A grouting material and a grouting material preparation device

Abstract

The application provides a grouting material and a grouting material preparation device, the grouting material comprises heavy-burning magnesium oxide, phosphate, borax, superfine fly ash and mixed water; wherein the mass ratio of magnesium and phosphorus of the grouting material is 3; the water-binder ratio of the grouting material is 0.18; the sand-binder ratio of the grouting material is 0.8; the borax content is 4% of the mass of the heavy-burning magnesium oxide; and the superfine fly ash content is 5% of the total mass of the heavy-burning magnesium oxide, the phosphate and the borax. The grouting material provided by the application effectively improves the setting time, early strength performance and fluidity of the grouting material by adding the borax and the superfine fly ash and further limiting the M / P of the grouting material, the borax content, the superfine fly ash content and the temperature of the mixed water, thereby providing a reliable implementation scheme for preparing the grouting material with the fast setting, early strength performance and good fluidity.

Description

Technical Field

[0001] This invention relates to the field of tunnel repair technology, and more specifically, to a grouting material and a grouting material preparation device. Background Technology

[0002] The content in this section only provides background information related to this invention and may not constitute prior art.

[0003] With the continuous development of infrastructure construction in my country, the requirements for tunnel repair technology are constantly increasing. Magnesium phosphate cement (MPC) has the characteristics of short setting time and high early strength. Using MPC to prepare grout can meet the early strength requirements of repair projects and broaden the application range of cement-based grout.

[0004] However, the quality of cement-based grouting materials on the market is currently inconsistent. Many grouting materials have uncontrollable setting times and fail to meet early strength requirements, leading to project delays and economic losses. Furthermore, grouting materials with low fluidity increase construction difficulty and time, affecting efficiency. Therefore, developing grouting materials with rapid setting, early strength, and good fluidity has profound significance and practical value. Summary of the Invention

[0005] In view of this, the first objective of the present invention is to provide a grouting material that at least overcomes the problems of uncontrollable setting time, poor early performance and fluidity of known cement-based grouting materials.

[0006] A second objective of this invention is to provide a grouting material preparation apparatus for preparing the aforementioned grouting material.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] On the one hand, the present invention provides a grouting material comprising: calcined magnesium oxide, phosphate, borax, ultrafine fly ash, and mixing water;

[0009] The grouting material has a magnesium-to-phosphorus mass ratio of 3; a water-to-cement ratio of 0.18; a sand-to-cement ratio of 0.8; a borax content of 4% of the mass of the recalcined magnesium oxide; and a superfine fly ash content of 5% of the total mass of the recalcined magnesium oxide, the phosphate, and the borax.

[0010] Optionally, the temperature of the mixing water is 40°C.

[0011] Optionally, the phosphate is ammonium dihydrogen phosphate.

[0012] On the other hand, the present invention provides a grouting material preparation apparatus for preparing the above-mentioned grouting material, comprising:

[0013] The body defines a storage space with an opening for taking out and putting in items;

[0014] A fixed component is disposed within the accommodating space and is capable of reciprocating along the height direction;

[0015] A stirring component is disposed within the accommodating space and located above the fixing component;

[0016] A stirring container is positioned on the fixed assembly; the opening of the stirring container faces the stirring component.

[0017] The door is configured to move along a predetermined movement path between a closed position where the retrieval opening is closed and an open position where the retrieval opening is open.

[0018] A drive assembly is configured to simultaneously provide the power required for movement to both the fixed assembly and the door, such that: when the fixed assembly moves upward, the door moves from the open position toward the closed position; and when the fixed assembly moves downward, the door moves from the closed position toward the open position.

[0019] Optionally, when the door is in the closed position, the accommodating space is in a sealed state.

[0020] Optionally, the motion path is an arc-shaped path, and the center of the arc-shaped path is located on the axis of the stirring component.

[0021] Optionally, the door includes two arc-shaped door bodies; the two door bodies can move along the movement path in opposite directions between the closed position and the open position.

[0022] Optionally, the driving component includes:

[0023] A lead screw is rotatably disposed along the height direction; the fixing assembly cooperates with the lead screw drive to convert the rotational motion of the lead screw into its own linear motion along the lead screw axis;

[0024] The first gear ring and the second gear ring are both coaxially arranged with the stirring component; the first gear ring, the second gear ring and the lead screw are connected by a gear transmission structure, so that the first gear ring and the second gear ring rotate synchronously with the lead screw, and the rotation directions of the first gear ring and the second gear ring are opposite; the two gate bodies are respectively connected to the first gear ring and the second gear ring;

[0025] A drive motor is connected to the lead screw to drive the lead screw to rotate.

[0026] Optionally, the interior of the body is provided with a receiving cavity, and the receiving cavity is provided with a clearance opening that communicates with the receiving space and allows the opening and closing door to pass through;

[0027] When the door is in the open position, it is hidden inside the accommodating cavity.

[0028] Optionally, the machine body is provided with a limiting groove, which extends along the movement path; the bottom of the opening and closing door is movably disposed within the limiting groove.

[0029] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0030] The grouting material provided by this invention, by adding borax and ultrafine fly ash, and further limiting the M / P ratio, borax content, ultrafine fly ash content and mixing water temperature of the grouting material, effectively improves the setting time, early strength performance and fluidity of the grouting material, thus providing a reliable implementation scheme for preparing grouting materials with fast setting, early strength performance and good fluidity. Attached Figure Description

[0031] Figure 1 Comparison of compressive strength of grout specimens at 15 min and 30 min under different borax dosages provided in Example 1 of the present invention;

[0032] Figure 2 A comparison diagram of the effect of M / P on the workability of grouting material provided in Embodiment 1 of the present invention;

[0033] Figure 3 A comparison diagram of the compressive strength of grout specimens at different curing ages under different M / P ratios is provided for Embodiment 1 of the present invention.

[0034] Figure 4 A comparative diagram showing the effect of ultrafine fly ash content on the workability of grouting material in Embodiment 1 of the present invention;

[0035] Figure 5 A comparison diagram of the compressive strength of grout specimens at different curing ages under different ultrafine fly ash admixtures provided in Example 1 of the present invention;

[0036] Figure 6 SEM image of the grout specimen when the ultrafine fly ash content is 2.5% as provided in Example 1 of the present invention;

[0037] Figure 7 SEM image of the grout specimen when the ultrafine fly ash content is 5% as provided in Example 1 of the present invention;

[0038] Figure 8SEM image of the grout specimen when the ultrafine fly ash content is 7.5% as provided in Example 1 of the present invention;

[0039] Figure 9 A comparative diagram showing the effect of mixing water at different temperatures on the workability of grouting material, provided in Embodiment 1 of the present invention;

[0040] Figure 10 A comparison of the compressive strength of grout specimens at different mixing water temperatures at 15 min and 30 min, provided for Example 1 of the present invention;

[0041] Figure 11 SEM image of grout specimen with mixing water temperature of 20°C, provided for Example 1 of the present invention;

[0042] Figure 12 SEM image of grout specimen with mixing water temperature of 30°C, provided for Example 1 of the present invention;

[0043] Figure 13 SEM image of grout specimens with a mixing water temperature of 40°C, provided for Example 1 of the present invention.

[0044] Figure 14 The graph showing the effect of ultrafine fly ash content on the exothermic reaction of grouting material in Embodiment 1 of the present invention;

[0045] Figure 15 This is a schematic diagram of the grout preparation device provided in Embodiment 2 of the present invention in one of its states; it shows the case when the opening and closing door is in the open position.

[0046] Figure 16 This is a schematic diagram of the grout preparation device provided in Embodiment 2 of the present invention in another state; it shows the case when the opening and closing door is in the closed position.

[0047] Figure 17 This is a schematic diagram of the structure of the machine body provided in Embodiment 2 of the present invention;

[0048] Figure 18 This is a structural schematic diagram of the fixing component, the driving component, and the opening / closing door in one of the states provided in Embodiment 2 of the present invention; it shows the situation when both door bodies of the opening / closing door are in the open position.

[0049] Figure 19 This is a schematic diagram of the fixed component, drive component, and opening / closing door in another state, as provided in Embodiment 2 of the present invention; it shows the situation when both door bodies of the opening / closing door are in the closed position.

[0050] Icons: 10-Main body, 12-Accommodation space, 13-Apartment opening, 14-Limiting groove, 20-Fixing component, 21-Connecting part, 22-Fixing part, 30-Stirring component, 40-Stirring container, 50-Drive component, 51-Lead screw, 52-First gear ring, 53-Second gear ring, 54-Drive motor, 55-Gear transmission structure, 551-Center gear, 552-First transmission gear, 553-Second transmission gear, 554-Third transmission gear, 60-Opening and closing door, 61-Door body. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments. The same reference numerals in the accompanying drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the described embodiments of this invention without creative effort are within the scope of protection of this invention.

[0052] Compared to the embodiments shown in the accompanying drawings, feasible embodiments within the scope of protection of this invention may have fewer components, other components not shown in the drawings, different components, components with different arrangements, or components with different connections, etc. Furthermore, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0053] Example 1

[0054] Embodiment 1 of the present invention provides a grouting material comprising calcined magnesium oxide, phosphate, borax, ultrafine fly ash, and mixing water. The grouting material is prepared from calcined magnesium oxide, phosphate, borax, ultrafine fly ash, mixing water, and quartz sand as raw materials.

[0055] The calcined magnesium oxide (MgO, abbreviated as M) is purchased from Dashiqiao Jubo High-Temperature Refractory Materials Co., Ltd., and is produced by calcining magnesite at 1800℃, appearing as a yellowish-brown powder. The phosphate can be ammonium dihydrogen phosphate (NH4H2PO4, abbreviated as P), which can be purchased from Wujiang Jinjin Light Chemical Co., Ltd., appearing as white crystals with a purity greater than 98%. Borax (Na2B4O7·10H2O, abbreviated as B) is selected from Tianjin Huasheng Scientific Reagent Co., Ltd., with a content ≥99.5%, appearing as a white powder. Ultrafine fly ash (UFA) can be purchased from Chengdu Bolei Resource Recycling Development Co., Ltd., producing Grade I fly ash. The mixing water can be tap water.

[0056] According to Embodiment 1 of the present invention, the grouting material has a magnesium-to-phosphorus mass ratio (M / P) of 3; a water-to-cement ratio (W / C) of 0.18; a sand-to-cement ratio (S / C) of 0.8; a borax content of 4% of the mass of reburned magnesium oxide; and an ultrafine fly ash content of 5% of the total mass of reburned magnesium oxide, phosphate, and borax. Furthermore, in the actual preparation of the grouting material, the temperature of the mixing water is 40°C.

[0057] The grouting material provided in Embodiment 1 of the present invention can be prepared by the following method. Specifically, the preparation method includes:

[0058] Step 10. After determining the proportions of each component of the grouting material, use an electronic scale to weigh and obtain the predetermined mass of reburned magnesium oxide, phosphate, borax and ultrafine fly ash.

[0059] Step 20. Add the predetermined mass of calcined magnesium oxide, phosphate, borax and ultrafine fly ash to a grouting material preparation device such as a cement mortar mixer and dry mix for 30 seconds to obtain a mixed dry material.

[0060] Step 30. According to the water-cement ratio of the grout, add the predetermined amount of mixing water to the mixed dry material, stir slowly for 30 seconds to obtain the mixed grout.

[0061] Step 40. According to the sand-binder ratio of the grout, add a predetermined amount of quartz sand to the mixed grout and stir quickly for 180 seconds to obtain the grout provided in Example 1 of the present invention.

[0062] To verify key performance indicators of the grout, such as fluidity, setting time, mechanical properties, hydration temperature rise, and microstructure, after obtaining the grout in step S40, the grout can be poured into a standard mold and placed on a vibration table to compact it and reduce internal air bubbles. After the grout has cured and set, it is demolded to obtain a grout specimen corresponding to the grout. For example, the dimensions of the grout specimen can be 25mm × 25mm × 280mm.

[0063] The fluidity of the grout can be tested according to the methods specified in GB / T 2419-2005 "Method for Measurement of Fluidity of Cement Mortar". The setting time of the grout can be tested according to the Vicat method in GB / T 1346-2011 "Test Method for Standard Consistency Water Requirement, Setting Time and Soundness of Cement". The mechanical properties of the grout can be tested according to the specifications in GB / T 17671-1999 "Test Method for Strength of Cement Mortar". The hydration temperature rise of the grout can be recorded in real time using an RC-4 repeatable temperature (humidity) recorder from Jiangsu Jingchuang Electric Co., Ltd. The microstructure of the grout can be obtained through SEM testing.

[0064] In the grouting material provided in Embodiment 1 of this invention, borax, as a retarder, mainly functions to extend the setting time of the grouting material, thereby achieving a controllable setting time without causing pipe blockage. Specifically, according to the reaction mechanism of borax, its physical function is to coat the MgO surface with a layer of borax magnesium, thus achieving a retarding effect and avoiding pipe blockage caused by the excessively rapid setting speed of magnesium phosphate cement.

[0065] To verify the effect of borax content on the performance of the grout, the inventors of this invention first fixed the grout's M / P=3, W / C=0.18, and S / C=0.8, and conducted an experiment on the effect of borax content on the grout's performance. The mix proportions used in the experiment on the effect of borax content on the grout's performance are shown in Table 1.

[0066] Table 1. Effect of Borax Content on Grouting Material Performance: Grouting Material Mix Proportion in the Experiment

[0067] Test number M / P W / C S / C Borax dosage 1 3 0.18 0.8 6% 2 3 0.18 0.8 4.5% 3 3 0.18 0.8 4%

[0068] After completing the experiment on the effect of borax dosage on the performance of grout, the fluidity and setting time of the grout under different borax dosages were obtained as shown in Table 2.

[0069] Table 2. Flowability and setting time of grout with different borax dosages

[0070] Test number Liquidity Initial setting time 1 - >10min 2 270mm 6min03s 3 255mm 5min30s

[0071] As shown in Table 2, the initial setting time of the grout decreased with decreasing borax content. When the borax content decreased from 6% to 4%, the corresponding initial setting time decreased from more than ten minutes to five and a half minutes, a decrease of more than 50%. When the borax content was 4.5%, the initial setting time was 6 minutes and 3 seconds, which was longer than that of the 4% borax content. When the borax content was low, the hydration rate of the grout was fast, and it would harden within minutes, resulting in insufficient flowability. With the increase of borax content, borax would inhibit the hydration reaction to a certain extent, giving the grout sufficient time to flow, thus increasing the initial fluidity. During the experimental study, it was found that when the borax content was 6%, the setting time was too slow and did not meet the fast-setting characteristics of tunnel anchor grout. When the borax content was 4% and 4.5%, both the initial setting time and fluidity of the grout met the requirements.

[0072] Secondly Figure 1 The compressive strength of grout specimens at 15 min and 30 min is shown under different borax dosages. It is worth noting that because the initial setting time of the grout specimens with 6% borax is longer, the mechanical strength data of these specimens at 15 min were not collected.

[0073] Depend on Figure 1It is evident that for 4% and 6% borax content, the compressive strength of the grout specimens increased by 24.4% at 30 minutes. At 30 minutes, the grout specimen with 4% borax content exhibited the highest compressive strength of 59.6 MPa, slightly higher than that with 4.5% borax content. The grout specimen with 6% borax content showed the lowest strength, at 47.9 MPa. This is because borax hinders the hydration reaction, inhibits the formation of struvite (i.e., a hydration product of magnesium phosphate cement), and alters the crystal structure of struvite, leading to a decrease in the strength of the grout specimens.

[0074] It is evident that there is no significant difference in the mechanical properties of the grout with borax dosages of 4% and 4.5%. Considering the influence of borax dosage on the flowability and initial setting time of the grout, Example 1 of this invention determines the borax dosage to be 4%.

[0075] To verify the effect of the M / P ratio on the performance of the grout, the inventors of this invention fixed the W / C ratio of the grout at 0.18, the S / C ratio at 0.8, and the borax content at 4%, and conducted an experiment on the effect of M / P on the performance of the grout. The mix proportions used in the experiment on the effect of M / P on the performance of the grout are shown in Table 3.

[0076] Table 3. Mix proportions of grouting material in the experiment on the effect of M / P on grouting material performance.

[0077] Test number M / P W / C S / C Borax dosage 1 2 0.18 0.8 4% 2 3 0.18 0.8 4% 3 4 0.18 0.8 4% 4 5 0.18 0.8 4%

[0078] After completing the test on the influence of M / P on the performance of grouting material, the results were obtained. Figure 2 The chart shows a comparison of the impact of M / P on the workability of the grouting material. (See figure.) Figure 2 As shown, the fluidity of the grout first increases and then decreases as the M / P ratio increases from 2:1 to 5:1. When M / P=3, the fluidity reaches its maximum value of 255 mm. When M / P=5, the fluidity reaches its minimum value of 177 mm, indicating low fluidity and making grouting operations difficult. The setting time of the grout decreases continuously as the M / P ratio increases from 2:1 to 5:1. When M / P=5, the setting time is the shortest, only 6 min 12 s. When M / P=2, the setting time is the longest, 12 min. This is because with the increase of MgO content, more water is used to wet the surface of magnesium oxide, resulting in a decrease in the mixing water content. Simultaneously, a large amount of phosphate cannot be fully dissolved in water and remains in the grout as solid particles, increasing the grout flow resistance and reducing the fluidity of the grout.

[0079] Secondly Figure 3 The diagram shows a comparison of the compressive strength of grout specimens at different curing ages under different M / P ratios. (Example:) Figure 3As shown, the grout exhibits high early strength, with compressive strength exceeding 30 MPa at both 15 and 30 minutes under different M / P ratios. Initially, the compressive strength of the grout increases with the curing period. This is because struvite, a hydration product of the grout, possesses high stability. With increasing curing time, the amount of struvite produced gradually increases, and the struvite crystals can interlock to form a network structure, further enhancing the compressive strength of the grout.

[0080] At a curing age of 28 days, the compressive strength of MPC grout decreased due to the potential decomposition of struvite. In a humid environment, struvite gradually hydrolyzes into Mg(OH)₂ and phosphates, leading to the destruction of its crystal structure. The resulting Mg(OH)₂ product, with its loose structure, causes increased porosity, thereby reducing its mechanical properties.

[0081] Furthermore, the intense heat release during the early hydration of the grout causes a sudden rise in local temperature, resulting in thermal stress microcracks. Over time, these microcracks propagate under load or environmental influences, weakening the overall structure.

[0082] When the M / P ratio increased from 2:1 to 3:1, the compressive strength of the grout specimens showed an increasing trend at each time point. The maximum compressive strengths of the grout specimens at 15 min, 30 min, 3 d, 7 d, and 28 d were 51.9 MPa, 59.8 MPa, 64.4 MPa, 57.8 MPa, and 54.4 MPa, respectively. When the phosphate content was high, a large number of undissolved phosphate particles were present in the grout specimens. Since the phosphate particles themselves have low strength, they cannot provide skeletal support, thus reducing the mechanical properties of the specimens. On the other hand, the increase in MgO content promoted the formation of struvite, increasing the mechanical properties of the specimens. When the M / P ratio increased from 3:1 to 5:1, the compressive strength of the grout specimens showed a decreasing trend at all curing ages. The compressive strength of the grout specimens was at its lowest value when the M / P ratio was 5:1. As the phosphate content decreases, the number of struvite crystals generated during hydration decreases, affecting the development of grout strength.

[0083] When M / P = 3:1, the compressive strength of the grout specimen reaches its maximum, and the subsequent compressive strength loss is relatively low. Taking into account factors such as the fluidity, initial setting time, and compressive strength of the grout, Example 1 of the present invention determines the M / P of the grout to be 3.

[0084] In the grouting material provided in Embodiment 1 of this invention, ultrafine fly ash is fine powder particles collected from the flue gas generated by burning pulverized coal in coal-fired power plants, and it has high adsorption activity. The role of ultrafine fly ash in the grouting material is mainly reflected in morphological effect, activity effect, and micro-aggregate effect.

[0085] Among them, ultrafine fly ash has a micro-aggregate effect and low porosity, which can improve the compactness of grouting materials. However, it may also lead to a decrease in the mechanical properties of the grouting materials. The main reasons are as follows:

[0086] 1. Due to its large specific surface area and porous structure, ultrafine fly ash exhibits strong adsorption capacity. When added to grout, it adsorbs some phosphates, thus reducing the formation of struvite. Furthermore, as a heterogeneous material, ultrafine fly ash contains impurities and carbon, which adsorb onto the surface of hydration products, forming loose and porous hydration products. Since struvite is a major source of strength in grout, its reduction significantly impacts the material's later strength development.

[0087] 2. The addition of ultrafine fly ash lowers the early pH value of the grout, delaying the dissolution of MgO and the formation of struvite, resulting in slow early strength development of the grout. Furthermore, pH changes may affect the ionization equilibrium of phosphates, thereby influencing the reaction rate and product formation.

[0088] 3. When the content of ultrafine fly ash increases, the effective water-cement ratio of the grout decreases, and it will replace part of the reburned magnesium oxide and phosphate, resulting in a reduction of hydration products and thus reducing the compressive strength of the grout.

[0089] Therefore, it is necessary to conduct further research on the dosage of ultrafine fly ash.

[0090] To verify the effect of ultrafine fly ash content on the performance of grouting material, the inventors of this invention fixed the grouting material's M / P=3, W / C=0.18, S / C=0.8, and borax content at 4%, and conducted experiments on the effect of ultrafine fly ash content on the grouting material's performance. The mix proportions used in the experiment on the effect of ultrafine fly ash content on the grouting material's performance are shown in Table 4.

[0091] Table 4. Mix proportions of grouting material in the experiment on the effect of ultrafine fly ash content on grouting material performance.

[0092] Test number M / P W / C S / C Borax dosage Ultrafine fly ash content 1 3 0.18 0.8 4% 2.5% 2 3 0.18 0.8 4% 5% 3 3 0.18 0.8 4% 7.5%

[0093] After completing the experiment on the effect of ultrafine fly ash content on the performance of grouting material, the following results were obtained: Figure 4 The diagram shows a comparison of the effects of ultrafine fly ash content on the workability of grouting materials.

[0094] like Figure 4 As shown, regarding the fluidity of the grout, the fluidity increased from 250 mm to 260 mm with the increase of ultrafine fly ash content. This indicates that ultrafine fly ash reduces the friction between cement particles, acting as a lubricant and making the grout flow more easily. The increase in fluidity was most significant when the ultrafine fly ash content increased from 5% to 7.5%.

[0095] The grouting material exhibited the shortest setting time (7 min 46 s) when the ultrafine fly ash content was 5%. Conversely, the grouting material with the ultrafine fly ash content of 7.5% had the longest setting time (8 min 46 s). This is because increasing the proportion of ultrafine fly ash slows the hydration process of the grouting material due to the reduced amount of cementitious material, resulting in a significant decrease in the heat release during hydration and consequently, an increase in the setting time.

[0096] Figure 5 This paper presents a comparison of the compressive strength of grout specimens at different curing ages under varying ultrafine fly ash content. Based on... Figure 5 It is evident that the early compressive strength of the grout increases with the curing age, but decreases with the increase of ultrafine fly ash content. Therefore, the addition of ultrafine fly ash will impair the mechanical properties of the grout to some extent, and the greater the ultrafine fly ash content, the greater the damage to mechanical properties. Furthermore, compared to grout without ultrafine fly ash, the mechanical loss of the grout is the greatest at 15 minutes, approximately 80%. When the ultrafine fly ash content is 7.5%, the compressive strength of the grout is the lowest, decreasing to 47.1 MPa at 3 days of curing, a reduction of 27.2% compared to the control group (i.e., the group with 0% ultrafine fly ash content). Although the grout has the highest fluidity at an ultrafine fly ash content of 7.5%, its mechanical properties are poor; therefore, the use of a 7.5% ultrafine fly ash content ratio for preparing grout is not considered. When the content of ultrafine fly ash is 2.5%, the grouting material has the smallest loss in compressive strength. At a curing age of 3 days, the compressive strength is 59.8 MPa, which is very small compared with the control group's 64.4 MPa.

[0097] Figures 6 to 8 SEM images of grout specimens with different ultrafine fly ash contents are shown. Figures 6 to 8 It is evident that some ultrafine fly ash particles fill the voids in the grout matrix, increasing its density. A small amount of ultrafine fly ash particles are also embedded around the struvite to form a denser network structure. However, with increasing ultrafine fly ash content, the fly ash content makes the grout matrix structure looser, resulting in lower compressive strength.

[0098] In summary, when preparing grouting materials, it is necessary to strictly control the dosage of ultrafine fly ash to achieve a balance between its plasticizing effect and reducing mechanical property loss. Therefore, Example 1 of this invention determines the dosage of ultrafine fly ash to be 5%.

[0099] In addition to the factors mentioned above that may affect the performance of grouting materials, the inventors of this invention have further discovered that the temperature of the mixing water is also one of the factors affecting the performance of grouting materials.

[0100] To verify the effect of mixing water temperature on the performance of the grout, the inventors of this invention fixed the grout's M / P=3, W / C=0.18, S / C=0.8, borax content at 4%, and ultrafine fly ash content at 5%, and conducted an experiment on the effect of mixing water temperature on the grout's performance. The mix proportions used in the experiment on the effect of mixing water temperature on the grout's performance are shown in Table 5.

[0101] Table 5. Mix proportions of grouting material in the experiment on the effect of mixing water temperature on grouting material properties.

[0102] Test number M / P W / C S / C Borax dosage Ultrafine fly ash content Mixing water temperature 1 3 0.18 0.8 4% 5% 20℃ 2 3 0.18 0.8 4% 5% 30℃ 3 3 0.18 0.8 4% 5% 40℃

[0103] Figure 9 A comparative graph showing the effect of mixing water at different temperatures on the workability of grouting materials is presented. According to... Figure 9 It can be seen that the fluidity and setting time of the grout decrease with increasing mixing water temperature. The grout exhibits the highest fluidity (255 mm) when the mixing water temperature is 20℃. At 30℃ and 40℃, the fluidity is 242 mm and 230 mm, respectively. Regarding setting time, the longest setting time (7 min 46 s) is observed at 20℃, while the shortest setting time (4 min 12 s) is observed at 40℃. This indicates that higher mixing water temperatures accelerate the hydration reaction, leading to faster formation of the grout structure and thus reducing fluidity and setting time.

[0104] Figure 10 The compressive strength of grout specimens at different mixing water temperatures was demonstrated at 15 min and 30 min. According to... Figure 10 It is evident that the early strength of the grout specimens increased significantly after 15 minutes as the mixing water temperature increased. When the mixing water temperature rose from 20℃ to 30℃, the compressive strength of the grout specimens increased by 115.7%. When the mixing water temperature rose from 30℃ to 40℃, the compressive strength of the grout specimens increased by 64.9%. This is because the hydration reaction rate of magnesium phosphate accelerates with increasing mixing water temperature, promoting the formation of more hydration products in a short time, thereby improving early strength.

[0105] For the compressive strength at 30 minutes, the grout specimen with a mixing water temperature of 20℃ showed the highest compressive strength, at 48.4 MPa. For grout specimens with mixing water temperatures of 30℃ and 40℃, the compressive strengths at 30 minutes were similar, at 42.1 MPa and 43.9 MPa, respectively. This indicates that the strength of the grout specimens at 30 minutes did not differ significantly under different mixing water temperatures, suggesting that high temperatures may accelerate the hydration reaction.

[0106] Figures 11 to 13SEM images of grout specimens at different mixing water temperatures are shown. Figures 11 to 13 It is evident that the crystal morphology of struvite varies under different mixing water temperatures. SEM images reveal that struvite crystals exhibit various forms, including long columnar, platy, and network structures. At a mixing water temperature of 20°C, the hydration reaction rate is slow, allowing sufficient time for crystal growth; thus, struvite primarily produces long columnar crystals with relatively small sizes. As the mixing water temperature increases, the crystal size continuously increases, the amount of hydration products increases, the system density increases, and the porosity decreases. In summary, the mechanical properties of the MPC grout are optimal at a mixing water temperature of 40°C. Therefore, Example 1 of this invention uses a mixing water temperature of 40°C.

[0107] Based on this, the inventors of this invention also conducted experiments on the effect of ultrafine fly ash content on the exothermic hydration reaction of grouting materials, in order to explore the influence of ultrafine fly ash on the exothermic hydration reaction of grouting materials. The mix proportions used in the experiment on the effect of ultrafine fly ash content on the performance of grouting materials are shown in Table 6.

[0108] Table 6. Mix proportions of grouting material in the experiment on the effect of ultrafine fly ash content on grouting material performance.

[0109] Test number M / P W / C S / C Borax dosage Ultrafine fly ash content Mixing water temperature 1 3 0.18 0.8 4% 2.5% 20℃ 2 3 0.18 0.8 4% 5.0% 20℃ 3 3 0.18 0.8 4% 7.5% 20℃

[0110] Figure 14 This is a graph showing the effect of ultrafine fly ash content on the exothermic reaction of grouting material. Figure 14 It can be seen that when the ultrafine fly ash content is 2.5%, the initial temperature of the grout is 13.8℃. When the hydration reaction begins, the grout rapidly heats up, reaching a peak temperature of 39.3℃ in about 12 minutes. Afterward, the exothermic temperature of the hydration reaction gradually decreases, and the grout specimen temperature cools to 27.4℃ in about 30 minutes. Compared to the 2.5% ultrafine fly ash content, when the ultrafine fly ash content is 5%, the grout reaches its maximum temperature of 46.9℃ in about 10 minutes. By comparing the 2.5% and 5% ultrafine fly ash content, it is found that an appropriate increase in ultrafine fly ash content raises the peak temperature and accelerates the time to peak temperature, which is consistent with the setting time test results.

[0111] For a 7.5% ultrafine fly ash content, the grout's temperature rises slowly after the hydration reaction begins, reaching a peak temperature of 36.0℃ in approximately 15 minutes. The overall exothermic reaction temperature fluctuation is relatively small. Comparison of the exothermic hydration reaction of grout with different ultrafine fly ash contents reveals that both the timing and magnitude of the temperature peak are related to the ultrafine fly ash content. Specifically, when the ultrafine fly ash content is 5%, the grout exhibits the highest temperature peak and the earliest occurrence time. This demonstrates that as the ultrafine fly ash content increases, the temperature peak initially increases and then decreases.

[0112] In summary, the grouting material provided in Embodiment 1 of the present invention, by adding borax and ultrafine fly ash, and further limiting the M / P ratio, borax content, ultrafine fly ash content and mixing water temperature of the grouting material, effectively improves the setting time, early strength performance and fluidity of the grouting material, thereby providing a reliable implementation scheme for preparing grouting materials with fast setting, early strength performance and good fluidity.

[0113] Example 2

[0114] As can be seen from Example 1 above, in the research and development stage of grouting materials, the grouting materials required for the test are usually prepared using a cement mortar mixer. However, the inventors of this invention have discovered that when a known cement mortar mixer is in operation, the mixing container 40 containing the materials is always exposed to the external environment. Since the raw materials for preparing the grouting material, such as calcined magnesium oxide, phosphate, and borax, are in powder form, dust or slurry is easily scattered and diffused into the external environment when mixing the mixture composed of multiple raw materials, thereby affecting the health of relevant personnel and polluting the environment.

[0115] Therefore, Embodiment 2 of the present invention provides a grout preparation apparatus, particularly a cement mortar mixer capable of preventing dust or slurry from flying during grout preparation. The grout preparation apparatus provided in Embodiment 2 of the present invention is at least suitable for preparing the grout described in Embodiment 1 above.

[0116] Figure 15 and Figure 16 These are schematic diagrams of the exemplary grouting material preparation device provided in Embodiment 2 of the present invention under two different states. First, as... Figure 15 As shown in Embodiment 2 of the present invention, the grouting material preparation device may include a body 10, a fixing component 20, a stirring component 30, a stirring container 40, and a driving component 50.

[0117] Reference Figure 15 or Figure 17 As shown, the body 10 defines a receiving space 12 with an opening for inserting or removing the mixing container 40, so that the mixing container 40 can be placed into the receiving space 12 through the opening. For example, the receiving space 12 can be a U-shaped notch formed on the body 10, where the front, left, and right sides of the notch can be open, while the top, bottom, and rear sides can be closed. The open portion of the notch can be considered the opening for inserting or removing the container.

[0118] The fixing component 20 is disposed within the accommodating space 12 and can reciprocate along the height direction. The fixing component 20 is mainly used to provide a carrier for the installation of the mixing container 40 and to drive the mixing container 40 to reciprocate along the height direction.

[0119] The stirring component 30 is disposed within the accommodating space 12 and located above the fixing component 20. The stirring component 30 is adapted to rotate under the drive of an independent driving component (not shown in the figure) so that when the stirring container 40 moves upward to the point where the stirring component 30 extends into the interior of the stirring container 40, the material inside the stirring container 40 can be stirred by the rotation of the stirring component 30.

[0120] The stirring container 40 is positioned on the fixing component 20. Furthermore, the opening of the stirring container 40 faces the stirring component 30.

[0121] The drive assembly 50 is configured to provide the power required for the motion of the stationary assembly 20. That is, the stationary assembly 20 is capable of reciprocating along the height direction under the drive of the drive assembly 50.

[0122] It is understandable that the structure of the grout preparation device described above is actually the same as that of a cement mortar mixer known in the prior art. With such devices, because the mixing container 40 is exposed to the outside through the opening of the containing space 12 throughout the entire operation, dust or slurry is easily scattered and diffused into the external environment when mixing mixtures of multiple raw materials.

[0123] Therefore, we will continue to refer to Figure 15 and Figure 16 The grout preparation device provided in Embodiment 2 of the present invention may further include an opening and closing door 60. The opening and closing door 60 is configured to move along a predetermined movement path between a closed position (closing the pick-up and drop-off port) and an open position (opening the pick-up and drop-off port). The movement path of the opening and closing door 60 may be an arc-shaped path, in which case the opening and closing mechanism of the opening and closing door 60 is similar to that of a revolving door. Of course, in other embodiments of the present invention, the movement path of the opening and closing door 60 may also be a straight path, in which case the opening and closing mechanism of the opening and closing door 60 is similar to that of a sliding door.

[0124] Understandably, by setting the opening and closing door 60, the access port of the accommodating space 12 can be selectively opened and closed as needed, thereby achieving the closing of the access port of the accommodating space 12 during mixing operations (see...). Figure 16 Furthermore, when the accommodating space 12 has the aforementioned U-shaped notch, the accommodating space 12 can be kept sealed when the opening and closing door 60 is in the closed position. This design can effectively prevent dust or slurry from flying around and spreading into the external environment during the mixing operation.

[0125] Based on this, Embodiment 2 of the present invention further specifies that the drive assembly 50 can also provide the power required for the movement of the opening and closing door 60. That is, the drive assembly 50 is configured to provide power to both the fixing assembly 20 and the opening and closing door 60 simultaneously, such that: when the fixing assembly 20 moves upward, the opening and closing door 60 moves from the open position to the closed position; when the fixing assembly 20 moves downward, the opening and closing door 60 moves from the closed position to the open position.

[0126] Based on the above settings, when preparing the grouting material described in Example 1 using the grouting material preparation device provided in Example 2 of the present invention, the preparation method described below can be adopted.

[0127] Specifically, the preparation method includes:

[0128] Step 100. After determining the proportions of each component of the grouting material, use an electronic scale to weigh and obtain the predetermined mass of reburned magnesium oxide, phosphate, borax and ultrafine fly ash.

[0129] Step 200. Add the predetermined mass of reburned magnesium oxide, phosphate, borax, and ultrafine fly ash to the mixing container 40. Then, position the mixing container 40 on the fixing component 20. Subsequently, the drive component 50 drives the fixing component 20 upwards, causing the mixing container 40 to move upwards synchronously. During this process, the opening / closing door 60 moves from the open position to the closed position along a predetermined path under the power provided by the drive component 50. When the mixing container 40 moves to the point where the stirring component 30 extends into the mixing container 40 and reaches a suitable position, the opening / closing door 60 moves to the closed position to close the access port of the accommodating space 12. Afterwards, the stirring component 30 rotates to dry-mix the materials in the mixing container 40 for 30 seconds to obtain a mixed dry material.

[0130] Step 300. The drive assembly 50 drives the fixed assembly 20 to move downwards, thereby causing the mixing container 40 to move downwards synchronously. During this process, the opening / closing door 60 moves from the closed position to the open position along a predetermined movement path under the power provided by the drive assembly 50. When the mixing container 40 moves downwards to the initial position, the opening / closing door 60 moves to the open position to open the loading / unloading port of the accommodating space 12. Then, according to the water-cement ratio of the grout, a predetermined amount of mixing water is added to the mixed dry material in the mixing container 40 through the loading / unloading port.

[0131] Based on this, referring to the method described in step 200, the fixing component 20 drives the mixing container 40 to move upward again until the stirring component 30 extends into the mixing container 40 and reaches a suitable position, and the opening and closing door 60 is closed again. After that, the stirring component 30 rotates to slowly stir the material in the mixing container 40 for 30 seconds to obtain a mixed slurry.

[0132] Step 400. Referring to step S300, first move the fixing component 20 downwards to drive the mixing component 30 until the opening / closing door 60 is in the open position. Then, according to the sand-binder ratio of the grout, add a predetermined amount of quartz sand to the mixed slurry in the mixing container 40 through the inlet / outlet.

[0133] Based on this, referring to the method described in step 200, the fixing component 20 drives the mixing container 40 to move upward again until the mixing component 30 extends into the mixing container 40 and reaches a suitable position, and the opening and closing door 60 is closed again. After that, the mixing component 30 rotates to quickly mix the material in the mixing container 40 for 180 seconds, and the grouting material described in Example 1 can be obtained.

[0134] As can be seen, the grout preparation device provided in Embodiment 2 of the present invention adds an opening and closing door 60 to the existing cement mortar mixer. This door, when closed during the mixing process, effectively prevents dust or grout from flying around and spreading into the external environment. Simultaneously, by using a single drive component 50 to provide the necessary power for the movement of both the fixed component 20 and the opening and closing door 60, the device structure is simplified, manufacturing and operating costs are reduced, and the linkage between the fixed component 20 and the opening and closing door 60 is achieved, significantly improving operational efficiency. This linkage design further reduces manual intervention, making the entire mixing process more automated.

[0135] In some possible embodiments, the door 60 is made of a transparent material, such as tempered glass, so that the interior of the accommodating space 12 can be viewed in real time when the door 60 is in the closed position.

[0136] In some possible embodiments, the movement path of the opening / closing door 60 can be an arc-shaped path, with the center of the arc located on the axis of the stirring member 30. That is, the opening / closing door 60 can rotate around the axis of the stirring member 30 to open or close the loading / unloading port.

[0137] Compared to a straight path, using an arc path can minimize the lateral volume of the entire grout preparation device, especially when the opening and closing door 60 is in the open position, thus facilitating the compact design of the device.

[0138] In some possible embodiments, the interior of the body 10 is provided with a receiving cavity (not shown in the figure), and the receiving cavity has a clearance opening 13 that communicates with the receiving space 12 and allows the opening and closing door 60 to pass through, see Figure 17 For example, the body 10 may be a hollow shell, so that the interior of the shell serves as a receiving cavity, and the clearance opening 13 may be formed on the rear side wall of the receiving space 12.

[0139] This allows the door 60 to move along a predetermined movement path through the clearance opening 13 between an open position inside the receiving cavity and a closed position outside the receiving cavity. When the door 60 is in the open position, it is concealed within the receiving cavity.

[0140] By designing the accommodating cavity and the clearance opening 13, the opening and closing door 60 can move between the open and closed positions. The accommodating cavity can also protect the opening and closing door 60 when it is in the open position. Furthermore, it can improve the aesthetics of the entire grouting material preparation device when it is not in use, and further optimize the structural design of the entire device.

[0141] In some possible embodiments, reference continues to be made to Figure 17 The body 10 is provided with a limiting groove 14, which extends along the movement path of the opening and closing door 60. The bottom of the opening and closing door 60 is movably disposed within the limiting groove 14. For example, the bottom of the opening and closing door 60 can slide or roll with the limiting groove 14.

[0142] When the door 60 moves between the open and closed positions along a predetermined movement path, the bottom of the door 60 is always within the limiting groove 14, thereby improving the stability of the door 60 during movement through the limiting groove 14.

[0143] In some possible embodiments, combined Figure 18 As shown, when the movement path of the opening and closing door 60 is an arc-shaped path, the opening and closing door 60 may further include two arc-shaped door bodies 61. For example, both door bodies 61 may adopt a quarter-circle arc structure, and when both door bodies 61 are in the open or closed position, they form a semi-circular opening and closing door 60.

[0144] The two doors 61 can move in opposite directions along the movement path between a closed position and an open position. In other words, the retrieval opening of the accommodating space 12 is opened or closed by two doors 61 moving in opposite directions.

[0145] Specifically, assuming that both doors 61 are initially in the following state... Figure 18 The opening position is shown, at which point the retrieval port of the accommodating space 12 is open. Based on this, when the fixing component 20 moves upward, one door 61 rotates clockwise from the open position to the closed position along the movement path, and the other door 61 rotates counterclockwise from the open position to the closed position along the movement path; when the fixing component 20 moves upward to the target position, both door 61 simultaneously reach the position shown. Figure 19The closed position shown allows the retrieval port to be closed by the cooperation of the two door bodies 61. When the fixing assembly 20 moves downward, the two door bodies 61 can move in opposite directions to open the retrieval port simultaneously.

[0146] Understandably, the design of the two doors 61 helps to reduce the time required to fully open or close the loading and unloading ports. On the other hand, it can distribute the total stroke required to open and close the door 60 to the two doors 61, so that the two doors 61 can open or close the loading and unloading ports with a smaller stroke. This helps to reduce the stroke of the fixing component 20, thereby reducing the volume of the entire grouting device in the height direction.

[0147] Furthermore, the drive assembly 50 can be constructed in such a way that it provides the power required for movement to both the fixed assembly 20 and the two door bodies 61 of the opening and closing door 60.

[0148] Combination Figure 18 As shown, the drive assembly 50 may include a lead screw 51, a first gear ring 52, a second gear ring 53, and a drive motor 54. The lead screw 51 is rotatably mounted on the ground along the height direction, for example, within the receiving cavity of the machine body 10. The fixing assembly 20 is driven by the lead screw 51, specifically through a threaded drive, to convert the rotational motion of the lead screw 51 into its own linear motion along the axial direction of the lead screw 51.

[0149] Exemplarily, the fixing component 20 may further include a connecting portion 21 and a fixing portion 22. The connecting portion 21 may be threadedly connected to the lead screw 51, and the connecting portion 21 may slide with the body 10 so that the connecting portion 21 can slide along the height direction. The fixing portion 22 is disposed on the connecting portion 21, specifically at the end of the connecting portion 21 opposite to the lead screw 51, and the stirring container 40 is positioned on the fixing portion 22. With this design, when the lead screw 51 rotates, the connecting portion 21 can drive the fixing portion 22 and the stirring container 40 to move along the height direction based on the threaded transmission principle.

[0150] Both the first gear ring 52 and the second gear ring 53 are coaxially arranged with the stirring component 30. That is, the center of the first gear ring 52 and the second gear ring 53 coincides with the center of the arc path of the opening and closing door 60. Furthermore, both the first gear ring 52 and the second gear ring 53 can be rotatably arranged on the machine body 10, for example, within the receiving cavity of the machine body 10.

[0151] The first gear ring 52, the second gear ring 53, and the lead screw 51 are connected by a gear transmission structure 55, enabling the first gear ring 52 and the second gear ring 53 to rotate synchronously with the lead screw 51, and the rotation directions of the first gear ring 52 and the second gear ring 53 are opposite. The two door bodies 61 are respectively connected to the first gear ring 52 and the second gear ring 53.

[0152] The drive motor 54 is connected to the lead screw 51 to drive the lead screw 51 to rotate. Exemplarily, the accompanying drawings of the present invention show a case where the output end of the drive motor 54 is directly connected to the lead screw 51. Of course, the drive motor 54 can also have other ways of being connected to the lead screw 51, as long as it can drive the lead screw 51 to rotate.

[0153] Based on the above configuration, when the drive motor 54 drives the lead screw 51 to rotate in the forward direction, the fixing component 20 will move upward along the height direction based on the thread transmission principle. During this process, the first gear ring 52 and the second gear ring 53 will rotate in opposite directions around the center of the arc path, thereby driving the two door bodies 61 to move in opposite directions from the open position to the closed position. Correspondingly, when the drive motor 54 drives the lead screw 51 to rotate in the reverse direction, the fixing component 20 will move downward along the height direction. During this process, the first gear ring 52 and the second gear ring 53 will drive the two door bodies 61 to move in opposite directions from the closed position to the open position.

[0154] It is worth noting that by adopting the above settings, it is only necessary to reasonably set the gear ratio between each gear in the gear transmission structure 55, as well as the gear ratio between each gear and each gear ring, so that when the lead screw 51 rotates multiple times, each gear ring rotates only a small angle, so that the fixed component 20 can smoothly reciprocate along the height direction for a predetermined distance, and each door 61 can smoothly move between the open position and the closed position.

[0155] Furthermore, the drive assembly 50 with the above-described structure can further improve the stability of each door 61 during movement through gear transmission, and the fixed assembly 20 is driven by a threaded transmission mechanism, which is conducive to more precise control of the position of the fixed assembly 20 in the height direction.

[0156] Furthermore, such as Figure 19 As shown, the gear transmission structure 55 may include a rotatable central gear 551, a first transmission gear 552, a second transmission gear 553, and a third transmission gear 554. The central gear 551 is coaxially arranged with the two gear rings, that is, the axis of the central gear 551 coincides with the center of the arc path of the opening and closing door 60. The first transmission gear 552 is coaxially arranged with the lead screw 51 and meshes with the central gear 551. The second transmission gear 553 meshes with the second gear ring 53 and the central gear 551 respectively, and the third transmission gear 554 meshes with the second transmission gear 553 and the first gear ring 52 respectively.

[0157] With this design, when the lead screw 51 rotates, the first transmission gear 552 causes the central gear 551 to rotate, which in turn causes the second transmission gear 553 to rotate, so that the second gear ring 53 rotates synchronously and in the same direction as the second transmission gear 553. Correspondingly, the second transmission gear 553 also causes the third transmission gear 554 to rotate, so that the first gear ring 52 rotates synchronously and in the same direction as the third transmission gear 554, and the second gear ring 53 rotates in the opposite direction to the first gear ring 52. This design enables transmission between the lead screw 51, the first gear ring 52, and the second gear ring 53 with a relatively small number of gears, and allows the first gear ring 52 and the second gear ring 53 to rotate in opposite directions.

[0158] In some possible embodiments, the fixing part 22 for positioning the stirring container 40 may further be an electromagnet. The stirring container 40 may be made of a magnetic material. When the electromagnet is energized, the stirring container 40 is magnetically attracted and fixed to the electromagnet. For example, the magnetic material may be ferritic stainless steel or martensitic stainless steel, so that the stirring container 40 can be attracted by the electromagnet while also taking into account the strength and corrosion resistance of the stirring container 40.

[0159] By using an electromagnet as the fixing part 22, it is beneficial to improve the stability of the mixing container 40 after it is fixed, as well as the convenience of disassembling and assembling the mixing container 40.

[0160] The above are merely preferred embodiments of the present invention and are not intended to limit the present 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 grout, characterized in that, Comprise: Dead-burned magnesium oxide, ammonium dihydrogen phosphate, borax, superfine fly ash and mixed water; Wherein, the magnesium-phosphorus mass ratio of the grouting material is 3; the water-binder ratio of the grouting material is 0.18; the sand-binder ratio of the grouting material is 0.8; the borax content is 4% of the mass of the dead-burned magnesium oxide; the superfine fly ash content is 5% of the total mass of the dead-burned magnesium oxide, the ammonium dihydrogen phosphate and the borax; the temperature of the mixed water is 40℃.

2. A grout preparation device for preparing the grout according to claim 1, characterized in that Comprise: Machine body, defining a containing space with a taking and placing opening; Fixed assembly, provided in the containing space and reciprocally movable along a height direction; Stirring component, provided in the containing space and located above the fixed assembly; Stirring container, positioned on the fixed assembly; the opening of the stirring container is opposite to the stirring component; Open-close door, configured to move along a predetermined movement path between a closed position closing the taking and placing opening and an open position opening the taking and placing opening; Driving assembly, configured to simultaneously provide power required by the movement of the fixed assembly and the open-close door, so that when the fixed assembly moves upward, the open-close door moves from the open position to the closed position, and when the fixed assembly moves downward, the open-close door moves from the closed position to the open position; The movement path is an arc-shaped path, and the center of the arc-shaped path is located on the axis of the stirring component; The open-close door comprises two arc-shaped door bodies; The two door bodies move in opposite directions along the movement path between the closed position and the open position; The driving assembly comprises: Lead screw, rotatably arranged along the height direction; the fixed assembly and the lead screw are drivingly matched to convert the rotational movement of the lead screw into the linear movement of the fixed assembly along the axial direction of the lead screw; First and second toothed rings, coaxially arranged with the stirring component; the first and second toothed rings and the lead screw are drivingly connected through a gear transmission structure, so that the first and second toothed rings rotate synchronously with the lead screw, and the rotation directions of the first and second toothed rings are opposite; the two door bodies are respectively connected to the first and second toothed rings; Driving motor, drivingly connected to the lead screw to drive the rotation of the lead screw.

3. The grout preparation device according to claim 2, characterized in that When the open-close door is in the closed position, the containing space is in a closed state.

4. The grout preparation device of claim 2, wherein The machine body is internally provided with a containing cavity, and the containing cavity is provided with a avoiding opening in communication with the containing space and for the open-close door to pass through; When the open-close door is in the open position, the open-close door is hidden in the containing cavity.

5. The grout preparation device of claim 2, wherein The machine body is provided with a limiting groove extending along the movement path, and the bottom of the open-close door is movably arranged in the limiting groove.

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