A hydrogel-cement-based composite grouting material suitable for use in dynamic underwater environments

Abstract

This invention belongs to the field of grouting material technology, specifically relating to a hydrogel-cement-based composite grouting material that can be used underwater in dynamic water conditions. It comprises the following raw materials in parts by weight: 99.5-99.98 parts cement, 0.02-0.5 parts reinforcing hydrogel, and 80-100 parts water. The reinforcing hydrogel is prepared by the following steps: (1) mixing polyvinyl alcohol solution and sodium alginate solution evenly and stirring under an ice-water bath; (2) adding cement hydration product phase – ettringite fiber dispersion and stirring evenly; (3) adding calcium chloride solution and performing a crosslinking reaction; (4) crushing and drying the crosslinking product to obtain solid particles; (5) immersing the solid particles in a mixed solution of glutaraldehyde and hydrochloric acid. After immersion, the reinforcing hydrogel is obtained. This composite grouting material significantly improves the underwater anti-dispersion ability of the grouting material, especially for underwater grouting repair projects at high flow rates.

Description

Technical Field

[0001] This invention belongs to the field of grouting materials technology, specifically relating to a hydrogel-cement-based composite grouting material that can be used in dynamic underwater environments. Background Technology

[0002] As engineering structures increasingly operate in complex underwater and offshore environments, the presence of water as a transport medium carries complex ions and other harmful substances that penetrate concrete materials, accelerating the deterioration of concrete structural performance. This necessitates the development of corresponding underwater repair materials and methods. Underwater repair places higher demands on traditional repair materials, leading to the emergence of underwater anti-dispersion grouting materials, which have wide applications in water conservancy projects, offshore oil platforms, and cross-river and cross-sea bridges. Underwater anti-dispersion grouting materials can be used for caisson sealing, cofferdams, caissons, riprap grouting, underwater continuous wall casting, underwater foundation leveling and filling, as well as large-diameter cast-in-place piles, wharves, dams, and reservoir repairs. Furthermore, it can be used for underwater foundations, seawall revetments, slope protection, pile sealing, and underwater engineering projects where ordinary concrete is difficult to apply.

[0003] Existing underwater anti-dispersion grouting materials mainly improve their anti-dispersion properties, hardening rate, and early strength by adding admixtures. For example, polycarboxylate superplasticizers can control the fluidity of the grout; sodium gluconate acts as a retarder to regulate setting time; early strength agents adjust the strength of the grout aggregate; hydroxyethyl methyl cellulose ether acts as an anti-dispersion agent to improve the anti-dispersion performance of the grout; and silica fume acts as a mineral additive to improve the physical and mechanical properties of the grout. However, these types of underwater anti-dispersion grouting materials are mostly used in underwater construction with low water flow velocities, and the hydroxyethyl methyl cellulose ether-based anti-dispersion agents can adversely affect the hardening of the grout, thus affecting its application in dynamic water environments.

[0004] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a hydrogel-cement-based composite grouting material that can be used in moving water, so as to facilitate the construction of the grouting material in moving water and reduce the dispersion of the grouting material in moving water.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a hydrogel-cement-based composite grouting material that can be used underwater, the underwater anti-dispersion grouting material comprising the following raw materials in parts by weight: 99.5-99.98 parts cement, 0.02-0.5 parts reinforced hydrogel and 80-100 parts water; the reinforced hydrogel is prepared by a method comprising the following steps: (1) mixing polyvinyl alcohol solution and sodium alginate solution evenly and stirring under an ice-water bath; (2) adding calcite fiber dispersion to the mixture obtained in step (1) and stirring evenly; (3) adding calcium chloride solution to the mixed solution obtained in step (2) and performing a crosslinking reaction; (4) crushing and drying the crosslinking product obtained after the crosslinking reaction to obtain solid particles; (5) immersing the solid particles in a mixed solution of glutaraldehyde and hydrochloric acid, and after immersion, obtaining the reinforced hydrogel.

[0007] Preferably, in step (1), the concentration of the polyvinyl alcohol solution and / or sodium alginate solution is 2 wt%, and the mass ratio of the polyvinyl alcohol solution to the sodium alginate solution is (8-10):9; the polyvinyl alcohol solution is prepared by dissolving polyvinyl alcohol in deionized water at 60-90°C.

[0008] Preferably, the ettringite fiber is prepared by a method comprising the following steps: mixing sulfoaluminate cement clinker with water evenly, hydrating at 60-70℃ for 70-74 hours, separating the solid and liquid, and drying to obtain the ettringite fiber; the mass ratio of the sulfoaluminate cement clinker to water is 1:(8-10).

[0009] Preferably, in step (2), the mass ratio of calcite fiber in the calcite fiber dispersion to the polyvinyl alcohol solution is (2-2.5):9; in step (2), after adding the calcite fiber dispersion, the stirring time is 0.5-1.5h.

[0010] Preferably, in step (3), the concentration of the calcium chloride solution is 1.5 wt%, and the mass ratio of the calcium chloride solution to the polyvinyl alcohol solution is 2-2.5; in step (3), the crosslinking reaction time is 2.5-3.5 h.

[0011] Preferably, in step (5), the mass ratio of the glutaraldehyde solution to the hydrochloric acid solution is (45-50):3; and the concentration of the glutaraldehyde solution is 50 wt%.

[0012] Preferably, the cement is at least one of silicate cement, phosphate cement, and sulfoaluminate cement.

[0013] Beneficial effects:

[0014] The components of the hydrogel-cement-based composite grouting material of the present invention, which can be used in dynamic underwater environments, include reinforced hydrogel, which helps to significantly improve the underwater anti-dispersion ability of the grouting material, especially for underwater grouting repair projects under high flow rates.

[0015] Traditional anti-dispersion grouting materials are often made by combining admixtures such as accelerators and thickeners with cementitious materials. After injection, the grout is difficult to agglomerate and form (traditional anti-dispersion grouting materials mainly improve their anti-dispersion performance by increasing the viscosity of the grout). However, the hydrogel-cement-based composite grouting material of this invention, applicable to underwater dynamic environments, relies on the water absorption properties of the reinforced hydrogel to adsorb and agglomerate relatively dispersed grout, enhancing the overall integrity of the grout (the reinforced hydrogel in this invention has minimal impact on the viscosity of the grout). Furthermore, traditional underwater grouting materials are highly dependent on the content of admixtures; even slight changes in admixture content can cause significant changes in grout performance, resulting in large performance fluctuations and a narrow control range. This invention mainly relies on the water-controlling properties of the reinforced hydrogel. By controlling parameters such as the water absorption ratio and rate of the reinforced hydrogel, the setting time of the cement, and the ratio of the reinforced hydrogel to cement, it achieves wide-threshold control and precise design of the grout performance, thereby facilitating rapid repair of concrete structures under different water flow velocities. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0017] Figure 1 This is a state diagram of the hydrogel-cement-based composite grouting material of the present invention, which can be used in dynamic water. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0019] The present invention will now be described in detail with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0020] This invention provides a hydrogel-cement-based composite grouting material that can be used in dynamic water, so as to facilitate the construction of the grouting material in dynamic water and reduce the dispersion of the grouting material in dynamic water.

[0021] The hydrogel-cement-based composite grouting material for use in dynamic underwater environments according to embodiments of the present invention comprises the following raw materials in parts by weight: 99.5-99.98 parts cement (e.g., 99.5, 99.6, 99.7, 99.8, or 99.98 parts), 0.02-0.5 parts reinforcing hydrogel (e.g., 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5 parts), and 80-100 parts water (e.g., 80, 85, 90, 95, or 100 parts); the reinforcing hydrogel... The following steps were used to prepare the product: (1) Polyvinyl alcohol solution and sodium alginate solution were mixed evenly and stirred in an ice-water bath; (2) Calcium alum fiber dispersion was added to the mixture obtained in step (1) and stirred evenly; (3) Calcium chloride solution was added to the mixed solution obtained in step (2) and crosslinking reaction was carried out; (4) The crosslinking product obtained after the crosslinking reaction was completed was crushed and dried to obtain solid particles; (5) The solid particles were immersed in a mixed solution of glutaraldehyde and hydrochloric acid. After the immersion was completed, the reinforced hydrogel was obtained.

[0022] The hydrogel-cement-based composite grouting material of the present invention, which can be used in dynamic water, can rely on the water absorption properties of the reinforced hydrogel (which is prepared by a specific method using sodium alginate and polyvinyl alcohol as the main raw materials; if sodium alginate or polyvinyl alcohol is used alone, it will affect the gelation) to adsorb and agglomerate the relatively dispersed grouting material together, thereby enhancing the integrity of the grouting material and significantly improving its anti-dispersion performance in dynamic water, which helps to achieve rapid repair of concrete structures in dynamic water.

[0023] Preferably, the amount of reinforced hydrogel used is 0.2-0.5 parts.

[0024] In a preferred embodiment of the hydrogel-cement-based composite grouting material of the present invention, which can be used underwater, in step (1), the concentration of the polyvinyl alcohol solution and / or sodium alginate solution is 2 wt%, and the mass ratio of the polyvinyl alcohol solution to the sodium alginate solution is (8-10):9 (e.g., 8:9, 8.5:9, 9:9, 9.5:9, or 10:9); the polyvinyl alcohol solution is prepared by dissolving polyvinyl alcohol in deionized water at 60-90°C (e.g., 60°C, 70°C, 80°C, or 90°C).

[0025] In a preferred embodiment of the hydrogel-cement-based composite grouting material of the present invention, which can be used in dynamic underwater environments, ettringite fibers are prepared by a method comprising the following steps: sulfoaluminate cement clinker is mixed uniformly with water, hydrated at 60-70°C (e.g., 60°C, 62°C, 64°C, 66°C, 68°C, or 70°C) for 70-74 hours (e.g., 70 hours, 71 hours, 72 hours, 73 hours, or 74 hours), then the solid and liquid are separated and dried to obtain ettringite fibers; the mass ratio of sulfoaluminate cement clinker to water is 1:(8-10) (e.g., 1:8, 1:8.5, 1:9, 1:9.5, or 1:10).

[0026] In a preferred embodiment of the hydrogel-cement-based composite grouting material of the present invention applicable to underwater dynamic environments, in step (2), the mass ratio of ettringite fiber to polyvinyl alcohol solution in the ettringite fiber dispersion is (2-2.5):9 (e.g., 2:9, 2.1:9, 2.2:9, 2.3:9, 2.4:9 or 2.5:9); in step (2), after adding the ettringite fiber dispersion, the stirring time is 0.5-1.5h (e.g., 0.5h, 0.8h, 1.0h, 1.2h or 1.5h; as long as the ettringite fiber dispersion is uniformly mixed with other raw materials).

[0027] In a preferred embodiment of the hydrogel-cement-based composite grouting material of the present invention that can be used underwater, in step (3), the concentration of calcium chloride solution is 1.5 wt%, and the mass ratio of calcium chloride solution to polyvinyl alcohol solution is 2-2.5 (e.g., 2, 2.1, 2.2, 2.3, 2.4 or 2.5); in step (3), the crosslinking reaction time is 2.5-3.5 h (e.g., 2.5 h, 2.8 h, 3 h, 3.2 h or 3.5 h).

[0028] In a preferred embodiment of the hydrogel-cement-based composite grouting material of the present invention that can be used underwater, in step (5), the mass ratio of glutaraldehyde solution to hydrochloric acid solution is (45-50):3 (e.g., 45:3, 46:3, 47:3, 48:3, 49:3 or 50:3); the concentration of glutaraldehyde solution is 50wt%, and the concentration of hydrochloric acid solution is 1mol / L.

[0029] In a preferred embodiment of the hydrogel-cement-based composite grouting material of the present invention, which can be used underwater, the cement is at least one of silicate cement, phosphate cement, and sulfoaluminate cement.

[0030] The following detailed description of the hydrogel-cement-based composite grouting material of the present invention, applicable to underwater dynamic environments, is provided through specific embodiments.

[0031] In the following embodiment:

[0032] The cement used is 72.5 grade sulfoaluminate cement; the polyvinyl alcohol solution is obtained by dissolving 2% polyvinyl alcohol in deionized water (polyvinyl alcohol Mw is 89000-98000, 99% hydrolyzed); the sodium alginate solution is obtained by dissolving 2% sodium alginate (analytical grade, Aladdin) in deionized water; the CaCl2 solution is a 1.5wt% CaCl2 aqueous solution; the ettringite fiber is obtained by hydrating sulfoaluminate cement clinker in deionized water at 70℃ for 72 hours. A water-to-solid ratio of 10 yields an ettringite fiber solution, which is ultrasonically dispersed for 5 minutes to obtain an ettringite fiber dispersion. The glutaraldehyde solution is a 50wt% deionized aqueous solution of glutaraldehyde (analytical grade, Aladdin). The hydrochloric acid solution (1mol / L) is a diluted solution of concentrated hydrochloric acid. The water is deionized water. The ice-water bath is provided by a magnetically stirred cold water bath at 5℃, and the warm water bath is provided by a magnetically stirred hot water bath at a temperature between 60℃ and 90℃. The grouting material is stirred by a rotary mixer.

[0033] Example 1

[0034] The hydrogel-cement-based composite grouting material for use in dynamic underwater environments in this embodiment comprises the following components in parts by weight: 99.98 parts cement, 0.02 parts reinforced hydrogel, and 80 parts water.

[0035] The raw materials for the reinforced hydrogel, by weight, include: 45 parts polyvinyl alcohol solution, 45 parts sodium alginate solution, 10 parts ettringite fiber, 100 parts CaCl2 solution, 94.34 parts glutaraldehyde solution, and 5.66 parts dilute hydrochloric acid solution.

[0036] The reinforced hydrogel was prepared by the following steps: (1) Polyvinyl alcohol solution and sodium alginate were mixed evenly in a warm water bath and then stored in an ice water bath. The mixture was stirred evenly in a magnetic stirring water bath to polymerize the mixture. The rotor speed was 500 r / min. (2) Calcium alum fiber dispersion was added to the above mixed solution and stirred for 1 h. (3) The above solution was poured into CaCl2 solution and crosslinked for 3 h. (4) The crosslinked product obtained in the above steps was placed in a small crusher and crushed for 1.5 min to obtain small particles (particle size less than 0.5 cm). The particles were further dried to obtain dry solid particles. (5) To further improve the degree of crosslinking, the product was soaked in a mixed solution of glutaraldehyde solution and hydrochloric acid solution (mass ratio of glutaraldehyde solution and hydrochloric acid solution was 50:3) at room temperature for 1 h to obtain the reinforced hydrogel.

[0037] Cement, water, and reinforced hydrogel (before mixing with cement, the reinforced hydrogel prepared in step (5) is washed and soaked to remove residual reaction materials) are mixed in a mortar mixer in a certain proportion. The rotation speed of the mortar mixer is 300 r / min and the mixing time is 120 s. The mixing instrument is stopped to obtain hydrogel-cement composite underwater anti-dispersion grouting material.

[0038] Example 2

[0039] The hydrogel-cement-based composite grouting material for use in dynamic underwater environments in this embodiment comprises the following components in parts by weight: 99.95 parts cement, 0.05 parts reinforced hydrogel, and 80 parts water.

[0040] The raw materials for the reinforced hydrogel, by weight, include: 45 parts polyvinyl alcohol solution, 45 parts sodium alginate solution, 10 parts ettringite fiber, 100 parts CaCl2 solution, 94.34 parts glutaraldehyde solution, and 5.66 parts dilute hydrochloric acid solution.

[0041] The reinforced hydrogel was prepared by the following steps: (1) Polyvinyl alcohol solution and sodium alginate were mixed evenly in a warm water bath and then stored in an ice water bath. The mixture was stirred evenly in a magnetic stirring water bath to polymerize the mixture. The rotor speed was 500 r / min. (2) Calcium alum fiber was ultrasonically dispersed in deionized water for 5 min. The above mixed solution was added and stirred for 1 h. (3) The above solution was poured into CaCl2 solution and crosslinked for 3 h. (4) The crosslinked product obtained in the above steps was crushed in a small crusher for 1.5 min to obtain small particles (particle size less than 0.5 cm). The particles were further dried to obtain dry solid particles. (5) To further improve the degree of crosslinking, the product was soaked in a mixed solution of glutaraldehyde solution and hydrochloric acid solution (mass ratio of glutaraldehyde solution and hydrochloric acid solution was 50:3) at room temperature for 1 h to obtain the reinforced hydrogel.

[0042] Cement, water, and reinforced hydrogel (before mixing with cement, the reinforced hydrogel prepared in step (5) is washed and soaked to remove residual reaction materials) are mixed in a mortar mixer in a certain proportion. The rotation speed of the mortar mixer is 300 r / min and the mixing time is 120 s. The mixing instrument is stopped to obtain hydrogel-cement composite underwater anti-dispersion grouting material.

[0043] Example 3

[0044] The hydrogel-cement-based composite grouting material for use in dynamic underwater environments in this embodiment comprises the following components in parts by weight: 99.90 parts cement, 0.10 parts reinforced hydrogel, and 80 parts water.

[0045] The raw materials for the reinforced hydrogel, by weight, include: 45 parts polyvinyl alcohol solution, 45 parts sodium alginate solution, 10 parts ettringite fiber, 100 parts CaCl2 solution, 94.34 parts glutaraldehyde solution, and 5.66 parts dilute hydrochloric acid solution.

[0046] The reinforced hydrogel was prepared by the following steps: (1) Polyvinyl alcohol solution and sodium alginate were mixed evenly in a warm water bath and then stored in an ice water bath. The mixture was stirred evenly in a magnetic stirring water bath to polymerize the mixture. The rotor speed was 500 r / min. (2) Calcium alum fiber was ultrasonically dispersed in deionized water for 5 min. The above mixed solution was added and stirred for 1 h. (3) The above solution was poured into CaCl2 solution and crosslinked for 3 h. (4) The crosslinked product obtained in the above steps was crushed in a small crusher for 1.5 min to obtain small particles (particle size less than 0.5 cm). The particles were further dried to obtain dry solid particles. (5) To further improve the degree of crosslinking, the product was soaked in a mixed solution of glutaraldehyde solution and hydrochloric acid solution (mass ratio of glutaraldehyde solution and hydrochloric acid solution was 50:3) at room temperature for 1 h to obtain the reinforced hydrogel.

[0047] Cement, water, and reinforced hydrogel (before mixing with cement, the reinforced hydrogel prepared in step (5) is washed and soaked to remove residual reaction materials) are mixed in a mortar mixer in a certain proportion. The rotation speed of the mortar mixer is 300 r / min and the mixing time is 120 s. The mixing instrument is stopped to obtain hydrogel-cement composite underwater anti-dispersion grouting material.

[0048] Example 4

[0049] The hydrogel-cement-based composite grouting material for use in dynamic underwater environments in this embodiment comprises the following components in parts by weight: 99.80 parts cement, 0.20 parts reinforced hydrogel, and 80 parts water.

[0050] The raw materials for the reinforced hydrogel, by weight, include: 45 parts polyvinyl alcohol solution, 45 parts sodium alginate solution, 10 parts ettringite fiber, 100 parts CaCl2 solution, 94.34 parts glutaraldehyde solution, and 5.66 parts dilute hydrochloric acid solution.

[0051] The reinforced hydrogel was prepared by the following steps: (1) Polyvinyl alcohol solution and sodium alginate were mixed evenly in a warm water bath and then stored in an ice water bath. The mixture was stirred evenly in a magnetic stirring water bath to polymerize the mixture. The rotor speed was 500 r / min. (2) Calcium alum fiber was ultrasonically dispersed in deionized water for 5 min. The above mixed solution was added and stirred for 1 h. (3) The above solution was poured into CaCl2 solution and crosslinked for 3 h. (4) The crosslinked product obtained in the above steps was crushed in a small crusher for 1.5 min to obtain small particles (particle size less than 0.5 cm). The particles were further dried to obtain dry solid particles. (5) To further improve the degree of crosslinking, the product was soaked in a mixed solution of glutaraldehyde solution and hydrochloric acid solution (mass ratio of glutaraldehyde solution and hydrochloric acid solution was 50:3) at room temperature for 1 h to obtain the reinforced hydrogel.

[0052] Cement, water, and reinforced hydrogel (before mixing with cement, the reinforced hydrogel prepared in step (5) is washed and soaked to remove residual reaction materials) are mixed in a mortar mixer in a certain proportion. The rotation speed of the mortar mixer is 300 r / min and the mixing time is 120 s. The mixing instrument is stopped to obtain hydrogel-cement composite underwater anti-dispersion grouting material.

[0053] Example 5

[0054] The hydrogel-cement-based composite grouting material for use in dynamic underwater environments in this embodiment comprises the following components in parts by weight: 99.50 parts cement, 0.50 parts reinforced hydrogel, and 80 parts water.

[0055] The raw materials for the reinforced hydrogel, by weight, include: 45 parts polyvinyl alcohol solution, 45 parts sodium alginate solution, 10 parts ettringite fiber, 100 parts CaCl2 solution, 94.34 parts glutaraldehyde solution, and 5.66 parts dilute hydrochloric acid solution.

[0056] The reinforced hydrogel was prepared by the following steps: (1) Polyvinyl alcohol solution and sodium alginate were mixed evenly in a warm water bath and then stored in an ice water bath. The mixture was stirred evenly in a magnetic stirring water bath to polymerize the mixture. The rotor speed was 500 r / min. (2) Calcium alum fiber was ultrasonically dispersed in deionized water for 5 min. The above mixed solution was added and stirred for 1 h. (3) The above solution was poured into CaCl2 solution and crosslinked for 3 h. (4) The crosslinked product obtained in the above steps was crushed in a small crusher for 1.5 min to obtain small particles (particle size less than 0.5 cm). The particles were further dried to obtain dry solid particles. (5) To further improve the degree of crosslinking, the product was soaked in a mixed solution of glutaraldehyde solution and hydrochloric acid solution (mass ratio of glutaraldehyde solution and hydrochloric acid solution was 50:3) at room temperature for 1 h to obtain the reinforced hydrogel.

[0057] Cement, water, and reinforced hydrogel (before mixing with cement, the reinforced hydrogel prepared in step (5) is washed and soaked to remove residual reaction materials) are mixed in a mortar mixer in a certain proportion. The rotation speed of the mortar mixer is 300 r / min and the mixing time is 120 s. The mixing instrument is stopped to obtain hydrogel-cement composite underwater anti-dispersion grouting material.

[0058] Example 6

[0059] The hydrogel-cement-based composite grouting material for use in dynamic underwater environments in this embodiment comprises the following components in parts by weight: 99.50 parts cement, 0.50 parts reinforced hydrogel, and 100 parts water.

[0060] The raw materials for the reinforced hydrogel, by weight, include: 45 parts polyvinyl alcohol solution, 45 parts sodium alginate solution, 10 parts ettringite fiber, 100 parts CaCl2 solution, 94.34 parts glutaraldehyde solution, and 5.66 parts dilute hydrochloric acid solution.

[0061] The reinforced hydrogel was prepared by the following steps: (1) Polyvinyl alcohol solution and sodium alginate were mixed evenly in a warm water bath and then stored in an ice water bath. The mixture was stirred evenly in a magnetic stirring water bath to polymerize the mixture. The rotor speed was 500 r / min. (2) Calcium alum fiber was ultrasonically dispersed in deionized water for 5 min. The above mixed solution was added and stirred for 1 h. (3) The above solution was poured into CaCl2 solution and crosslinked for 3 h. (4) The crosslinked product obtained in the above steps was crushed in a small crusher for 1.5 min to obtain small particles (particle size less than 0.5 cm). The particles were further dried to obtain dry solid particles. (5) To further improve the degree of crosslinking, the product was soaked in a mixed solution of glutaraldehyde solution and hydrochloric acid solution (mass ratio of glutaraldehyde solution and hydrochloric acid solution was 50:3) at room temperature for 1 h to obtain the reinforced hydrogel.

[0062] Cement, water, and reinforced hydrogel (before mixing with cement, the reinforced hydrogel prepared in step (5) is washed and soaked to remove residual reaction materials) are mixed in a mortar mixer in a certain proportion. The rotation speed of the mortar mixer is 300 r / min and the mixing time is 120 s. The mixing instrument is stopped to obtain hydrogel-cement composite underwater anti-dispersion grouting material.

[0063] Comparative Example 1

[0064] The grouting material of this comparative example comprises the following components in parts by weight: 99.98 parts cement and 80 parts water; place the cement and water in a mortar mixer, rotate at 300 r / min, and mix for 120 s; stop the mixing instrument to obtain the grouting material of this comparative example.

[0065] Comparative Example 2

[0066] The only difference between this comparative example and Example 5 is that step (2) is omitted (i.e., the step of adding calcite fiber is omitted); the rest are the same as Example 5.

[0067] Comparative Example 3

[0068] The only difference between this comparative example and Example 5 is that the amount of calcite fiber used in step (2) is 20 parts; the rest are the same as in Example 5.

[0069] Comparative Example 4

[0070] The only difference between this comparative example and Example 5 is that the amount of calcite fiber used in step (2) is 5 parts; the rest are the same as in Example 5.

[0071] Comparative Example 5

[0072] The only difference between this comparative example and Example 5 is that step (5) is omitted (i.e., the step of soaking the dried solid particles obtained in step (4) with a mixed solution of glutaraldehyde and hydrochloric acid is omitted); the rest are consistent with Example 5.

[0073] Comparative Example 6

[0074] The only difference between this comparative example and Example 5 is that in step (3), the CaCl2 solution is poured in and crosslinked for 1 hour before step (4) is performed; the rest is the same as in Example 5.

[0075] Comparative Example 7

[0076] The only difference between this comparative example and Example 5 is that in step (3), the CaCl2 solution is poured in and crosslinked for 5 hours before step (4); the rest is the same as in Example 5.

[0077] Performance testing:

[0078] The erosion loss rate of the grouting materials in Examples 1-6 and Comparative Examples 1-7 was tested.

[0079] Experimental Method: To measure the underwater erosion loss rate of the grouting material, each sample was tested three times. A petri dish was placed at the bottom of a beaker containing 1000 mL of water, and a uniformly rotating stirring head at 250 r / min was placed on the water surface to simulate a water flow environment. During the uniformly rotating stirring process, M0 (50 g) of grouting material was taken each time and injected into the petri dish at the bottom of the beaker (grouting could be done using a grouting pipe). After 2 minutes, the petri dish was removed, and the remaining mass M of the grouting material was weighed. n The underwater scouring loss rate of the grouting material is calculated by formula (1).

[0080] S=(M0-Mn ) / M0 (1)

[0081] In the formula, S is the underwater scouring loss rate of the grouting material; M0 is the initial mass of the grouting material, which is 50g in this embodiment; M n The remaining mass of the grout after 2 minutes (the sulfoaluminate cement used in the composite grout of Examples 1-6 is fast-hardening cement, which allows the composite grout of Examples 1-6 to harden quickly; the grout lost in the first 2 minutes of grouting can reach more than 85% of the total loss of the grout under dynamic water; after 2 minutes of grouting, there will basically be no more large-scale grouting material being washed away by passive water; therefore, when conducting the scouring loss rate test, this invention characterizes the early anti-dispersion performance of the grout by testing the scouring loss rate after 2 minutes of grouting under dynamic water).

[0082] The results are shown in Table 1 below.

[0083] Table 1. Test Results of Erosion Loss Rate

[0084]

[0085]

[0086] As shown in Table 1 above, in Examples 1-5, the mass loss rate of the grout under dynamic water gradually decreased with the increase of the reinforcing hydrogel content; when the mass ratio of reinforcing hydrogel to cement reached 0.5%, the underwater loss rate of the grout was only 16.8%. Compared with Comparative Example 1, the scouring loss rate of the grout in Example 5 under dynamic water environment was reduced by 77.6%.

[0087] Compared with Comparative Example 2, the grouting material of Example 5 also has a significantly lower scouring loss rate in dynamic water environment. The main mechanism is that the ettringite fiber improves the crosslinking degree of the hydrogel, thereby improving its mechanical properties and expansion. On the other hand, the ettringite fiber prolongs the underwater life of the hydrogel and improves the hydrogel's anti-dispersion and anti-aging properties.

[0088] The experimental results of Comparative Examples 3 and 4 and Example 5 show that only an appropriate amount of ettringite fiber can effectively improve the performance of hydrogel materials, while too little or too much fiber will not achieve a similar effect.

[0089] A comparison of the experimental results of Examples 5, 6, and 7 with that of Example 5 shows that both insufficient and excessive crosslinking time lead to deterioration of hydrogel performance and affect the anti-dispersion properties of cement-based grouting materials. On the one hand, too short a crosslinking time reduces the water absorption rate of the hydrogel and decreases the agglomeration of the grouting material in a dynamic water environment; on the other hand, too long a crosslinking time results in poor toughness and easy breakage of the hydrogel. Furthermore, through... Figure 1It can be seen that under the action of moving water, a sufficient amount of reinforced hydrogel can significantly improve the anti-dispersion ability of the grout.

[0090] In summary: The main reason why the use of reinforced hydrogel can significantly improve the anti-dispersion performance of rapid-hardening cement-based grouting is that the reinforced hydrogel has a high specific surface area. The fiber-reinforced structure can adsorb water-based liquid cement paste, thereby hindering the dispersibility of cement paste under dynamic water and improving the agglomeration of the grouting. In addition, compared with traditional anti-dispersion grouting, the hydrogel-cement-based composite grouting of the present invention, which can be used under dynamic water, also has the following advantages: (1) Traditional anti-dispersion grouting often improves the anti-dispersion performance of grouting by changing the cement composition, such as using silica fume or reducing the water-cement ratio. However, the present invention can achieve such effects without changing the cement composition (the cement composition has little effect on the composite grouting of the present invention); and changing the cement composition is also applicable to the present invention. In this case, the grouting performance can be further improved; (2) Traditional anti-dispersion grouting uses thickeners and early-setting agents to improve the anti-dispersion performance of grouting. Such inventions sacrifice some of the performance of grouting (e.g., using thickeners and early-setting agents). Thickeners and early-strength agents often significantly reduce the early fluidity or pumpability of grouting materials, greatly shorten the grouting window period of grouting materials, making construction inconvenient, or the use of early-strength agents often causes the strength of grouting materials to shrink in the later stage. The strength of the composite grouting material of the present invention increases with age and will not shrink in strength. (3) The performance control range of traditional anti-dispersion grouting materials is small and the designability is poor. Generally speaking, the content of admixtures in traditional methods is low, and a slight change in the admixtures will cause a large change in the performance of grouting materials, and the controllability is not strong. However, the composite grouting material of the present invention can adjust the proportion of reinforced hydrogel according to actual needs (e.g., the requirements for anti-dispersion performance), and the designability is strong.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hydrogel-cement-based composite grouting material that can be used in dynamic underwater environments, characterized in that, The composite grouting material comprises the following raw materials in parts by weight: 99.5-99.98 parts cement, 0.02-0.5 parts reinforcing hydrogel, and 80-100 parts water; The reinforced hydrogel was prepared using a method comprising the following steps: (1) Mix the polyvinyl alcohol solution and sodium alginate solution evenly and stir under an ice-water bath; the concentration of the polyvinyl alcohol solution and sodium alginate solution is 2wt%, and the mass ratio of the polyvinyl alcohol solution and sodium alginate solution is (8-10):9; (2) Add calcite fiber dispersion to the mixture obtained in step (1) and stir until homogeneous; the mass ratio of calcite fiber in the calcite fiber dispersion to the polyvinyl alcohol solution is (2-2.5):9; (3) Add calcium chloride solution to the mixed solution obtained after step (2) to carry out cross-linking reaction; the cross-linking reaction time is 2.5-3.5h; (4) The cross-linking product obtained after the cross-linking reaction is completed is crushed and dried to obtain solid particles; (5) The solid particles are immersed in a mixed solution of glutaraldehyde solution and hydrochloric acid solution. After immersion, the reinforced hydrogel is obtained.

2. The hydrogel-cement-based composite grouting material for use in dynamic underwater environments as described in claim 1, characterized in that, The polyvinyl alcohol solution is prepared by dissolving polyvinyl alcohol in deionized water at 60-90°C.

3. The hydrogel-cement-based composite grouting material for use in dynamic underwater environments as described in claim 1, characterized in that, The ettringite fiber is prepared by a method including the following steps: sulfoaluminate cement clinker is mixed evenly with water, hydrated at 60-70℃ for 70-74 hours, then the solid and liquid are separated and dried to obtain the ettringite fiber. The mass ratio of the sulfoaluminate cement clinker to water is 1:(8-10).

4. The hydrogel-cement-based composite grouting material for use in dynamic underwater environments as described in claim 1, characterized in that, In step (2), after adding the calcium alum fiber dispersion, the stirring time is 0.5-1.5 h.

5. The hydrogel-cement-based composite grouting material for use in dynamic underwater environments as described in claim 1, characterized in that, In step (3), the concentration of the calcium chloride solution is 1.5 wt%, and the mass ratio of the calcium chloride solution to the polyvinyl alcohol solution is 2-2.

5.

6. The hydrogel-cement-based composite grouting material for use in dynamic underwater environments as described in claim 1, characterized in that, In step (5), the mass ratio of the glutaraldehyde solution to the hydrochloric acid solution is (45-50):3; The concentration of the glutaraldehyde solution is 50 wt%.

7. The hydrogel-cement-based composite grouting material for use in dynamic underwater environments as described in claim 1, characterized in that, The cement is at least one of silicate cement, phosphate cement, and sulfoaluminate cement.

Images