Underwater fast anti-seepage and long-acting reinforcing plugging material and preparation method thereof

Abstract

The application discloses a water under quick anti-seepage long-acting reinforcing plugging material, and further discloses a preparation method of the plugging material, which comprises the following steps: step 1, preparing a polyelectrolyte binder powder by using a polycation electrolyte and a polyanion electrolyte; step 2, preparing sand and gravel with a particle size of 0.2-2 mm; step 3, preparing silicate cement with a particle size of 0.002-0.05 mm; and step 4, preparing the plugging material by using the polyelectrolyte binder powder, the sand and gravel and the silicate cement prepared in the above steps. The plugging material can realize quick plugging and long-acting reinforcement of a seepage position of a water under earth and rock dam.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of anti-seepage reinforcing plugging materials, and particularly relates to a plugging material for underwater rapid anti-seepage and long-acting reinforcement. BACKGROUND

[0002] Earth-rock dams have natural advantages of local material, simple structure, simple construction and easy maintenance, and are widely used in dam construction in the world. There are a large number of earth-rock dams in China, most of which were built in the 1950s-1970s, and therefore have problems of low construction standard, poor construction quality, aging function, and the like, and have safety hazards. In addition, under the influence of global climate change, a small number of reservoirs have been in danger, which not only brings loss of life and property, but also brings challenges to the safe operation and management of earth-rock dams. Targeted plugging of seepage channels is the key to treating seepage hazards of earth-rock dams, and therefore, how to simultaneously achieve efficient and rapid plugging and long-acting reinforcement of seepage parts of earth-rock dams underwater has become a problem to be solved.

[0003] At present, plugging materials can be divided into two categories: granular plugging materials and chemical plugging materials. The former is mainly cement material, and the latter is most represented by polyurethane material, which is generally configured into slurry that can be poured into seepage channels. Among them, the cement plugging material has advantages of high strength of the formed stone body, good durability, rich material sources, simple process equipment, low cost, and the like, but the formed stone body is easy to weather and disintegrate under dry conditions; under long-term water conditions, due to the water solubility of silicates, the formed stone body is easy to dissolve out, has poor stability, and has the risk of plugging failure. The polyurethane grouting material has advantages of low viscosity, good pourability, adjustable gel time within several seconds to several hours, good anti-seepage property, and no environmental pollution, and is widely used in reinforcement, anti-seepage and plugging engineering of dams and reservoirs. However, the strength of the polyurethane grouting material is low, generally with a compressive strength of 6-30 MPa, and the strength after water absorption is greatly reduced compared with that in the dry state, which is not conducive to the formation of a high-strength combination with wet earth and stone, and cannot form a satisfactory reinforced layer. In addition, the bonding strength of the water-soluble polyurethane gel body to the earth and stone is generally lower than the tensile strength of the gel body itself, so that under the condition of dry-wet cycle, the bonding interface between the gel body and the earth and stone is damaged due to the shrinkage of the gel body, and water seepage phenomenon occurs.

[0004] Therefore, based on the uneven surface of the earth-rock dam and the special underwater environment, it is a difficult problem in the field to develop a new plugging material for underwater rapid anti-seepage and long-acting reinforcement of earth-rock dams, so as to achieve long-acting reinforcement of the earth-rock dam underwater.

[0005] The Chinese patent "Preparation method of reinforcing and plugging material for underground coal mine" (application number: CN202310980931.1, publication date: 2023.12.01, publication number: CN117143448A) discloses a preparation method of reinforcing and plugging material for underground coal mine. The method adds additives and sulfosalicylic acid to the reinforcing and plugging material to obtain a reinforcing and plugging material with good mechanical properties, antistatic properties, and flame retardant properties, which can be effectively applied to underground coal mines with good reinforcing and plugging effect. However, the plugging material prepared by this method has uncontrollable setting time in a water-rich environment, which is difficult to operate, leading to the risk of repair failure.

[0006] The Chinese patent "Self-plugging concrete and preparation method thereof" (application number: CN202310429493.X, publication date: 2023.09.01, publication number: CN116675483A) discloses a self-plugging concrete and a preparation method thereof. The method does not add water to maximize the absorption and expansion of superabsorbent polymer (SAP) during the preparation process, so that the internal material can fully maintain its reactivity, thereby ensuring that the SAP can maximize its effectiveness when the surface material cracks. However, this method only uses the water absorption and expansion of the particles to consolidate and plug the cracks, which is prone to dehydration under dry conditions, resulting in new cracks and collapse of the matrix. SUMMARY

[0007] The purpose of the present application is to provide a plugging material for underwater rapid anti-seepage and long-term reinforcement, which can achieve rapid plugging and long-term reinforcement of the seepage part of an underwater earth-rock dam.

[0008] Another purpose of the present application is to provide a preparation method of the above-mentioned plugging material.

[0009] The technical solution adopted by the present application is a preparation method of a plugging material for underwater rapid anti-seepage and long-term reinforcement, which is implemented according to the following steps:

[0010] Step 1: Prepare a polyelectrolyte adhesive powder using a polycation electrolyte and a polyanion electrolyte;

[0011] Step 2: Prepare sand with a particle size of 0.2-2mm;

[0012] Step 3: Prepare silicate cement with a particle size of 0.002-0.05mm;

[0013] Step 4: Prepare the plugging material using the polyelectrolyte adhesive powder, sand, and silicate cement prepared in the above steps.

[0014] The present application also has the following characteristics:

[0015] The polycationic electrolyte is one of polyethyleneimine, polyamide-epichlorohydrin or polyvinylpyridine; and the polyanionic electrolyte is polyacrylic acid or phosphotungstic acid.

[0016] The step 1 is specifically:

[0017] The polycationic electrolyte solution with a mass fraction of 5-30wt% is added into the polyanionic electrolyte solution with a mass fraction of 5-30wt%, the pH of the mixed solution is adjusted to 5-9, and then the mixed solution is immersed into liquid nitrogen for 10-60min after being fully mixed by magnetic stirring, and the excess water is removed by freeze-drying, and the particle size distribution is controlled to be 0.0002-0.075mm after grinding and passing through a 200-2000 mesh screen, so that the polyelectrolyte binder powder is obtained.

[0018] The volume ratio of the polycationic electrolyte solution to the polyanionic electrolyte solution is 1-9:9-1.

[0019] The sand in the step 2 is obtained by passing industrial sand through an 8-80 mesh screen.

[0020] In the step 3, the industrial grade silicate cement is classified by using a 250-8000 mesh screen to obtain the silicate cement.

[0021] In the step 3, the silicate cement is composed of tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite and gypsum according to a mass ratio of 50-70:15-30:5-10:5-10:3-5.

[0022] The step 4 is specifically:

[0023] The polyelectrolyte binder powder, the sand and the silicate cement with a mass ratio of 1:1-4:2-4 are uniformly mixed by using a ball milling method, so that the plugging material is obtained.

[0024] Another technical solution of the present application is the underwater rapid anti-seepage and long-acting reinforced plugging material which is prepared by the above preparation method.

[0025] The present application has the following advantages:

[0026] The method of the present application realizes rapid and efficient plugging of the leakage site by underwater chemical adhesion and cement mechanical plugging of sand castle worm, realizes long-term reinforcement of the earth and rockfill dam by regulating the size distribution of raw materials, using the mortise and tenon structure between the plugging raw materials and the damaged site, the capillary action between the raw materials and water, and the chemical bonding action between the adhesive and the earth and rock blocks. First, select the silicate cement with fast hydration speed, gypsum, sand with controllable particle size, and the polyelectrolyte adhesive powder which is sticky when it comes into contact with water and has controllable particle size as raw materials, regulate the best setting time by regulating the ratio of silicate cement and gypsum, and regulate the mechanical properties by regulating the ratio of adhesive and cement matrix to meet the best operation time and initial strength requirements of actual underwater repair; second, regulate the particle size distribution of silicate cement, gypsum, sand and adhesive powder to meet the mortise and tenon structure that is compatible with the earth and rock block matrix to improve the mechanical properties between the plugging material and the damaged matrix; combined with the capillary action of sand, the stability and strength of the soil body in underwater environment can be effectively improved through the mechanisms of moisture adjustment, particle communication, cementation effect and drainage effect, the water erosion resistance of the soil body is enhanced, and the safety and stability of the underwater engineering and soil structure are protected; at the same time, the crosslinking between the polyelectrolyte adhesive and the earth and rock body forms adsorption force such as hydrogen bond and van der Waals force on the surface of the damaged body, thereby realizing long-term reinforcement of the earth and rockfill dam, and the material production cost is low, there is no special requirement for production equipment, and it has good application prospect in the field of anti-seepage reinforcement and plugging materials. DETAILED DESCRIPTION

[0027] The present application will be described in detail below in combination with specific embodiments.

[0028] The preparation method of the underwater rapid anti-seepage and long-term reinforcement plugging material of the present application is specifically implemented according to the following steps:

[0029] Step 1, preparing the polyelectrolyte adhesive powder which is sticky when it comes into contact with water;

[0030] The specific steps are as follows: add the polycation electrolyte solution with a mass fraction of 5-30wt% to the polyanion electrolyte solution with a mass fraction of 5-30wt%, wherein the volume ratio of the polycation electrolyte solution to the polyanion electrolyte solution is 1-9:9-1, adjust the pH of the mixed solution to 5-9, and then mix them thoroughly under the aid of magnetic stirring, immediately immerse the mixed solution in liquid nitrogen for 10-60min, remove the excess water by freeze-drying, finally, grind it with a mortar and sieve it through a 200-2000 mesh sieve to control the particle size distribution at 0.0002-0.075mm, and the polyelectrolyte adhesive powder which is sticky when it comes into contact with water can be obtained.

[0031] The polycationic electrolyte is any one of polyethyleneimine (PEI), polyamide-epichlorohydrin (PAE-Cl) or polyvinylpyridine (PVP); and the polyanionic electrolyte is any one of polyacrylic acid (PAA), phosphotungstic acid (PW 12 ) or the like.

[0032] Step 2: Preparation of sand with controllable capillary action particle size

[0033] Specific steps are as follows: passing industrial sand through an 8-80 mesh sieve to control the particle size distribution at 0.2-2 mm, so as to obtain sand with controllable capillary action particle size.

[0034] Step 3: Preparation of silicate cement with controllable particle size

[0035] Specific steps are as follows: grading industrial silicate cement using a 250-8000 mesh sieve to control the particle size distribution at 0.002-0.05 mm, so as to obtain silicate cement with controllable particle size.

[0036] The silicate cement is composed of tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), tetracalcium aluminoferrite (C4AF) and gypsum (CaSO4) in a mass ratio of 50-70:15-30:5-10:5-10:3-5.

[0037] Step 4: Preparation of a new plugging material for underwater rapid anti-permeation and long-term reinforcement

[0038] Specific steps are as follows: mixing the water-sticking polyelectrolyte binder powder of step 1, the sand with controllable capillary action particle size of step 2 and the silicate cement with controllable particle size of step 3 in a mass ratio of 1:1-4:2-4 using a ball milling method, so as to obtain a new plugging material for underwater rapid anti-permeation and long-term reinforcement.

[0039] The method can realize long-term underwater reinforcement of the earth and rockfill dam, improve stability and durability, and achieve rapid and efficient plugging and long-term reinforcement of the earth and rockfill dam underwater through regulation of material composition, structure and action mechanism, and synergistic effect of the three.

[0040] Example 1

[0041] Step 1, preparation of the polyelectrolyte adhesive powder that sticks to water;

[0042] A 15wt% polyamide-epichlorohydrin (PAE-Cl) solution is added to a 10wt% phosphotungstic acid (PW 12 ) solution, and the volume ratio is adjusted to 1:9 and the pH is adjusted to 7. The mixture is fully mixed with magnetic stirring, then immediately immersed in liquid nitrogen for 30 min, and freeze-dried to remove excess water. Finally, the mixture is ground with a mortar and sieved through a 500 mesh screen to control the particle size distribution at about 0.025 mm, and the polyelectrolyte adhesive powder that sticks to water is obtained;

[0043] Step 2, preparation of sand with controllable capillary action particle size;

[0044] The industrial sand is sieved through a 50 mesh screen to control the particle size distribution at about 0.27 mm, and the sand with controllable capillary action particle size is obtained;

[0045] Step 3, preparation of silicate cement with controllable particle size;

[0046] The tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), tetracalcium aluminoferrite (C4AF) and gypsum (CaSO4) in the industrial silicate cement are classified by a 5000 mesh screen to control the particle size distribution at about 0.0026 mm, and the silicate cement with controllable particle size is obtained by mixing the components in a mass ratio of 60:25:7:5:3;

[0047] Step 4, preparation of a new plugging material with underwater rapid anti-seepage and long-term reinforcement.

[0048] The water-sticky polyelectrolyte binder powder of step 1, the sand with controllable capillary action particle size of step 2, and the silicate cement with controllable particle size of step 3 are mixed uniformly in a mass ratio of 25:25:50 by ball milling, and a new plugging material with underwater rapid anti-seepage and long-term reinforcement is obtained.

[0049] Example 2

[0050] Step 1, preparation of water-sticky polyelectrolyte binder powder;

[0051] A 5wt% polyamide-epichlorohydrin (PAE-Cl) solution is added to a 30wt% phosphotungstic acid (PW 12 ) solution, and the volume ratio is adjusted to 9:1 and the pH is adjusted to 5. With the aid of magnetic stirring, the mixture is fully mixed, then immediately immersed in liquid nitrogen for about 10 min, and freeze-dried to remove excess water. Finally, the mixture is ground with a mortar and sieved through a 1000 mesh sieve to control the particle size distribution at about 0.002 mm, and a water-sticky polyelectrolyte binder powder is obtained;

[0052] Step 2, preparation of sand with controllable capillary action particle size;

[0053] The industrial sand is sieved through an 80 mesh sieve to control the particle size distribution at about 0.2 mm, and sand with controllable capillary action particle size is obtained;

[0054] Step 3, preparation of silicate cement with controllable particle size;

[0055] The tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), tetracalcium aluminoferrite (C4AF) and gypsum (CaSO4) in industrial grade silicate cement are classified by a 1340 mesh sieve to control the particle size distribution at about 0.01 mm, and the silicate cement with controllable particle size is obtained by mixing the gypsum in a mass ratio of 65:20:5:5:5;

[0056] Step 4, preparation of a new plugging material with underwater rapid anti-seepage and long-term reinforcement.

[0057] The water-sticky polyelectrolyte binder powder of step 1, the sand with controllable capillary action particle size of step 2, and the silicate cement with controllable particle size of step 3 are mixed uniformly in a mass ratio of 25:25:50 by ball milling, and a new plugging material with underwater rapid anti-seepage and long-term reinforcement is obtained.

[0058] Example 3

[0059] Step 1, preparation of water-sticky polyelectrolyte binder powder;

[0060] A 15wt% polyethyleneimine (PEI) solution was added to a 15wt% phosphotungstic acid (PW 12 ) solution, and the volume ratio was adjusted to 6:4 and the pH to 7. The mixture was fully mixed with magnetic stirring, immediately immersed in liquid nitrogen for about 60 min, and freeze-dried to remove excess water. Finally, the mixture was ground with a mortar and passed through a 1000 mesh sieve to control the particle size distribution at about 0.013 mm, and a water-sticky polyelectrolyte binder powder was obtained.

[0061] Step 2, preparation of sand with controllable capillary action particle size;

[0062] The industrial sand was sieved through a 60 mesh sieve to control the particle size distribution at about 0.25 mm, and sand with controllable capillary action particle size was obtained.

[0063] Step 3, preparation of silicate cement with controllable particle size;

[0064] The industrial silicate cement was classified by a 5000 mesh sieve to control the particle size distribution at about 0.0026 mm, and silicate cement with controllable particle size was obtained by mixing the silicate cement with gypsum in a mass ratio of 60:21:10:5:4.

[0065] Step 4, preparation of a new type of sealing material for underwater rapid anti-permeation and long-term reinforcement.

[0066] The water-sticky polyelectrolyte binder powder of step 1, the sand with controllable capillary action particle size of step 2, and the silicate cement with controllable particle size of step 3 were mixed uniformly by ball milling in a mass ratio of 20:20:60, and a new type of sealing material for underwater rapid anti-permeation and long-term reinforcement was obtained.

[0067] Example 4

[0068] Step 1, preparation of a water-sticky polyelectrolyte binder powder;

[0069] A 15wt% polyethyleneimine (PEI) solution was added to a 15wt% polyacrylic acid (PAA) solution, and the volume ratio was adjusted to 5:5 and the pH to 8. The mixture was fully mixed with magnetic stirring, immediately immersed in liquid nitrogen for about 30 min, and freeze-dried to remove excess water. Finally, the mixture was ground with a mortar and passed through a 1000 mesh sieve to control the particle size distribution at about 0.002 mm, and a water-sticky polyelectrolyte binder powder was obtained.

[0070] Step 2, preparation of sand with controllable capillary action particle size;

[0071] The industrial sand is passed through an 80-mesh sieve to control the particle size distribution at about 0.2 mm, thereby obtaining the sand with controllable capillary action particle size;

[0072] Step 3, preparation of Portland cement with controllable particle size;

[0073] The tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), tetracalcium aluminoferrite (C4AF) and gypsum (CaSO4) in the industrial Portland cement are classified by a 5000-mesh sieve to control the particle size distribution at about 0.0026 mm, and then mixed with gypsum according to a mass ratio of 65:11:10:10:4, thereby obtaining the Portland cement with controllable particle size;

[0074] Step 4, preparation of a new sealing material for underwater rapid anti-seepage and long-term reinforcement.

[0075] The water-sticking polyelectrolyte binder powder of Step 1, the sand with controllable capillary action particle size of Step 2 and the Portland cement with controllable particle size of Step 3 are mixed uniformly by a ball milling method according to a mass ratio of 15:55:30, thereby obtaining the new sealing material for underwater rapid anti-seepage and long-term reinforcement.

[0076] Table 1 is a comparison table of performance test results of the sealing materials prepared in Examples 1-4 of the present application and the traditional Portland cement sealing material. The tested performances include the underwater setting time of the two materials after being combined with earth-rock blocks and the mechanical properties after being soaked in water for one month.

[0077] Table 1 comparison table of performance test results

[0078]

[0079] As shown in the data listed in Table 1, compared with the traditional Portland cement sealing material, the new sealing material for underwater rapid anti-seepage and long-term reinforcement of earth-rock dams prepared by the present application realizes rapid and efficient sealing of the underwater seepage position within 2 min due to the synergistic effect of underwater chemical adhesion of the sandcastle worm and mechanical sealing of the cement with controllable setting time. The mortise and tenon structure between the sealing material and the earth-rock blocks, the capillary action between the sand and water and the chemical bond between the adhesive and the earth-rock blocks make the mechanical properties of the material and earth-rock block compound still as high as about 150 MPa after being soaked in water for one month, thereby improving the underwater stability of the sealing material and realizing long-term reinforcement of the earth-rock dam.

Claims

1. A method for preparing underwater rapid seepage prevention and long-term reinforcement sealing materials, characterized in that, The specific steps are as follows: Step 1: Prepare polyelectrolyte binder powder using polycationic electrolyte and polyanionic electrolyte; Step 2: Prepare sand and gravel with a particle size of 0.2–2 mm; Step 3: Prepare silicate cement with a particle size of 0.002–0.05 mm; Step 4: Prepare sealing material using the polyelectrolyte adhesive powder, gravel, and silicate cement obtained in the above steps; Step 1 is as follows: Add a 5-30 wt% polycationic electrolyte solution to a 5-30 wt% polyanionic electrolyte solution, adjust the pH of the mixed solution to 5-9, stir magnetically to ensure thorough mixing, immediately immerse the mixed solution in liquid nitrogen for 10-60 minutes, freeze dry to remove excess water, grind and pass through a 200-2000 mesh sieve, control the particle size distribution to 0.0002-0.075 mm, and the polyelectrolyte binder powder is obtained. In step 1, the polycationic electrolyte is one of polyethyleneimine, polyamide-epoxychloropropane, or polyvinylpyridine; the polyanionic electrolyte is polyacrylic acid or phosphotungstic acid. The volume ratio of the polycationic electrolyte solution to the polyanionic electrolyte solution is 1-9:9-1.

2. The method for preparing the underwater rapid seepage prevention and long-term reinforcement sealing material according to claim 1, characterized in that, The gravel in step 2 is obtained by passing industrial-grade gravel through an 8-80 mesh sieve.

3. The method for preparing the underwater rapid seepage prevention and long-term reinforcement sealing material according to claim 1, characterized in that, In step 3, industrial-grade silicate cement is graded by sieving through a 250-8000 mesh sieve to obtain silicate cement.

4. The method for preparing the underwater rapid seepage prevention and long-term reinforcement sealing material according to claim 1, characterized in that, In step 3, the silicate cement is composed of tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite, and gypsum in a mass ratio of 50-70:15-30:5-10:5-10:3-5.

5. The method for preparing the underwater rapid seepage prevention and long-term reinforcement sealing material according to claim 1, characterized in that, Step 4 is as follows: The sealing material is obtained by uniformly mixing polyelectrolyte binder powder, gravel, and silicate cement in a mass ratio of 1:1~4:2~4 using a ball milling method.

6. An underwater rapid seepage prevention and long-term reinforcement sealing material, characterized in that, It is prepared by any of the preparation methods described in claims 1-5.

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