Facility Maintenance Division of Kukje Chemical & Construction Co., Ltd.
Kukje Hybrid Composite
Fiber reinforcement sheet in concrete structures & Method for reinforcement of concrete structures by using the fiber reinforcement sheet(Patent no. 10-1540243)
It is a ductility-increasing seismic reinforcement method that improves load-bearing capacity of structures by embedding high-strength aramid fiber and sheet-shaped high-ductility PET fiber sheet into the structure that requires reinforcement such as old concrete and steel structures, using the impregnating agent. As the fiber, lighter than reinforced concrete, is used, lightweight features can be achieved. In addition, this Method has the advantage of excellent safety, compared to other reinforcement methods, as the abrupt brittle fracture caused by linear behavior can be prevented by mixing two or more types of fiber at appropriate ratio while enabling an increase in ductility.
1) As it is a high ductile material(elongation rate: 8.0% or higher), it provides more excellent seismic reinforcement effect, compared to other fiber reinforcement methods.
2) It is more cost-effective, compared to other fiber reinforcement methods.
3) As it is a nonconductive material, no electricity can flow through it.
4) As it is a lightweight material, it causes no additional strain of weight on the structures.
5) It enables seismic reinforcement for bridges, various architectural, civil engineering structures.
6) With the water permeability rate of '0', it prevents infiltration of contaminants.
7) The high ductile fiber sheet, which is corrosion-free, protects the structures from corrosion.
| Item Name | Width (mm) of reinforcement material | Thickness (mm) of reinforcement material | Test data |
|---|---|---|---|
| KHC-P Fiber(200) | 100 ~ 300 | 2.0, 3.0 |
Elongation rate : 8.0% or higher Tensile strength: 200MPa or higher |
| KHC-P Fiber (400) | 100 ~ 300 | 2.5 |
Elongation rate: 8.0% or higher Tensile strength: 400MPa or higher |
| Glass Fiber | 500 | 1.0 |
Elongation rate: 2.0% or higher Tensile strength: 500MPa or higher |
The KCH fiber shows the deformation rate of 8.0% at its fracture, making it effective for seismic retrofit that increases ductility, compared to existing carbon fiber(CF), glass fiber(GF), and hybrid fiber sheet(HFC).
Deformation rate at fracture (%)
| Types of fiber sheet | CF Sheet (carbon fiber) | GF Sheet (glass fiber) | HFC Sheet (hybrid fiber) | KHC Sheet (high ductile fiber) |
|---|---|---|---|---|
| Deformation rate (%) at fracture | 0.94 | 2.0 | 2.8 | 8.0 |
| Note | Deformation rate at fracture: Deformation rate when fiber is fractured during the tensile test of fiber sheet. | |||
Brittle fracture can be prevented with reinforcement of vulnerable part, using the KHC fiber that has excellent ductility.
Flexural fracture at the lower part of bridge
Destruction of architectural structures
Various civil engineering and architectural structures can be reinforced, such as bridges, slabs, walls of various forms.
Bridge reinforcement method
Slab and wall reinforcement method(1)
Slab and wall reinforcement method(2)
Slab and wall reinforcement method(3)
The KHC-fiber reinforced real-scale bridge showed an 122% increase in maximum load, 198% increase in deformation rate, and 275% increase in ductility rate, compared to ordinary bridges not reinforced, thus demonstrating the ductile behavior that prevents brittle fracture.
Structures not reinforced
Behavior after reinforcement with high ductile fiber sheet(KHC)
| Testpiece | P max (kN) | △max(mm) | Ductility rate |
|---|---|---|---|
| Structure not reinforced | 172 | 44.6 | 2.95 |
| KHC sheet reinforcement | 211 | 88.4 | 8.11 |
| Remarks | 122% | 198% | 275% |
Note. Pmax : maximum load, △max : maximum displacement, ductility: seismic performance indicator for the seismic reinforcement that increases ductility(Seismic reinforcement effect is larger as the ductility rate is higher)
1) It can prevent collapse caused by bending and inadequate load-bearing capacity of compression members during the earthquake, and enables restoration and increase of the load-bearing capacity of structures.
2) It enables protection and repair of the surface of concrete and steel structures affected by chemical actions such as seawater, sewage, freezing-thawing, salt damage, etc.
3) It enables repair and reinforcement of concrete structures that require extension of lifetime and greater durability.
1. Substrate treatment
2. Primer and adhesive application(KSE)
3. Attachment of high ductile fiber sheet (KHC + KSE)
4. Finish painting and curing (K3380)
