composite reinforcement made of basalt fibers, which were originally developed for the space industry.

Basalt fiber complex thread. One such thread contains hundreds of monofilaments. From a variety of such threads, roving (rope) is produced, which is the main material for the basalt rebar manufacturing.

Composite rebar structure

Basalt composite rebar consists of a polymer matrix and reinforcing elements. Thousands of continuous basalt fibers of high strength, combined with each other into a core by a polymer matrix, act as reinforcing elements. Outside, the rod is pulled together by a winding basalt twisted thread, which gives the surface a constant continuous ribbing. Composite rebar diameters range from 4 to 16 mm.

Features of basalt composite rebar

There is no material flow under any load at all sections of elastic and plastic deformation. It allows you to use the most complete range of tensile strength characteristics.

  • The design resistance of basalt reinforcement exceeds the resistance of reinforcement made of class A-III steel (A300, A300s) approximately three times.
  • Relative elongation of basalt reinforcement under tension is 8–10 times less than that of steel reinforcement of the corresponding strength – it retains its size very well and is less deformed.
  • The modulus of elasticity of basalt reinforcement is lower than that of steel, but higher than that of fiberglass.
  • The specific gravity of composite reinforcement is 4 times less than that of steel, which leads to a decrease in the weight of the frame, the cost of handling and transport costs.
  • Basalt reinforcement does not corrode, which leads to a concrete service life increase.
  • The coefficient of thermal expansion (CTE) of basalt rebar practically corresponds to the CTE of concrete, which completely excludes the formation of cracks and exposure of the reinforcement mesh during operation of the structure due to temperature differences.
  • The thermal conductivity of composite rebar is more than a hundred times less than that of steel, which improves the thermal performance of reinforced concrete.
  • Basalt rebar does not lose its working properties even at low temperatures.
  • Basalt rebar is radio-transparent, diamagnetic and dielectric

Comparative characteristics
of various rebar types

Index Basalt Rebar Fiberglass Rebar Steel Rebar
Reinforcing material basalt fiber fiberglass stell
Tensile strength, MPa 800 – 1 100 600 – 1 000 360 – 420
Elastic module, GPa (DSTU requirements) 70–75 (43-45) 50–60 200
Relative extension, % 1.33–1.86 2.2 14 (для А3)
Coefficient of linear temperature deformation in the temperature range from 0 to 200 ° С, m / ºС (for concrete ɑ = 0.7-1.0 · 10-5) 0.5–0.9·10-5 0.9–1.2·10-5 1.3–1.5·10-5
Density, g/cm³ 1.9 1.9 7.80
Working temperature range, ºС –70…+160 –70…+160 –70…+50
Thermal conductivity coefficient, W/(m·ºК) 0.36 0.5 46
Electrical properties dielectric dielectric conductor
Magnetic properties diamagnet diamagnet conductor
Resistant to corrosion, acids and alkalis not exposed not exposed exposed



More about
Technobasalt® Rebar

Technobasalt® Rebar Range

The range of Technobasalt® basalt rebar covers all major areas of construction.

Where is Technobasalt® rebar used

The range of application of basalt rebar is huge. We propose to study in more detail the technologies in which it is applied.

A few words from our team

Our company is constantly in the process of innovation, improving our product range. The high quality of our products allows us to deliver our products to 54 countries around the world.

Anton Shandra

General Director, Technobasalt Invest

We try to follow our principle – to make products reliable and efficient.

Sergey Kvasun

Head of the reinforcement shop, Technobasalt Invest

Your question

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