As the process of developing building cases progresses, There was great emphasis on strengthening the concrete beams. One way to strengthen these beams is to use fiberglass, The manufactured product is called GFRC, That is, concrete reinforced with fiberglass.
GFRC uses fiberglass and concrete, Both have advantages on their own, But combining them makes something great. Fiberglass gives its anti-alkali properties to concrete and makes concrete ready for use in many cases.
In this mix, Both retain their physical and chemical identity, However, they produce a range of properties that cannot be achieved using either ingredient alone.
Concrete is a weight-bearing material. While the surrounding matrix maintains the desired locations and orientation, And as a connector, It transfers the load between them and protects them from environmental damage. Fiberglass plays an important role in the process of strengthening concrete beams.
When someone says fiberglass, We think of insulated or fiberglass boats, But perhaps it is better to consider concrete because it is a good partner for concrete in the process of strengthening concrete beams. Technically, Fiberglass is a very fine glass fiber used in boat building or other products.
this matter , Although it is called fiberglass, It is actually fiberglass reinforced with glass fibers in a polymer composite. If we use cement and portland sand instead of polymer, The resulting material is made of reinforced concrete and, after being combined with fiberglass, is called GFRC or sometimes. How are the methods of making concrete elements using fiberglass in the process of strengthening concrete beams?
In the process of strengthening concrete beams, There are three ways to make GFRC concrete elements:
• Traditional manual spraying
• Vibratory casting
• Spray mixture
The traditional and perhaps the best way to strengthen concrete beams is to manually spray GFRC into the mold. This is how most precast GFRC cladding panels are manufactured, As well as most decorative precast GFRC. Using the direct spray method, You need a concentric shredder gun that is fed by a GFRC spool that is pulled into the shredder gun and mixed into the nozzle.
This mixture has a higher fiber content (4-6%) than that obtained with pre-mixing and is the recommended method for larger boards. This work requires experienced workers, expensive equipment and strict quality control.
In strengthening concrete beams for vibratory casting, Mixed GFRC is used for molding and casting to achieve a homogeneous product. This is a much simpler method, But it requires waterproof molds and does not work well with stone molds.
Spraying GFRC with chopped fibers in the mixture requires a peristaltic pump and a special spray head. This method requires less experience than manual spraying and has higher resistance than vibration casting.
But most of the GFRC decorative parts, Which is the product of the process of strengthening concrete beams, Especially counter tables, or fireplace surround, It is manufactured using the two-layer method. The top layer is a thin, decorative layer and the back layer is thicker and contains fiberglass. GFRC is usually applied in two layers about 3/8 inch thick and compacted using a roller or vibrating table.
What are the uses, advantages and limitations of using concrete in the process of strengthening concrete beams with fiberglass?
GFRC fiber mixed concrete, Which is the result of the process of strengthening concrete beams, Usually used in the following works:
• Building renovation works
• Water and drainage
• Cover panels for bridges and tunnels
• How to create permanent templates
• Architectural coatings
• Sound barriers and panels
• Repair and industrial flooring works
But the characteristics of this type of concrete can be briefly mentioned as follows:
• GFRC concrete is resistant to chemicals.• GFRC concrete is resistant to chemicals.
• It is characterized by high durability, long life and resistance to all weather conditions.
• Compared to regular concrete, It has better shrinkage properties.
• Fire-resistant.
• The low permeability of GFRC increases its resistance to air and water pollution.
• It is environmentally friendly.
• Due to its light weight, It reduces the dead load of the building.
• High speed in implementation and installation.
In strengthening concrete beams in the past 30 years, GFRC is used to produce many concrete products, Especially thin architectural cladding panels, As well as decorative concrete such as domes, sculptures, plantations and fountains. at recent days , Craftsmen have discovered decorative concrete with the benefits of GFRC for decorative panels (such as fireplace surrounds), and concrete work surfaces, And artificial stonework.
But at the time of use, It is important to keep GFRC concrete from drying out for a long time after it is poured. Cover the concrete piece with plastic or a wet bag overnight, But use it as soon as it gains enough strength. Most GFRC parts work 16 to 24 hours after casting and then forming.
The use of fiberglass in the process of strengthening concrete beams is very limited because it causes severe damage and loss of strength due to abrasion and forces generated during the movement of aggregate in the mixer. Much attention has been paid to fully understanding the mechanical properties and performance characteristics of GFRC in designing its components. For example , He reports several projects for the construction of wall panels made of GFRC in England and the United States.