KR20230174389A - Fireproof construction method for tunnel - Google Patents

Abstract

The present invention relates to a tunnel fireproof construction method. Specifically, the present invention can simply perform fireproofing construction to protect a tunnel from fire at low cost, while suppressing contamination of the inner wall of the tunnel, enabling low-concentration contamination removal even by low-pressure watering, and providing high-concentration contamination removal. This relates to a tunnel fireproof construction method that maintains fireproof function for a long period of time even during high-pressure water spray cleaning and further prevents toxic gases from being emitted in the event of a fire.

Description

Fireproof construction method for tunnel}

The present invention relates to a tunnel fireproof construction method. Specifically, the present invention can simply perform fireproofing construction to protect a tunnel from fire at low cost, while suppressing contamination of the inner wall of the tunnel, enabling low-concentration contamination removal even by low-pressure watering, and providing high-concentration contamination removal. This relates to a tunnel fireproof construction method that maintains fireproof function for a long period of time even during high-pressure water spray cleaning and further prevents toxic gases from being emitted in the event of a fire.

Recently, large-scale fires have occurred frequently in road and railway tunnels around the world, causing serious economic and social losses. In particular, unlike fires in ground structures, tunnel fires occur in closed spaces, so the temperature rises very rapidly and the fire duration is long compared to the standard fire curve. Therefore, fire-resistant construction is necessary to secure evacuation and response time necessary for fire extinguishing and rescue activities in the event of a tunnel fire, thereby reducing casualties as well as damage to roads and tunnels and traffic inconveniences.

In particular, since cargo vehicles that can generate high temperatures in the event of fire pass through tunnels, it is very important to ensure stability against damage threats such as explosions caused by fire and deterioration of the mechanical properties of structural materials. Furthermore, the concrete forming the inner wall of the tunnel is made of rebar. In the case of inserted reinforced concrete, the bearing capacity may be greatly reduced due to damage such as explosion or cracking of the concrete member due to a rapid increase in temperature of the reinforcing bar member in the event of a fire.

Conventional fire-resistant construction methods for tunnels include using fire-resistant concrete such as fiber-mixed concrete, attaching fire-resistant panels to concrete inner walls, and applying fire-resistant coating materials to concrete inner walls.

Here, the method of using fireproof concrete is to disperse the fireproofing agent inside the concrete before hardening. It is difficult to uniformly disperse the fireproofing agent inside the high-viscosity concrete, and when a large amount of fireproofing agent is dispersed, the physical properties such as strength of the concrete are affected. There is a problem with this degradation.

In addition, the method of attaching a fireproof panel to a concrete inner wall is a method of attaching fireproof panels of a certain size to the concrete inner wall and assembling them. Since the internal specifications and curvatures of each tunnel are different, standardization is difficult and the work of attaching the fireproof panel is complicated and There is a problem with it taking a long time.

Furthermore, the method of applying a fire-resistant coating to the concrete inner wall is a method of applying a fire-resistant coating to the concrete inner wall to form a fire-resistant layer with a certain thickness, which prevents the fire-resistant layer from becoming insufficient during regular high-pressure water spray cleaning to remove contamination from the tunnel inner wall. Due to durability, there is a problem that the fire resistance function is lost or shortened when the fire resistance layer is at least partially removed, and when an epoxy adhesive is applied on the fire resistance layer to improve the durability of the fire resistance layer, toxic gases are emitted due to combustion in the event of a fire. There is a problem.

Therefore, it can be performed simply at low cost, and at the same time, contamination of the inner wall of the tunnel can be suppressed, low-concentration contamination can be removed even by low-pressure spraying, and fire resistance can be maintained for a long time even during high-pressure spray cleaning to remove high-concentration contamination. Furthermore, there is an urgent need for tunnel fire-resistant construction methods that prevent toxic gases from being released in the event of a fire.

The purpose of the present invention is to provide a tunnel fireproofing construction method that can be performed simply at low cost.

In addition, the purpose of the present invention is to provide a tunnel fireproofing construction method that can suppress contamination of the inner walls of a tunnel, remove low-concentration contamination even with low-pressure water spraying, and maintain fireproof function for a long period of time even when washing with high-pressure water spraying to remove high-concentration contamination. Do it as

Furthermore, the purpose of the present invention is to provide a tunnel fireproof construction method that prevents toxic gases from being discharged in the event of a fire.

In order to solve the above problems, the present invention,

Concrete pouring and curing processes for manufacturing concrete members to form the inner wall of a tunnel; A fire-resistant layer forming process of forming a fire-resistant layer on one surface of the concrete member; and a ceramic reinforcement layer forming process of forming a ceramic reinforcement layer on the fire resistance layer.

Here, a tunnel fireproof construction method is provided, wherein the ceramic reinforcement layer has a hardness of 6H or more.

In addition, a tunnel fireproofing construction method is provided, wherein the ceramic reinforcement layer has a thickness of 200 to 300 ㎛.

Meanwhile, the ceramic reinforcement layer is formed from a one-component ceramic coating agent, and the ceramic coating agent contains 35 to 55% by weight of colloidal silica, 5 to 12% by weight of ethyl alcohol, 0.1 to 0.23% by weight of barium sulfate, and octahedron based on the total weight. Agent A containing 1 to 2% by weight of potassium titanate and 10 to 17% by weight of pigment, 30 to 35% by weight of 3-glycidyl-oxypropyl-trimethoxysilane, 0.01 to 0.2% by weight of wetting agent, No. 1 Additive for paint 0.01~0.2% by weight, additive for second paint 0.01~0.2% by weight, 1,2-Bis(triethoxysily)ethane 0.5~1.5% by weight, silanol functional silicone liquid 0.1~0.8% by weight, formic acid 0.01~0.2 A tunnel fireproofing construction method is provided, characterized in that it contains agent B containing 0.1 to 0.2 weight % of glacial acetic acid and 0.1 to 0.29 weight % of a storage stabilizer.

In addition, a tunnel fireproofing construction method is provided, characterized in that the concrete member is manufactured into a reinforced concrete member by pouring a concrete mix while placing reinforcing bars inside the formwork when pouring the concrete.

In addition, before performing the fire resistance layer forming process, tunnel fire resistance construction is characterized in that chipping or latex application and wire mesh or metal lath attachment are additionally performed on the surface of the concrete member where the fire resistance layer is formed. Provides a method.

Furthermore, a tunnel fire-resistant construction method is provided, wherein the fire-resistant layer is formed by applying a fire-resistant coating material by a spray coating method.

Here, a fire-resistant construction method for a tunnel is provided, wherein the fire-resistant coating agent includes vermiculite cemetitious.

Meanwhile, a tunnel fireproof construction method is provided, wherein the fireproof layer has a thickness of 25 to 45 mm.

The tunnel fireproof construction method according to the present invention forms a fireproof layer by spraying a fireproof coating and forms a reinforcement layer by spraying a one-component ceramic coating on the fireproof layer, 1 to 2 mm below the surface of the fireproof layer. It hardens after absorption and shows excellent effects that can be performed simply at low cost.

In addition, the tunnel fireproofing construction method according to the present invention can suppress contamination by a ceramic reinforcement layer formed on the fireproof layer, can remove low-concentration contamination even by low-pressure water spraying, and maintains a long-term fireproof function even when washing with high-pressure water spray to remove high-concentration contamination. It shows excellent effects that can be maintained.

Additionally, colors can be freely selected to improve brightness inside the tunnel.

Furthermore, the tunnel fireproofing construction method according to the present invention shows an excellent effect in that the ceramic reinforcement layer formed on the fireproof layer does not emit toxic gases in the event of a fire.

Figure 1 schematically shows a flow chart of the tunnel fireproofing construction method according to the present invention.
Figure 2 is a photograph showing the results of a high-pressure water spray test in an example.
Figure 3 is a photograph showing the fire resistance test results in Examples.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure will be thorough and complete, and so that the spirit of the invention can be sufficiently conveyed to those skilled in the art. Like reference numerals refer to like elements throughout the specification.

Figure 1 schematically shows a flow chart of the tunnel fireproofing construction method according to the present invention.

As shown in FIG. 1, the tunnel fireproofing construction method according to the present invention may sequentially include a concrete pouring and curing process (100), a fireproof layer forming process (200), and a ceramic reinforcement layer forming process (300).

In the concrete pouring and curing process (100), concrete mix is poured into the formwork to form the inner wall of the tunnel, and a vibrator is used to ensure that the reinforcement is tightly filled, and curing is carried out at room temperature (20 ± 2°C) and relative temperature. It can be carried out for about 28 days while maintaining constant temperature and humidity at a humidity (RH) of 50±10%. Additionally, when the inner wall of the tunnel is formed of reinforced concrete, the concrete mix can be poured with the reinforcing bars placed inside the formwork.

In addition, before performing the fire-resistant layer forming process 200, as a pre-treatment, the concrete surface can be chipped, latex applied, and wire mesh or metal lath attached to improve the adhesion of the fire-resistant layer to the concrete surface. Next, the fire-resistant coating can be applied by spraying. Here, the fireproof coating can be a material mixed with fly ash, blast furnace slag, etc. in vermiculite cemetitious, which is widely used in fireproof structures of tunnels and plants, and the thickness of the formed fireproof layer is about 25 to 45 mm. It can be. After application, it undergoes the same curing conditions and period as concrete curing.

Lastly, the ceramic reinforcement layer forming process 300 can be performed by applying and then curing a specific one-component ceramic coating agent. Here, the formed ceramic reinforcement layer may be formed to have a thickness of 200 to 300 ㎛, has excellent antifouling properties, and has a hardness of 6H or more, which can effectively prevent damage to the fire-resistant layer even during high-pressure water spray cleaning, and can be used at temperatures above 1,000°C. It has non-combustible and flame-retardant properties, which not only further improves fire resistance, but also does not emit toxic gases in the event of a fire, minimizing human damage due to asphyxiation.

Accordingly, the tunnel fire-resistant construction method according to the present invention does not use fire-resistant concrete such as fiber-mixed concrete or fire-resistant panels, but forms a fire-resistant layer by spraying a fire-resistant coating and applying a ceramic coating through a spraying process of a one-component ceramic coating. Since it forms a reinforcing layer, it can be performed simply at low cost. At the same time, contamination of the inner wall of the tunnel can be suppressed by a specific ceramic reinforcing layer, and low-concentration contamination can be removed even with low-pressure water spraying. It is also fire-resistant for a long time even during high-pressure spray cleaning to remove high-concentration contamination. It maintains its function and, furthermore, prevents toxic gases from being emitted in the event of a fire, showing an excellent effect in minimizing casualties due to suffocation, etc.

Specifically, the one-component ceramic coating agent contains, based on the total weight, 35 to 55% by weight of colloidal silica, 5 to 12% by weight of ethyl alcohol, 0.1 to 0.23% by weight of barium sulfate, 1 to 2% by weight of potassium octatitanate, and Agent A containing 10 to 17% by weight of pigment, 30 to 35% by weight of 3-glycidyl-oxypropyl-trimethoxysilane, 0.01 to 0.2% by weight of wetting agent, 0.01 to 0.2% by weight of additive for the first paint, Second paint additive 0.01~0.2% by weight, 1,2-Bis(triethoxysily)ethane 0.5~1.5% by weight, silanol functional silicone liquid 0.1~0.8% by weight, formic acid 0.01~0.2% by weight, glacial acetic acid 0.1~0.2% by weight and agent B containing 0.1 to 0.29% by weight of a storage stabilizer.

The colloidal silica (aka silica sol) is a negatively charged amorphous silica (Si0 ₂ ) fine particle that forms a colloidal state in water and has a spherical silica fine particle structure. Here, the colloidal silica functions as a ceramic coating agent with excellent incombustibility and resistance to heat. If the colloidal silica content is less than 35% by weight, the adhesive strength is weakened, while if it exceeds 55% by weight, glossiness is reduced.

The ethyl alcohol (ethylalcohol) has the chemical formula of C ₂ H ₅ OH, and here, when volatilized at low temperature, it lowers the curing temperature around the base material and performs the function of assisting the low temperature curing characteristics of the one-component ceramic coating agent. Here, when the content of ethyl alcohol is less than 5% by weight, the leveling of the surface of the reinforcing layer is weakened, while when it exceeds 12% by weight, there is a disadvantage in that the adhesion of the reinforcing layer to the fire resistance layer is weakened.

The barium sulfate has the chemical formula BaSO ₄ and functions to prevent color changes in pigments. Here, if the content of barium sulfate is less than 0.1% by weight, the viscosity of the coating agent decreases and workability is reduced, while if it exceeds 0.23% by weight, the color of the reinforcement layer is easily discolored.

The potassium octatitanate is used to improve the adhesion performance of the reinforcing layer. When the content is less than 1% by weight, the adhesion of the reinforcing layer to the fireproof layer decreases, and when the content exceeds 2% by weight, cracks occur in the reinforcing layer.

When the amount of the pigment is less than 10% by weight, the ability to express the color of the reinforcement layer is weakened, while when it exceeds 17% by weight, the gloss of the reinforcement layer is reduced. The 3-glycidyl-oxypropyl-trimethoxysilane is used to maintain gloss. When the content is less than 30% by weight, the gloss of the reinforcing layer decreases and the adhesive strength weakens, whereas when the content exceeds 35% by weight, the gloss of the reinforcing layer decreases and the adhesive strength weakens. Although the glossiness of the reinforcement layer increases, there is a risk of cracks occurring.

If the content of the wetting agent is less than 0.01% by weight, the gloss of the reinforcing layer decreases, and if it exceeds 0.2% by weight, there is a risk of weakening the adhesion of the reinforcing layer to the fireproof layer. The first paint additive is a silicone additive, and the content is 0.01%. If it is less than 0.2% by weight, the leveling property of the reinforcing layer will be weakened, and if it is more than 0.2% by weight, there is a risk that the adhesion of the reinforcing layer to the fireproof layer will be weakened.

The second additive for paint is a silicone surfactant. When the content is less than 0.01% by weight, there is no leveling of the reinforcement layer, and when it is more than 0.2% by weight, there is a risk that the wetting power of the reinforcement layer may be reduced.

The 1,2-Bis(triethoxysily)ethane (1,2-bis(triepoxysilyl)ethane) is an example of siloxane. When the content is less than 0.5% by weight, the safety of the reinforcement layer is weakened, and when the content exceeds 1.5% by weight, the stability of the reinforcement layer is weakened. There is a disadvantage that the pH increases.

The silanol functional silicone liquid contains a silanol (Si-OH) group having a hydroxyl group (-OH) on the silicon element. If the content is less than 0.1% by weight, there is a risk of generating harmful substances, and if the content exceeds 0.8% by weight, There is a risk that the adhesion of the reinforcing layer to the fireproof layer may be weakened.

The formic acid is a type of organic acid. When the content is less than 0.01% by weight, the exothermic reaction is weak, and when the content exceeds 0.2% by weight, the exothermic reaction occurs excessively, raising the risk of gel generation. When the glacial acetic acid content is less than 0.1% by weight, the exothermic reaction is weak, and when the content exceeds 0.2% by weight, there is a risk of gel generation. If the storage stabilizer is less than 0.1% by weight, the storage properties of the ceramic coating are reduced, and if it is more than 0.29% by weight, there is a risk that the adhesion of the reinforcing layer to the fireproof layer will be weakened.

The method for producing the one-component ceramic coating agent is 35 to 55% by weight of colloidal silica, 5 to 12% by weight of ethyl alcohol, 0.1 to 0.23% by weight of barium sulfate, 1 to 2% by weight of potassium octatitanate, and 10 to 17% by weight of pigment. A first stirring step of putting agent A containing into a stirrer and stirring it; In the stirrer, 30 to 35% by weight of 3-glycidyl-oxypropyl-trimethoxysilane, 0.01 to 0.2% by weight of wetting agent, 0.01 to 0.2% by weight of additive for first paint, and 0.01 to 0.2% by weight of additive for second paint. %, 1,2-Bis(triethoxysily)ethane 0.5~1.5% by weight, silanol functional silicone liquid 0.1~0.8% by weight, formic acid 0.01~0.2% by weight, glacial acetic acid 0.1~0.2% by weight, and storage stabilizer 0.1~0.29% by weight. A second stirring step of adding and stirring the provided agent B; and a cooling step of cooling the one-component ceramic coating agent that has undergone the second stirring step.

In the first and second stirring steps, the temperature in the stirrer is stirred at a stirring speed of 50 to 200 rpm in a temperature range of 25 to 45 ° C. If the temperature in the stirrer is maintained below 25°C in the first and second stirring steps, the gloss of the reinforcing layer will decrease, the binder formation of the one-component ceramic coating will not be formed, and there is a risk that the adhesion of the reinforcing layer to the fireproof layer will decrease. . Meanwhile, if the temperature in the stirrer exceeds 45°C, there is a risk that the adhesion of the reinforcing layer to the fireproof layer will decrease and cracks may occur in the reinforcing layer.

If the stirring speed of the stirrer is less than 50 rpm, there is a risk that the exothermic reaction may not occur properly and the adhesion of the coating agent may decrease. On the other hand, if the stirring speed of the stirrer exceeds 200 rpm, there is a risk that excessive heat is generated and the gloss of the coating agent decreases. More specifically, the first and second stirring steps are mainly performed at a temperature of 33 to 35° C. and a stirring speed of 120 to 150 rpm.

The reason that the agent A, which mainly consists of silica and color components, is first placed in the stirrer and stirred linearly is to facilitate the control of the viscosity of the coating agent, and the agent B, which consists of a component with a silane acidity of 4 or less, is added to the stirrer and stirred. A two-step stirring operation is performed in which the product is placed in a stirrer and stirred to mix with the pre-stirred agent A.

The stirring operation time of the stirrer has characteristics that are opposite to the stirring temperature and stirring speed, and has an operation time of 30 minutes to 10 hours. After the above-mentioned stirring operation is completed, a cooling step is provided to cool the one-component ceramic coating agent mixed with agent A and agent B, and the cooling step is performed within a cooling temperature range of 5 to 40 ° C.

In the cooling step, if the cooling temperature of the coating agent is cooled at a low temperature of less than 5℃, there is a risk that the reaction may not occur as the freezing point is reached, and if the cooling temperature exceeds 40℃, the fireproof layer may form due to gelling of the coating agent. There is a risk that the adhesion of the reinforcing layer may decrease.

[Example]

1. High pressure water spray test

For the comparative example in which a structure was manufactured with a thickness of 25 mm using powdered vermiculite-based lightweight refractory cement and the example in which the surface of the structure was coated with a ceramic reinforcing layer, watering at a pressure of 200 bar was performed for 1 minute each, and watering was performed. Before/after photos are as shown in Figure 2.

As shown in Figure 2, it was confirmed that the surface of the lightweight refractory cement structure of the comparative example in which the ceramic reinforcement layer was not formed was damaged during high-pressure water spraying, while the surface of the lightweight refractory cement structure of the example in which the ceramic reinforcement layer was formed was not damaged even by high-pressure water spraying. .

2. Fire resistance test

Jet firing (reaching 1,000°C within 20 seconds) was performed on the lightweight refractory cement structure coated with the ceramic reinforcement layer of the example, and the results are shown in FIG. 3.

As shown in Figure 3, it was confirmed that the cement structure of the example was not damaged even when flame was applied.

Although this specification has been described with reference to preferred embodiments of the present invention, those skilled in the art may make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims described below. It will be possible to implement it. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, it should be considered to be included in the technical scope of the present invention.

Claims (9)

Concrete pouring and curing processes for manufacturing concrete members to form the inner wall of a tunnel;
A fire-resistant layer forming process of forming a fire-resistant layer on one surface of the concrete member; and
A tunnel fireproof construction method comprising a ceramic reinforcement layer forming process of forming a ceramic reinforcement layer on the fireproof layer. According to paragraph 1,
A tunnel fireproofing construction method, characterized in that the ceramic reinforcement layer has a hardness of 6H or more. According to paragraph 2,
A tunnel fireproofing construction method, characterized in that the ceramic reinforcement layer has a thickness of 200 to 300 ㎛. According to any one of claims 1 to 3,
The ceramic reinforcement layer is formed from a one-component ceramic coating agent,
The ceramic coating agent contains 35 to 55% by weight of colloidal silica, 5 to 12% by weight of ethyl alcohol, 0.1 to 0.23% by weight of barium sulfate, 1 to 2% by weight of potassium octatitanate, and 10 to 17% by weight of pigment, based on the total weight. Agent A containing %, 30-35% by weight of 3-glycidyl-oxypropyl-trimethoxysilane, 0.01-0.2% by weight of wetting agent, 0.01-0.2% by weight of additive for first paint, additive for second paint 0.01~0.2% by weight, 1,2-Bis(triethoxysily)ethane 0.5~1.5% by weight, silanol functional silicone liquid 0.1~0.8% by weight, formic acid 0.01~0.2% by weight, glacial acetic acid 0.1~0.2% by weight, and storage stabilizer 0.1~ A tunnel fireproofing construction method, characterized in that it contains agent B containing 0.29% by weight. According to any one of claims 1 to 3,
A tunnel fireproof construction method, characterized in that when pouring the concrete, the concrete member is manufactured into a reinforced concrete member by pouring a concrete mix with reinforcing bars placed inside the formwork. According to any one of claims 1 to 3,
A tunnel fireproof construction method, characterized in that chipping or applying latex and attaching wire mesh or metal lath to the surface of the concrete member where the fireproof layer is formed is additionally performed before performing the fireproof layer forming process. According to any one of claims 1 to 3,
A tunnel fire-resistant construction method, characterized in that the fire-resistant layer is formed by applying a fire-resistant coating material by a spray coating method. In clause 7,
A tunnel fireproof construction method, characterized in that the fireproof coating includes vermiculite cemetitious. According to any one of claims 1 to 3,
A tunnel fireproof construction method, characterized in that the thickness of the fireproof layer is 25 to 45 mm.