Cold-resistant pouring type expansion joint structure and construction method thereof

Abstract

The invention provides a cold-resistant pouring type expansion joint structure and a construction method thereof.The structure comprises a bonding layer, a PUC elastomer layer and a wear-resistant surface layer which are sequentially arranged from bottom to top, and glass fiber gridding cloth is further arranged in the PUC elastomer layer; anchoring areas are arranged on the sections of the two sides of the structure, anchoring ribs are embedded in the anchoring areas, and a water guide groove is formed in the bottom of each anchoring area and communicated with a bridge drainage system through an inclined guide pipe. And a deformation joint is arranged between the PUC elastomer layer and the bridge deck pavement layer. The method is suitable for cold regions, reliable in performance and simple and convenient to construct.

Description

Technical Field

[0001] The invention belongs to the technical field of expansion joint structure design, and in particular relates to a cold-resistant cast-type expansion joint structure and a construction method thereof. Background Art

[0002] As an important component of bridge structures, the performance of bridge expansion joints directly affects the service life of bridges and driving comfort. In cold regions, bridge expansion joints face even more severe challenges.

[0003] Traditional expansion joints are susceptible to material embrittlement and cracking in low-temperature environments, which degrades the joint's sealing performance. Water infiltration can corrode the bridge's structural steel, shortening its service life. Furthermore, traditional expansion joints are prone to deformation and separation when subjected to repeated vehicle loads, impacting driving safety and comfort.

[0004] Furthermore, existing expansion joint construction processes are complex, quality assurance is difficult, and the construction environment is demanding. For example, in low-temperature conditions, some materials exhibit poor adhesion and curing properties, resulting in the overall performance of the expansion joint failing to meet design requirements. Therefore, developing a cold-resistant, cast-in-place expansion joint structure and construction method suitable for cold regions, with reliable performance and ease of construction, is of great practical significance. Summary of the Invention

[0005] To this end, the present invention provides a cold-resistant cast-type expansion joint mechanism and a construction method thereof.

[0006] A first aspect of the present invention provides a cold-resistant cast-type expansion joint structure, comprising a bonding layer, a PUC elastomer layer, and a wear-resistant surface layer arranged in sequence from bottom to top;

[0007] The PUC elastomer layer is cast by an elastomer mixture, and the elastomer mixture comprises, by weight percentage:

[0008] Polyurethane prepolymer 20-30%, cement 40-50%, fine aggregate 20-30%, mineral filler 6%-13%, curing agent 3-6%, plasticizer 1%-3%, antioxidant 0.5%-1%, leveling agent 0.5%-1%, defoaming agent 0.2%-0.6%;

[0009] Anchoring areas are provided on both sides of the structure, wherein anchoring bars are pre-embedded in the anchoring areas and filled with anchoring mixture. The anchoring bars are connected to the beam body in an inverted L shape, and the anchoring mixture is a composite material of concrete and steel fiber.

[0010] A deformation joint is provided between the PUC elastomer layer and the bridge deck pavement layer, and the joint width W is calculated according to the following formula:

[0011] W=α·ΔT·L+ε·L+β·L

[0012] Where α is the linear expansion coefficient, ΔT is the annual extreme temperature difference, L is the bridge span, ε is the concrete shrinkage strain, β is the creep coefficient, and W ranges from 20 to 75 mm;

[0013] The PUC elastomer layer is provided with a crisscross glass fiber mesh cloth inside, the mesh cloth layer spacing is 10-20mm, and the top layer of mesh cloth is 5-8mm away from the bottom surface of the wear-resistant surface layer;

[0014] A water channel is provided at the bottom of the anchoring area, which is connected to the bridge drainage system through an inclined conduit with an inclination angle of 15°-30°;

[0015] The cross section of the deformation joint is wavy, the height difference between the wave crest and the wave trough is 3-5 mm, and the ratio of the wavelength to the seam width W is 1:1.2-1:1.5.

[0016] As a preferred embodiment, the low-temperature performance of the PUC elastomer layer satisfies the following requirements: tensile elongation at break at -30°C ≥ 300%, elastic recovery rate ≥ 90%, and shear strength at the interface with concrete ≥ 2.5 MPa.

[0017] As a preferred embodiment, the slot width of the anchoring area is 1.2-1.5 times the design width of the expansion joint, the longitudinal spacing of the anchor bars is 100-150 mm, and the bent ends thereof are embedded in the beam body to a depth of ≥50 mm.

[0018] As a preferred embodiment, the wear-resistant surface layer is an epoxy resin layer mixed with silicon carbide particles, with a thickness of 3-5 mm, and is formed with the PUC elastomer layer through hot pressing to form an interface interlocking structure.

[0019] As a preferred embodiment, a gradient modulus transition zone is provided between the PUC elastomer layer and the bridge deck pavement layer. The transition zone is formed by a gradient mixture of the elastomer mixture and the bridge deck pavement material in a volume ratio of 1:1-1:3, and has a thickness of 15-25 mm.

[0020] As a preferred embodiment, a temperature compensation element is embedded in the water guide groove. The element is a shape memory alloy spring with a shrinkage rate of 8%-12% below -20°C, which is used to offset low-temperature shrinkage stress.

[0021] A second aspect of the present invention provides a construction method for a cold-resistant cast-type expansion joint structure, comprising the following steps:

[0022] S1. Base surface treatment: roughen the concrete at the beam end joints, remove the laitance, and apply interface agent;

[0023] S2. Anchorage Area Construction: Cut the bridge deck pavement according to the designed slot width, implant anchor bars, and pour the anchorage mix in layers. Maintain a discharge temperature of ≥160°C and a compaction density of ≥98%.

[0024] S3. PUC elastomer pouring: Pour the elastomer mixture heated to 180-200℃ into the tank continuously, scrape it twice and insert temperature sensors to control the temperature difference between layers to ≤10℃;

[0025] S4. Interface strengthening: Laying a glass fiber mesh cloth before the initial setting of the PUC elastomer, followed by coating with a wear-resistant surface material;

[0026] S5. Gradient curing: First, heat to 60°C at a rate of 5°C / h and hold for 8 hours, then cool naturally to room temperature. During curing, the humidity is controlled at 50%-70%;

[0027] S6. Drainage system integration: When pre-buried water channel at the bottom of the anchoring area, install inclined conduit at the same time, and set anti-backflow valve at the conduit outlet.

[0028] As a further preferred embodiment, the expansion rate of the elastomer mixture in step S3 is controlled at 0.5%-1.2%, the stirring time is ≥45 min, and the construction is carried out when the on-site air humidity is ≤65%.

[0029] As a further preferred embodiment, after the curing step S5 is completed, a performance verification is performed, which includes the following steps:

[0030] A -30°C low-temperature tensile test was used to verify the interface bonding strength;

[0031] The displacement adaptability under 20-year equivalent load was simulated through vehicle fatigue test;

[0032] Use infrared thermal imager to detect internal defects of the elastomer layer;

[0033] The drainage efficiency of the water channel is verified through water tightness test.

[0034] The above technical solution of the present invention has the following advantages over the prior art:

[0035] The present invention comprises a multi-layer structure consisting of an adhesive layer, a PUC elastomer layer and a wear-resistant surface layer. Each layer performs different functions. The adhesive layer ensures a stable connection with the bridge deck, the PUC elastomer layer provides good elasticity and deformation ability, and the wear-resistant surface layer enhances surface wear resistance, thereby improving the overall performance of the expansion joint.

[0036] The expansion joint width, W, is precisely calculated by factoring in factors such as the linear expansion coefficient, annual extreme temperature differences, bridge span, concrete shrinkage strain, and creep coefficient. The range of values is 20-75mm, effectively adapting to bridge deformations due to temperature fluctuations, concrete shrinkage and creep, and other factors, reducing the risk of expansion joint damage. Furthermore, the wavy cross-section design (with a peak-to-trough height difference of 3-5mm and a wavelength-to-joint width, W, ratio of 1:1.2-1:1.5) further enhances deformation adaptability and avoids stress concentration.

[0037] The anchoring area is pre-embedded with inverted L-shaped anchor bars and filled with a composite material of concrete and steel fiber, which enhances the connection strength between the expansion joint and the beam body and improves the overall stability. The slot width of the anchoring area is 1.2-1.5 times the design width of the expansion joint, the longitudinal spacing of the anchor bars is 100-150mm, and the bent ends are embedded in the beam body to a depth of ≥50mm, ensuring the anchoring effect. A water guide groove is set at the bottom of the anchoring area and connected to the bridge drainage system through an inclined conduit (the inclination angle is 15°-30°), which can effectively remove water accumulation in the expansion joint and prevent problems such as structural corrosion caused by water accumulation. The embedded temperature compensation element (shape memory alloy spring, the shrinkage rate is 8%-12% below -20°C) can offset the low-temperature shrinkage stress and extend the service life of the expansion joint.

[0038] The PUC elastomer layer is interwoven with a crisscross pattern of fiberglass mesh, with interlayer spacing of 10-20mm. The top layer is 5-8mm from the bottom of the wear-resistant surface layer, enhancing the overall strength and toughness of the PUC elastomer layer and improving its crack resistance. A gradient modulus transition zone, 15-25mm thick, is placed between the PUC elastomer layer and the bridge deck pavement layer. This zone is composed of a gradient blend of PUC elastomer and bridge deck pavement material in a volume ratio of 1:1-1:3, ensuring a smoother modulus transition and reducing interfacial damage caused by significant modulus differences. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a cross-sectional schematic diagram of the expansion joint structure during cold-resistant pouring provided by an embodiment of the present invention.

[0040] Among them, 1. Bonding layer; 2. PUC elastomer layer; 3. Wear-resistant surface layer; 4. Anchoring area; 5. Anchoring reinforcement; 6. Expansion joint; 7. Beam body; 8. Bridge deck pavement layer; 9. Glass fiber mesh cloth; 10. Modulus transition zone; 11. Water guide channel; 12. Inclined conduit. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] In a first aspect of the embodiments of the present disclosure, a cold-resistant cast-in-place expansion joint structure is provided, such as Figure 1 As shown, it includes a bonding layer, a PUC elastomer layer and a wear-resistant surface layer arranged in sequence from bottom to top.

[0043] In the embodiment of the present disclosure, the PUC elastomer layer is cast by an elastomer mixture, and the elastomer mixture comprises, by weight percentage:

[0044] Polyurethane prepolymer 20-30%, cement 40-50%, fine aggregate 20-30%, mineral filler 6%-13%, curing agent 3-6%, plasticizer 1%-3%, antioxidant 0.5%-1%, leveling agent 0.5%-1%, defoaming agent 0.2%-0.6%.

[0045] A deformation joint is provided between the PUC elastomer layer and the bridge deck pavement layer. The joint width W is calculated according to the following formula:

[0046] W=α·ΔT·L+ε·L+β·L

[0047] Where α is the linear expansion coefficient, ΔT is the annual extreme temperature difference, L is the bridge span, ε is the concrete shrinkage strain, β is the creep coefficient, and W ranges from 20 to 75 mm. The expansion joint has a wavy cross-section, with a peak-to-trough height difference of 3 to 5 mm, and a wavelength-to-width ratio of 1:1.2 to 1:1.5.

[0048] A crisscross glass fiber mesh is provided inside the PUC elastomer layer, the mesh layer spacing is 10-20 mm, and the top layer of mesh is 5-8 mm away from the bottom surface of the wear-resistant surface layer.

[0049] As a preferred embodiment, a gradient modulus transition zone is provided between the PUC elastomer layer and the bridge deck pavement layer. The transition zone is formed by mixing the PUC elastomer and the bridge deck pavement material in a gradient volume ratio of 1:1-1:3, and has a thickness of 15-25 mm. Figure 1 It is a cross-sectional drawing, in which the gradual modulus transition zones are arranged at intervals in the length direction of the expansion joint structure, and the deformation joints are also arranged at intervals in the length direction of the expansion joint structure.

[0050] As a preferred embodiment, the low-temperature performance of the PUC elastomer layer satisfies the following requirements: tensile elongation at break at -30°C ≥ 300%, elastic recovery rate ≥ 90%, and shear strength at the interface with concrete ≥ 2.5 MPa.

[0051] The wear-resistant surface layer is an epoxy resin layer mixed with silicon carbide particles, with a thickness of 3-5mm. It is formed with the PUC elastomer layer by hot pressing to form an interface interlocking structure. It should be noted that the interface interlocking structure is a common connection structure method in this field, and the interface interlocking structure will not be described in detail here.

[0052] In the embodiment disclosed herein, anchoring areas are provided on both side cross-sections of the expansion joint structure, in which anchoring bars are embedded and filled with anchoring mixture, and the anchoring bars are connected to the beam body in an inverted L shape, and the anchoring mixture is a composite material of concrete and steel fiber; a water guide trough is provided at the bottom of the anchoring area, and the water guide trough is connected to the bridge drainage system through an inclined conduit, and the inclination angle is 15°-30°.

[0053] As a preferred embodiment, the groove width of the anchoring area is 1.2-1.5 times the design width of the expansion joint, the longitudinal spacing of the anchor bars is 100-150mm, and the bent ends are embedded in the beam to a depth of ≥50mm. It should be noted that in the disclosed embodiment, the other end of the water channel is connected to the PUC elastomer layer and / or wear-resistant surface layer of the expansion joint structure to collect rainwater (not shown in the figure).

[0054] As a preferred embodiment, a temperature compensation element is embedded in the water channel. This element is a shape memory alloy spring (not shown in the figure) with a shrinkage rate of 8%-12% below -20°C to offset low-temperature shrinkage stress. It should be noted that the shape memory alloy spring is arranged along the depth of the water channel.

[0055] A second aspect of the embodiments of the present disclosure provides a construction method for a cold-resistant cast-type expansion joint structure, comprising the following steps:

[0056] S1. Base surface treatment: roughen the concrete at the beam end joints, remove the slurry and apply interface agent;

[0057] S2. Anchorage area construction: Cut the bridge deck pavement according to the designed slot width, implant anchor bars, and pour the anchorage mixture in layers. Control the discharge temperature to be ≥160°C and the compaction density to be ≥98%;

[0058] S3. PUC Elastomer Casting: After mixing the elastomer mixture with water, continuously pour the elastomer mixture heated to 180-200°C into the trough. Scrape the mixture twice and insert temperature sensors to control the temperature difference between layers to ≤10°C. It should be noted that in the disclosed embodiment, the water content of the elastomer mixture after mixing with water is less than 20%.

[0059] S4, interface strengthening: laying glass fiber mesh cloth before the initial setting of PUC elastomer, and then coating the wear-resistant surface material;

[0060] S5, gradient curing: first raise the temperature to 60℃ at a rate of 5℃ / h and hold for 8h, then cool naturally to room temperature. During the curing period, the humidity is controlled at 50%-70%;

[0061] S6. Drainage system integration: When pre-buried water channel at the bottom of anchoring area, install inclined conduit simultaneously, and set anti-backflow valve at the conduit outlet.

[0062] As a further preferred embodiment, the expansion rate of the elastomer mixture in step S3 is controlled at 0.5%-1.2%, the stirring time is ≥45 min, and the construction is carried out when the on-site air humidity is ≤65%.

[0063] As a further preferred embodiment, after the curing step S5 is completed, a performance verification is performed, which includes the following steps:

[0064] A -30°C low-temperature tensile test is used to verify the interface bonding strength. Specifically, a sample with an expansion joint structure interface is placed in a specific low-temperature test environment, and the ambient temperature is kept stable at -30°C. Then, a tensile force is applied to the sample until the sample interface is damaged. The tensile force value at this time is recorded to evaluate whether the interface bonding strength meets the design requirements.

[0065] An on-board fatigue test is performed to simulate the displacement adaptability under 20 years of equivalent load. A test device similar to the actual bridge expansion joint structure is set up at the test site. A vehicle is used to drive on the expansion joint according to a predetermined loading method and frequency to simulate the loads that may be encountered during 20 years of actual use. The displacement changes of the expansion joint structure during the test and whether any damage occurs are observed to evaluate its displacement adaptability.

[0066] An infrared thermal imager is used to detect internal defects in the elastomer layer; the infrared thermal imager is used to scan the surface of the elastomer layer of the expansion joint structure. Since when there are defects (such as holes, cracks, etc.) inside the elastomer layer, its heat conduction characteristics will be different from those of normal parts, and different temperature distributions will appear on the infrared thermal image. By analyzing the infrared thermal image, it can be determined whether there are defects inside the elastomer layer, as well as the location and approximate situation of the defects.

[0067] The drainage efficiency of the water channel is verified through a watertightness test. A certain amount of water is injected into the relevant parts of the expansion joint structure (such as the PUC elastomer layer and / or the wear-resistant surface layer) to simulate rainwater conditions. Water is allowed to flow naturally into the water channel. The drainage efficiency is calculated by measuring the amount of water discharged from the inclined conduit within a certain period of time to evaluate whether the drainage capacity of the water channel meets the design requirements.

[0068] The present invention comprises a multi-layer structure consisting of an adhesive layer, a PUC elastomer layer and a wear-resistant surface layer. Each layer performs different functions. The adhesive layer ensures a stable connection with the bridge deck, the PUC elastomer layer provides good elasticity and deformation ability, and the wear-resistant surface layer enhances surface wear resistance, thereby improving the overall performance of the expansion joint.

[0069] The expansion joint width, W, is precisely calculated by factoring in factors such as the linear expansion coefficient, annual extreme temperature differences, bridge span, concrete shrinkage strain, and creep coefficient. The range of values is 20-75mm, effectively adapting to bridge deformations due to temperature fluctuations, concrete shrinkage and creep, and other factors, reducing the risk of expansion joint damage. Furthermore, the wavy cross-section design (with a peak-to-trough height difference of 3-5mm and a wavelength-to-joint width, W, ratio of 1:1.2-1:1.5) further enhances deformation adaptability and avoids stress concentration.

[0070] The anchoring area is pre-embedded with inverted L-shaped anchor bars and filled with a composite material of concrete and steel fiber, which enhances the connection strength between the expansion joint and the beam body and improves the overall stability. The slot width of the anchoring area is 1.2-1.5 times the design width of the expansion joint, the longitudinal spacing of the anchor bars is 100-150mm, and the bent ends are embedded in the beam body to a depth of ≥50mm, ensuring the anchoring effect. A water guide groove is set at the bottom of the anchoring area and connected to the bridge drainage system through an inclined conduit (the inclination angle is 15°-30°), which can effectively remove water accumulation in the expansion joint and prevent problems such as structural corrosion caused by water accumulation. The embedded temperature compensation element (shape memory alloy spring, the shrinkage rate is 8%-12% below -20°C) can offset the low-temperature shrinkage stress and extend the service life of the expansion joint.

[0071] The PUC elastomer layer is interwoven with a crisscross pattern of fiberglass mesh, with interlayer spacing of 10-20mm. The top layer is 5-8mm from the bottom of the wear-resistant surface layer, enhancing the overall strength and toughness of the PUC elastomer layer and improving its crack resistance. A gradient modulus transition zone, 15-25mm thick, is placed between the PUC elastomer layer and the bridge deck pavement layer. This zone is composed of a gradient blend of PUC elastomer and bridge deck pavement material in a volume ratio of 1:1-1:3, ensuring a smoother modulus transition and reducing interfacial damage caused by significant modulus differences.

[0072] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A cold-resistant cast-in-place expansion joint structure, characterized in that: It includes a bonding layer, a PUC elastomer layer and a wear-resistant surface layer arranged in sequence from bottom to top; The PUC elastomer layer is cast by an elastomer mixture, and the elastomer mixture comprises, by weight percentage: Polyurethane prepolymer 20-30%, cement 40-50%, fine aggregate 20-30%, mineral filler 6%-13%, curing agent 3-6%, plasticizer 1%-3%, antioxidant 0.5%-1%, leveling agent 0.5%-1%, defoaming agent 0.2%-0.6%; Anchoring areas are provided on both sides of the structure, wherein anchoring bars are pre-embedded in the anchoring areas and filled with anchoring mixture. The anchoring bars are connected to the beam body in an inverted L shape, and the anchoring mixture is a composite material of concrete and steel fiber. A deformation joint is provided between the PUC elastomer layer and the bridge deck pavement layer, and the joint width W is calculated according to the following formula: W=α·ΔT·L+ε·L+β·L Where α is the linear expansion coefficient, ΔT is the annual extreme temperature difference, L is the bridge span, ε is the concrete shrinkage strain, β is the creep coefficient, and W ranges from 20 to 75 mm; The PUC elastomer layer is provided with a crisscross glass fiber mesh cloth inside, the mesh cloth layer spacing is 10-20mm, and the top layer of mesh cloth is 5-8mm away from the bottom surface of the wear-resistant surface layer; A water channel is provided at the bottom of the anchoring area, which is connected to the bridge drainage system through an inclined conduit with an inclination angle of 15°-30°; The cross section of the deformation joint is wavy, the height difference between the wave crest and the wave trough is 3-5 mm, and the ratio of the wavelength to the seam width W is 1:1.2-1:1.

5.

2. The cold-resistant cast-in-place expansion joint structure according to claim 1, characterized in that: The low-temperature performance of the PUC elastomer layer satisfies the following requirements: tensile elongation at break at -30°C ≥300%, elastic recovery rate ≥90%, and shear strength at the interface with concrete ≥2.5 MPa.

3. The cold-resistant cast-in-place expansion joint structure according to claim 1, characterized in that: The slot width of the anchoring area is 1.2-1.5 times the design width of the expansion joint, the longitudinal spacing of the anchor bars is 100-150mm, and the bent end thereof is embedded in the beam body to a depth of ≥50mm.

4. The cold-resistant cast-type expansion joint structure according to claim 1, wherein the wear-resistant surface layer is an epoxy resin layer mixed with silicon carbide particles, with a thickness of 3-5 mm, and forms an interface interlocking structure with the PUC elastomer layer through hot pressing.

5. The cold-resistant cast-in-place expansion joint structure according to claim 1, characterized in that: A gradient modulus transition zone is provided between the PUC elastomer layer and the bridge deck pavement layer. The transition zone is formed by gradient mixing of the elastomer mixture and the bridge deck pavement material in a volume ratio of 1:1-1:3, and has a thickness of 15-25 mm.

6. The cold-resistant cast-in-place expansion joint structure according to claim 1, characterized in that: A temperature compensation element is embedded in the water guide groove. The element is a shape memory alloy spring with a shrinkage rate of 8%-12% below -20°C, which is used to offset low-temperature shrinkage stress.

7. A construction method for a cold-resistant cast-type expansion joint structure, characterized in that: The steps include: S1. Base surface treatment: roughen the concrete at the beam end joints, remove the slurry and apply interface agent; S2. Anchorage area construction: Cut the bridge deck pavement according to the designed slot width, implant anchor bars, and pour the anchorage mixture in layers. Control the discharge temperature to be ≥160°C and the compaction density to be ≥98%; S3. PUC elastomer pouring: After mixing the elastomer mixture with water, continuously pour the elastomer mixture heated to 180-200℃ into the tank, scrape it twice and insert temperature sensors to control the temperature difference between layers to ≤10℃; S4, interface strengthening: laying glass fiber mesh cloth before the initial setting of PUC elastomer, and then coating the wear-resistant surface material; S5, gradient curing: first raise the temperature to 60℃ at a rate of 5℃ / h and hold for 8h, then cool naturally to room temperature. During the curing period, the humidity is controlled at 50%-70%; S6. Drainage system integration: When pre-buried water channel at the bottom of anchoring area, install inclined conduit simultaneously, and set anti-backflow valve at the conduit outlet.

8. The construction method of cold-resistant cast-type expansion joint according to claim 7, characterized in that: In step S3, the expansion rate of the elastomer mixture is controlled at 0.5%-1.2%, the stirring time is ≥45 minutes, and the construction is carried out when the on-site air humidity is ≤65%.

9. The construction method of cold-resistant cast-type expansion joint according to claim 1, characterized in that: After the curing is completed, step S5 performs performance verification, including the following steps: A -30°C low-temperature tensile test was used to verify the interface bonding strength; The displacement adaptability under 20-year equivalent load was simulated through vehicle fatigue test; Use infrared thermal imager to detect internal defects of the elastomer layer; The drainage efficiency of the water channel is verified through water tightness test.

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