GFRP Rebar FAQs

1. Strength: composite reinforcement has strength characteristics which are 2-3 times superior to steel reinforcement.
2. Durability: the coefficient of temperature expansion of composite reinforcement is close to the coefficient of thermal expansion of concrete, so that in concrete structures there are no associated micro defamations, microcracks and the overall durability of the structure is substantially increased. 
3. Corrosion resistance: As we know that steel rebars are prone to corrosion and have a life of 20-25 years whereas GFRP Rebars are 100% anti corrosive in nature and have a life of over 80 years making it much more durable. 
4. Chemical resistance – composite reinforcement has great chemical resistance in various aggressive environments, it is not susceptible to corrosion which also positively affects the durability. 
5. Lightweight: composite reinforcement with comparable strength characteristics is lighter than steel reinforcement by almost 4 times. 
6. Low thermal conductivity: due to low thermal conductivity, “temperature bridges” are not formed on the structures, which reduces the thennal loss to 34% and accordingly the conditioning cost of the building. 
7. Easy installation: composite rebars can be cut from the bay of any given length which increases speed of work at site, later fastened with plastic clips, special fasteners/clamps or just with traditional binding wires.Easy transportation and storage: you can fold the composite rebars into coils at the time of production, which allows us to use even cars, autos, scooters for transportation and save on transport cost significantly. 

As we know that GFRP rebars have a density of only 1.9 Tons/m³ making it almost 4 times lighter than metal rebars. This helps in loading 4 time more material into trucks than steel and can save a significant amount on logistics costs. 

Custom length: unlike metal reinforcement, composite Rebars can be provided in custom lengths which can help in reducing costs as no overlapping is required and time, labor cost is saved.

Yes, you can use MRG GFRP Rebars together with metal rebars in some cases where it is necessary.

1. Modulus of elasticity: the modulus of elasticity of composite reinforcement is almost 4 times lower than that of metal reinforcement, even with an equal diameter. In other words, it easily bends. For this reason, it can be mostly used in ground applications where usage in floors requires additional calculations. 
2. Dielectric :composite reinforcement unlike metal reinforcement cannot be welded by electric welding. 
3. Temperature: when heated to a temperature of 600 degrees Celsius, the compound that binds the composite reinforcement fibers softens so much that the reinforcement loses its elasticity.
   To increase the stability of the structure in the event of fire, additional measures should be taken to heat protect the structures that use composite reinforcement.
4.  Bending: composite reinforcement unlike metal reinforcement does not have mechanical properties which are elastic, thus it doesn’t allow you to bend material on site.

Due to higher fatigue properties, GFRP Rebars have a higher resistance to cyclical loads of high intensity, which makes GFRP Rebars workable during earthquakes subject to a detailed design report on the same.

Both composite reinforcement and metal reinforcement have approximately the same adhesion to concrete/cement.

 Any binding can be used while using GFRP Rebars. Traditional binding wires can be surely used as well as plastic clips or knitting wire with the help of plastic fix clips.

Composite reinforcement is fire resistant up to 600 degrees Celsius. Once the temperature exceeds 600 degrees Celsius, the compound that binds the composite reinforcement fibers softens. Composite reinforcement does not burn directly, and studies show that structures are sustainable during a fire.

No, as the mechanical properties of GFRP Rebars are elastic, thus it does not allow you to bend the material on site. However, you can get your desired bend/curved elements prefabricated as per your requirement.

The change in ambient temperatures on the strength of composite reinforcement is practically unaffected. GFRP Rebars can be used at temperatures from (-70 degrees Celsius) to (+120 degrees Celsius) without being affected. 

When reinforcing concrete/cement structures with GFRP Rebars, special requirements to the components of the concrete mixture (cement, aggregates additives) are not presented. It is also possible to use composite reinforcement with Portland cement and its varieties (sulfate resistant, hydrophobic etc.) The quality of concrete mixtures and the technology of their preparation should ensure the production of concrete structures that meet the requirements for standardized quality indicators.

Yes, at the same time it is required to provide the necessary reinforcement area and the compliance with the requirements for fire resistance of a concrete structure. Depending on the loads and design features, additional calculations of the designers are needed. According to the general recommendations, GFRP Rebars can be used in load bearing structures of buildings up to 3 floors with detachable formwork and up to 5 floors with fixed formwork.

Yes, the corrosion resistance of composites piles is substantially higher than that of steel reinforced concrete piles. 

Indian standards of GFRP Rebars in India are IS 18255: 2023, IS 18256: 2023 and IRC: 137-2022.

GFRP Rebars come in standard length of 12 meters. But since we can coil them, we can make custom lengths of up to 5kms which helps save in your overlapping cost.

Yes, GFRP Rebars are brittle in nature but only break or snap at a tensile strength of 1000+ megapascal.

 While handling the material and using GFRP Rebars, it is advised to wear safety hand gloves since GFRP Rebars are made from Fiberglass, they have small threads which may cause irritation if used with bare hands.

The rebar revolution of GFRP Rebars began in 2019 by MRG Composites in India. We started the wave and now the growth and usage of the material will grow exponentially in India in the coming future since the Bureau of Indian Standard has published its own standards.

GFRP Rebars are tested in a different way to the metal rebars. In the case of GFRP Rebars, couplers/grippers are to be installed on both end of the Rebars to perform major tests like tensile. Further details on testing are mentioned in test methods in IS 18255:2023