A cast-in-place concrete plastic stage slurry jet enhancement method

Abstract

This invention relates to a method for reinforcing cast-in-place concrete during its plastic stage using grout jetting, belonging to the field of concrete reinforcement technology. The grout jet-reinforced concrete during the plastic stage is composed of a common concrete matrix (component A) and a high-performance grout (component B). The high-performance grout (component B) is injected into the common concrete matrix (component A) during its plastic stage using a high-pressure rotating jet method, and the two components fuse in situ to form reinforced concrete. This invention enables in-situ high-pressure rotating jet reinforcement of concrete during its initial plastic stage, solving problems such as uneven reinforcement, separation of the old and new interfaces, uncontrollable strength improvement, material waste, and damage to the matrix after hardening. It also considers ease of construction, controllable strength, structural integrity, and economy.

Description

Technical Field

[0001] This invention belongs to the field of high-performance concrete materials and preparation technology, and is applicable to improving the performance of cast-in-place concrete during the plastic period of building floor slabs, foundation slabs, and large-volume cast-in-place pile caps. Background Technology

[0002] Existing technologies for enhancing the strength and reinforcing defects of cast-in-place concrete can be mainly divided into two categories, both of which have significant drawbacks:

[0003] (1) Pre-mixing of reinforcing materials before pouring Traditional methods involve pre-mixing silica fume, mineral powder, and expanding agents at the batching plant in a single batch to improve overall concrete strength. However, this approach is prone to localized strength deficiencies in large-volume concrete, and the overall mix design significantly increases costs. Furthermore, the lack of targeted reinforcement and the uniform high-strength mix design across all areas leads to material waste. Additionally, the concrete loses its fluidity during transportation and pumping, making it impossible to provide targeted reinforcement to specific areas.

[0004] (2) External reinforcement / grouting reinforcement process after hardening After the concrete has fully hardened, reinforcement methods such as high-pressure grouting, steel bonding, carbon fiber cloth, and drilling are used. The drawbacks are: the pores and cracks inside the hardened concrete close, making it difficult for the grout to penetrate and only surface repair is possible; drilling damages the original concrete structure, creating new damage; the construction process is complex, requiring curing and significantly extending the construction period; the bond between the old and new concrete is weak, easily leading to delamination and detachment, resulting in poor durability; and it can only repair surface defects, failing to improve the overall density and strength of the substrate.

[0005] (3) Shortcomings of existing plastic stage grouting technology A small number of existing plastic grouting technologies only use static grouting with fixed straight pipes, without rotating or synchronously lifting jet structures: the grout only diffuses vertically along the grouting pipe, with a narrow lateral diffusion range, resulting in localized concentration in the reinforced area and extremely poor uniformity; the grouting pressure is singular and uncontrollable, with high pressure easily dispersing concrete aggregates and low pressure resulting in insufficient penetration; the viscosity, water-to-solid ratio, and plastic window period of the grout are not limited, making the grout prone to segregation and bleeding, causing internal honeycomb pores; there is no quantitative matching formula for the reinforcement volume, the amount of reinforcing material used depends on experience, the strength improvement is uncontrollable, and there are problems of excessive waste or insufficient reinforcement.

[0006] In summary, existing technologies cannot achieve uniform, quantitatively controllable, and in-situ integrated internal reinforcement during the plastic stage before the initial setting of concrete. They suffer from technical defects such as poor uniformity, high cost, weak interfacial bonding, low construction controllability, and unstable reinforcement effect.

[0007] CN117166608B discloses "a construction method for the strength of concrete beam-column joints based on post-grouting". This method uses high-pressure jet grouting. However, CN117166608B only discloses the basic idea of ​​"grouting to strengthen beam-column joints during the plastic stage of concrete". It still has technical defects such as poor uniformity of concrete at the joint, high cost, weak interface bonding, low construction controllability, and unstable reinforcement effect. Summary of the Invention

[0008] To address the aforementioned deficiencies in the existing technologies, this invention proposes a slurry jet reinforcement method for cast-in-place concrete during the plastic stage. This method enables in-situ high-pressure rotating jet reinforcement of concrete during the initial setting and plastic stage, solving problems such as uneven reinforcement, separation of the old and new interfaces, uncontrollable strength improvement, material waste, and damage to the matrix after hardening. It also balances ease of construction, controllable strength, structural integrity, and economy.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for reinforcing cast-in-place concrete during its plastic phase using grout jetting involves using grout jetting to reinforce the concrete. The reinforced concrete is composed of a common concrete matrix (component A) and a high-performance cement grout (component B). The high-performance cement grout (component B) is injected into the common concrete matrix (component A) during its plastic phase using a high-pressure rotating jetting method, causing the two components to fuse in situ to form the reinforced concrete. The specific construction steps are as follows: S1. Cast ordinary concrete matrix of component A on site, and simultaneously mix and prepare high-performance cement slurry of component B according to the preset mix ratio. S2. The prepared high-performance grout of component B is transported to the feed end of the high-pressure grouting pump. The high-pressure grouting pump is started at low speed and transported to the grouting pipe. The lifting and rotating device of the grouting pipe is started. S3. Insert the grouting pipe vertically into the ordinary concrete matrix of component A to the preset grouting depth, and increase the output pressure of the high-pressure grouting pump to the design grouting pressure; by rotating the grouting pipe and lifting it upward at a uniform speed, the high-performance grout of component B is evenly dispersed into the interior of the ordinary concrete matrix of component A in the form of a jet. S4. After the grouting pipe is raised to the preset termination height, the grouting pump pressure is reduced, the rotation and lifting action of the grouting pipe is stopped, and the lifting and rotating device is moved to the next grouting point. Repeat steps S3-S4 to complete the full-area jet enhancement construction.

[0010] Furthermore, the plasticity period is defined as the stage before the initial setting of the ordinary concrete of component A, when it possesses thixotropic flow properties, and the slump of the ordinary concrete of component A is ≥100mm; the high-performance cement paste of component B is composed of cement, mineral admixtures, chemical additives, and mixing water, and the dynamic viscosity of component B is <1000mPa. S; The pressure control range of the high-pressure rotating jet grouting is 5-20 MPa; The lifting speed μ, rotation speed γ, and spray influence width d of the grouting pipe satisfy the quantitative relationship: μ / γ=d; The volume of cementitious material before and after reinforcement of the ordinary concrete matrix of component A and the high-performance cement slurry of component B satisfies: V=V1+αV1; where V is the total volume of the reinforced concrete, V1 is the volume of the ordinary concrete matrix of component A before reinforcement, and α is the strength matching reinforcement coefficient. The value of α is determined according to the difference in concrete strength before and after reinforcement. The reinforcement coefficient α is in the range of 0.05-0.4; when the target strength improvement is ≤30%, α is 0.05-0.2; when the target strength improvement is >30%, α is 0.2-0.4.

[0011] Furthermore, the mineral admixtures of the B component high-performance cement slurry are selected from any one or more compound combinations of silica fume, mineral powder, bentonite, and expansive agent.

[0012] Further, by mass percentage, the proportion of the high-performance cement slurry of component B is: 40%–65% cement, 20%–45% mineral admixtures, 0.3%–2.5% chemical additives, and the remainder is mixing water; the dynamic viscosity of the high-performance cement slurry of component B is controlled within the range of 100–800 mPa. S.

[0013] Furthermore, the ordinary concrete matrix of component A is commercial pumped concrete with a slump greater than 220mm and an initial setting time ≥3h, ensuring a sufficient plastic construction window period; the expansion agent accounts for 3% to 8% of the total mass of solid powder of component B high-performance cement slurry, and is used to counteract shrinkage cracks during the grouting hardening process.

[0014] Furthermore, the injection influence width d is selected based on the outlet diameter of the grouting pipe and the grouting pressure; the rotation speed γ of the grouting pipe is 10-60 r / min, and the lifting speed μ is determined according to the formula μ=γ. d. Synchronous matching and control.

[0015] Furthermore, in step S2, the pipeline pre-filling stage, the high-pressure grouting pump outputs a low-speed flow rate of 10% to 30% of the rated grouting flow rate until the B component grout flows out of the grouting pipe outlet continuously and uniformly without air bubbles.

[0016] Furthermore, before inserting the grouting pipe to the preset depth in step S3, the blockage of impurities at the outlet of the grouting pipe is cleaned in advance, and the grouting pump is kept to continuously supply material at a low flow rate during the insertion process to prevent concrete aggregate from clogging the outlet.

[0017] Furthermore, in step S3, the inlet and outlet of the pipeline are equipped with a filter device. The filter device consists of a filter top cover, a pressure gauge interface, a replaceable filter screen, and a filter bottom cover. The filter top cover, the replaceable filter screen, and the filter bottom cover are connected in sequence by a farrdle or thread. The feed inlet is located on the outside of the filter bottom cover, and the feed direction is opposite to the direction of gravity. The discharge outlet is located on the outside of the filter top cover. The filter top cover is equipped with a pressure gauge interface.

[0018] By adopting the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art: This invention utilizes grouting during the plastic thixotropic stage before the initial setting of concrete, where the matrix is ​​not yet hardened. There is no interface delamination between the grout and the original concrete, resulting in a unified, integrated molding process with significantly higher bond strength than grouting after hardening. The grouting pipe rotates synchronously and is lifted at a uniform speed, with a ring-shaped high-pressure jet spreading laterally to expand the reinforcement width and provide uniform reinforcement across the entire area, eliminating localized weak points. The grout viscosity, water-to-solid ratio, grouting pressure, rotation speed, and reinforcement coefficient are all set with numerical ranges and quantitative calculation formulas, eliminating the need for traditional experience-based construction and allowing for precise design of strength enhancement. The compounding of silica fume, expanding agent, and bentonite reduces viscosity, enhances penetration, counteracts hardening shrinkage, and prevents internal micro-cracks. It eliminates the need to increase the overall mix ratio of the matrix concrete, allowing grouting only at the required reinforcement points, significantly saving on reinforcing cementitious materials and reducing project costs. Simultaneous construction with concrete pouring eliminates the need for curing, shortening the overall construction period and making it suitable for large-volume, large-area cast-in-place projects.

[0019] Furthermore, by adjusting the enhancement coefficient α, this invention can precisely increase the compressive strength of the matrix concrete by 10% to 40%; the slurry jet is uniformly dispersed, the cementitious phase inside the concrete is continuously distributed, there are no areas of strength dispersion, and the standard deviation of strength is reduced by more than 60%; the high-pressure jet fills the gaps between aggregates, increasing the concrete permeability pressure by 2 to 3 times and improving the impermeability grade to P6 to P12, making it suitable for waterproof structures such as basements and pools; in-situ fusion in the plastic stage, there is no weak layer at the interface between new and old concrete, the splitting tensile strength is increased by more than 25%, and there are no delamination, peeling, or debonding defects.

[0020] Simultaneous with concrete pouring, eliminating the need for secondary curing and drilling reinforcement, thus shortening the construction cycle by more than 30%; and only requiring the addition of component B slurry to areas needing reinforcement according to the design, without needing to increase the overall amount of component A adhesive, reducing the total consumption of cementitious materials by 15%~35%; component B viscosity <1000mPa S-type concrete has excellent fluidity and is not prone to pipe blockage; it has a wide plastic window period (construction can be carried out throughout the entire process before initial setting), and a high tolerance for errors in on-site construction; it does not require drilling or grooving of the formed concrete, does not damage the original steel reinforcement and aggregate skeleton structure, and has no secondary damage; it is suitable for various cast-in-place scenarios such as pumped floor slabs, large-volume foundation concrete, slope shotcrete, and composite cast-in-place layers; the equipment is modular and mobile, and the location can be flexibly switched.

[0021] The B component of this invention is a compound of silica fume and an expansion agent, with a shrinkage rate of ≤0.02% after hardening, which effectively inhibits internal micro-cracks; the mineral admixture optimizes the hydration products, reduces the calcium hydroxide content, significantly improves the resistance to sulfate corrosion and carbonization, and more than doubles the structural service durability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the slurry jet enhancement method for cast-in-place concrete during the plastic stage according to the present invention; Figure 2 This is a flowchart of a method for enhancing the plasticity stage of cast-in-place concrete using slurry jetting, according to the present invention. Figure 3 This is an exploded view of the filtration device of the present invention; Figure 4 This is a schematic diagram of the overall filtration device of the present invention. Detailed Implementation

[0023] The following is in conjunction with the appendix Figure 1-4 The present invention will be further described in detail below to facilitate a clear understanding of the invention, but these descriptions do not constitute a limitation thereof.

[0024] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Example 1 As attached Figure 1-4 As shown in this embodiment, a method for reinforcing cast-in-place concrete during the plastic stage using slurry jet reinforcement is employed. The plastic stage slurry jet reinforced concrete is formed by combining a component A ordinary concrete matrix with a component B high-performance cement slurry.

[0027] In this embodiment, the plasticity period is defined as the stage before the initial setting of the ordinary concrete of component A, when it possesses thixotropic flow properties, and the slump of the ordinary concrete of component A is ≥100mm. The high-performance cement slurry of component B is composed of cement, mineral admixtures, chemical additives, and mixing water, and the dynamic viscosity of component B is <1000mPa. S. The pressure control range for high-pressure rotating jet grouting is 5–20 MPa. The lifting speed μ, rotation speed γ, and spray width d of the grouting pipe 2 satisfy the quantitative relationship: μ / γ = d. The volume of cementitious material before and after reinforcement with component A ordinary concrete matrix and component B high-performance cement grout satisfies: V = V1 + αV1. Where V is the total volume of the reinforced concrete, V1 is the volume of component A ordinary concrete matrix before reinforcement, and α is the strength matching reinforcement coefficient, the value of which is determined according to the difference in concrete strength before and after reinforcement. In this embodiment, the reinforcement coefficient α is in the range of 0.05–0.4. When the target strength improvement is ≤30%, α is 0.05–0.2. When the target strength improvement is >30%, α is 0.2–0.4. The mineral admixtures of component B high-performance cement grout are selected from any one or more compound combinations of silica fume, mineral powder, bentonite, and expansive agent.

[0028] Specifically, by mass percentage, the proportion of component B high-performance cement slurry is: cement 40%–65%, mineral admixtures 20%–45%, chemical additives 0.3%–2.5%, and the remainder is mixing water. The dynamic viscosity control range of component B high-performance cement slurry is 100–800 mPa. S.

[0029] In this embodiment, the ordinary concrete matrix of component A is commercial pumped concrete with a slump greater than 220mm and an initial setting time ≥3h, ensuring a sufficient plastic construction window. The expansive agent is a sulfoaluminate type expansive agent, with a dosage of 3% to 8% of the total mass of solid powder in component B high-performance cement slurry, used to counteract shrinkage cracks during the grouting hardening process.

[0030] The high-performance cement slurry of component B is injected into the ordinary concrete matrix of component A, which is in the plastic stage, using a high-pressure rotating jet method. The two are fused in situ to form reinforced concrete.

[0031] like Figure 2 As shown, the specific construction steps are as follows: S1. Cast ordinary concrete matrix of component A on site, and simultaneously mix and prepare high-performance cement slurry of component B according to the preset mix ratio.

[0032] S2. The prepared high-performance cement slurry of component B is transported to the feed end of the high-pressure grouting pump, and the high-pressure grouting pump is started at low speed to complete the pre-filling of the pipeline. In step S2, during the pipeline pre-filling stage, the high-pressure grouting pump outputs a flow rate of 10% to 30% of the rated grouting flow rate through the conveying pipe 3 at low speed until component B slurry flows out continuously and evenly from the outlet 4 of the grouting pipe 2 without air bubbles.

[0033] like Figure 3-4 As shown, a filter device is installed at both the inlet and outlet of the pipeline. The filter device consists of a filter cover 9, a pressure gauge interface 5, a replaceable filter screen 6, and a filter bottom cover 7. The filter cover 9, the replaceable filter screen 6, and the filter bottom cover 7 are connected in sequence by a farrdle or thread. The feed inlet 8 is located on the outside of the filter bottom cover 7, and the feed direction is opposite to the direction of gravity. The discharge outlet 4 is located on the outside of the filter cover 9. The filter cover 9 is equipped with a pressure gauge interface 5.

[0034] S3. After the high-performance cement slurry of component B has completely filled the grouting pipe 2, start the lifting and rotating device 1 that is matched with the grouting pipe 2.

[0035] S4. Vertically insert grouting pipe 2 into the A-component ordinary concrete matrix to the preset grouting depth, and increase the output pressure of the high-pressure grouting pump to the design grouting pressure. By rotating and uniformly lifting grouting pipe 2, the B-component high-performance cement grout is evenly dispersed into the A-component ordinary concrete matrix in a jet form.

[0036] In this embodiment, the injection influence width d is selected based on the orifice diameter of the grouting pipe 2 outlet 4 and the grouting pressure. Adjacent grouting areas overlap, with no blank reinforcement areas. The rotation speed γ of the grouting pipe 2 is 10–60 r / min, and the lifting speed μ is determined according to the formula μ = γ. d. Synchronous matching and control.

[0037] Before inserting the grouting pipe 2 to the preset depth in step S4, clean the outlet 4 of the grouting pipe 2 to remove any blockages or impurities. During the insertion process, maintain a continuous micro-flow of material from the grouting pump to prevent concrete aggregate from clogging the outlet 4.

[0038] S5. After the grouting pipe 2 is raised to the preset termination height, the pressure of the grouting pump is reduced, the rotation and lifting action of the grouting pipe 2 is stopped, and the lifting and rotating device 1 is moved to the next grouting point. Repeat steps S4-S5 to complete the full-area jet enhancement construction.

[0039] Example 2: High-stress composite reinforcement in the core area of ​​beam-column joint (integrated beam-column casting) 1. Use Cases At the intersection of the frame beam and column, the core area of ​​the node has dense stirrups and stress concentration. The A component of the matrix is ​​C40, and the node area is required to be upgraded to C50. The beam and column are cast in one piece and grouting is carried out during the plastic window period of the concrete.

[0040] 2. Material Proportioning Component A C40 concrete, slump 230mm, initial setting time 4.5h.

[0041] Component B: Cement 62%, Silica fume 15%, Mineral powder 13%, Expansion agent 5%, Admixture 5%. Water-to-solid ratio 0.33, viscosity 450 mPa. s.

[0042] 3. Parameter Settings Strength increased by 25%, α=0.20. Node thickness 1000mm, deep grouting pressure 17MPa. Width d=300mm, rotation speed 30r / min, lifting speed 9000mm / min. Grouting points are arranged in a quincunx pattern inside the node, with full overlap coverage.

[0043] 4. Detection Results The average strength of the core sample in the core area of ​​the node was 51.6 MPa, the shear bearing capacity of the node was increased by 32%, the grout penetration in the densely reinforced area was uniform, and there were no blockages or local loose defects. The ductility of the node under seismic load was significantly better than that of the unreinforced ordinary beam-column node.

[0044] Comparative example: Static grouting of straight pipes during the plasticity period (no rotation, no synchronous lifting, existing simple plastic grouting). Corresponding to the beam-column joint condition in Example 2, grouting is also performed before the initial setting of component A, but a fixed straight pipe is used without a rotating lifting device; only vertical static grouting is performed. The materials and grouting pressure of the remaining component B are completely consistent with those in Example 3. The process difference is that grouting pipe 2 is fixed in place, with only vertical discharge and no transverse annular jet diffusion.

[0045] Results of the comparison: (1) The grout only spreads vertically along the grouting pipe 2, and the lateral diffusion width is less than 80mm. There are large areas of blank areas without grout in the dense reinforcement area of ​​the node.

[0046] (2) The strength of the core sample at the node is extremely discrete, with the lowest being only 43 MPa, which does not meet the C50 reinforcement target.

[0047] (3) Local accumulation of slurry causes local bulging of the nodes and separation of aggregates, resulting in a localized water-bleeding and loose layer inside after molding.

[0048] (4) There is no speed-speed matching formula control, which relies entirely on manual experience, and the reinforcement effect is uncontrollable.

[0049] The above embodiments and comparative examples illustrate that the embodiments of the present invention can realize in-situ high-pressure rotating jet reinforcement in the initial plastic stage of concrete, effectively solving problems such as uneven reinforcement, separation of new and old interfaces, uncontrollable strength improvement, material waste, and damage to the matrix after hardening, while taking into account the convenience of construction, controllable strength, structural integrity and economy.

[0050] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the structure of the present invention. The arrangement and quantity of the present invention are not limited to this example and can be optimized according to actual engineering conditions. Any modifications, equivalent changes, and decorations made to the above embodiments based on the technical principles of the present invention, without departing from the scope of the present invention, are still within the scope of the present invention.

Claims

1. A method for reinforcing cast-in-place concrete during its plastic stage using slurry jet reinforcement, characterized in that, The plastic-stage grout jet-reinforced concrete is formed by combining component A (ordinary concrete matrix) and component B (high-performance grout). The high-performance grout is injected into the plastic-stage component A ordinary concrete matrix using a high-pressure rotating jet method, where the two fuse in situ to form reinforced concrete. The specific construction steps are as follows: S1. Cast ordinary concrete matrix of component A on site, and simultaneously mix and prepare high-performance cement slurry of component B according to the preset mix ratio. S2. The prepared high-performance grout of component B is transported to the feed end of the high-pressure grouting pump. The high-pressure grouting pump is started at low speed and transported to the grouting pipe. The lifting and rotating device of the grouting pipe is started. S3. Insert the grouting pipe vertically into the ordinary concrete matrix of component A to the preset grouting depth, and increase the output pressure of the high-pressure grouting pump to the design grouting pressure; by rotating the grouting pipe and lifting it upward at a uniform speed, the high-performance grout of component B is evenly dispersed into the interior of the ordinary concrete matrix of component A in the form of a jet. S4. After the grouting pipe is raised to the preset termination height, the grouting pump pressure is reduced, the rotation and lifting action of the grouting pipe is stopped, and the lifting and rotating device is moved to the next grouting point. Repeat steps S3-S4 to complete the full-area jet enhancement construction.

2. The method for enhancing the plasticity stage of cast-in-place concrete through grout jetting according to claim 1, characterized in that: The A component, ordinary concrete matrix, is commercial pumped concrete with a slump greater than 220 mm and an initial setting time ≥ 3 h. The B component, high-performance slurry, is a compound of cement, mineral admixtures, chemical additives, and mixing water, with a dynamic viscosity < 1000 mPa. S.

3. The method for enhancing the plasticity stage of cast-in-place concrete through grout jetting according to claim 1, characterized in that: The plasticity period is defined as the stage before the initial setting of the ordinary concrete of component A, when it possesses thixotropic flow properties, and the slump of the ordinary concrete of component A is ≥100mm; the pressure control range of the high-pressure rotating jet grouting is 5~20MPa; the lifting speed μ, rotation speed γ, and spray influence width d of the grouting pipe satisfy the quantitative relationship: μ / γ=d; the volume of the cementitious material before and after reinforcement with the ordinary concrete matrix of component A and the high-performance cement slurry of component B satisfies: V=V1+αV1; where V is the total volume of the reinforced concrete, V1 is the volume of the ordinary concrete matrix of component A before reinforcement, and α is the strength matching reinforcement coefficient. The value of α is determined according to the difference in concrete strength before and after reinforcement. The reinforcement coefficient α ranges from 0.05 to 0.4; when the target strength improvement is ≤30%, α is 0.05~0.2; when the target strength improvement is >30%, α is 0.2~0.

4.

4. The method for enhancing the plasticity stage of cast-in-place concrete through grout jetting according to claim 2, characterized in that: The mineral admixtures of the high-performance slurry in component B are selected from any one or more compound combinations of silica fume, mineral powder, bentonite, and expanding agent.

5. A method for enhancing the plasticity stage of cast-in-place concrete through grout jetting according to claim 3, characterized in that: The high-performance slurry of component B, by mass percentage, comprises: 40%–65% cement, 20%–45% mineral admixtures, 0.3%–2.5% chemical additives, with the remainder being mixing water; the dynamic viscosity of the high-performance slurry of component B is controlled within the range of 100–800 mPa. S.

6. A method for enhancing the plasticity stage of cast-in-place concrete through grout jetting according to claim 5, characterized in that: The expansion agent is added at a rate of 3% to 8% of the total mass of solid powder in component B of the high-performance grout, and is used to counteract shrinkage cracks during the grouting hardening process.

7. A method for enhancing the plasticity stage of cast-in-place concrete through grout jetting according to claim 6, characterized in that: The injection width d is selected based on the outlet diameter of the grouting pipe and the grouting pressure; the rotation speed γ of the grouting pipe is 10-60 r / min, and the lifting speed μ is determined according to the formula μ=γ. d. Synchronous matching and control.

8. A method for enhancing the plasticity stage of cast-in-place concrete through grout jetting according to claim 7, characterized in that: In step S2, the pipeline pre-filling stage, the high-pressure grouting pump outputs a low-speed flow rate of 10% to 30% of the rated grouting flow rate until the B component grout flows out of the grouting pipe outlet continuously and evenly without air bubbles.

9. The method for enhancing the plasticity stage of cast-in-place concrete through grout jetting according to claim 8, characterized in that: Before inserting the grouting pipe to the preset depth in step S4, clean the grouting pipe outlet to remove any blockages or impurities. During the insertion process, maintain a continuous micro-flow from the grouting pump to prevent concrete aggregate from clogging the outlet.

10. The method for enhancing the plasticity stage of cast-in-place concrete through grout jetting according to claim 9, characterized in that: In step S2, the inlet and outlet of the pipeline are equipped with a filter device. The filter device consists of a filter top cover, a pressure gauge interface, a replaceable filter screen, and a filter bottom cover. The filter top cover, the replaceable filter screen, and the filter bottom cover are connected in sequence by a farrdle or thread. The feed inlet is located on the outside of the filter bottom cover, and the feed direction is opposite to the direction of gravity. The discharge outlet is located on the outside of the filter top cover. The filter top cover is equipped with a pressure gauge interface.

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