Composite repairing material for underwater defects of ultra-deep concrete diaphragm wall and targeted repairing method

Abstract

The invention discloses a composite repairing material for underwater defects of an ultra-deep concrete diaphragm wall and a targeted repairing method, the repairing material can perform targeted repairing on concrete defects under high pressure, high humidity and low temperature, and has the functions of groutability, adhesion in water, quick setting, early strength, high toughness, high impermeability and targeted repairing. When meeting water, the super absorbent resin SAP added in the composite repairing material can rapidly absorb water, saturate and crack and then rapidly expand and block, and meanwhile, the magnetic slurry is released, so that the magnetic targeted attraction and the water saturation performance in the repairing process are ensured, the long-term hydration of a cement base material is ensured, and the shrinkage and micro-expansion of the slurry after solidification are weakened; the material shrinkage deformation is prevented. The added magnetic nano ferroferric oxide forms guidance of a magnetic field through a built-in coil in the grouting pipe and double positioning of magnetic response of the toughening material, so that the material can flow to a targeted area, meanwhile, the toughness of the material is improved by adding the toughening material, and the deformability of a repaired area is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete engineering defect repair, in particular to an underwater defect composite repair material for super-deep concrete cutoff wall and a targeted repair method. BACKGROUND

[0002] High dam and reservoir construction is on deep buried cover layer, and the super-deep concrete cutoff wall is the core impermeable structure of the high dam. The integrity and continuity of the cutoff wall directly affect the safety state of the dam. However, during the construction and service of the cutoff wall under the deep cover layer, various defects of the cutoff wall are inevitable. In order to ensure the safety of the dam, the repair of the cutoff wall defects becomes very important. Under the deep buried cover layer, the cutoff wall is deeply buried, and the repair site is located in the deep underground, so the repair operation is extremely difficult to construct, and it is necessary to develop an underwater repair process suitable for super-deep and narrow space. Moreover, the deep underground temperature is low, the pressure is high, the humidity is saturated, and even there is moving water, so the repair must be carried out under high pressure, high humidity and low temperature conditions. Using traditional grouting materials, high pressure, low temperature and high humidity conditions will have a great adverse effect on the curing speed, degree and final performance of the materials. If there is moving water, water will dilute and flush the unhardened repair material, which will seriously affect its adhesion, curing and final filling degree. At the same time, for the super-deep environment, the repair area also needs to withstand a large water pressure, soil pressure and structural deformation, so the repair material needs to have high toughness, micro-expansion and certain deformation ability after forming, in order to adapt to the stress change and avoid cracking or debonding with the matrix.

[0003] Therefore, in the high pressure, high humidity, low temperature and narrow environment, how to ensure that the slurry can accurately reach the target area, effectively displace underground water and fully fill the defects is a key challenge. There are comprehensive high requirements for material performance (grouting, water adhesion, fast setting and early strength, high toughness) and repair technology (reliable grouting, quality control). During the repair process, the material needs to be accurately diffused and filled to the defect position, and when it reaches the defect position, the material must react (gel or initial setting) very quickly, obtain enough resistance to dispersion in a short time, prevent being carried away by water flow, and at the same time, the material needs to be effectively cured on the water-saturated surface or underwater, and form long-term and high-strength adhesion with the old concrete (usually wet or even with water). During operation, facing complex and extreme working conditions, the repair material has high toughness, low shrinkage and deformation adaptability.

[0004] In order to realize the defect repair of underwater concrete, Chinese patents CN202411138699.8, CN202410805310.4, CN202410714142.8, CN202410547756.1 and CN202311126925.6 etc. provide a kind of underwater repair material, but the above prior art disclosed many underwater repair materials need to be repaired in still water working condition, cannot be quickly solidified in the dynamic water condition of super deep environment and reliably repaired, and still has the problems of poor adhesion with old concrete, low impermeability, poor toughness etc. Therefore, how to develop a kind of concrete defect repair material under high pressure, high humidity and low temperature, which has the functions of pourability, underwater adhesion, fast setting, early strength, high toughness, high impermeability and targeted repair, is still a problem to be solved. SUMMARY

[0005] In view of the problems in the background art, the purpose of the present application is to provide a kind of underwater defect composite repair material and targeted repair method for super deep concrete cutoff wall.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme:

[0007] The first aspect of the present application is to provide a kind of underwater defect composite repair material for super deep concrete cutoff wall, which comprises repair material 1 and repair material 2, wherein,

[0008] The repair material 1 comprises the following components by weight: water 250-300 parts, cement 600-650 parts, blast furnace slag powder 350-400 parts, magnesium oxide 80-100 parts, silicon powder 2-5 parts, water reducing agent 2-5 parts, alkali 80-100 parts, sodium silicate 180-200 parts, internal solid microcapsule material 5-20 parts, magnetic agent 3-12 parts, polymer dispersing agent 1-3 parts, interface agent 3-12 parts, temperature thixotropic agent 0.5-2 parts;

[0009] The repair material 2 comprises the following components by weight: water 250-300 parts, cement 600-650 parts, blast furnace slag powder 350-400 parts, magnesium oxide 80-100 parts, silicon powder 2-5 parts, alkali 80-100 parts, sodium silicate 180-200 parts, water reducing agent 2-5 parts, toughening material 10-30 parts, impermeability enhancer 5-10 parts, temperature thixotropic agent 0.5-2 parts, defoaming agent 1-3 parts, anti-dispersing agent 2-5 parts.

[0010] Preferably, the cement is fast-setting early-strength cement, the alkali is sodium hydroxide or potassium hydroxide, the water reducing agent is selected from polycarboxylic acid high-efficiency water reducing agent (PCE), and the particle size of the blast furnace slag powder, magnesium oxide and silicon powder is greater than 100 mesh.

[0011] Preferably, the internal solid microcapsule material is a superabsorbent resin SAP; the magnetic agent is selected from magnetic nano-iron oxide; the polymeric dispersant is selected from sodium polyacrylate; the temperature thixotropic agent is selected from block polyether modified polyurethane; and the interfacial agent is selected from water-based epoxy resin.

[0012] Preferably, the defoaming agent is calcium phosphate, the toughening material is steel fiber with a length less than 5mm, the temperature thixotropic agent is block polyether modified polyurethane, the anti-permeation reinforcing agent is amino-modified silicon dioxide, and the anti-dispersion agent is hydroxypropyl methylcellulose ether.

[0013] The second aspect of the present application provides a preparation method of the above-mentioned underwater defect composite repair material for super-deep concrete cutoff wall, comprising the following steps:

[0014] (1) Preparation of repair material 1:

[0015] S11, mix cement, blast furnace slag powder, magnesium oxide and silicon powder in a dry state, and stir to mix uniformly to obtain mixed solid material 1;

[0016] S12, mix magnetic nano-iron oxide and sodium polyacrylate in a dry state according to the formula, and stir to mix uniformly. After uniform stirring, a proper amount of water is added to mix in the stirring process, so that the sodium polyacrylate is adsorbed on the magnetic nano-iron oxide particles. Then, superabsorbent resin SAP is added, stirred, and water is added in the stirring process, so that the mixture reaches a viscous state, and at the same time, the magnetic nano-iron oxide is uniformly wrapped in the water-absorbent resin, to obtain viscous functional microcapsules of internally solid magnetic nano-iron oxide, which is referred to as internally solid magnetic microcapsules for short;

[0017] S13, mix water, water reducing agent, alkali and sodium silicate uniformly according to the formula, then add temperature thixotropic agent and interfacial agent, and mix uniformly to obtain mixed liquid material 1;

[0018] S14, add mixed liquid material 1 to mixed solid material 1, stir and mix, then add viscous functional microcapsules of internally solid magnetic nano-iron oxide, stir and mix uniformly to obtain repair material 1;

[0019] (2) Preparation of repair material 2:

[0020] S21, mix cement, blast furnace slag powder, magnesium oxide, silicon powder, steel fiber and amino-modified silicon dioxide in a dry state according to the formula, and mix uniformly to obtain mixed solid material 2;

[0021] S22, mix water, water reducing agent, alkali, sodium silicate uniformly according to the formula, then add temperature thixotropic agent, defoaming agent and anti-dispersion agent, and mix uniformly to obtain mixed liquid material;

[0022] S23, the mixed liquid material 2 is added to the mixed solid material 2, and stirred to obtain the repair material 2.

[0023] Preferably, in steps S13 and S23, the stirring time is 5-10 minutes.

[0024] The third aspect of the present application provides a method for repairing underwater defects of an ultra-deep concrete cutoff wall by using the composite repair material, comprising the following steps:

[0025] A1, after drilling a hole in the repair area, the accumulated water in the repair area is replaced by injecting inert gas foam perfluorohexone through the grouting pipe, and the inert gas foam perfluorohexone is released through the grouting pipe before grouting to create a low-water bonding interface in the repair area;

[0026] A2, during the injection of inert gas foam perfluorohexone into the grouting pipe, release the repair material 1 immediately, and stop the injection of the repair material 1 when the grouting pressure and flow rate detected by the pressure gauge and flow meter of the grouting system change;

[0027] A3, after the repair material 1 stops grouting, a small coil is energized at the end of the grouting pipe, a magnetic field is formed at the end of the grouting pipe, the magnetic response of the magnetic iron oxide in the concrete interface is enhanced, and the repair material 2 is immediately grouted through the magnetic navigation technology of the magnetic field attraction, and the repair material 2 is attracted to flow to the repair area through the magnetic response of the steel fiber.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] (1) The present application provides a composite repair material for underwater defects of an ultra-deep concrete cutoff wall, which is a repair material that can be used in high pressure, high humidity and low temperature environments, and has the functions of groutability, underwater adhesion, fast setting, early strength, high toughness, high impermeability and targeted repair. The raw materials are water, cement, blast furnace slag powder, magnesium oxide, sodium silicate, sodium hydroxide, silicon powder and water reducing agent, which meet the requirements of fast setting, early strength and micro-expansion in high pressure and high humidity environments, and the use of an interface agent, water-based epoxy resin, improves the bonding strength between the repair material and the old concrete interface during the repair process in moving water.

[0030] (2) In the present application, the temperature thixotropic agent block polyether modified polyurethane added makes the obtained repair material have the characteristics of low viscosity and strong groutability when pumping, and the viscosity increases sharply when it comes into contact with cold underground water, thereby improving the anti-erosion ability of the composite repair material and the retention rate of the repair material.

[0031] (3) In the present application, (unsaturated) superabsorbent resin SAP microcapsules are added. When the composite repair material meets water, the superabsorbent resin SAP microcapsules can quickly absorb water, saturate and break, and then quickly expand to block, while releasing magnetic slurry, ensuring the magnetic targeted attraction of the repair process, and the water saturation performance of the superabsorbent resin SAP, ensuring the long-term hydration of the cement-based material, reducing the shrinkage in the later period, having micro-expansion, and preventing the shrinkage and deformation of the composite repair material.

[0032] (4) In the present application, the magnetic nano-ferroferric oxide and steel fiber are added. Through the guidance of the magnetic field formed by the coil in the grouting pipe and the double positioning mechanism of the magnetic response of the steel fiber, the composite repair material can flow to the target area, and the addition of the steel fiber improves the toughness of the composite repair material and enhances the deformation ability of the repair area, that is, the repair material prepared by the present application has the functions of magnetic navigation and magnetic response.

[0033] (5) In the present application, water-based epoxy resin and surface functionalized nanomaterial amino-modified silicon dioxide are added. Through the bridging of the nano-particles to the capillary pores of the concrete, a double bonding layer of mechanical interlocking + chemical bonding is formed, which improves the interfacial bonding strength and impermeability of the repair area. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a schematic diagram of the targeted repair process of underwater defects of the super-deep anti-seepage wall;

[0035] Figure 2 It is a schematic diagram of the magnetic navigation and magnetic response process of the repair material 2 in the repair process of the underwater defects of the super-deep anti-seepage wall;

[0036] Figure 3 It is a schematic diagram of the repair interface of the underwater defects of the super-deep anti-seepage wall. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments.

[0038] Embodiment 1

[0039] Preparation of repair material 1:

[0040] (1) 645 parts of cement, 270 parts of blast furnace slag powder, 80 parts of magnesium oxide and 5 parts of silicon powder are stirred in a dry state, and mixed uniformly to obtain a solid mixture;

[0041] (2) 250 parts of water, 90 parts of sodium hydroxide, 5 parts of water reducing agent and 180 parts of sodium silicate are mixed uniformly to obtain a liquid mixture;

[0042] (3) Inner solid magnetic microcapsule preparation: dry state of magnetic nanometer four iron oxide and sodium polyacrylate are stirred and mixed uniformly, after stirring uniformly, water is added in the stirring process to mix, so that the sodium polyacrylate is adsorbed on the magnetic nanometer four iron oxide particles; then high water absorption resin SAP is added, stirred, and water is added in the stirring process to make the mixture reach a viscous state, while the magnetic nanometer four iron oxide is uniformly wrapped in the water absorption resin, and a viscous inner solid magnetic nanometer four iron oxide functional microcapsule, i.e. inner solid magnetic microcapsule, is obtained; wherein the weight ratio of high water absorption resin SAP, magnetic four iron oxide and sodium polyacrylate is 1:0.6:0.15;

[0043] (4) The liquid mixture is added to the solid mixture, stirred and mixed, and then 0.6wt% of the total weight of the solid mixture, i.e. 6 parts of inner solid magnetic microcapsule, is added, stirred uniformly, and a slurry is obtained.

[0044] Example 2

[0045] The steps are basically the same as those of Example 1, except that 0.9wt% of the total weight of the solid mixture, i.e. 9 parts of inner solid magnetic microcapsule, is added to obtain a slurry.

[0046] Example 3

[0047] The steps are basically the same as those of Example 1, except that 1.2wt% of the total weight of the solid mixture, i.e. 12 parts of inner solid magnetic microcapsule, is added to obtain a slurry.

[0048] Comparative Example 1

[0049] The steps are basically the same as those of Example 1, except that no inner solid magnetic capsule is added to obtain a slurry.

[0050] The slurry prepared in Examples 1-3 and Comparative Example 1 is tested for expansion, strength and deformation. The results are shown in Table 1 below.

[0051] Table 1

[0052]

[0053] As can be seen from the results in Table 1, compared with the slurry obtained by not adding inner solid magnetic capsules in Comparative Example 1, the slurry with inner solid magnetic capsules has a significant increase in expansion and volume deformation, and the higher the proportion of inner solid magnetic capsules, the greater the expansion and volume deformation, and the 28d compressive strength is slightly reduced.

[0054] Example 4

[0055] (1) 645 parts of cement, 270 parts of blast furnace slag powder, 80 parts of magnesium oxide and 5 parts of silicon powder are dry mixed uniformly to obtain a solid mixture;

[0056] (2) 2.2 parts of magnetic nano-Fe3O4 in dry state and 0.6 parts of sodium polyacrylate are stirred and mixed uniformly, after uniform stirring, 0.5 parts of water is added and mixed in the stirring process, so that the sodium polyacrylate is adsorbed on the magnetic nano-Fe3O4 particles, then 3.7 parts of superabsorbent resin SAP is added and stirred uniformly with the mixed magnetic nano-Fe3O4 particles, and 1.5 parts of water is added in the stirring process, so that the mixture reaches a viscous state, so that the magnetic nano-Fe3O4 is uniformly wrapped in the SAP, to obtain the inner solid magnetic microcapsule;

[0057] (3) 248 parts of water, 90 parts of sodium hydroxide, 5 parts of water reducing agent, 180 parts of sodium silicate and 0.4 parts of block polyether modified polyurethane (temperature thixotropic agent), 2.2 parts of water-based epoxy resin (interface agent) are mixed uniformly to obtain a liquid mixture;

[0058] (4) The liquid mixture is added to the solid mixture, stirred and mixed, then 0.9wt% of the total weight of the solid mixture, i.e. 9 parts of inner solid magnetic microcapsule, is added and stirred uniformly to obtain a slurry.

[0059] The water-cement ratio of the prepared material is 0.25, and the slurry is immediately poured into the rough interface of the old concrete after stirring and forming. A part of the slurry is taken out after curing in a standard curing box at 20±1℃ to a specified age for testing the bonding strength, and a part is placed in a water tank with a flow rate of 2mm / s and water temperature of 5±1℃, 20±1℃ for impact resistance test. The uniformly stirred slurry is immediately placed in a 5±1℃ standard curing box and a 20±1℃ standard curing box respectively for expansion test, and the bonding strength, expansion and impact resistance test results are carried out at different curing temperatures, as shown in Table 2 below.

[0060] Table 2

[0061]

[0062] As can be seen from the results in Table 2, compared with the slurry without inner solid magnetic microcapsule, temperature thixotropic agent and interface agent, the expansion, bonding strength and impact resistance of the slurry after adding are all significantly improved; compared with the curing at 20℃, the expansion and bonding strength of the slurry cured at low temperature (5℃) are slightly reduced, but the impact resistance is significantly enhanced.

[0063] Example 5

[0064] (1) 640 parts of cement, 270 parts of blast furnace slag powder, 80 parts of magnesium oxide, 5 parts of silicon powder and 5 parts of amino-modified silicon dioxide are dry mixed uniformly to obtain a mixture 1;

[0065] (2) 250 parts of water, 90 parts of sodium hydroxide, 5 parts of water reducing agent, 180 parts of sodium silicate and 1 part of calcium phosphate are mixed uniformly to obtain a mixture 2.

[0066] (3) Add mixture 2 to the dry-mixed mixture 1, stir and shape to obtain the slurry.

[0067] The water-cement ratio of the prepared material is 0.25. After shaping, the slurry with the mold is immediately placed in a standard curing box at 20±1°C for curing until the specified age, and then taken out for testing of the compressive strength, deformation and impermeability. The impermeability test is performed according to the water penetration height method in GB / T 50082-2009. The performance of the slurry with the added amino-modified silicon dioxide and calcium phosphate is tested at different curing temperatures. The results of the elastic deformation, strength and impermeability tests are shown in Table 3 below.

[0068] Table 3

[0069]

[0070] As can be seen from the results in Table 3, compared with the slurry without the added impermeability agent and defoaming agent, the impermeability and compressive strength of the slurry with the added agent are significantly increased. Compared with the curing at 20°C, the elastic deformation and impermeability of the slurry cured at low temperature (5°C) are slightly weakened.

[0071] Example 6

[0072] (1) Dry-mix 630 parts of cement, 270 parts of blast furnace slag powder, 80 parts of magnesium oxide, 5 parts of silicon powder, 5 parts of amino-modified silicon dioxide (impermeability enhancing agent) and 10 parts of steel fiber (toughening material) to obtain mixture 1;

[0073] (2) Mix 250 parts of water, 90 parts of sodium hydroxide, 5 parts of water reducing agent, 180 parts of sodium silicate and 1 part of calcium phosphate (defoaming agent) to obtain mixture 2;

[0074] (3) Add mixture 2 to the dry-mixed mixture 1, stir and shape to obtain the slurry.

[0075] The water-cement ratio of the prepared material is 0.25. After shaping, the slurry with the mold is immediately placed in a standard curing box at 20±1°C for curing until the specified age, and then taken out for testing of the compressive strength, deformation and impermeability. The impermeability test is performed according to the water penetration height method in GB / T 50082-2009. The performance of the slurry with the added steel fiber, amino-modified silicon dioxide and calcium phosphate is tested at different curing temperatures. The results of the bending and tensile deformation, shear deformation, compressive strength and impermeability tests are shown in Table 4 below.

[0076] Table 4

[0077]

[0078] As shown by the results in Table 4, compared with not incorporating steel fibers (toughening materials), amino-modified silicon dioxide (anti-permeation enhancer) and calcium phosphate (defoaming agent), the anti-permeation performance, strength and deformation capacity of the slurry after incorporation are obviously increased; compared with the curing condition of 20°C, the performance of the slurry under low temperature conditions is reduced, but compared with not incorporating steel fibers, amino-modified silicon dioxide and calcium phosphate, the performance is still obviously improved under low temperature conditions.

[0079] Example 7

[0080] (1) 630 parts of cement, 270 parts of blast furnace slag powder, 80 parts of magnesium oxide, 5 parts of silicon powder, 5 parts of amino-modified silicon dioxide and 10 parts of steel fibers are mixed and uniformly dry-mixed to obtain a mixture 1;

[0081] (2) 250 parts of water, 90 parts of sodium hydroxide, 5 parts of water reducing agent, 180 parts of sodium silicate, 1 part of calcium phosphate, 1 part of hydroxypropyl methylcellulose ether and 1 part of block polyether modified polyurethane are uniformly mixed to obtain a mixture 2.

[0082] (3) The mixture 2 is added to the uniformly dry-mixed mixture 1, and stirred and formed to obtain a slurry.

[0083] The water-cement ratio of the prepared material is 0.25, and after stirring and forming, the slurry is immediately poured into the interface of rough old concrete. A part is placed in a water tank with a flow rate of 2 mm / s and water temperature of 5±1°C and 20±1°C for anti-impact test, a part is immediately placed in a 5±1°C standard curing box and a 20±1°C standard curing box respectively for expansion test, and a part of the slurry with a mold is placed in a 20±1°C standard curing box for curing until the specified age, and then taken out for testing the compressive strength and deformation. The results of the expansion, deformation, strength and impact test are shown in Table 5 below.

[0084] Table 5

[0085]

[0086] As shown by the results in Table 5, the functional B component materials (defoaming agent + toughening material + anti-permeation enhancer + temperature thixotropic agent + anti-dispersant) are incorporated under different curing temperatures for performance testing. Compared with not incorporating the functional B component materials, the anti-impact performance, strength and deformation, and fluidity capacity of the slurry after incorporation are obviously increased; compared with the curing condition of 20°C, the fluidity under low temperature (5°C) conditions is obviously reduced, and the deformation and strength performance are reduced, but compared with not incorporating the functional B component materials, the performance is still obviously improved under low temperature conditions.

[0087] Test Example 1

[0088] An underwater defect composite repair material and targeted repair method for an ultra-deep concrete anti-seepage wall, comprising the following steps:

[0089] 1. Preparation of repair material 1:

[0090] (1) Dry mix 630 parts of cement, 270 parts of blast furnace slag powder, 80 parts of magnesium oxide, 5 parts of silica powder, 5 parts of amino-modified silicon dioxide, and 10 parts of steel fiber uniformly;

[0091] (2) Mix 2.2 parts of magnetic nano-magnetite and 0.6 parts of sodium polyacrylate in dry state uniformly, after uniform stirring, add 0.5 parts of water during stirring to make the sodium polyacrylate adsorbed on the magnetic nano-magnetite particles; then add 3.7 parts of superabsorbent resin (SAP) and stir uniformly with the mixed magnetic nano-magnetite particles, and add 1.5 parts of water during stirring to make the mixture reach a viscous state, to obtain functional microcapsules with internal solid magnetic nano-magnetite;

[0092] (3) Mix 248 parts of water, 90 parts of sodium hydroxide, 5 parts of water reducing agent, 180 parts of sodium silicate, and 0.4 parts of block polyether modified polyurethane, 2.2 parts of water-based epoxy resin uniformly, add to the dry mixed solid mixture and stir, and add the functional microcapsules with internal solid magnetic nano-magnetite prepared in No. 1, stir and shape, to obtain repair material 1.

[0093] 2. Preparation of repair material 2

[0094] (1) Dry mix 630 parts of cement, 270 parts of blast furnace slag powder, 80 parts of magnesium oxide, 5 parts of silica powder, 5 parts of amino-modified silicon dioxide, and 10 parts of steel fiber uniformly, to obtain a solid mixture;

[0095] (2) Mix 250 parts of water, 90 parts of sodium hydroxide, 5 parts of water reducing agent, 180 parts of sodium silicate, 1 part of calcium phosphate, 1 part of hydroxypropyl methylcellulose ether, and 1 part of block polyether modified polyurethane uniformly, then add to the dry mixed solid mixture, stir and shape, to obtain repair material 2.

[0096] 3. Concrete defect repair

[0097] Put the defect model of a certain concrete dam in the indoor water tank, repair the defect under the condition of flowing water at a flow rate of 2 mm / s and water temperature of 5±1℃ through the self-made grouting pipe, and set three working conditions:

[0098] The first working condition: directly pour in repair material 2, stop after pouring in for 1.5 minutes;

[0099] The second working condition: first pour in repair material 1 through the grouting pipe, then pour in repair material 2 after 30 seconds, and stop after pouring in for 1 minute;

[0100] The third working condition is: first, the repairing material 1 is filled into the grouting pipe, and after 30 seconds, the repairing material 2 is filled into the grouting pipe, and during the filling of the repairing material 2, a magnetic field is generated by exciting the coil built in the grouting pipe, and the filling is stopped after 1 minute;

[0101] The specific steps of the third working condition are as follows:

[0102] (1) The upstream of the cutoff wall repair area as shown in Figure 1 is drilled, and then the inert gas foam perfluorohexanone is released through the grouting pipe to displace the accumulated water in the crack area, so as to create a water-free bonding interface in the defect repair area;

[0103] (2) During the injection of the inert gas foam perfluorohexanone into the grouting pipe, the repairing material 1 is immediately filled, and according to the flow of groundwater, the slurry flows to the area to be repaired; when the filling is stopped after 30 seconds, the filling of the repairing material 1 is stopped;

[0104] (3) The small coil built in the end of the grouting pipe is electrified, a magnetic field is formed at the end of the grouting pipe, the magnetic response of the magnetic magnetite adhered to the old concrete interface is enhanced, and through the magnetic navigation technology of the magnetic field attraction, the repairing material 2 containing the functional component B is immediately filled, and through the magnetic response of the steel fiber, the repairing material 2 is attracted to flow to the repair area in a targeted manner, as shown in Figures 2-3 .

[0105] After the grouting is completed, the impact echo method is used to evaluate the defect filling effect. The functional component B material (defoaming agent + toughening material + anti-permeation enhancer + temperature thixotropic agent + anti-dispersant) is mixed at different curing temperatures to carry out performance tests. The average penetration height and crack filling effect results are shown in Table 6.

[0106] Table 6

[0107]

[0108] As can be seen from the results in Table 6, only working condition 3 realizes the efficient targeted repair of underwater defects of the super-deep concrete cutoff wall.

[0109] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes to the technical solutions and improvement concepts of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. An underwater defect composite repair material for ultra-deep concrete cutoff wall, characterized by, The repair material 1 and the repair material 2 are included, wherein, The repair material 1 includes the following components by weight: water 250-300 parts, cement 600-650 parts, blast furnace slag powder 350-400 parts, magnesium oxide 80-100 parts, silicon powder 2-5 parts, water reducing agent 2-5 parts, alkali 80-100 parts, sodium silicate 180-200 parts, internal solid microcapsule material 5-20 parts, magnetic agent 3-12 parts, polymer dispersant 1-3 parts, interface agent 3-12 parts, temperature thixotropic agent 0.5-2 parts; The repair material 2 includes the following components by weight: water 250-300 parts, cement 600-650 parts, blast furnace slag powder 350-400 parts, magnesium oxide 80-100 parts, silicon powder 2-5 parts, alkali 80-100 parts, sodium silicate 180-200 parts, water reducing agent 2-5 parts, toughening material 10-30 parts, anti-permeation reinforcing agent 5-10 parts, temperature thixotropic agent 0.5-2 parts, defoaming agent 1-3 parts, anti-dispersion agent 2-5 parts.

2. The underwater defect composite repair material for ultra-deep concrete cutoff wall according to claim 1, characterized in that: The cement is a fast-setting early-strength cement, the alkali is sodium hydroxide or potassium hydroxide, the water reducing agent is a polycarboxylic acid-based high-efficiency water reducing agent, the blast furnace slag powder, the magnesium oxide, and the silicon powder all have a particle size greater than 100 mesh; the internal solid microcapsule material is a superabsorbent resin SAP; the magnetic agent is a magnetic nano-Fe3O4; the polymer dispersant is sodium polyacrylate; and the temperature thixotropic agent is a block polyether-modified polyurethane; and the interface agent is a water-based epoxy resin.

3. The underwater defect composite repair material for ultra-deep concrete cutoff wall according to claim 1, characterized in that: The defoaming agent is calcium phosphate, the toughening material is steel fiber with a fiber length less than 5 mm, the temperature thixotropic agent is a block polyether-modified polyurethane, the anti-permeation reinforcing agent is amino-modified silicon dioxide, and the anti-dispersion agent is hydroxypropyl methylcellulose ether.

4. A method for preparing the underwater defect composite repair material for ultra-deep concrete cutoff wall according to any one of claims 1 to 3, characterized in that, The method includes the following steps: (1) preparing the repair material 1: S11, according to the formula, the cement, the blast furnace slag powder, the magnesium oxide, and the silicon powder are stirred and mixed uniformly in a dry state to obtain mixed solid material 1; S12, according to the formula, the magnetic nano-Fe3O4 and the sodium polyacrylate in a dry state are stirred and mixed uniformly, and then water is added during the stirring process to make the sodium polyacrylate adsorbed on the magnetic nano-Fe3O4 particles; then the superabsorbent resin SAP is added and stirred, and water is added during the stirring process to make the mixture reach a viscous state, and at the same time, the magnetic nano-Fe3O4 is uniformly wrapped in the water-absorbent resin to obtain viscous internal magnetic nano-Fe3O4 functional microcapsules; S13, according to the formula, the water, the water reducing agent, the alkali, and the sodium silicate are mixed uniformly, and then the temperature thixotropic agent and the interface agent are added and mixed uniformly to obtain mixed liquid material 1; S14, the mixed liquid material 1 is added to the mixed solid material 1, stirred and mixed, and then the viscous internal magnetic nano-Fe3O4 functional microcapsules are added and stirred uniformly to obtain the repair material 1; (2) preparing the repair material 2: S21, according to the formula, the cement, the blast furnace slag powder, the magnesium oxide, the silicon powder, the steel fiber, and the amino-modified silicon dioxide are mixed uniformly in a dry state according to the proportion to obtain mixed solid material 2; S22, according to the formula, water, water reducing agent, alkali, sodium silicate are mixed uniformly, then temperature thixotropic agent, defoaming agent and anti-dispersant are added and mixed uniformly to obtain mixed liquid material; S23, the mixed liquid material 2 is added into the mixed solid material 2 and stirred uniformly to obtain the repair material 2.

5. The method of preparing an underwater defect composite repair material for ultra-deep concrete cutoff walls according to claim 4, characterized in that: In steps S13 and S23, the stirring time is 5-10 minutes.

6. A method for targeted repair of underwater defects in super deep concrete cutoff walls using the composite repair material according to any one of claims 1 to 3, characterized in that: Comprising the following steps: A1, drilling holes in the repair area, then replacing water with air by using air drive water replacement technology through the grouting pipe, and releasing inert gas foam perfluorohexanone to displace the accumulated water in the repair area through the grouting pipe before grouting, so as to create a less water bonding interface in the repair area; A2, during the injection of inert gas foam perfluorohexanone into the grouting pipe, the repair material 1 is immediately poured in, and when the grouting system pressure gauge and flow meter detect that the grouting pressure and flow change, the pouring of the repair material 1 is stopped; A3, stop pouring the repair material 1, power on the small coil inside the end of the grouting pipe, form a magnetic field at the end of the grouting pipe, enhance the magnetic response of the magnetic iron oxide in the concrete interface, through the magnetic navigation technology of magnetic field attraction, pour in the repair material 2, and use the magnetic response of the steel fiber to attract the directional flow of the repair material 2 to the repair area.

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