Grouting material and preparation method thereof

Abstract

The invention relates to a grouting material and a preparation method thereof, and belongs to the technical field of grouting materials. The grouting material is prepared from the following components in parts by mass: 100 parts of a cementing material, 1 to 5 parts of an anti-dispersion flocculant, 0.1 to 1 part of a thickening agent, 1.0 to 4.0 parts of a water reducing agent, 1 to 3 parts of an additive and 35 to 40 parts of water, the cementing material is obtained by mixing Portland cement and a mineral admixture according to the mass ratio of (7.5-9): (1-2.5). The grouting material can keep good stability in an underwater environment, does not generate excessive dispersion and loss phenomena, ensures that a predetermined area is accurately filled in the underwater environment, and can be quickly condensed and hardened to form a high-strength consolidated body, so that the requirements of different underwater engineering are met.

Description

Technical Field

[0001] This invention belongs to the field of grouting material technology, and particularly relates to a grouting material and its preparation method. Background Technology

[0002] Underwater engineering construction (bridge pile foundation reinforcement, wharf repair, tunnel support, etc.) commonly relies on grouting materials to fill voids, reinforce soil, or repair damaged structures to ensure the stability and safety of the project. However, during underwater grouting, traditional grouting materials are prone to dispersion and loss, resulting in ineffective filling of the intended area and difficulty in forming a uniform and sufficiently strong consolidated body. This not only affects the quality of the project, potentially leading to insufficient structural load-bearing capacity and leakage, but also increases construction costs and time.

[0003] Although some underwater non-dispersible grouting materials are available on the market, these materials still suffer from drawbacks such as unstable performance, high cost, and some environmental pollution. Therefore, developing an underwater non-dispersible, high-strength, low-shrinkage, and cost-controllable grouting material has become a key technical problem that urgently needs to be solved in the field of underwater engineering construction. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a grouting material and its preparation method. This grouting material maintains good stability in underwater environments, preventing excessive dispersion and loss, ensuring accurate filling of predetermined areas underwater, and rapidly solidifying to form a high-strength solidified body, meeting the needs of various underwater engineering projects. Furthermore, this grouting material is low in cost, highly efficient in production, has minimal environmental impact, and is environmentally friendly.

[0005] The first objective of this invention is to provide a grouting material, which, by weight, comprises 100 parts of cementitious material, 1-5 parts of anti-dispersion flocculant, 0.1-1 parts of thickener, 1.0-4.0 parts of water-reducing agent, 1-3 parts of admixture, and 35-40 parts of water;

[0006] The cementitious material is obtained by mixing silicate cement and mineral admixtures at a mass ratio of (7.5-9):(1-2.5). Silicate cement has a fast early hydration rate, which can quickly provide early strength and meet the structural stability requirements in the early stage of the project. The mineral admixture has high pozzolanic activity. Under the stimulation of calcium hydroxide, a cement hydration product, it undergoes a secondary hydration reaction to generate more gel substances, thereby improving the later strength of the grout and improving its microstructure, making the solidified body more compact. In addition, under this ratio, the mineral admixture can effectively reduce the early hydration heat of silicate cement and help the later strength growth of the grout. At the same time, it can improve the fluidity of the grout and provide good strength and workability for the grout at different stages.

[0007] In one embodiment of the present invention, the preparation of the anti-dispersion flocculant includes the following steps:

[0008] S1. Ethylene oxide is stirred evenly in a solvent to obtain the base material;

[0009] S2. The first initiator is stirred evenly in water to obtain an initiator solution;

[0010] S3, complexing agent, second initiator and oxidant are stirred evenly in water to obtain a mixed solution;

[0011] S4. Simultaneously add the initiator solution and the mixed solution to the substrate. After the addition is complete, continue the reaction and obtain the anti-dispersion flocculant by spray drying.

[0012] In one embodiment of the present invention, in S1, the solvent is selected from one or more of toluene, xylene, diethyl ether, and toluenecyclohexanone;

[0013] The mass ratio of ethylene oxide to solvent is 100:(300-400);

[0014] The stirring speed is 50rpm-70rpm, the time is 25min-35min, and the temperature is 40℃-60℃.

[0015] In one embodiment of the present invention, in S2, the first initiator is selected from one or more of potassium hydroxide, ammonium persulfate, lauroyl peroxide, and potassium persulfate;

[0016] The mass ratio of the first initiator to water is (13-19):100;

[0017] The stirring speed is 48 rpm-65 rpm, and the stirring time is 8 min-12 min.

[0018] In one embodiment of the present invention, in S3, the complexing agent is selected from one or more of sodium ethylenediaminetetraacetate, sodium tripolyphosphate, diethanolamine, triethanolamine and sodium pyrophosphate;

[0019] The second initiator is selected from one or more of ammonium persulfate, benzoyl peroxide, potassium persulfate, and diisopropyl peroxide.

[0020] The oxidant is selected from one or more of hydrogen peroxide, sodium hypochlorite, and sodium perborate;

[0021] The mass ratio of the complexing agent, the second initiator, the oxidant, and water is (10-12):(0.4-0.6):(1.8-2.2):(145-1555);

[0022] The stirring speed is 48 rpm-65 rpm, and the stirring time is 18 min-22 min.

[0023] In one embodiment of the present invention, in S4, the mass ratio of the substrate, initiator solution and mixed solution is (400-500):(110-120):(160-165);

[0024] The gas pressure during addition is 1.8 atm-2.2 atm, the rotation speed is 95 rpm-105 rpm, the dropping rate of the initiator solution is 0.8 drops / second-1.2 drops / second, and the dropping rate of the mixed solution is 0.4 drops / second-0.6 drops / second.

[0025] The continued reaction was carried out at a temperature of 58℃-62℃ for 1.5h-2.5h.

[0026] The spray drying temperature is 110℃-130℃.

[0027] In one embodiment of the present invention, the anti-dispersion flocculant is synthesized through a specific polymerization reaction and possesses a unique cross-linked network molecular structure. This structure can rapidly dissolve in water and form a three-dimensional network structure, effectively encapsulating the cementitious material and preventing it from being washed away by water flow in an underwater environment. This effectively prevents the dispersion of silicate cement and mineral admixtures underwater, maintaining the integrity of the grout and accurately filling the predetermined area. Simultaneously, by precisely controlling the dosage of the anti-dispersion flocculant, the anti-dispersion performance is ensured while avoiding negative impacts on other properties of the grout.

[0028] In one embodiment of the present invention, the silicate cement is selected from one or more of P.O42.5, P.O52.5, P.I42.5 and P.II52.5; the mineral admixture is selected from one or more of granulated blast furnace slag, coal gangue and slag powder;

[0029] The particle size of the silicate cement and the mineral admixture is independently 10μm-55μm; under this particle size condition, the specific surface area of ​​the cementitious material can be significantly increased, thereby greatly improving its activity; when mixed and reacted with other materials, a larger specific surface area means more reaction sites, thus making the reaction more complete and improving the performance of the grouting material.

[0030] In one embodiment of the present invention, the thickener is selected from one or more of hydroxypropyl methylcellulose, xanthan gum, succinate gum and guar gum; it increases the viscosity of the grout, further improves the anti-dispersion properties of the grout, and makes the grout less likely to be washed away by water flow underwater;

[0031] The water-reducing agent is selected from one or more of polycarboxylate water-reducing agents, melamine water-reducing agents, and aminosulfonate water-reducing agents; the water-reducing agent has a high water reduction rate, which reduces the amount of water used while ensuring the fluidity of the grout, thereby reducing the water-cement ratio and improving the strength of the grout.

[0032] The admixture is selected from reinforcing agents and / or retarder; the reinforcing agent is selected from one or more of lithium carbonate, sodium carbonate, and sodium nitrite, which can accelerate the early hydration reaction of cement, improve early strength, and meet the construction progress requirements of some underwater engineering projects with high requirements for early strength; the retarder is selected from one or more of sodium gluconate, sodium phosphate, sodium citrate, and sodium pyrophosphate, which can appropriately extend the setting time and avoid affecting construction operations due to excessively rapid setting; in short, the setting time and early strength of the grout can be adjusted by the admixture to meet different construction conditions and engineering requirements.

[0033] A second objective of this invention is to provide a method for preparing the aforementioned grouting material, comprising the following steps:

[0034] S1. Dry mix the cementitious material, water-reducing agent and additives evenly to obtain a mixed powder;

[0035] The anti-dispersing flocculant, thickener, and water are mixed evenly to obtain a mixture.

[0036] S2. Add the mixture to the powder mixture and stir evenly in stages to obtain the grouting material.

[0037] In one embodiment of the present invention, the dry mixing speed is 48 rpm-52 rpm and the time is 4 min-6 min; thorough dry mixing lays the foundation for subsequent staged mixing, so that the solid components are evenly distributed.

[0038] The wet mixing speed is 48 rpm-52 rpm, and the time is 8 min-12 min; thorough wet mixing can promote chemical reactions between various components and form a stable and uniform slurry structure.

[0039] The staged mixing involves first stirring at 48-52 rpm for 4-6 minutes, letting it stand for 1-3 minutes, and then continuing to stir at 110-130 rpm for 8-12 minutes. This ensures that the mixture and powder react fully to form a uniform slurry. If the mixing is uneven, the components will be unevenly distributed in the grout, resulting in local performance differences and seriously affecting product quality and stability.

[0040] The technical solution of the present invention has the following advantages compared with the prior art:

[0041] (1) The anti-dispersion flocculant in the grouting material of the present invention undergoes a polymerization reaction through bulk polymerization. During the initiator-catalyzed process, carboxyl groups are generated on the polymer chain, which can effectively increase the surface activity of cement particles, reduce the water requirement for cement particle hydration, and improve the fluidity of the grouting material. In addition, due to its long branched chain, it can form a "bridging" effect between cement particles, forming a stable floc structure, thereby improving the anti-dispersion ability of the grouting material.

[0042] (2) The grouting material described in this invention can resist water erosion underwater, maintain its integrity, and not easily disperse, ensuring that its effective components can accurately fill the predetermined area and play their role. At the same time, the grouting material can quickly and uniformly solidify and harden in the underwater environment, forming a solidified body with sufficient strength and durability, meeting the structural strength and stability requirements of underwater engineering. In addition, production costs are reduced through raw material and process optimization, ensuring that the preparation process and products are environmentally friendly and reducing pollution emissions. Attached Figure Description

[0043] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0044] Figure 1 The images show the water immersion conditions of the grouting material at different times in Test Example 1 of this invention; the left image shows the grouting material when it is freshly prepared, the middle image shows the grouting material after three months of storage, and the right image shows the grouting material after six months of storage. Detailed Implementation

[0045] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.

[0046] In this invention, unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0047] In this invention, unless otherwise stated, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0048] In this invention, unless otherwise specified, the experimental methods used in the embodiments of this invention are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0049] In this invention, unless otherwise stated, the preparation of the anti-dispersion flocculant used in the embodiments of this invention includes the following steps: 100g of ethylene oxide is dissolved in 350g of toluene and stirred at 60rpm for 30min at 50℃ to obtain a base material; 15.5g of potassium hydroxide initiator is added to 100g of distilled water and stirred at 50rpm for 10min to obtain an initiator solution; 10.8g of sodium ethylenediaminetetraacetate complexing agent, 0.5g of ammonium persulfate, and 2.0g of hydrogen peroxide oxidant are added sequentially to 150g of distilled water and stirred at 50rpm for 20min to obtain a mixed solution; under conditions of 2atm and 100rpm, the initiator solution (dropping rate of 1 drop / second) and the mixed solution (dropping rate of 0.5 drops / second) are simultaneously dripped into the base material; after the dripping is completed, the material is kept at 60℃ for 2h, and then spray-dried at 120℃ to obtain anti-dispersion flocculant powder.

[0050] Example 1

[0051] The grouting material in this embodiment, by weight, includes:

[0052]

[0053] Specifically, the following steps are included:

[0054] S1. Add silicate cement, mineral admixtures, reinforcing agents and water-reducing agents to a mixer and mix at 50 rpm for 5 minutes to obtain a uniform mixed powder.

[0055] Add the anti-dispersing flocculant, thickener and water to the mixer and stir at 50 rpm for 10 minutes to obtain a uniform mixture.

[0056] S2. Add the mixture evenly to the powder mixture, stir at 50 rpm for 5 minutes, let stand for 2 minutes, and then stir at 120 rpm for 10 minutes to obtain a uniform grouting material.

[0057] Comparative Example 1

[0058] The basic structure is the same as in Example 1, except for the composition of the grout, which is as follows:

[0059]

[0060] Comparative Example 2

[0061] The basic structure is the same as in Example 1, except for the composition of the grout, which is as follows:

[0062]

[0063] Test Example 1

[0064] Based on Example 1, water immersion tests were conducted on the grouting material at different times (freshly prepared, after three months of storage, and after six months of storage), and the results are as follows. Figure 1 As shown. From Figure 1 It can be seen that the grouting material at different times did not easily disperse during the pouring into water, and the boundary between the grouting material and the water layer was clear, indicating that the grouting material in the embodiment has good anti-dispersion and stability. This is because the main chain of the anti-dispersion flocculant is composed of C-C and CO bonds during the bulk polymerization process. The bond energy is high and it is not easy to break, giving it excellent structural stability.

[0065] Test Example 2

[0066] Based on Example 1 and Comparative Examples 1-2, the grouting material was tested for final setting time, spread, suspended solids content, strength, etc.

[0067] Final setting time (min): Determined according to the standard "Test Methods for Standard Consistency Water Requirement, Setting Time and Soundness of Cement" (GB / T1346-2011);

[0068] Flowability (mm): Determined according to the standard "Method for Determination of Flowability of Cement Mortar" (GB / T 2419-2005);

[0069] Suspended solids content (%): determined according to the standard "Technical Requirements for Underwater Non-Dispersible Concrete Flocculants" (GB / T37990-2019);

[0070] Strength (MPa): Determined according to the standard "Test Method for Strength of Cement Mortar (ISO)" (GB / T 17671-1999);

[0071] Table 1 shows the relevant test results:

[0072] Table 1

[0073]

[0074] As shown in Table 1, the grouting material of this embodiment has a short final setting time, eliminating the retarding effect of existing materials on cement grout. It is suitable for rapid underwater grouting and shortens the construction cycle. Furthermore, it is significantly superior to existing materials in terms of suspended solids control and strength improvement. This is because the anti-dispersion flocculant with a specific structure used in the grouting material can quickly form a three-dimensional network structure after dissolving in water. This structure can connect cement and mineral admixture particles through a "bridging" mechanism. When the grouting material is in an underwater environment, the bridging structure can resist water erosion, prevent the grouting material from dispersing, and maintain the integrity of the grouting material, thereby effectively solving the problem of underwater dispersion and loss.

[0075] Comparing Example 1 and Comparative Example 1, it can be seen that when ZND-2 (mainly composed of vinyl chloride-vinyl acetate copolymer) is used as an anti-dispersibility flocculant, the final setting time of the grout is longer, the spread is significantly reduced, and the suspended solids content is significantly increased. This is because ZND-2 cannot effectively reduce the tricalcium aluminate content in cement, resulting in a longer setting time for the grout. Furthermore, because ZND-2 cannot reduce the hydrophilicity of cement particle surfaces, the suspended solids content is high, and it cannot achieve good anti-dispersibility.

[0076] Comparing Example 1 and Comparative Example 2, it can be seen that when NR-6 (mainly composed of sodium polyacrylate) is used as an anti-dispersion flocculant, the final setting time of the grout is further prolonged, which is not conducive to rapid underwater construction; the fluidity decreases, making it difficult to complete the sealing and filling of leaks; and the early and late strength development is not ideal. NR-6 will complex with calcium ions in the grout to form a stable chelate, thereby affecting the hydration of calcium ions, resulting in a longer setting time and poorer fluidity and strength of the grout.

[0077] Test Example 3

[0078] Based on Example 1, the influence of the particle size of mineral admixtures on the performance of grouting materials was investigated. Table 2 shows the relevant variables and test results:

[0079] Table 2

[0080]

[0081] As shown in Table 2, with the decrease in the particle size of the mineral admixture, the fluidity of the grout gradually decreases, the suspended solids content decreases, and the 7-day and 28-day strengths show an upward trend. This indicates that the smaller the particle size of the mineral admixture, the greater its mineral activity, which has a certain effect on strength increase.

[0082] Test Example 4

[0083] Based on Example 1, the effect of the amount of mineral admixture (with the total amount of silicate cement and mineral admixture being 100 parts) on the performance of the grouting material was investigated. Table 3 shows the relevant variables and test results:

[0084] Table 3

[0085]

[0086] As shown in Table 3, with the increase of mineral admixture dosage, the fluidity of the grout increases, and the suspended solids content gradually increases, indicating a decrease in its non-dispersibility. In terms of strength, both early and later strength decrease with the addition of mineral admixture.

[0087] Test Example 5

[0088] Based on Example 1, the effect of the dosage of anti-dispersing flocculant (as a percentage of the total dosage of silicate cement and mineral admixtures) on the performance of the grouting material was investigated. Table 4 shows the relevant variables and test results:

[0089] Table 4

[0090]

[0091]

[0092] As can be seen from Table 4, with the increase of the amount of anti-dispersing flocculant, the final setting time, fluidity and suspended solids content of the grout gradually decrease. In terms of early and late strength, with the increase of the amount of anti-dispersing agent, it also shows a gradual downward trend.

[0093] In summary, the larger the particle size and the higher the dosage of the mineral admixture, the greater the fluidity of the underwater non-dispersible grout, but the strength decreases accordingly, and the suspended solids content gradually increases. With the increase of the dosage of anti-dispersible flocculant, the setting time and suspended solids content of the underwater anti-dispersible grout gradually decrease, and the spread decreases. The strength increases with the increase of the dosage of anti-dispersible flocculant.

[0094] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A grouting material, characterized in that, The grouting material, by weight, comprises 100 parts of cementitious material, 1-5 parts of anti-dispersion flocculant, 0.1-1 parts of thickener, 1.0-4.0 parts of water-reducing agent, 1-3 parts of admixture, and 35-40 parts of water; The cementitious material is obtained by mixing silicate cement and mineral admixtures in a mass ratio of (7.5-9):(1-2.5).

2. The grouting material according to claim 1, characterized in that, The preparation of the anti-dispersing flocculant includes the following steps: S1. Ethylene oxide is stirred evenly in a solvent to obtain the base material; S2. The first initiator is stirred evenly in water to obtain an initiator solution; S3, complexing agent, second initiator and oxidant are stirred evenly in water to obtain a mixed solution; S4. Simultaneously add the initiator solution and the mixed solution to the substrate. After the addition is complete, continue the reaction and obtain the anti-dispersion flocculant by spray drying.

3. The grouting material according to claim 2, characterized in that, In S1, the solvent is selected from one or more of toluene, xylene, diethyl ether, and toluenecyclohexanone; The mass ratio of ethylene oxide to solvent is 100:(300-400); The stirring speed is 50rpm-70rpm, the time is 25min-35min, and the temperature is 40℃-60℃.

4. The grouting material according to claim 2, characterized in that, In S2, the first initiator is selected from one or more of potassium hydroxide, ammonium persulfate, lauroyl peroxide, and potassium persulfate; The mass ratio of the first initiator to water is (13-19):100; The stirring speed is 48 rpm-65 rpm, and the stirring time is 8 min-12 min.

5. The grouting material according to claim 2, characterized in that, In S3, the complexing agent is selected from one or more of sodium ethylenediaminetetraacetate, sodium tripolyphosphate, diethanolamine, triethanolamine, and sodium pyrophosphate; The second initiator is selected from one or more of ammonium persulfate, benzoyl peroxide, potassium persulfate, and diisopropyl peroxide. The oxidant is selected from one or more of hydrogen peroxide, sodium hypochlorite, and sodium perborate; The mass ratio of the complexing agent, the second initiator, the oxidant, and water is (10-12):(0.4-0.6):(1.8-2.2):(145-1555); The stirring speed is 48 rpm-65 rpm, and the stirring time is 18 min-22 min.

6. The grouting material according to claim 2, characterized in that, In S4, the mass ratio of the substrate, initiator solution, and mixed solution is (400-500):(110-120):(160-165); The gas pressure during addition is 1.8 atm-2.2 atm, the rotation speed is 95 rpm-105 rpm, the dropping rate of the initiator solution is 0.8 drops / second-1.2 drops / second, and the dropping rate of the mixed solution is 0.4 drops / second-0.6 drops / second. The continued reaction was carried out at a temperature of 58℃-62℃ for 1.5h-2.5h. The spray drying temperature is 110℃-130℃.

7. The grouting material according to claim 1, characterized in that, The silicate cement is selected from one or more of P.O42.5, P.O52.5, P.I42.5 and P.II52.5; the mineral admixture is selected from one or more of granulated blast furnace slag, coal gangue and slag powder. The particle size of the silicate cement and the mineral admixture is independently 10μm-55μm.

8. The grouting material according to claim 1, characterized in that, The thickener is selected from one or more of hydroxypropyl methylcellulose, xanthan gum, shunshui gum, and guar gum; The water-reducing agent is selected from one or more of polycarboxylate water-reducing agents, melamine water-reducing agents, and aminosulfonate water-reducing agents; The admixture is selected from reinforcing agents and / or retarder; the reinforcing agent is selected from one or more of lithium carbonate, sodium carbonate and sodium nitrite; the retarder is selected from one or more of sodium gluconate, sodium phosphate, sodium citrate and sodium pyrophosphate.

9. The method for preparing the grouting material according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Dry mix the cementitious material, water-reducing agent and additives evenly to obtain a mixed powder; The anti-dispersing flocculant, thickener, and water are mixed evenly to obtain a mixture. S2. Add the mixture to the powder mixture and stir evenly in stages to obtain the grouting material.

10. The method for preparing grouting material according to claim 9, characterized in that, The dry mixing speed is 48 rpm-52 rpm, and the time is 4 min-6 min; The wet mixing speed is 48 rpm-52 rpm, and the time is 8 min-12 min; The staged stirring involves first stirring at a speed of 48 rpm to 52 rpm for 4 to 6 minutes, letting it stand for 1 to 3 minutes, and then continuing to stir at a speed of 110 rpm to 130 rpm for 8 to 12 minutes.

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