Epoxy resins, which today have a very high efficiency of materials in strengthening, repairing, and strengthening various structures, especially in composite products, are composed of epoxy resin and hardeners. These materials are also used to manufacture solid moulds, with good adhesion to various layers, high chemical resistance (especially in very acidic and alkaline environments) and good tensile, compressive and flexural strength in the construction industry. Epoxy Resin is also used to produce various electrical components due to its insulation and in the aerospace, aircraft and automotive industries for internal and external connections. However, the most effective use of epoxy resin can be seen in the manufacture of FRP composites.
Another area of application of epoxy resin is using this product like a floor covering for halls, factories and other surfaces to increase the resistance of concrete against corrosion agents and chemicals.
4 mm thick epoxy coating increases the compressive strength of concrete by about 21100 kg/cm. Epoxy resin with low concentration and high penetration strength has high initial and final stability.
Properties of epoxy resin
- Resistance to chemicals
- High resistance to water and moisture
- Resistant to absorption of mechanical and thermal stresses
- High abrasion and impact resistance
- Excellent adhesion to materials and compatibility with a variety of fibres and FRP systems
- High filling capability
- Low weight and low volume
- Durability and high speed of repair
Disadvantages of epoxy resin
- Its price is higher than other types of resin.
- Epoxy resin processing is time-consuming because the curing time of epoxy resin and polymerization process is lengthy.
- Epoxy resin is not flexible and is prone to cracking.
- Does not work at temperatures below 5 degrees Celsius.
The characteristics of epoxy baked goods depend on the following:
- Type of epoxy
- Type and amount of hardener
- Degree of networking
- The nature and volume of additives
Cause the epoxy and hardener mixture does not dry
When working with epoxy resin, we may encounter the following problems:
- Epoxy resin does not dry
- Epoxy resin becomes viscous and soft
Here are some things to keep in mind to avoid these problems:
- See the correct mixing ratio
The resin does not dry due to a lack of hardeners in the system.
- Existence of water or moisture in the system
The epoxy resin mixing container is not completely dry, or the work surface or air is wet
- Epoxy and hardener do not mix well
- Temperature control
The air temperature should not be less than 10 degrees. The surface temperature is less than 5 degrees Celsius because the epoxy and hardening reaction stops at low temperatures, and the resin does not dry out. Excessive heat can also interfere with the drying of the epoxy resin. The air used can be 50 degrees Celsius.
- Surface contamination
Contaminated work surfaces are like grease and dust that interfere with the drying of epoxy resin.
Types of epoxy resins and their applications
Epoxy putty is a solvent-free two-component material based on an epoxy resin used to level the bed surface and fill joints and cracks in reinforcement projects, reinforcing the structure with FRP composites. Epoxy resin has high adhesion and has a high mechanical, chemical and thermal resistance. It is also called epoxy repair because it is used to restore concrete surfaces to install FRP fibres in reinforcement projects.
Epoxy remover can be used on vertical and horizontal surfaces and does not shrink and shrink during setting. This product quickly penetrates the cracks and acts as an integrated system after setting. High strength, lack of impact against moisture and environmental factors, ease of application and increased adhesion of epoxy putty are the advantages of this epoxy resin that has led to its use in the reinforcement of buildings.
In addition to topics related to FRP composite reinforcement, filling pores and cracks, and levelling and repairing damaged concrete, epoxy putty can be used in bathrooms, factory floors, swimming pools, and as an intermediate layer of epoxy resin flooring.
Epoxy primer is a two-component material based on epoxy resins that can penetrate deep into the concrete and prepare concrete surfaces in the reinforcement and reinforcement of structures with FRP composites. The adhesion of this epoxy resin is high and has excellent penetration power, so it has many applications in structural support.
This product can be used in industrial tanks and metal structures due to its good adhesion to metal surfaces.
Epoxy primer can be used as a primer for repair mortar and epoxy industrial flooring in concrete surfaces, gymnasiums, laboratories, etc., in addition to use in FRP composite reinforcement issues. This product withstands stresses from the floor when used as the floor surface.
The most helpful epoxy resin in building reinforcement with FRP and consists of two parts, epoxy resin and hardener and has very high strength. Uses of the epoxy resin include: making FRP composites for use in various industries such as building restoration and reinforcement, making FRP composites, automotive, aircraft and …
Some of the features of epoxy adhesive that have made this product very popular are:
- The tensile, flexural and compressive strength of the epoxy adhesive is very high. Therefore, they play a significant role in the construction of FRP composites and the building reinforcement industry.
- Epoxy resin is very resistant to various chemicals such as acids, salts, oils, solvents, etc. and is not affected by these substances.
- The price of epoxy adhesive is very economical due to its high adhesion and wide application
- Epoxy resins are very resistant to heat, abrasion and moisture.
- The epoxy adhesive does not shrink when hardened and creates very high adhesion at all levels.
Injectable epoxy resin
Injectable epoxy resin is a two-component, solvent-free material consisting of two components, hardener and agent. It is used to fill joints and repair concrete cracks, and strengthen and reinforce structural elements such as beams, columns, resin floors, etc. It has high adhesion and permeability and cracks repair in concrete.
Epoxy injection resin is a dilute yellow liquid that has high resistance to chemicals and impact. This epoxy resin can easily penetrate the cracks and perform the task of repairing concrete cracks with high adhesion and hardening strength. It does not shrink when dry; it can be used on dry and wet concrete surfaces to repair concrete cracks and strengthen structural elements.
The steps of repairing concrete cracks are as follows: after removing the contamination from the surface of the packer or nipple element, which is responsible for transferring the resin into the break, we place it at certain intervals, then continue the injection operation until the injected epoxy resin rejects. Finally, the concrete is cracked to ensure the correctness of the reinforcement. Injected epoxy resin is widely used in support of structural members and the repair of concrete cracks.
Epoxy mortar is a solvent-free three-component product based on epoxy resin with precise granulation and low weight. Epoxy mortar does not have fluid, so it is suitable for use on horizontal and overhead surfaces. High mechanical strength and anti-corrosion properties of epoxy mortar are among them. It is also used in laying concrete surfaces. These mortars do not need a primer.
Dough epoxy gel
The epoxy gel is used in cases where it is not possible to saturate the FRP fibres. This epoxy gel is used in laminate installation and FRP rebar installation in the NSM method and high and vertical surfaces. The combination of paste epoxy gel with silica sand can be used as a repair mortar.
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