Method and structure for repairing expansion joint of bottom plate of hydraulic structure

Abstract

The invention relates to the technical field of hydraulic structure bottom plate construction, in particular to a hydraulic structure bottom plate expansion joint repairing method and structure. The repairing method comprises the steps that S1, an opening is formed in the top of an expansion joint body; s2, a low-speed curing sealing body is injected into the opening; s4, after the rapid curing sealing body is cured, a surface layer flexible water stop belt is formed after the rapid curing sealing body is completely cured; and S5, under the action of external force, the surface layer flexible water stop belt deforms towards the interior of the opening, so that the uncured slow curing sealing body in the opening is squeezed into the hole. According to the method, the surface layer flexible water stop belt is rapidly cured, the preliminary water stop effect is achieved, the curing waiting time in severe cold areas is relatively shortened, and the curing time can be shortened by adding a curing agent into the polyurea coating when necessary.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic structure bottom plate construction, and in particular to a method and structure for repairing expansion joints of hydraulic structure bottom plates. Background Art

[0002] The main hydraulic structures are: ① water retaining structures, such as various dams, sluices, dikes and seawalls; ② discharge structures, such as various overflow dams, shore spillways, discharge tunnels and diversion gates; ③ water intake structures, also known as water intake structures, such as intake gates, deep water inlets and pumping stations; ④ water transmission structures, such as water diversion (supply) tunnels, aqueducts, water transmission pipelines and channels; ⑤ river regulation structures, such as groins, sluice dams, submerged dams, revetments and diversion dikes.

[0003] As an important part of hydraulic structures, the bottom plate usually serves as a flow channel. The expansion joints on the bottom plate are gaps deliberately set to withstand deformation, and a certain width and depth are reserved to allow the hydraulic structure to move relative to it without damage. However, during long-term use, the expansion joints of the bottom plate may open due to uneven foundation settlement, earthquakes, and other reasons, and the water-stopping materials may be damaged.

[0004] Therefore, the present invention aims at the problems of water seepage and difficulty in repair of the expansion joints of the bottom plate of existing hydraulic structures due to the damage of the water stop, and discloses a method and structure for repairing the expansion joints of the bottom plate of hydraulic structures. Summary of the invention

[0005] The purpose of the present invention is to provide a method and structure for repairing expansion joints of the bottom plate of hydraulic structures, so as to solve the problems that the curing waiting time of polysulfide sealants, epoxy resins or polyurethane sealants in cold regions is long, and the polysulfide sealants, epoxy resins or polyurethane sealants cannot effectively fill the gaps.

[0006] To achieve the above object, a method for repairing expansion joints of the bottom plate of a hydraulic structure is provided, which comprises the following steps:

[0007] S1. An opening is provided at the top of the expansion joint body;

[0008] S2, injecting a slow-curing sealant into the opening to fill the opening;

[0009] S3, sealing the quick-curing sealant on the opening surface;

[0010] S4, waiting for the quick-curing sealant to cure, and forming a surface flexible waterstop after the quick-curing sealant is completely cured;

[0011] The surface flexible water stop is used to form a preliminary seal on the side of the opening facing the water surface;

[0012] S5. Under the action of external force, the surface flexible water stop is deformed inwardly of the opening, so that the uncured slow-curing sealant in the opening is squeezed into the pores;

[0013] After the slow-curing sealant is completely cured, it is used to form a final seal on the pores in the expansion joint body.

[0014] The above-mentioned pores include gaps and cracks. When the high-pressure closed-hole plate cannot be filled in the expansion joint body due to deformation between the bottom plates, a gap will be generated between the two. The cracks are caused by damage to the original waterstop (the original waterstop includes the high-pressure closed-hole plate and the copper sheet waterstop) due to extrusion or deformation.

[0015] In order to adapt to the low temperature environment in severe cold areas and shorten the entire construction waiting period, the time for the above-mentioned fast-curing sealant to be completely cured must be faster than the time for the slow-curing sealant to lose fluidity. In this way, the fast-curing sealant can be used to form a preliminary seal and create a sealed environment for the slow-curing sealant. In this way, the construction period becomes waiting for the fast-curing sealant to be completely cured, while the slow-curing sealant cures on its own. Compared with waiting for the slow-curing sealant with good fluidity to completely block the pores, the construction waiting period is greatly shortened. If necessary, a curing agent can be added to the fast-curing sealant to further shorten the construction waiting period.

[0016] The time when the slow curing sealant (100) loses fluidity is T1, the time when the fast curing sealant (200) is completely cured is T2, the construction time of the fast curing sealant (200) is T3, and the time when the slow curing sealant (100) fully fills the pores is T4, and the following relationship is obtained:

[0017] T1-T2≥T3+T4.

[0018] A expansion joint repair structure is also provided, which is constructed using the above-mentioned method for repairing expansion joints of the bottom plate of a hydraulic structure. The repair structure specifically comprises:

[0019] The expansion joint body has an original water stop disposed inside;

[0020] An opening is provided at the top of the expansion joint body, wherein a slow-curing sealing body is provided in the opening, and the slow-curing sealing body is used to fill the pores;

[0021] as well as,

[0022] A fast-curing sealing body, which is arranged above the opening and forms a surface flexible waterstop connected to the water-facing surface after the fast-curing sealing body is completely cured;

[0023] The fast-curing sealant forms a preliminary seal for the opening after being completely cured;

[0024] Wherein, the slow-curing sealant comprises polysulfide sealant, epoxy resin or polyurethane sealant;

[0025] The fast curing sealant comprises an interface layer, a base cloth and a polyurea layer;

[0026] The interface layer, the base cloth and the polyurea layer are arranged in sequence from bottom to top;

[0027] The interface layer, the base cloth and the polyurea layer together constitute a surface flexible water stop.

[0028] Among them, the slow-curing sealant preferably uses polysulfide sealant, which has the following advantages:

[0029] Adhesion: Polysulfide sealant has good adhesion to various materials such as cement, steel, glass, wood, natural stone, etc. Its bonding strength is ≥0.2Mpa and its elongation is ≥300%.

[0030] Water resistance: Polysulfide sealant is stable to seawater, tap water and distilled water, and its weight change to seawater is small, showing good water resistance.

[0031] Acid and alkali resistance: Polysulfide sealant is not resistant to concentrated acids and alkalis, but is stable to dilute inorganic acids, alkalis and various salts.

[0032] Heat aging resistance: Polysulfide sealant has good heat aging resistance and can work for a long time under the conditions of -40℃~120℃.

[0033] Oil resistance and solvent resistance: Polysulfide sealant has good oil resistance and solvent resistance, is not easily combined with oil and non-polar solvents, and shows good oil resistance and solvent resistance.

[0034] Weather resistance: Polysulfide sealant is not easily damaged under ultraviolet rays and has excellent UV resistance, ensuring its long-term use in outdoor environments.

[0035] Low temperature flexibility: Polysulfide sealant has good low temperature flexibility and is suitable for use in low temperature environments.

[0036] In summary, due to its excellent performance characteristics, polysulfide sealant can more easily enter the expansion joint during the extrusion deformation process and can achieve a better water-stopping effect.

[0037] As a further improvement of the technical solution, a steel plate is arranged above the surface flexible water stop strip, and a bulge is provided at the bottom of the steel plate;

[0038] During the engagement of the protrusion with the opening, pressure is applied to the surface flexible waterstop above the opening, causing it to bend inwardly.

[0039] Wherein, the opening is a second opening chiseled out from the top of the expansion joint body, and the second opening is a V-shaped groove;

[0040] Alternatively, the opening is a first opening formed by the expansion joint body itself;

[0041] And in the case of the first opening, a sealing block is inserted into the first opening so that the surface of the sealing block is flush with the water-facing surface.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. The method and structure for repairing expansion joints of the bottom plate of hydraulic structures can quickly solidify through the flexible waterstop on the surface in severely cold areas, thereby playing a preliminary water-stopping role and relatively shortening the waiting time for solidification in severely cold areas. If necessary, a curing agent can be added to the polyurea coating to shorten its curing time. The single-component polyurea or two-component brushing polyurea selected for the polyurea coating has the characteristics of high mechanical properties, large elongation, high anti-seepage and antifreeze properties, good durability, and convenient construction and quality control. It can achieve a double water-stopping effect when combined with polysulfide sealant.

[0044] 2. The method and structure for repairing expansion joints of the bottom plate of hydraulic structures. After the fluidity of the polysulfide sealant is reduced in a low-temperature environment, it can also fully fill the pores after the flexible waterstop strip on the surface that is deformed by force is squeezed, thereby improving the final water-stopping effect.

[0045] 3. The method and structure for repairing expansion joints of the bottom plate of hydraulic structures protects the surface flexible waterstop by setting the steel plate, improves its closeness to the water-facing surface, and increases the sealing performance; more importantly, the extrusion force on the polysulfide sealant is more stable by the extrusion of the bulge at the bottom of the steel plate.

[0046] 4. The method and structure for repairing expansion joints of the bottom plate of hydraulic structures. The V-shaped groove has two main functions: one is to facilitate the filling of slow-curing sealants (polysulfide sealants); the other is that the polysulfide sealants are more likely to enter the expansion joints during the extrusion process;

[0047] Moreover, the support points of the surface flexible waterstop formed on both sides of the V-shaped groove have a span of 120mm, so that the deformation of the surface flexible waterstop will be more moderate. The height difference between the bulge at the bottom of the steel plate and the bottom surface of the steel plate is 4-6mm, which can allow the uncured polysulfide sealant to fully flow into the gaps and cracks. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the repair structure in the first embodiment of the present invention;

[0049] Figure 2This is a schematic diagram of the composition structure of the rapid curing sealing body of the present invention;

[0050] Figure 3 It is a schematic diagram of the width of the expansion joint body and the length of the surface flexible waterstop in the first embodiment of the present invention;

[0051] Figure 4 is a schematic diagram of a repair structure in a second embodiment of the present invention;

[0052] Figure 5 is a schematic diagram of a repair structure in a third embodiment of the present invention;

[0053] Figure 6 is a schematic diagram of a repair structure in a fourth embodiment of the present invention;

[0054] Figure 7 Schematic diagram of the repair structure in the fifth embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0056] Joint waterstop is one of the key technologies of hydraulic structures. The existing "Technical Specifications for Waterstops of Hydraulic Structures" (DL / T5215-2005) stipulates the type, size, material and construction requirements of profile waterstops, but the clauses on construction and quality control are relatively general, the requirements are not detailed enough, and the construction methods of waterstops in severe cold regions are not involved.

[0057] To this end, the present invention provides a method for repairing expansion joints of the bottom plate of a hydraulic structure, which uses two sealing bodies with different curing times to seal the opening of the expansion joint facing the water surface, and uses a fast-curing sealing body to form a preliminary seal. At this time, the slow-curing sealing body has better fluidity and filling capacity, and can more effectively fill small gaps and irregular surfaces, thereby ensuring a more comprehensive seal.

[0058] See also Figure 1 As shown in the figure:

[0059] Reference numeral 100 is a slow-curing sealant, 200 is a fast-curing sealant, 300 is a closed-cell foam board, 400 is a copper sheet water stop, 500 is an expansion joint body, and 510 is a first opening.

[0060] In the first embodiment, the closed-cell foam board 300 at a distance of 50-60 mm from the water-facing surface in the expansion joint body 500 is firstly dug out, so that the expansion joint body 500 is close to the side of the water-facing surface, and the first opening 510 is formed by the expansion joint body 500 itself, and then the slow-curing sealant 100 is injected into the first opening 510, and then the fast-curing sealant 200 is sealed on the surface of the first opening 510 within 4-10 hours. At this time, the fast-curing sealant 200 can form a preliminary seal for the first opening 510 after curing, which, on the one hand, has a preliminary waterproof effect, and on the other hand, provides basic conditions for the slow-curing sealant 100 to penetrate into cracks and gaps, so that the slow-curing sealant 100 can fully fill the cracks and gaps, providing basic guarantee for later sealing and waterproofing, and the slow-curing sealant 100 can form a double water-stopping effect with the fast-curing sealant 200 that has been cured first after curing.

[0061] See also Figure 2 As shown, in this embodiment, the fast-curing sealant 200 includes an interface layer 210, a base cloth 220 and a 2-3 mm polyurea layer 230, which together constitute a surface flexible water stop, and the slow-curing sealant 100 can be a polysulfide sealant, an epoxy resin or a polyurethane sealant. In short, the slow-curing sealant 100 has a slower curing speed than the fast-curing sealant 200. Assume that:

[0062] The time when the slow curing sealant 100 loses fluidity is T1, the time when the fast curing sealant 200 is completely cured is T2, the time when the fast curing sealant 200 is applied is T3, and the time when the slow curing sealant 100 fully fills the cracks and gaps is T4, and the following relationship is obtained:

[0063] T1-T2≥T3+T4.

[0064] The specific implementation steps of this embodiment are as follows:

[0065] A closed-cell foam board 300 made of polyethylene is partially dug out at the top of the expansion joint body 500, so that a first opening 510 is formed at the top of the expansion joint body 500, and the depth of the first opening 510 is controlled to be 50-60 mm, and then polysulfide sealant is injected into the first opening 510. After the first opening 510 is filled, the surface flexible water stop is manufactured. The base surface is first treated, including:

[0066] Use a wire brush or angle grinder to remove the protrusions, peeling, delamination and severe carbonization and looseness on the surface of the base to expose the fresh concrete base surface;

[0067] After the repaired base surface is completely cured, the base surface is repeatedly cleaned (including cleaning of loose soil, cement slurry, attachments, paint and grease, etc.) to keep the working surface clean.

[0068] The treated concrete base must be firm, flat, clean, not loose, sandy, or delaminated, and meet the requirements of the polyurea construction specification. Then, epoxy putty is used to repair defects such as pores. The primer material is fully stirred with a mixer. The primer is evenly applied to the surface of the concrete base by brushing or scraping to form an interface layer 210. Then, a base cloth 220 is set on the interface layer 210, and finally the polyurea layer 230 is constructed, wherein:

[0069] The construction of polyurea layer 230 adopts a two-component polyurea construction process. For specific requirements, see the "Technical Specifications for Construction of Polyurea Coatings for Hydropower and Water Conservancy Projects" (DL / T 5317-2014). However, it should be noted that the overlap width between the two polyurea application surfaces should be no less than 50mm.

[0070] Preferably, the polyurea construction and maintenance adopts natural curing, and measures should be taken during the curing period to prevent dust or water droplets from splashing onto the incompletely cured polyurea layer 230 .

[0071] About polyurea layer 230 defect repair:

[0072] When the polyurea layer 230 has defects such as pinholes, bubbles, peeling and damage, it should be repaired. The raw materials can be used for repair by brushing. When repairing defects such as bubbles, peeling and damage, in order to prevent the re-painted coating from bonding poorly with the original polyurea coating, the surface of the existing polyurea coating should be roughened, and then the interlayer treatment agent should be brushed on the overlapping parts. The repair range should be larger than 150mm around the defect.

[0073] The quality of polyurea layer 230 shall meet the requirements of Table 1, and before each batch of two-component polyurea coating, a sample of 200mm×200mm and thickness not less than 1.5mm shall be coated, and the appearance quality shall be evaluated and the sample shall be kept for future reference. The two-component polyurea coating sample shall be placed at room temperature for 7d and 21d before mechanical properties such as tensile strength and elongation at break shall be tested. The test results shall meet the requirements of Chapter 4 of DL / T5317-2014.

[0074] Table 1 Quality requirements of polyurea layer 230

[0075]

[0076]

[0077] The following table shows the technical performance indicators of two-component polyurea.

[0078] Table 2 Basic properties of two-component polyurea anti-seepage protection materials

[0079]

[0080] Table 3 Durability requirements for two-component polyurea anti-seepage protection materials

[0081]

[0082]

[0083] Table 4 Special performance requirements of two-component polyurea anti-seepage protection materials

[0084] Serial number project Technical indicators Testing according to specifications 1 Hardness(Shore A) ≥90 GB / T531.1-2008 2 Abrasion resistance / [(750g / 500r) / mg] ≤30 GB / T23446-2009 3 Impact resistance / (kg.m) ≥1.0 GB / T23446-2009 4 A component NCO (%) ≥16.8 GB / T12009.4-2016 5 Hydroxyl value of component B (mgKOH / g) 0 6 Environmental performance Materials meet environmental protection requirements

[0085] After the polyurea layer 230 is completely cured, pressure is applied to the surface flexible waterstop above the first opening 510 to cause it to bend toward the first opening 510. Since the top of the first opening 510 has been blocked, the uncured polysulfide sealant in the first opening 510 can only be squeezed into the gap between the high-pressure closed-cell plate 300 and the expansion joint body 500 (due to the deformation between the bottom plates, the high-pressure closed-cell plate 300 cannot be filled in the expansion joint body 500, and a gap will be generated between the two), or squeezed into the cracks generated by the high-pressure closed-cell plate 300 and the copper sheet waterstop 400.

[0086] It should be noted here that, due to its high fluidity, the polysulfide sealant has already flowed into the gaps and cracks when injected into the first opening 510, but it cannot fully fill the gaps and cracks, resulting in the failure of the fully cured polysulfide sealant to tightly block the gaps and cracks. The present embodiment applies pressure to the surface flexible waterstop through the external environment, such as: the gravity of the water flow, the gravity of the soil or other pressures in the environment, causing the surface flexible waterstop to deform, thereby squeezing the polysulfide sealant in the first opening 510, so that it fully fills the gaps and cracks, thereby improving the sealing effect of the gaps and cracks after the polysulfide sealant is fully cured.

[0087] In this embodiment, the primer material used for the interface layer 210 is preferably epoxy primer. Before applying the polyurea, the epoxy primer is pre-applied to the concrete surface to enhance the bonding strength between the base cloth 220 and the polyurea layer 230 and the concrete, seal the surface defects of the concrete, and block water vapor.

[0088] Table 5 Inspection items, performance requirements and test methods for epoxy primers entering the factory

[0089]

[0090] In addition, if the time between the current and next construction of polyurea coating exceeds 4 hours, there needs to be an overlap of 150±2mm, and an interlayer treatment agent should be used at the overlap.

[0091] Table 6 Inspection items, performance requirements and test methods for interlayer treatment agents entering the factory

[0092]

[0093] This embodiment also discloses a structure for repairing expansion joints of the bottom plate of a hydraulic structure. The structure is constructed using the above-mentioned repair method. Figure 1 As shown, it includes a first opening 510, and the first opening 510 is filled with a slow-curing sealant 100. When filling, wait for 3-5 minutes to allow the slow-curing sealant 100 to have enough time to flow into the gaps and cracks, and then continue to inject the slow-curing sealant 100 to fill the first opening 510, and then seal it with a surface flexible waterstop. Under the pressure of the environment, the surface flexible waterstop is deformed, so that the slow-curing sealant 100 is squeezed into the gaps and cracks.

[0094] The surface flexible water stop strip is composed of an interface layer 210, a base cloth 220 and a 2-3 mm polyurea layer 230, and the interface layer 210, the base cloth 220 and the 2-3 mm polyurea layer 230 are arranged in sequence from bottom to top.

[0095] As a preferred example, Figure 3 As shown, the transverse width a of the expansion joint body 500 is 20 mm, and the length b of the surface flexible waterstop strips on both sides of the expansion joint body 500 is 150 mm.

[0096] It should be noted here that since this embodiment does not cause damage to the top of the expansion joint body 500, the first opening 510 is directly formed by the expansion joint body 500 itself, and the pressure in the environment is used to deform the surface flexible waterstop strip. Therefore, the advantage of this embodiment is that the construction process is simple.

[0097] Second embodiment, the repair method of this embodiment includes the following steps:

[0098] A portion of the closed-cell foam board 300 made of polyethylene is dug out at the top of the expansion joint body 500, so that a first opening 510 is formed at the top of the expansion joint body 500, and the depth of the first opening 510 is controlled to be 50-60mm, and then polysulfide sealant is injected into the first opening 510. After the first opening 510 is filled, the surface flexible waterstop is made (the process is the same as that in the first embodiment, so it is not repeated here), and the polyurea layer 230 is completely cured.

[0099] like Figure 4As shown, a steel plate 600 is laid above the surface flexible waterstop (i.e., the quick-curing sealant 200 after complete curing), and the bottom of the steel plate 600 has a protrusion. During the process of the protrusion engaging with the first opening 510, pressure is applied to the surface flexible waterstop above the first opening 510 to cause it to bend toward the first opening 510. Since the top of the first opening 510 has been blocked, the uncured polysulfide sealant in the first opening 510 can only be squeezed into the gap between the high-pressure closed-cell plate 300 and the expansion joint body 500.

[0100] Although the number of process steps is increased compared with the first embodiment, the provision of the steel plate 600 protects the surface flexible waterstop strip, improves its closeness to the water-facing surface, and increases the sealing performance; more importantly, through the extrusion of the bulge at the bottom of the steel plate 600, the extrusion force on the polysulfide sealant (i.e., the slow-curing sealant 100) is made more stable.

[0101] Preferably, the height difference between the bottom protrusion of the steel plate 600 and the bottom surface of the steel plate 600 is 10-20 mm, and the corresponding deformation amount of the surface flexible waterstop is also 10-20 mm.

[0102] This embodiment also discloses a structure for repairing expansion joints of the bottom plate of a hydraulic structure. The structure is constructed using the repair method disclosed in this embodiment. Figure 1 As shown, it includes a first opening 510, and the first opening 510 is filled with a slow-curing sealant 100. When filling, wait for 3-5 minutes to allow the slow-curing sealant 100 to have enough time to flow into the gaps and cracks, and then continue to inject the slow-curing sealant 100 to fill the first opening 510, and then seal it with a surface flexible waterstop.

[0103] The surface flexible water stop strip is composed of an interface layer 210, a base cloth 220 and a 2-3 mm polyurea layer 230, and the interface layer 210, the base cloth 220 and the 2-3 mm polyurea layer 230 are arranged in sequence from bottom to top;

[0104] A steel plate 600 is arranged above the surface flexible water stop strip, and a protrusion is provided at the bottom of the steel plate 600 for squeezing the slow-curing sealing body 100 in the first opening 510 so that it can fully flow into the gaps and cracks.

[0105] The third embodiment, the specific implementation steps of the repair method of this embodiment are as follows:

[0106] A portion of the closed-cell foam board 300 made of polyethylene is dug out from the top of the expansion joint body 500, so that a first opening 510 is formed on the top of the expansion joint body 500, and the depth of the first opening 510 is controlled to be 50-60 mm, and then polysulfide sealant is injected into the first opening 510 to fill the first opening 510. Figure 5 As shown, a 4-12 cm thick sealing block 700 is inserted into the first opening 510, and the surface of the sealing block 700 is made flush with the water-facing surface, and then the surface flexible waterstop is made (the process is the same as in the first embodiment, so it is not repeated here). After the polyurea layer 230 is completely cured, a steel plate 600 is laid on the surface flexible waterstop (i.e. the fast-curing sealing body 200 after complete curing). The bottom of the steel plate 600 has a protrusion, and the protrusion is used to squeeze the sealing block 700 to make it slide inward along the first opening 510, further squeezing the uncured polysulfide sealant in the first opening 510 so that it can fully flow into the gaps and cracks.

[0107] Because the sealing block 700 compensates for the distance, the height difference between the bottom protrusion of the steel plate 600 and the bottom surface of the steel plate 600 in this embodiment is 6-8mm, and the corresponding deformation of the surface flexible waterstop is also 6-8mm, thereby avoiding damage to the surface flexible waterstop due to excessive deformation.

[0108] This embodiment also discloses a structure for repairing expansion joints of the bottom plate of a hydraulic structure. The difference from the third embodiment is that a sealing block 700 is inserted into the first opening 510 before sealing the surface flexible waterstop.

[0109] Fourth embodiment, the specific implementation steps of the repair method of this embodiment are as follows:

[0110] See also Figure 6 As shown, a V-shaped groove with a depth of 50-60 cm is chiseled out on the top of the expansion joint body 500, and the width of the left and right sides is 50 cm respectively, so that a second opening 520 is formed at the top of the expansion joint body 500, and then polysulfide sealant is injected into the second opening 520. After the second opening 520 is filled, the surface flexible waterstop is made (the process is the same as that in the first embodiment, so it is not repeated here). After the polyurea layer 230 is completely cured, the surface flexible waterstop is obtained, and then pressure is applied to the surface flexible waterstop above the second opening 520 to cause it to bend toward the second opening 520, and the uncured polysulfide sealant in the second opening 520 is forced to flow into the gaps and cracks.

[0111] The present embodiment also discloses a structure for repairing expansion joints of the bottom plate of a hydraulic structure. The structure is constructed using the repair method of the present embodiment, and includes a second opening 520. The second opening 520 is filled with a slow-curing sealant 100. During the filling, wait for 3-5 minutes to allow the slow-curing sealant 100 to have enough time to flow into the gaps and cracks. Then, continue to inject the slow-curing sealant 100 to fill the second opening 520, and then seal it with a surface flexible waterstop (the specific structural composition has been disclosed above, so it will not be repeated here).

[0112] The second opening 520 is a V-shaped groove with a depth of 50-60 cm.

[0113] In the fifth embodiment, a V-shaped groove with a depth of 50-60 cm is chiseled out on the top of the expansion joint body 500, and the width of the left and right sides is 50 cm respectively. In this way, a second opening 520 is formed on the top of the expansion joint body 500, and then polysulfide sealant is injected into the second opening 520. After the second opening 520 is filled, a surface flexible waterstop is made (the process is the same as that in the first embodiment, so it will not be repeated here), and the surface flexible waterstop is obtained after the polyurea layer 230 is completely cured.

[0114] See also Figure 7 As shown, a steel plate 600 is laid above the surface flexible waterstop (i.e., the quick-curing sealant 200 after complete curing), and the bottom of the steel plate 600 has a protrusion, which is used to apply pressure to the surface flexible waterstop above the second opening 520, causing it to bend toward the second opening 520, and the uncured polysulfide sealant in the second opening 520 is forced to flow into the gaps and cracks.

[0115] In this embodiment, the second opening 520 is a V-shaped groove, so the support points formed on both sides of the second opening 520 for the surface flexible waterstop have a span of 120mm. In this way, the deformation of the surface flexible waterstop will be more moderate, and the height difference between the protrusion at the bottom of the steel plate 600 and the bottom surface of the steel plate 600 is 4-6mm, which can allow the uncured polysulfide sealant in the second opening 520 to fully flow into the gaps and cracks.

[0116] The present embodiment also discloses a structure for repairing expansion joints of the bottom plate of a hydraulic structure. The structure is constructed using the repair method of the present embodiment, and includes a second opening 520. The second opening 520 is filled with a slow-curing sealant 100. The filling is performed by waiting for 3-5 minutes to allow the slow-curing sealant 100 to have enough time to flow into the gaps and cracks. The slow-curing sealant 100 is then injected to fill the second opening 520, and then the surface flexible waterstop is sealed (the specific structural composition has been disclosed above, so it will not be repeated here). A steel plate 600 is pressed above the surface flexible waterstop, and a protrusion is provided at the bottom of the steel plate 600. The protrusion is used to apply pressure to the surface flexible waterstop above the second opening 520, causing it to bend toward the second opening 520, and the uncured polysulfide sealant in the second opening 520 is forced to flow into the gaps and cracks.

[0117] In summary, at present, many projects have waterstop failure and leakage problems due to construction methods and quality control reasons. With the advancement of science and technology, new technologies, new processes and new materials have been continuously applied in the field of waterstopping of hydraulic structure joints in the past decade. The present invention is a polyurea coating waterstop suitable for base plate repair, a coated waterstop used for waterstopping of building joints, the material is single-component polyurea or two-component brushed polyurea, and the polyurea coating waterstop is to coat polyurea on the surface of concrete, and after curing, it is bonded to the concrete to form a surface flexible waterstop, which is an externally attached waterstop formed on site by brushing.

[0118] In extremely cold areas, the surface flexible waterstop can quickly solidify to play a preliminary water-stopping role, which relatively shortens the waiting time for solidification in extremely cold areas. If necessary, a curing agent can be added to the polyurea coating to shorten its curing time. The single-component polyurea or two-component brushing polyurea used in the polyurea coating has high mechanical properties, large elongation, high anti-seepage and anti-freeze properties, good durability, and is easy to construct and easy to control in quality. It can achieve a double water-stopping effect when combined with polysulfide sealant.

[0119] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for repairing expansion joints of hydraulic structures, characterized in that: The steps include: S1. Setting an opening at the top of the expansion joint body (500); S2, injecting a slow-curing sealing body (100) into the opening to fill the opening; S3, sealing the quick-curing sealing body (200) on the opening surface; S4, waiting for the quick-curing sealant (200) to cure, and forming a surface flexible water stop after the quick-curing sealant (200) is completely cured; The surface flexible water stop is used to form a preliminary seal on the side of the opening facing the water surface; S5. Under the action of external force, the surface flexible water stop is deformed toward the opening, so that the uncured slow-curing sealing body (100) in the opening is squeezed into the pore; After the slow-curing sealing body (100) is completely cured, it is used to form a final seal on the pores in the expansion joint body (500).

2. The method for repairing expansion joints of the bottom plate of a hydraulic structure according to claim 1, characterized in that: The slow-curing sealant (100) has stronger fluidity than the fast-curing sealant (200), and the time it takes for the slow-curing sealant (100) to lose fluidity is slower than the time it takes for the fast-curing sealant (200) to fully cure.

3. The method for repairing expansion joints of the bottom plate of a hydraulic structure according to claim 2 is characterized in that: The time when the slow curing sealant (100) loses fluidity is T1, the time when the fast curing sealant (200) is completely cured is T2, the construction time of the fast curing sealant (200) is T3, and the time when the slow curing sealant (100) fully fills the pores is T4, and the following relationship is obtained: T1-T2≥T3+T4.

4. An expansion joint repair structure, characterized in that: The method for repairing expansion joints of the bottom plate of a hydraulic structure according to any one of claims 1 to 3 is used for construction, and the repair structure specifically comprises: The expansion joint body (500) has an original water stop disposed inside; An opening is arranged at the top of the expansion joint body (500), a slow-curing sealing body (100) is arranged in the opening, and the slow-curing sealing body (100) is used to fill the pores; as well as, A fast-curing sealing body (200), wherein the fast-curing sealing body (200) is arranged above the opening, and after the fast-curing sealing body (200) is completely cured, a surface flexible water stop is formed to be connected to the water-facing surface; The fast-curing sealing body (200) forms a preliminary seal for the opening after being completely cured; Wherein, the slow-curing sealant (100) comprises polysulfide sealant, epoxy resin or polyurethane sealant; The fast curing sealant (200) comprises an interface layer (210), a base cloth (220) and a polyurea layer (230); The interface layer (210), the base cloth (220) and the polyurea layer (230) are arranged in sequence from bottom to top; The interface layer (210), the base cloth (220) and the polyurea layer (230) together constitute a surface flexible water stop strip.

5. The expansion joint repair structure according to claim 4, characterized in that: A steel plate (600) is arranged above the surface flexible water stop strip, and a protrusion is provided at the bottom of the steel plate (600); During the engagement of the protrusion with the opening, pressure is applied to the surface flexible waterstop above the opening, causing it to bend inwardly.

6. The expansion joint repair structure according to claim 5, characterized in that: The opening is a second opening (520) chiseled out from the top of the expansion joint body (500), and the second opening (520) is a V-shaped groove.

7. The expansion joint repair structure according to claim 5, characterized in that: The opening is a first opening (510) formed by the expansion joint body (500) itself.

8. The expansion joint repair structure according to claim 7, characterized in that: A sealing block (700) is inserted into the first opening (510), so that the surface of the sealing block (700) is flush with the water-facing surface.

9. The expansion joint repair structure according to claim 4, characterized in that: The original water stop comprises a high-pressure closed-hole plate (300) and a copper sheet water stop (400).

10. The expansion joint repair structure according to claim 4, characterized in that: The pores include gaps and cracks.

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