Maybe FRP is new to some people, but this method is a rapidly evolving method of structural strengthening. But FRP reinforced attraction is the most advanced system in which it uses a specific fiber to wind or follow the structural members to increase its strength. This is very advantageous because it has the ability to add important capabilities to existing columns, beams, walls, and slabs. It can improve the axial, shear and flexural bearing capacity of the component, and improve the rigidity and ductility of the component.

Fiber-reinforced plastic (FRP) composites have a high strength-to-weight ratio and are considered an innovative method to strengthen concrete structures while adding minimal additional weight to the structure. The fiber reinforced plastic (FRP) reinforced masonry structure is an integrated reinforcement system based on carbon fiber, glass fiber, aramid fiber and other fibers and epoxy resin. This is an ideal technology because it combines the advantages of non-corrosive and lightweight advanced composite materials in the form of FRP. In addition, by prestressing carbon fiber reinforced polymer (CFRP), laminates can also more effectively use their tensile capacity to strengthen the structure.

For various reasons, any concrete structure shows signs of damage and aging in the early stages of construction, leading to reinforcement and repair works.

Methods of structural repair and renovation

The basic function/operation of the structure should not be hindered

The sensitivity of the structure to seismic events must be within acceptable standards

Historical buildings/structures of significant archaeological value sometimes exceed the cost factor of the addition. Such a structure must be reconstructed without changing its aesthetic and architectural characteristics

The renovation project must adopt the latest construction technology that has the least impact on the normal operation of the building

In order to prolong the service life of the structure, the cost of the entire building must be practical and reasonable

The practice of repair and refurbishment requires unusual construction methods, is a highly technical task and requires the utmost care while being implemented. Must provide very skilled craftsmanship to implement the recommended measures

Based on the above aspects, methods such as surface repair, protection, waterproofing, repair and reinforcement can be used.

Carbon fiber based (CFRP)

The most common FRP system used for concrete reinforcement is carbon fiber based (CFRP). Unlike glass fiber systems, carbon has superior mechanical properties and higher tensile strength, stiffness and durability. The use of prefabricated carbon fiber reinforced polymer laminate is generally limited to straight or slightly curved surfaces, such as the top or bottom surfaces of slabs and beams. Prefabricated FRP lamiante are usually rigid and cannot be bent on site to wrap columns or beams.

However, fiber-reinforced polymer(FRP) fabric can provide continuous unidirectional wrap, can easily adapt to any geometric shape, and can wrap almost any shape. Fiber-reinforced plastic wrap can be glued to the tensile side of structural members, such as slabs or beams, to provide additional tensile reinforcement and increase the modulus of rupture. It is wound on the web of the joist and beam to increase its shear strength, and it is wound on the column to increase its shear and axial strength, and improve ductility and energy dissipation.

The adhesive system

The adhesive system used to bond the FRP to the concrete substrate may include: a primer to penetrate the concrete substrate and improve the bonding system. Epoxy putty used to fill small gaps on the surface of the substrate and provide a smooth surface bonded with fiber reinforced plastic. Adhesive used to soak the fabric and bond it to the prepared substrate. And a protective coating to protect the bonding system from potentially damaging environmental and mechanical influences. In most cases, ultraviolet (UV) light has a negative impact on FRP-reinforced epoxy resins, but acrylic and cement-based paints and other types of paint can protect them.