Many facilities are installed to increase convenience of everyday life in cities where we live. The structures, which form a part of those facilities, unavoidably become old with degraded durability and load-bearing capacity due to environmental factors such as natural disaster, fatigue accumulation, etc., over time after completion of construction.
The failure to repair those unstable structure, leaving them unattended, will give rise to risks from collapse of structure, and sometimes, may result in large-scale calamities involving injury or loss of life, and furthermore, add to the confusion caused by prolonged paralysis of major social infrastructures and transportation networks. Consequently, significant inconvenience will be caused to routine lives of the public, along with tremendous construction costs arising from restoration works. Moreover, conventional methods significantly increase the vulnerability of structures to the fire and make reinforcement materials combusted during the fire, leading to failure of structural reinforcement functions, even after structural reinforcement. In response to that, our company developed the NCP Method[patent no. 10-1395192] which improves necessary functions, such as tensile strength, and makes the structure more lightweight by using the nonflammable FRP jointly developed by Korea Institute of Civil Engineering and Building Technology, to strengthen nonflammable performance and fire resistance, ensuring conformity to related laws and regulation, stronger advantage in terms of cost effectiveness, workability, safety and greater structural reinforcement and nonflammable performance, compared to other methods.

This method drastically applies the concrete structure repair reinforcement technique(Patent no. 10-1395192), using the non-flammable FRP panel(commonly called “NCP Panel”), drastically improving the non-flammability and fire resistance performance which could not be adequately achieved by conventional reinforcement materials. The NCP panel, made with the resin containing eco-friendly inorganic fire retardant agent which does not generate harmful combustion gas during fire, is fixed to the surface of structure by using the specially designed multi-purpose hollow anchor, and then is integrated with the pressure-injected flame retardant adhesive resin. It is an innovative repair reinforcement method can strengthen fire resistance reinforcement against fire, as well as repair reinforcement of structures.

• • Pretreatment of substrate

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  • Water jet cleaning

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  • Installation of NCP panel and multi-purpose hallow anchor

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  • Fixing anchor installation and RFS-02 sealing

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  • RFI-01 injection and filling

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  • Finish painting(if necessary) and completion

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① Nonflammable(semi-nonflammable) reinforcement material that complements the shortcomings of conventional reinforcement materials vulnerable to fire.
② Nonflammable(semi-nonflammable) material, not generating toxic gas during the fire
③ Excellent performance with high tensile strength(400MPa or higher)
④ Suitable for structural and fire resistance reinforcement of major multi-use facilities, particularly, such as subway, airport, railroad, road tunnel,
     underground shopping complex, etc.
⑤ The material which is free from corrosion and nonconductive
⑥ Excellent chemical resistance, neutralization resistance, freeze-thawing
⑦ Lightweight reinforcement material with little increase in self-weight, easy to process and design, and excellent cost-effectiveness

The nonflammable FRP reinforcement panel was not combusted during the fire, unlike ordinary reinforcement materials, in a real-scale fire test conducted by the Korea Institute of Civil Engineering and Building Technology. Furthermore, no combustion gas was generated and no crack, perforation, melting, etc., occurred on the surface of the reinforcement material.

The load test conducted by the Korea Institute of Civil Engineering and Building Technology for comparison between non-reinforced large-scale beam and NCP panel-reinforced real-scale beam

Multi-purpose hallow anchor

Multi-purpose hallow anchor is used to prevent premature exfoliation of NCP panel installed on concrete structures intended to be reinforced, and to enable synchronized movement of the NCP panel and the structure intended for reinforcement. Moreover, multi-purpose hallow anchor is used for injection of injecting agent and can function as air outlet and inspection hole, and is made from STS to prevent corrosion after installation.

Flame retardant injecting agent

RFI-01 is a low viscosity and high adhesion flame retardant injecting agent and used for injection & filling that makes the fixing anchor, NCP panel, and concrete structure(intended for reinforcement) adhered and integrated into single unit when the NCP Method is applied.

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  Subway, railroad tunnel, etc.

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  Road tunnel(underground pedestrian road)

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  Power cable tunnel, public utility conduits, etc.

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  Lower part of bridge(elevated bridge)

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  Ordinary architectural structures

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  Multi-use facilities

As there is a mounting concern about fire worldwide, large-scale fire in closed space, such as domestic fire incidents including the Cheonju Uam Shopping District fire(1993), Busan Refrigerated Warehouse fire(1998), Daegu Subway Fire(2003), Daegu Dalseong Tunnel fire(2005), and overseas fire incidents, including the Mont Blanc Tunnel fire(1990) in France, Green Belt Tunnel Fire in Denmark(1994), fire in Channel linking between England and France under the Strait of Dover(1996), Gotthard Tunnel fire(2001), and Windsor Tower fire in Spain(2005), has weakened the strength of structures, causing significant problems such as prolonged disconnection of transportation networks, the social infrastructures, as well as collapse of structures and human casualties. Such concern has become increasingly tangible amid the trend towards longer tunnels. The Daegu Subway Fire on February 18, 2004, was caused by the fire set on rail car no. 1079, a large-scale disaster that completely burned 12 rail cars down and causing 198 deaths(estimate). Among good examples are included the fire at Onsu Station of Seoul Metro Line in 2005 and the fire in the new box tunnel structure during the construction of Incheon Airport Railroad. So, R&D(Research and Development) have been constantly pushed forward to develop railroad tunnel fire prevention technology necessary to minimize casualties and property damage in the event of fire. Railroad tunnels, stretching roughly 1,440km, are expected to be constructed across Korea for the next 20 years, including the X-shaped high speed railroad networks such as Honam High Speed Railway, GTX(Great Train eXpress), and new railroads built under the metropolitan transportation network plan of the Ministry of Land, Transport and Maritime Affairs in 2000s, as well as the vast railway tracks of existing urban railroad in domestic municipalities. The demand for long railroad tunnels with a length of 1km or longer is expected to surge to keep pace with the trend for high speed railway.

In that way, there has been a heightened anxiety of the public about disasters, such as fire, and an increasing demand for safety. Accommodating such demand of the society, government has taken actions to strengthen the regulations related to construction and fire prevention, which mandate the use of nonflammable materials, including the Railroad Safety Act, Building Act, Urban Railroad Act, Fire Service Act, and Multi-Use Facility Act.

The NCP Method represents the technology that can satisfy such social demand. If applied to major multi-use facilities such as subway, road, railroad tunnel, architectural structures, the NCP Method can prevent fire-induced damage and collapse and preclude secondary disaster, helping save time taken to complete restoration of structures and minimize financial loss arising from restoration process. In addition, the NCP method is expected to find wider applications even to the seismic reinforcement that leverages the physical performance, such as excellent tensile strength, and fire protection performance.