Double-liquid magnesium phosphate early-strength high-strength grouting material and preparation method thereof

Abstract

The invention discloses a double-liquid magnesium phosphate early-strength high-strength grouting material and a preparation method thereof.The grouting material is composed of a liquid A and a liquid B. The liquid A is composed of powder A and water in parts by weight and comprises dead burned magnesia powder, a defoaming agent, steel slag powder, a retarder I and water, and the liquid B is composed of powder B and water in parts by weight and comprises powder B and water in parts by weight. Wherein the monopotassium phosphate, the superfine powder, the polymer rubber powder, the retarder II and the water have the advantages that the stirring time is shortened, the setting time is controllable, the flowability is good, the repair requirement can be met more quickly, the construction period is shortened, and the cane sugar and the borax are used as the retarders, so that the setting time can be controlled, and the early strength can be improved; surplus phosphate in a grouting material matrix is consumed by using the steel slag powder, so that some amorphous gel products can be generated, and the mechanical property is improved; the redispersible latex powder is utilized to form a polymer film in the slurry to wrap a hydration product, so that the water resistance is improved, and the synergistic modification effect is achieved.

Description

Technical Field

[0001] The invention belongs to the field of technical construction engineering, and in particular relates to a double-liquid magnesium phosphate early-strength and high-strength grouting material and a preparation method thereof. Background Art

[0002] As major transportation and energy projects expand into deep, geologically complex areas, a large number of "ultra-long, ultra-deep, and ultra-high-stress" tunnels and underground projects have emerged. During development, the rock mass is subject to the coupling effects of deep faults, high water pressure, and other factors. The dense fracture networks that develop within it become a key hidden danger. These fractures are highly permeable and highly connected, exacerbating transient hazards such as sudden water and mud bursts and surrounding rock collapses. They also undermine the integrity of the rock mass, leading to the instability of support structures, disrupting groundwater systems, and deteriorating the ecological environment. Traditional fracture repair materials (such as cement-based grouts) are slow to set and have poor permeability, making it difficult to effectively seal leakage channels and restore rock strength, severely limiting project safety and long-term stability.

[0003] Magnesium phosphate cement is a specialty cementitious material composed primarily of dead-burned magnesium oxide and soluble phosphates (such as ammonium dihydrogen phosphate and potassium dihydrogen phosphate). These ingredients are mixed in specific proportions and harden rapidly through an acid-base neutralization reaction. Its hydration products, primarily struvite crystals, offer outstanding advantages such as rapid setting, high early strength, excellent adhesion, and volume stability. It is widely used in rapid repair, emergency repair, and construction. This discovery, building on previous research, further refines the formulation of magnesium phosphate cement grouting materials to enhance their mechanical properties. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a double-liquid magnesium phosphate early-strength and high-strength grouting material with shortened stirring time, controllable setting time, good fluidity, faster meeting repair requirements, and reduced construction period. Sucrose and borax are used as retarders, which can not only control the setting time but also improve the early strength; steel slag powder is used to consume excess phosphate in the grouting material matrix to generate some amorphous gel products, thereby improving mechanical properties; and redispersible latex powder is used to form a polymer film in the slurry to wrap the hydration product, thereby improving water resistance and achieving a synergistic modification effect.

[0005] To achieve the above object, the present invention provides the following technical solution: a double-liquid magnesium phosphate early-strength high-strength grouting material: the grouting material consists of liquid A and liquid B, wherein: Liquid A is composed of powder A and water in parts by weight, including 300-350 parts of dead-burned magnesium oxide powder, 0.33 parts of defoaming agent, 10-60 parts of steel slag powder, 3-3.5 parts of retarder, and 50-90 parts of water.

[0006] Liquid B is composed of powder B and water in parts by weight, including 140-190 parts of potassium dihydrogen phosphate, 30 parts of ultrafine powder, 0.75-3 parts of polymer rubber powder, 23-32 parts of retarder II, and 30-60 parts of water.

[0007] Furthermore, the dead-burned magnesium oxide powder in the liquid A has a purity of not less than 92% and a specific surface area of not less than 300 m2 / kg, and the first retarder is sucrose with a purity of 99.5%.

[0008] Furthermore, the purity of potassium dihydrogen phosphate in the B liquid is not less than 99%, and its pH is 4.2-4.5. The second retarder is borax decahydrate with a purity of not less than 99%. The ultrafine powder is ultrafine fly ash.

[0009] Furthermore, the defoaming agent is a polyether modified defoaming agent.

[0010] Furthermore, the polymer powder is redispersible latex powder.

[0011] A preparation method of a double-liquid magnesium phosphate early-strength and high-strength grouting material, the preparation method comprising the following steps: S1, according to the weight ratio of powder A, weigh the corresponding raw materials respectively, stir the powder evenly, add the corresponding proportion of water and mix evenly to prepare liquid A; S2, according to the weight ratio of powder B, weigh the corresponding raw materials respectively, stir the powder evenly, add the corresponding proportion of water and mix evenly to prepare liquid B; S3, mixing liquid A and liquid B evenly to obtain a double-liquid magnesium phosphate early-strength and high-strength grouting material.

[0012] Furthermore, the dry powder in S1 and S2 is stirred for 2 minutes, and water is added and stirred for 2 minutes.

[0013] Furthermore, in step 3, solution A and solution B are mixed and stirred for 1 minute.

[0014] Compared with the prior art, the beneficial effects of the present invention are: the magnesium phosphate cement-based two-liquid grouting material of the present invention greatly shortens the stirring time due to the presence of liquid A and liquid B, the setting time is controllable, the fluidity is good, the 2h compressive strength can reach 30MPa, the repair requirements are met more quickly, and the construction period is reduced.

[0015] Using sucrose and borax as retarders can not only control the setting time but also improve the early strength; By using steel slag powder to consume the excess phosphate in the grouting material matrix, some amorphous gel products can be generated to improve the mechanical properties; by using redispersible latex powder to form a polymer film in the slurry to wrap the hydration product, the water resistance can be improved, thus achieving a synergistic modification effect. DETAILED DESCRIPTION Example 1

[0016] The raw materials of the double-liquid magnesium phosphate early-strength and high-strength grouting material provided by the present invention are as follows: Liquid A: 330 parts dead-burned magnesium oxide; 3.3 parts sucrose; 0.66 parts water reducer, 0.33 parts defoamer; 0.25 parts expander; 62 parts water; Solution B: 165 parts potassium dihydrogen phosphate; 29.7 parts borax; 44 parts water; Double-liquid magnesium phosphate early strength and high strength grouting is prepared according to the following steps: The first step is to weigh the corresponding raw materials according to the component ratio, stir the powder evenly, add the corresponding proportion of water and mix evenly to prepare liquid A; The second step is to weigh the corresponding raw materials according to the component ratio, stir the powder evenly, add the corresponding proportion of water and mix evenly to prepare liquid B; The third step is to mix liquid A and liquid B evenly to obtain double-liquid magnesium phosphate early strength and high strength grouting material. Example 2

[0017] Compared with the above embodiment, the difference is that the raw material composition of the double-liquid magnesium phosphate early strength and high strength grouting material is as follows: Liquid A: 330 parts dead-burned magnesium oxide; 3.3 parts sucrose; 0.66 parts water reducer, 0.33 parts defoamer; 0.25 parts expander; 71 parts water; Solution B: 189 parts potassium dihydrogen phosphate; 36 parts borax; 50 parts water; Example 3

[0018] Compared with the above embodiment, the difference is that the raw material composition of the double-liquid magnesium phosphate early strength and high strength grouting material is as follows: Liquid A: 330 parts dead-burned magnesium oxide; 3.3 parts sucrose; 0.66 parts water reducer, 0.33 parts defoamer; 0.25 parts expander; 59 parts water; Solution B: 147 parts potassium dihydrogen phosphate; 29 parts borax; 39 parts water; Example 4

[0019] Compared with the above embodiment, the difference is that the raw material composition of the double-liquid magnesium phosphate early strength and high strength grouting material is as follows: Liquid A: 300 parts dead-burned magnesia; 15 parts steel slag; 3.2 parts sucrose; 0.66 parts water reducer, 0.33 parts defoamer; 0.25 parts expansion agent; 72 parts water; Liquid B: 160 parts potassium dihydrogen phosphate; 30 parts ultrafine fly ash; 21 parts borax; 38 parts water; Example 5

[0020] Compared with the above embodiment, the difference is that the raw material composition of the double-liquid magnesium phosphate early strength and high strength grouting material is as follows: Liquid A: 294 parts dead-burned magnesia; 24 parts steel slag; 2.94 parts sucrose; 0.66 parts water reducer, 0.33 parts defoamer; 0.25 parts expansion agent; 75 parts water; Liquid B: 147 parts potassium dihydrogen phosphate; 29.7 parts ultrafine fly ash; 20 parts borax; 34 parts water; Example 6

[0021] Compared with the above embodiment, the difference is that the raw material composition of the double-liquid magnesium phosphate early strength and high strength grouting material is as follows: Liquid A: 297 parts dead-burned magnesia; 24 parts steel slag; 2.97 parts sucrose; 0.66 parts water reducer, 0.33 parts defoamer; 0.25 parts expander; 72 parts water; Liquid B: 148 parts potassium dihydrogen phosphate; 24 parts ultrafine fly ash; 3 parts latex powder; 23 parts borax; 40 parts water; Example 7

[0022] Compared with the above embodiment, the difference is that the raw material composition of the double-liquid magnesium phosphate early strength and high strength grouting material is as follows: Liquid A: 297 parts dead-burned magnesia; 24 parts steel slag; 2.97 parts sucrose; 0.66 parts water reducer, 0.33 parts defoamer; 0.25 parts expander; 72 parts water; Liquid B: 148 parts potassium dihydrogen phosphate; 24 parts ultrafine fly ash; 0.75 parts latex powder; 23 parts borax; 40 parts water; Example 8

[0023] Compared with the above embodiment, the difference is that the raw material composition of the double-liquid magnesium phosphate early strength and high strength grouting material is as follows: Liquid A: 314 parts dead-burned magnesium oxide; 3.3 parts sucrose; 0.66 parts water reducer, 0.33 parts defoamer; 0.25 parts expander; 66 parts water; Liquid B: 156 parts potassium dihydrogen phosphate; 24 parts ultrafine fly ash; 21 parts borax; 40 parts water; Performance indicators Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Setting time (initial setting S) 420 570 390 375 345 300 375 450 2H compression resistance 30.3 22.7 26.5 32.4 34.3 31.4 36.3 30.5 3D compression resistance 42.77 33.5 37.2 42.4 45.9 43.01 47.01 42.3 28D compression resistance 49.6 45.7 47.4 50.9 55.6 52.1 58.6 51.8 Fluidity mm 278 305 284 280 265 262 265 275 In summary: In the present invention, sucrose can be used as a retarder to improve the working performance of the grouting material, and slow down the setting speed when reacting with dead-burned magnesium oxide. In addition, sucrose can improve the fluidity of liquid A and the early strength of the grouting material to a certain extent; the added steel slag contains oxides such as calcium oxide and iron oxide, which can react with potassium dihydrogen phosphate to generate an amorphous gelled product, thereby reducing the phosphate component in the system. Under normal circumstances, the phosphate component in the magnesium phosphate system does not react sufficiently, which greatly affects the durability, improves the density, improves the mechanical properties, and enhances the durability; the added polymer powder can form a polymer film to wrap the hydration product and the unreacted components, cross-link with the hydration product to increase the cohesion, improve the compressive strength, and prevent water penetration, thereby improving the water resistance.

[0024] The basic principles, main features and advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0025] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A double-liquid magnesium phosphate early-strength high-strength grouting material, characterized by: The grouting material consists of liquid A and liquid B, where: Liquid A is composed of powder A and water in parts by weight, including 300-350 parts of dead-burned magnesium oxide powder, 0.33 parts of defoaming agent, 10-60 parts of steel slag powder, 3-3.5 parts of retarder, and 50-90 parts of water; Liquid B is composed of powder B and water in parts by weight, including 140-190 parts of potassium dihydrogen phosphate, 30 parts of ultrafine powder, 0.75-3 parts of polymer rubber powder, 23-32 parts of retarder II, and 30-60 parts of water.

2. A double-liquid magnesium phosphate early-strength and high-strength grouting material according to claim 1, characterized in that: The dead-burned magnesium oxide powder in the liquid A has a purity of not less than 92% and a specific surface area of not less than 300 m2 / kg. The first retarder is sucrose with a purity of 99.5%.

3. The double-liquid magnesium phosphate early-strength and high-strength grouting material according to claim 1, characterized in that: The purity of potassium dihydrogen phosphate in the B liquid is not less than 99%, and its pH is 4.2-4.

5. The second retarder is borax decahydrate with a purity of not less than 99%. The ultrafine powder is ultrafine fly ash.

4. The double-liquid magnesium phosphate early-strength and high-strength grouting material according to claim 1, characterized in that: The defoamer is a polyether modified defoamer.

5. The double-liquid magnesium phosphate early-strength and high-strength grouting material according to claim 1, characterized in that: The polymer powder is redispersible latex powder.

6. The method for preparing a double-liquid magnesium phosphate early-strength and high-strength grouting material according to any one of claims 1 to 5, characterized in that The preparation method comprises the following steps: S1, according to the weight ratio of powder A, weigh the corresponding raw materials respectively, stir the powder evenly, add the corresponding proportion of water and mix evenly to prepare liquid A; S2, according to the weight ratio of powder B, weigh the corresponding raw materials respectively, stir the powder evenly, add the corresponding proportion of water and mix evenly to prepare liquid B; S3, mixing liquid A and liquid B evenly to obtain a double-liquid magnesium phosphate early-strength and high-strength grouting material.

7. The preparation method according to claim 5, wherein: The dry powders in S1 and S2 were stirred for 2 minutes, and water was added and mixed for 2 minutes.

8. The preparation method according to claim 5, wherein: In step 3, solution A and solution B were mixed and stirred for 1 min.