Tunnel lining carbonation prevention device based on carbon dioxide adsorption and application method

Abstract

A carbonation prevention device for tunnel lining based on carbon dioxide adsorption and an application method. There are original cable trenches or drainage ditches on both sides of the road surface. Several groups of water tanks are arranged at intervals above the original cable trenches or drainage ditches. A feeding device is arranged above the water tanks. Several groups of covers are arranged on the top of the water tanks. The feeding device is electrically connected to a control module arranged therein. By using the device of the present invention, feeding can be carried out as needed, different feeding intervals are adopted for different concentration sections, which is more cost-saving, can effectively reduce the concentration of carbon dioxide in the tunnel, and while slowing down the carbonation speed of the tunnel lining concrete, also reduces the risk of crystallization blockage of the tunnel drainage system.

Description

Technical Field

[0001] The present invention belongs to the technical field of preventing carbonation of tunnel lining concrete, and particularly relates to a tunnel lining carbonation prevention device based on carbon dioxide adsorption and an application method thereof. Background Art

[0002] In recent years, with the large-scale application of concrete structures, their durability problems have gradually attracted attention. Among them, the damage of reinforced concrete structures caused by concrete carbonation is one of the important reasons for the decline or even failure of concrete functions. In the initial stage of the formation of reinforced concrete, alkaline media such as calcium hydroxide existing in its pores have a good protective effect on steel bars. However, over time, carbon dioxide gas in the air penetrates into the concrete through fine pores and reacts with calcium hydroxide therein to form calcium carbonate and water, weakening the protective effect on steel bars and making the steel bars more prone to corrosion. When the carbonation situation is relatively serious, the concrete components will show chipping, and when the damage reaches a certain extent, the entire structure may even collapse. Therefore, the prevention and control of concrete carbonation have gradually received attention in the construction fields such as factories, residential buildings, and bridges.

[0003] However, different from outdoor buildings such as buildings, the carbon dioxide content in tunnels is generally higher than that in the outdoor environment, which is jointly caused by factors such as a large amount of exhaust gas emissions from passing vehicles and poor ventilation in the tunnel. This poses higher requirements for the prevention and control of carbonation of tunnel reinforced concrete linings.

[0004] At present, there are mainly two methods for preventing and controlling carbonation of reinforced concrete in tunnels: (1) Optimization of concrete materials, that is, selecting acid-resistant cement varieties, acid-resistant aggregates, appropriate admixtures, suitable mix ratios, etc., and adopting more strict pouring and vibrating processes to ensure the compactness of concrete, thereby optimizing concrete materials and improving their prevention ability against carbonation problems; (2) Using coatings or tiles for protection, that is, spraying solutions, paints and other materials or pasting tiles on the concrete surface to block the surface pores of the reinforced concrete, so that carbon dioxide in the air cannot enter the interior of the concrete material and prevent the occurrence of the carbonation process. However, these methods have the following defects:

[0005] (1) Although the concrete material optimization method can slow down the carbonation speed of concrete to a certain extent, it is only applicable to unbuilt tunnels (considering carbonation problems when designing their concrete materials). However, most of the existing tunnels with durability problems are early-built tunnels, and this method cannot solve the urgent problem.

[0006] (2) Method for protecting coatings or tiles. Currently, the most commonly used method in tunnels is to use tiles on the side walls and fireproof coatings on the arch. There are relatively few tunnels that purposefully use anti-carbonation coatings. Therefore, this poses requirements for the airtightness of the currently used coatings or tile protection. In addition, since the carbonation situation of the concrete behind the coatings cannot be known in real time, it is difficult to judge the effectiveness and durability period of this protection measure.

[0007] (3) The above two methods do not consider the changing trend of the carbon dioxide content in the tunnel. Both use the same level of protection measures throughout the section, resulting in high costs. In addition, due to the enclosure of carbon dioxide, the carbon dioxide concentration in the tunnel is continuously high, which increases the risk of crystallization blockage diseases in the tunnel drainage system. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a tunnel lining anti-carbonation device based on carbon dioxide adsorption and an application method that are reasonably designed, simple in structure, and can be flexibly set according to the carbon dioxide concentration in the tunnel.

[0009] The technical solution adopted to solve the above technical problem is: For a tunnel lining anti-carbonation device based on carbon dioxide adsorption, original cable trenches or drainage side ditches are provided on both sides of the road surface. Several groups of water tanks are arranged at intervals above the original cable trenches or drainage side ditches. A feeding device is arranged above the water tanks. Several groups of covers are arranged on the top of the water tanks. The feeding device is electrically connected to the control module arranged therein.

[0010] The water tank of the present invention is: The water tank body is of a U-shaped structure. A clamping plate is arranged on the upper edge of the water tank body. An oversaturated calcium and magnesium ion solution is placed in the water tank body.

[0011] The feeding device of the present invention is: The material box is a hollow structure with an open top. The upper edge of the material box is fixed to the cross brace plate through threaded fasteners. The cross brace plate is placed on the top of the water tank body. A motor is arranged at the front end inside the material box, and a control module is arranged at the rear end. A driving gear is arranged on the output shaft of the motor. The driving gear meshes with a driven gear. The driven gear meshes with a rack installed on the upper edge of the baffle. A sliding groove is arranged on the lower edge of the material box. The baffle is arranged in the sliding groove. A feeding port is arranged at the front end of the material box. The back-and-forth movement of the baffle opens or closes the feeding port.

[0012] A motor cover is arranged outside the motor of the present invention.

[0013] The interior of the material box of the present invention is a smooth curved surface structure, and the rear curved surface is higher than the front curved surface.

[0014] An inlet is arranged on the cross brace plate corresponding to the material box of the present invention.

[0015] The control module of the present invention is as follows: The micro camera is electrically connected to the PLC controller through a wire, the 5G module is electrically connected to the PLC controller, the micro camera is arranged on the front cover plate of the material box, and the PLC controller and the 5G module are arranged at the rear part inside the material box.

[0016] The application method of the tunnel lining carbonation prevention device based on carbon dioxide adsorption of the present invention consists of the following steps:

[0017] S1. Length design: Along the straight tunnel, the carbon dioxide concentration shows an increasing trend. Shorten the length of the water tank, increase the number of water tanks, and at the same time, each water tank is equipped with the same feeding device; Along the curved tunnel, the carbon dioxide concentration also increases along the line, but carbon dioxide is likely to accumulate at the place with a larger turning radius, resulting in a significant increase in concentration. The length of the water tank should be shortened at the corresponding part, the number of water tanks should be increased, and at the same time, the number of feeding devices should be increased; Due to the influence of traffic wind in the two-way tunnel, there will be a sudden increase in carbon dioxide concentration in some parts of the tunnel. The length of the water tank should be shortened at the corresponding part, the number of water tanks should be increased, and at the same time, the number of feeding devices should be increased.

[0018] S2. Device installation: Open the covers of multiple original cable trenches or drainage side ditches with a total length longer than the designed water tank. Hang both sides of the water tank on the flat parts on both sides above the original cable trench or drainage side ditch. Inject supersaturated calcium and magnesium ion solution into the water tank, and install the cross brace plate of the feeding device on the flat parts on both sides above the original cable trench or drainage side ditch at the same time. Cover the cover and fix it, and the device starts to operate.

[0019] S3. Feeding interval setting: Reasonably set the replenishment time interval T of the feeding device according to the carbon dioxide concentration situation to ensure the same carbonation prevention effect in different sections of the tunnel.

[0020] S4. Regular feeding: After a time T, the concentration of calcium and magnesium ion solution in the water tank decreases. The control module controls the baffle of the feeding device to move away from the feeding port, and the material in the material box falls into the water tank from the feeding port. After the feeding is completed, the baffle returns to its original position, and the device continues to operate.

[0021] S5. Sediment inspection: The micro camera regularly takes pictures of the sediment situation in the water tank and uploads them to the configuration software through the 5G module. Judge whether the sediment reaches the degree that needs to be cleaned by manual identification or image analysis means. If not, the device continues to work; If so, go to S6.

[0022] S6. Sediment cleaning: The cleaning personnel enter the tunnel and open the cover of the original cable trench or drainage side ditch at the water tank to be cleaned, clean the sediment in the water tank, and supplement the calcium and magnesium soluble substances in the feeding device.

[0023] The present invention has the following advantages compared with the prior art:

[0024] (1) Different from material optimization and coating methods, the present invention adsorbs carbon dioxide using a supersaturated solution of calcium and magnesium ions, actively preventing and controlling from the fundamental mechanism of concrete carbonation problems, with higher carbonation prevention efficiency.

[0025] (2) The present invention adopts a demand-oriented feeding method, that is, different feeding intervals are used for different concentration ranges, which is more cost-saving.

[0026] (3) The device of the present invention is arranged in the original cable trench, taking into account the convenience during use, inspection, cleaning and maintenance while not affecting the tunnel clearance section.

[0027] (4) The present invention can reduce the concentration of carbon dioxide in the tunnel, while slowing down the carbonation rate of tunnel lining concrete and reducing the risk of crystallization blockage in the tunnel drainage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of an embodiment of the present invention.

[0029] Figure 2 is Figure 1 a top view (with cover plate) of the original cable trench or drainage side ditch 1 in

[0030] Figure 3 is Figure 1 a top view (without cover plate) of the original cable trench or drainage side ditch 1 in

[0031] Figure 4 is Figure 1 a schematic structural diagram of the water tank 2 in

[0032] Figure 5 is Figure 1 a schematic structural diagram of the feeding device 3 in

[0033] Figure 6 is Figure 5 a top view of

[0034] Figure 7 is Figure 5 a side view of

[0035] Figure 8 is a tunnel carbon dioxide distribution diagram.

[0036] In the figure: 1. Original cable trench or drainage side ditch; 2. Water tank; 3. Feeding device; 4. Control module; 5. Cover plate; 6. Road surface; 2-1. Clamping plate; 2-2. Water tank body; 2-3. Supersaturated calcium and magnesium ion solution; 3-1. Cross bracing plate; 3-2. Material box; 3-3. Motor cover; 3-4. Baffle; 3-5. Motor; 3-6. Driven gear; 3-7. Chute; 3-8. Feeding port; 3-9. Threaded fastener; 4-1. Miniature camera; 4-2. 5G module; 4-3. PLC controller; 4-4. Electric wire. Specific implementation mode

[0037] The following further elaborates on the present invention in conjunction with the attached drawings and embodiments, but the present invention is not limited to these embodiments.

[0038] Embodiment 1

[0039] In Figures 1 to 7 this embodiment, a carbonization prevention device for tunnel lining based on carbon dioxide adsorption according to the present invention is provided. On both sides of the road surface 6, there are original cable trenches or drainage side ditches 1. The device is arranged in the original cable trench or drainage side ditch 1, reducing the secondary damage to the road surface caused by road surface grooving. Several groups of water tanks 2 are arranged at intervals above the original cable trench or drainage side ditch 1. The length and quantity of the water tanks 2 are determined according to the carbon dioxide concentration in the tunnel. A solution capable of absorbing carbon dioxide is placed in the water tank 2 to absorb and convert gaseous carbon dioxide into crystals, reducing the carbon dioxide concentration in the tunnel. Further, in this embodiment, the water tank 2 is composed of a clamping plate 2-1 and a water tank body 2-2 connected. The water tank body 2-2 is of a U-shaped structure. The clamping plate 2-1 is welded or integrally processed on the upper edge of the water tank body 2-2. The clamping plate 2-1 is placed on the upper edge of the original cable trench or drainage side ditch 1 to clamp the water tank body 2-2 above the original cable trench or drainage side ditch 1, ensuring the stability of the water tank 2. A supersaturated calcium and magnesium ion solution 2-3 is placed in the water tank body 2-2. The supersaturated calcium and magnesium ion solution 2-3 adsorbs the carbon dioxide in the tunnel, actively preventing from the fundamental mechanism angle of the concrete carbonization problem, and having a higher carbonization prevention efficiency.

[0040] Above the water tank 2, a feeding device 3 is installed. The feeding device 3 is used to control the concentration of the solution in the water tank 2. The feeding device 3 is composed of a cross brace 3-1, a material box 3-2, a motor cover 3-3, a baffle 3-4, a motor 3-5, a driven gear 3-6, a chute 3-7, a feeding port 3-8, and a threaded fastener 3-9. The material box 3-2 is a hollow structure with an open top. At the upper edge of the material box 3-2, a motor 3-5 is provided at the end of the threaded fastener 3-9, and a control module is provided at the rear end and fixed on the cross brace 3-1. The cross brace 3-1 is placed on the top of the water tank body 2-2, and the cross brace 3-1 fixes this device on the water tank body 2-2. In the front of the material box 3-2, the motor 3-5 is fixed on the cross brace 3-1 through a bracket. To prevent the solid material in the material box 2 from entering the motor 3-5 and affecting the normal operation of the motor 3-5, a motor cover 3-3 is provided outside the motor 3-5. A driving gear is provided on the output shaft of the motor 3-5. The driving gear meshes with the driven gear 3-6, and the driven gear 3-6 meshes with the rack installed on the upper edge of the baffle 3-4. A chute 3-7 is provided at the lower edge of the material box 3-2, and the baffle 3-4 is arranged in the chute 3-7. The chute 3-7 plays a role in limiting and guiding the baffle 3-4. When the motor 3-5 rotates, it drives the driving gear to rotate, drives the driven wheel to rotate, so that the rack moves back and forth, and then drives the baffle 3-4 to move back and forth to achieve the purpose of controlling the opening and closing of the feeding port 3-8. The feeding port 3-8 is provided at the front end of the material box 3-2. The back-and-forth movement of the baffle 3-4 opens or closes the feeding port 3-8. Preferably, the inside of the material box 3-2 is a smooth curved surface structure, and the rear curved surface is higher than the front curved surface. This design ensures that the solid material in the material box 3-2 smoothly slides out from the feeding port 3-8 and prevents the occurrence of material jamming. At the position corresponding to the material box 3-2 on the cross brace 3-1, a feeding port is provided for adding solid materials and repairing the motor 3-5.

[0041] Several groups of cover plates 5 are arranged on the top of the water tank 2, and there are gaps between adjacent cover plates 5 for carbon dioxide to pass through. The cover plate 5 is covered on the water tank 2. On the one hand, it serves as the top cover of the water tank 2 to prevent impurities from falling into it. On the other hand, it presses the water tank 2 tightly on the upper part of the original cable trench or drainage side ditch 1 to prevent it from shifting. The feeding device 3 is electrically connected to the control module 4 arranged therein, and the control module 4 is used to monitor the crystallization situation in the water tank 2 and control the operation of the feeding device 3. The control module 4 includes a micro camera 4-1, a 5G module 4-2, a PLC controller 4-3, and a wire 4-4. The micro camera 4-1 is electrically connected to the PLC controller 4-3 through the wire 4-4, and the 5G module 4-2 is electrically connected to the PLC controller 4-3. The micro camera 4-1 is arranged on the front cover plate of the material box 3-2 to monitor the crystallization situation in the material box 3-2 and transmit the data to the PLC controller 4-3. The PLC controller 4-3 and the 5G module 4-2 are arranged at the rear part inside the material box 3-2. The PLC controller 4-3 is powered by a storage battery and is connected to the configuration software through the 5G module 4-2 to transmit the picture monitored by the micro camera 4-1 to the configuration software, judge whether to start the motor 3-5 for feeding or cleaning the sediment, and adjust the solution concentration in the water tank body 1-2. The model of the PLC controller 4-3 is Siemens S7-200, and the model of the 5G module 4-2 is Huawei MH500.

[0042] The application method of the tunnel lining anti-carbonization device based on carbon dioxide adsorption consists of the following steps:

[0043] S1. Length design: As Figure 8 shown, since the carbon dioxide value varies along the longitudinal direction of the tunnel, that is, the carbon dioxide concentrations of tunnels with different alignments and different sections are different, so the concrete carbonization risks are different. Therefore, it is necessary to reasonably design the length and quantity of the water tanks 2 according to different carbon dioxide concentration situations. Along the straight tunnel, the carbon dioxide concentration shows an increasing trend. Shorten the length of the water tank 2, increase the quantity of the water tanks 2, and at the same time, each water tank 2 is equipped with the same feeding device 3; for the curved tunnel, the carbon dioxide concentration also increases along the line, but carbon dioxide is easy to accumulate at the place with a larger turning radius, resulting in a significant increase in concentration. The length of the water tank 2 should be shortened at the corresponding part, the quantity of the water tanks 2 should be increased, and at the same time, the quantity of the feeding devices 3 should be increased; due to the influence of traffic wind in the two-way tunnel, there will be a phenomenon that the carbon dioxide concentration suddenly increases locally in the tunnel. The length of the water tank 2 should be shortened at the corresponding part, the quantity of the water tanks 2 should be increased, and at the same time, the quantity of the feeding devices 3 should be increased;

[0044] S2. Device Installation: Open the covers 5 of multiple original cable trenches or drainage side ditches 1 with a total length longer than the designed water tank 2. Hang both sides of the water tank 2 on the flat areas on both sides above the original cable trench or drainage side ditch 1. Inject a supersaturated calcium and magnesium ion solution 2 - 3 into the water tank 2, and install the cross brace 3 - 1 of the feeding device 3 on the flat areas on both sides above the original cable trench or drainage side ditch 1 at the same time. Cover the cover 5 and fix it. Then the device starts to operate;

[0045] S3. Feeding Interval Setting: Reasonably set the replenishment time interval T of the feeding device 3 according to the carbon dioxide concentration. The interval time is shortened in areas with high concentration and lengthened in areas with low concentration to ensure the same anti - carbonization effect in different sections of the tunnel;

[0046] S4. Regular Feeding: After a time T, the concentration of the calcium and magnesium ion solution in the water tank 2 decreases. The control module 4 controls the baffle 3 - 4 of the feeding device 3 to move away from the feeding port 3 - 8. The material in the hopper 3 - 2 falls into the water tank 2 through the feeding port 3 - 8 to adjust the solution concentration in the water tank 2. After feeding, the baffle 3 - 4 returns to its original position and the device continues to operate. In the tunnel section with a high carbon dioxide concentration and a relatively dense arrangement of devices, the feeding interval should be shortened accordingly. While in the section with a low carbon dioxide concentration and a small number of installed devices, the feeding interval can be appropriately lengthened.

[0047] S5. Sediment Inspection: The micro - camera 4 - 1 regularly takes pictures of the sediment situation in the water tank 2 and uploads them to the configuration software through the 5G module 4 - 2. Determine whether the sediment reaches the level that needs to be cleaned by means of manual identification or image analysis. If not, the device continues to work; if so, go to S6;

[0048] S6. Sediment Cleaning: The cleaning personnel enter the tunnel, open the cover 5 of the original cable trench or drainage side ditch 1 at the location of the water tank 2 to be cleaned, clean the sediment in the water tank 2, and replenish the calcium - magnesium soluble substances in the feeding device 3.

Claims

1. A carbonation prevention device for tunnel lining based on carbon dioxide adsorption, characterized in that: On both sides of the road surface (6), there are original cable trenches or drainage side ditches (1). Several groups of water tanks (2) are arranged at intervals above the original cable trenches or drainage side ditches (1). The water tank (2) includes a water tank body (2-2). The water tank body (2-2) is of a U-shaped structure. A clamping plate (2-1) is arranged on the upper edge of the water tank body (2-2). An oversaturated calcium and magnesium ion solution (2-3) is placed in the water tank body (2-2); A feeding device (3) is arranged above the water tank (2). Several groups of covers (5) are arranged on the top of the water tank (2). The feeding device (3) is electrically connected to the control module (4) arranged therein. The feeding device (3) includes a material box (3-2). The material box (3-2) is a hollow structure with an open top. The upper edge of the material box (3-2) is fixed to the cross brace plate (3-1) through a threaded fastener (3-9). The cross brace plate (3-1) is placed on the top of the water tank body (2-2). A motor (3-5) is arranged at the front end of the material box (3-2), and a control module (4) is arranged at the rear end. A driving gear is arranged on the output shaft of the motor (3-5). The driving gear meshes with a driven gear (3-6). The driven gear (3-6) meshes with a rack arranged along the upper edge of the baffle (3-4). A chute (3-7) is arranged on the lower edge of the material box (3-2). The baffle (3-4) is arranged in the chute (3-7). A feeding port (3-8) is arranged at the front end of the material box (3-2). The reciprocating movement of the baffle (3-4) opens or closes the feeding port (3-8).

2. The carbonation prevention device for tunnel lining based on carbon dioxide adsorption according to claim 1, characterized in that: A motor cover (3-3) is arranged outside the motor (3-5).

3. The carbonation prevention device for tunnel lining based on carbon dioxide adsorption according to claim 1, characterized in that: The interior of the material box (3-2) is of a smooth curved surface structure, and the rear curved surface is higher than the front curved surface.

4. The carbonation prevention device for tunnel lining based on carbon dioxide adsorption according to claim 1, characterized in that: A feeding port is arranged at the position corresponding to the material box (3-2) on the cross brace plate (3-1).

5. The carbonation prevention device for tunnel lining based on carbon dioxide adsorption according to claim 1, characterized in that The control module (4) is: A micro camera (4-1) is electrically connected to a PLC controller (4-3) through a wire (4-4). A 5G module (4-2) is electrically connected to the PLC controller (4-3). The micro camera (4-1) is arranged on the front cover plate of the material box (3-2). The PLC controller (4-3) and the 5G module (4-2) are arranged at the rear part inside the material box (3-2).

6. The application method of the carbonation prevention device for tunnel lining based on carbon dioxide adsorption according to any one of claims 1 to 5, characterized in that It consists of the following steps: S1. Length Design: Along the straight tunnel, the carbon dioxide concentration shows an increasing trend. Shorten the length of the water tank (2), increase the number of water tanks (2), and at the same time, each water tank (2) is equipped with the same feeding device (3); along the curved tunnel, the carbon dioxide concentration also increases along the line, but carbon dioxide is likely to accumulate at the place with a larger turning radius, resulting in a significant increase in concentration. The length of the water tank (2) should be shortened at the corresponding part, the number of water tanks (2) should be increased, and at the same time, the number of feeding devices (3) should be increased; due to the influence of traffic wind in the two-way tunnel, there will be a sudden increase in carbon dioxide concentration in some parts of the tunnel. The length of the water tank (2) should be shortened at the corresponding part, the number of water tanks (2) should be increased, and at the same time, the number of feeding devices (3) should be increased. S2. Device Installation: Open the covers (5) of multiple original cable trenches or drainage side ditches (1) with a total length longer than the designed water tank (2). Hang both sides of the water tank (2) on the flat parts on both sides above the original cable trench or drainage side ditch (1). Inject supersaturated calcium and magnesium ion solution (2-3) into the water tank (2), and at the same time, install the cross braces (3-1) of the feeding device (3) on the flat parts on both sides above the original cable trench or drainage side ditch (1). Cover the cover (5) and fix it, and the device starts to operate. S3. Feeding Interval Setting: Reasonably set the replenishment time interval T of the feeding device (3) according to the carbon dioxide concentration situation to ensure the same anti-carbonation effect in different sections of the tunnel. S4. Regular Feeding: After time T, the concentration of calcium and magnesium ion solution in the water tank (2) decreases. The control module (4) controls the baffle (3-4) of the feeding device (3) to move away from the feeding port (3-8). The material in the material box (3-2) falls into the water tank (2) from the feeding port (3-8). After feeding, the baffle (3-4) returns to its original position, and the device continues to operate. S5. Sediment Inspection: The micro camera (4-1) regularly takes pictures of the sediment situation in the water tank (2) and uploads them to the configuration software through the 5G module (4-2). Determine whether the sediment reaches the degree that needs to be cleaned by means of manual identification or image analysis. If not, the device continues to work; if so, go to S6. S6. Sediment Cleaning: The cleaning personnel enter the tunnel, open the cover (5) of the original cable trench or drainage side ditch (1) at the water tank (2) to be cleaned, clean the sediment in the water tank (2), and replenish the calcium and magnesium soluble substances in the feeding device (3).

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