A framework construction method based on concrete plastic period slurry jet enhancement

Abstract

The application relates to a framework construction method based on concrete plastic period slurry jet enhancement, and belongs to the technical field of concrete framework construction in building engineering, which is composed of ordinary concrete columns, ordinary concrete beams and slurry jet enhanced beam-column joints. The concrete of the beam-column joint is prepared by using high-strength slurry high-pressure jet enhancement technology in the plastic period stage. The jet point number of the high-strength slurry in the core area of the beam-column joint is single or multiple. There is a formula relationship among the high-pressure jet pressure, the jet point number and the horizontal section size of the beam-column joint. In the application, the high-pressure jet high-strength slurry is used to enhance the joint in situ in the concrete plastic period, and a standardized parameter matching system is matched, so that the high-strength and high-density core area of the beam-column joint is formed, the large-grade concrete grade difference framework structure is adapted, and the overall bearing capacity and the anti-seismic performance of the framework structure are greatly improved.

Description

Technical Field

[0001] This invention belongs to the technical field of performance improvement of concrete frame structures in building engineering, specifically involving a construction method for frame structures based on plastic period slurry jet reinforcement nodes, which is applicable to improving the material performance of the core area of ​​beam-column joints in reinforced concrete frame structures such as high-rise buildings and large public buildings. Background Technology

[0002] Reinforced concrete frame structures are widely used in various building projects due to their advantages such as clear force distribution, flexible spatial layout, and mature construction. In the conventional frame structure design and construction system, in order to meet the differentiated requirements of vertical load-bearing and seismic resistance, a concrete mix design method of "high-grade concrete for columns and low-grade concrete for beams" is generally adopted, that is, high-grade concrete is used for frame columns, while low-grade concrete is used for frame beams and floor slabs.

[0003] The core area of ​​the beam-column joint, as a key load-bearing hub in a frame structure, plays a crucial role in transferring internal forces between beams and columns, resisting seismic loads, and balancing structural deformation, making it a critical part of the structure's seismic resistance. In existing construction techniques, the mainstream construction method for beam-column joints with different concrete grades is the joint boundary pouring process. This involves setting up separating components such as retaining formwork and wire mesh to pour concrete of higher grade for columns and lower grade for beams and slabs separately, achieving differentiated pouring of beams and columns.

[0004] Existing technologies generally suffer from the following drawbacks:

[0005] 1. Poor compatibility of different concrete grades leads to a significant conflict between construction costs and quality. Conventional high-grade concrete pouring methods significantly increase the cost of concrete materials in beam and slab areas, and high-grade concrete has high shrinkage, which can easily cause shrinkage cracks in beams and slabs. Traditional segmented pouring processes have low precision in separating sections, which can easily lead to problems such as mixing of high and low grade concrete and the infiltration of low-grade concrete into the core area of ​​the joint, resulting in insufficient strength in the core area of ​​the joint. Moreover, existing processes can only adapt to small differences in concrete grade, and when the difference in concrete grade between beams and columns is large, the stress defects at the joint will be amplified dramatically.

[0006] 2. Lack of standardized construction parameters leads to low controllability of construction quality. Traditional joint grouting and reinforcement construction lacks a precise parameter matching system. It does not adapt the jet pressure and grouting point according to the joint cross-sectional size, nor does it limit the grouting construction window, equipment operating parameters, and grout mixing parameters. The construction process relies entirely on workers' experience, resulting in significant differences in joint reinforcement effects under different working conditions, poor project quality stability, and an inability to achieve standardized and regulated construction.

[0007] 3. Lack of utilization of the thixotropic properties of concrete at joints. Existing technology does not utilize the thixotropic properties of concrete during its plastic period after pouring. At this time, the concrete has good fluidity and plasticity, which is the best window for grout bonding and reinforcement. However, later reinforcement completely misses this construction opportunity, resulting in poor bonding between the reinforcement grout and the original concrete, and the interface is prone to delamination and separation problems.

[0008] In recent years, to address the construction challenges and quality issues associated with beam-column joints where the concrete grades of beams and slabs are inconsistent, a method for constructing concrete beam-column joints based on post-grouting has emerged (patent authorization number: CN117166608B). This method employs high-pressure jet grouting and includes the following steps: Step 1, core area concrete strength design: The concrete strength of the core area is designed and calculated based on the concrete strength of the column and beam. Step 2, core area concrete production: The mix ratio of high-performance grouting material is designed according to the grade difference requirements between the beam and column at the beam-column joint, and the core area concrete is pre-dry-mixed. Step 3, formwork erection at the beam-column joint: Limiting components are erected at the beam-column joint and their positions are fixed. During construction, the core area and other areas are simultaneously poured with the same concrete as the beam-slab area, and high-performance cement grout is injected through high-pressure grouting before the initial setting of the concrete in the beam-slab area. However, the above-mentioned technologies cannot quantitatively match the grout dosage, easily leading to an imbalance in the water-cement ratio: an excessively high water-cement ratio results in shrinkage and cracking of the joint later on; an excessively low water-cement ratio results in poor grout fluidity, insufficient penetration, and the formation of internal voids. Furthermore, it is impossible to accurately design the high-strength grout mix ratio through iterative calculations, making it impossible to consistently guarantee that the joint strength is 2-3 times higher than that of the beam and slab. The grouting method relies entirely on experience; CN117166608B only vaguely proposes "multi-point grouting for large cross-sections and single-point grouting for small cross-sections," without providing millimeter-level quantitative segmentation thresholds. Specifically, for multi-point grouting of large cross-sections, the reference pressure P0 is still used, and excessive single-point pressure causes impact disturbance, leading to separation of uncured concrete aggregates, resulting in delamination, honeycomb voids, and hollow areas. For single-point grouting of small cross-sections, the pressure is too low, resulting in insufficient penetration depth of the high-strength grout, only surface reinforcement, and insufficient strength at the core of the joint. The comparison document lacks coordinated constraints on the lifting and rotation speeds of the grouting pipe; an imbalance in speed matching can lead to missed spraying and localized grout accumulation. For beam-column joints with dense reinforcement, the spray width cannot be accurately matched, resulting in large blind spots in reinforcement areas obscured by stirrups and longitudinal reinforcement. The comparative documents reveal several issues: The pulping system lacks specifications for a high-speed forced pulper with a speed ≥800 r / min and a mixing time ≥3 min, leading to potential slurry agglomeration, poor homogeneity, and significant fluctuations in slurry strength. The high-pressure grouting pump lacks precise control requirements (output pressure adjustment accuracy ≤ ±0.2 MPa), resulting in inconsistent grouting volumes due to pressure fluctuations. The drive system does not employ frequency conversion for synchronous control of rotation and lifting speeds, failing to dynamically adapt to different spray widths. Furthermore, the comparative documents do not clearly define the rigidity time of the plasticity period or the slump measurement threshold, making it highly susceptible to missing the optimal fusion window. CN117166608B only describes a single construction method and does not constitute an integrated technical system combining frame structure product construction with a complete set of quantitative construction parameters.CN117166608B only discloses the basic concept of "grouting reinforcement of beam-column joints in the plastic stage of concrete", but lacks a complete quantitative calculation model, graded section point standards, adaptive jet pressure rules, precise equipment parameters, quantitative window period of the plastic stage, 6-level grade difference adaptation system, and water-cement ratio conservation method. It cannot solve a series of core engineering defects such as existing process experience-based construction, large quality fluctuations, poor adaptation of large grade differences, delamination at the interface between new and old concrete, uneven internal reinforcement of joints, and lack of standardized equipment control. Summary of the Invention

[0009] To address the aforementioned shortcomings of existing technologies, this invention proposes a construction method for frame structures based on grout jet reinforcement during the plastic stage of concrete. By employing high-pressure jet high-strength grout for in-situ reinforcement of joints during the plastic stage of concrete, coupled with a standardized parameter matching system, high-strength and high-density molding of the core area of ​​beam-column joints is achieved. This method is suitable for frame structures with large differences in concrete grade, significantly improving the overall load-bearing capacity and seismic performance of the frame structure.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A construction method for a frame structure based on concrete grout jet reinforcement during the plastic stage is disclosed. The frame structure, with grout jet reinforcement at the plastic stage joints, consists of ordinary concrete columns, ordinary concrete beams, and grout jet-reinforced beam-column joints. The concrete for the beam-column joints is prepared using high-strength grout high-pressure jet reinforcement technology during the plastic stage. The number of jet points for the high-strength grout in the core area of ​​the beam-column joint can be single-point or multi-point. The method includes the following steps: Step 1: Pour ordinary concrete column (1) up to the bottom elevation of ordinary concrete beam (2-1); Step 2: Pour ordinary concrete beams (2-1) and ordinary concrete floor slabs (2-2). Use concrete of the same grade as the beams and slabs to pour the core area of ​​the beam-column joints. Pour the concrete to the top elevation of the floor slab. At the same time, start the grouting equipment to prepare high-strength grout according to the designed high-strength grout mix ratio. Step 3: During the plastic stage of the concrete in the core area of ​​the beam-column joint, a high-pressure jet grouting pump is used to inject the high-strength grout into the core area of ​​the beam-column joint through the grouting pipe at a certain rotation speed and lifting speed, forming a concrete grout jet-reinforced beam-column joint (3); Step 3 is repeated for all beam-column joint core areas to complete the construction of the frame structure.

[0011] Furthermore, the high-pressure jet pressure and the number of jet points, as well as the horizontal cross-sectional dimensions of the beam-column joint, have the following relationship: P = kP0 / m, m = 1 when W ∈ (0, 600], L ∈ (0, 600], m = 2 when W ∈ (600, 900], L ∈ (600, 900], m = 4 when W ∈ (900, 1200], L ∈ (900, 1200]); where: P is the jet pressure, k is a reference coefficient, and k is determined based on the beam-column reinforcement ratio and the ring... The ambient temperature and humidity, and the type of concrete admixture are pre-calibrated, with a value range of 0.7 to 1.3; P0 is the reference pressure, with a value range of 12MPa to 20MPa; m is the number of grouting jet points; W and L are the cross-sectional dimensions, with units of mm; the high-strength grout is made primarily of cement-based materials, with a standard cubic compressive strength of not less than 80MPa, and its water-cement ratio satisfies the following formula: (W3 / B3) = (W1+W2) / (B1+B2), where: W1, W2, and W3 represent the design values ​​of the water content of the beam and slab concrete in the core area of ​​each volume node, the water content of the high-strength grout, and the overall water content after jet reinforcement, respectively; B1, B2, and B3 represent the design values ​​of the amount of cementitious material used in the beam and slab concrete in the core area of ​​each volume node, the amount of cementitious material used in the high-strength grout, and the amount of overall cementitious material used after jet reinforcement, respectively.

[0012] Furthermore, the high-strength grout is a cement-based material; the concrete grade difference between the beams and columns of the frame structure is within 6 grade differences, expressed by concrete grade as follows: beams and slabs C30, columns C45 and above; beams and slabs C35, columns C45 and above; beams and slabs C40, columns C50 and above; the grouting points within the beam-column joints are arranged symmetrically and uniformly; large cross-section joints with a cross-sectional dimension > 900mm adopt a four-point diagonally symmetrical hole arrangement, medium cross-section joints with a cross-sectional dimension of 600-900mm adopt a two-point opposing hole arrangement, and small cross-section joints with a cross-sectional dimension ≤ 600mm adopt a central single-point hole arrangement.

[0013] Furthermore, the plasticity stage of the concrete in the core area of ​​the beam-column joint refers to the state in which the concrete is thixotropic within 1 hour after the concrete is poured, and its slump is not less than 100mm.

[0014] Furthermore, in step two, the mix proportion of the high-strength grout is determined by iterative calculation based on the target strength of the node concrete and the overall water-cement ratio formula. After molding, the overall compressive strength of the core area of ​​the node is not lower than the compressive strength of the column concrete.

[0015] Furthermore, in step three, after the concrete pouring and vibration of the core area of ​​the node and ordinary concrete beams and slabs are completed, the concrete slump is monitored in real time to ensure that the slump is ≥100mm, thus locking in the construction window during the plastic period.

[0016] Furthermore, in step three, the number of grouting points is determined according to the cross-sectional dimensions of the beam-column joint. Small cross-section joints are grouted using a single-point grouting method at the center, while medium and large cross-section joints are grouted using a multi-point symmetrical and uniformly distributed hole grouting method. The rotational speed and lifting speed of the grouting pipe satisfy the following relationship: μ / γ=d, where: γ is the rotational speed, μ is the lifting speed, and d is the injection effect width; In step three, different cross-sectional nodes are matched with specific jet pressures. The larger the cross-sectional size and the more grouting points, the jet pressure at a single point is adaptively reduced according to the formula P=kP0 / m to avoid concrete segregation and hollow defects. In step three, the grouting process is completed within 60 minutes after the concrete is poured. After the grouting is completed, it is allowed to set and does not require secondary vibration. It achieves self-compacting fusion by relying on the impact force of the grout jet and the thixotropic properties of the concrete.

[0017] Furthermore, in step three, the output pressure adjustment accuracy of the high-pressure jet grouting pump is ≤ ±0.2MPa, and the lifting speed and rotation speed of the grouting pipe are precisely controlled by frequency conversion to adapt to different spray width requirements.

[0018] Furthermore, the pulping equipment adopts a high-speed forced pulper with a pulping speed of not less than 800 r / min and a pulping and stirring time of not less than 3 min to ensure that the high-strength slurry is homogeneous, free of lumps, and has uniform fluidity. A filter device is installed at the discharge port of the pulping equipment; at the same time, a filter device is also installed at the inlet of the grouting pipe.

[0019] Furthermore, the filtration 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 threads. 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, and a pressure gauge interface is provided on the filter top cover.

[0020] By adopting the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art: 1. Fundamentally improve the structural performance of beam-column joints. This invention innovatively utilizes the thixotropic properties of concrete during its 1-hour plasticity period and high slump after pouring. High-strength grout is injected via high-pressure jetting while the concrete is not yet hardened. The grout can fully penetrate and fuse with the original joint concrete, filling the internal pores of the concrete, eliminating micro-cracks, and significantly improving the density and overall strength of the concrete in the core area of ​​the joint. Compared with traditional post-reinforcement processes, the grout and the original concrete are integrally formed, eliminating interface delamination problems, and significantly improving the structural integrity, fatigue resistance, and seismic performance.

[0021] 2. Adaptable to large-grade differences in concrete for beams and columns, reducing construction costs. This invention can adapt to concrete mix ratios for beams and columns within six grade differences, covering the mainstream construction conditions of C30 / C35 / C40 concrete for beams and slabs combined with high-grade concrete for columns. It eliminates the need to use high-grade concrete for the entire beam and slab, avoiding the high cost and cracking problems caused by the large-scale use of high-grade concrete. At the same time, it solves the defects of traditional segmented pouring of concrete, such as mixed concrete and insufficient joint strength, thus balancing structural safety and economy.

[0022] 3. Achieve standardized and precise control of construction parameters. This invention establishes a complete set of standardized construction parameter systems by matching grouting point locations with cross-sectional dimensions, jet pressure formulas, and combining the operating parameter relationships of grouting equipment with the water-cement ratio formula of the grout. It abandons the traditional experience-based construction mode, and construction parameters can be precisely adapted to nodes with different cross-sectional dimensions, ensuring uniform and stable node reinforcement effects under various working conditions, and significantly improving the controllability and standardization of project construction quality.

[0023] 4. Simple construction process, high efficiency, and wide applicability. This invention completes the joint reinforcement construction simultaneously after concrete pouring, eliminating the need for additional processes such as drilling, reinforcement, and curing. This results in high construction efficiency and does not delay the overall construction schedule. Furthermore, the high-strength grout has a compressive strength of no less than 80MPa, providing excellent reinforcement. The parameter system is compatible with the cross-sectional dimensions of conventional building beam-column joints, making it widely applicable to various reinforced concrete frame structure projects, demonstrating strong versatility.

[0024] 5. Compared with the existing technology CN117166608B, it has the following advantages: Section-point grading and quantitative matching system: It pioneered a three-section modular division of 600 / 900 / 1200mm, clearly defining the fixed point rule of m=1 / 2 / 4, while the comparative document only vaguely describes multi-point grouting without numerical range constraints; Adaptive inverse proportional formula for jet pressure: It achieves automatic attenuation of single-point pressure under multi-point conditions, solving the problem of grouting disturbance and segregation in large sections, while the comparative document lacks pressure and point-based linkage control logic; Coupled water-cement ratio conservation formula for native concrete + high-strength grout: It quantitatively controls the overall strength and shrinkage performance after mixing, while the comparative document lacks a water-cement ratio calculation model for the mixing system, relying only on empirical grout preparation; Dual quantitative constraints on the plasticity period: Rigid 60min time limit + slump ≥100mm The dual-indicator method for determining thixotropic state is used, but the comparative document only vaguely mentions "grouting before initial setting" and lacks quantitative quality control standards. The formula linking the grouting pipe rotation / lifting speed with the spray width aims to achieve uniform coverage across the entire cross-section and eliminate blind spots in densely reinforced areas, while the comparative document lacks speed coordination matching rules. A complete set of standardized parameter closed-loop systems is also used, including grout compressive strength ≥80MPa, compatibility with 6 grade differences, grouting speed, grouting pump pressure adjustment accuracy, and symmetrical hole layout rules forming a complete technical chain, while the comparative document lacks a complete set of quantitative parameter standards. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the frame structure of the present invention based on the plasticity period slurry jet reinforcement node; Figure 2 This is a flowchart of the construction method for a frame structure based on a plastic-period slurry jet-reinforced node 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

[0026] 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.

[0027] 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.

[0028] 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.

[0029] As attached Figure 1-4 As shown in the figure, this embodiment presents a construction method for a frame structure based on concrete slurry jet reinforcement during the plastic stage, as follows: Figure 1 As shown, the frame structure based on the grout jet reinforcement node during the plastic stage consists of cast-in-place ordinary concrete columns 1, cast-in-place ordinary concrete beams 2, and grout jet reinforced beam-column nodes 3. The concrete of the beam-column nodes is prepared using high-strength grout high-pressure jet reinforcement technology during the plastic stage. The number of jet points of the high-strength grout in the core area of ​​the beam-column node can be single-point or multi-point. Figure 2 As shown, the specific steps include the following: Step 1: Pour ordinary concrete column (1) up to the bottom elevation of ordinary concrete beam (2-1); Step 2: Pour ordinary concrete beams (2-1) and ordinary concrete floor slabs (2-2). Use concrete of the same grade as the beams and slabs to pour the core area of ​​the beam-column joint, pouring the concrete to the top elevation of the floor slab. At the same time, start the grouting equipment to prepare high-strength grout according to the designed high-strength grout mix ratio. In Step 2, the high-strength grout mix ratio is determined by iterative calculation based on the target strength of the joint concrete and the overall water-cement ratio formula. After molding, the overall compressive strength of the core area of ​​the joint is not lower than the compressive strength of the column concrete. Step 3: During the plastic stage of the concrete in the core area of ​​the beam-column joint, a high-pressure jet grouting pump is used to inject the high-strength grout into the core area of ​​the beam-column joint through the grouting pipe at a certain rotation speed and lifting speed, forming a concrete grout jet-reinforced beam-column joint (3); Step 3 is repeated for all beam-column joint core areas to complete the construction of the frame structure.

[0030] The plastic phase of the concrete in the core area of ​​the beam-column joint refers to the state where the concrete is thixotropic within one hour after pouring, with a slump of not less than 100mm. In step three, after the concrete in the core area of ​​the joint and ordinary concrete beams and slabs is poured and vibrated, the concrete slump is monitored in real time to ensure that the slump is ≥100mm, thus locking in the construction window of the plastic phase.

[0031] In this embodiment, in step two, a high-speed forced pulping machine is used, with a pulping speed of not less than 800 r / min and a pulping and stirring time of not less than 3 min, to ensure that the high-strength slurry is homogeneous, free of lumps, and has uniform fluidity. A filter device is installed at the discharge port of the pulping equipment. Simultaneously, a filter device is also installed at the inlet of the grouting pipe. The filter device consists of a filter upper cover 4, a pressure gauge interface 5, a replaceable filter screen 6, and a filter lower cover 7. The filter upper cover 4, the replaceable filter screen 6, and the filter lower cover 7 are connected sequentially by a farrdle or threads. The feed inlet 8 is located outside the filter lower cover 7, with the feed direction opposite to the direction of gravity. The discharge outlet 9 is located outside the filter upper cover 4, and the filter upper cover 4 is equipped with a pressure gauge interface 5.

[0032] In step three, the number of grouting points is determined based on the cross-sectional dimensions of the beam-column joint. Small cross-section joints are grouted using a single-point grouting method at the center, while medium and large cross-section joints are grouted using a multi-point symmetrical and uniformly distributed hole grouting method.

[0033] The rotational speed and lifting speed of the grouting pipe satisfy the following relationship: μ / γ=d, where γ is the rotational speed, μ is the lifting speed, and d is the spray width.

[0034] In step three, different cross-sectional nodes are matched with specific jet pressures. The larger the cross-sectional size and the more grouting points, the more adaptively the jet pressure at a single point is reduced according to the formula P=kP0 / m, so as to avoid concrete segregation and hollow defects.

[0035] In step three, the grouting process is completed within 60 minutes after the concrete is poured. After the grouting is completed, it is allowed to set and does not require secondary vibration. It achieves self-compacting fusion by relying on the impact force of the grout jet and the thixotropic properties of the concrete.

[0036] In step three, the output pressure adjustment accuracy of the high-pressure jet grouting pump is ≤ ±0.2MPa, and the lifting and rotating speeds of the grouting pipe are precisely controlled by frequency conversion to adapt to different spray width requirements.

[0037] The high-pressure jet pressure, the number of jet points, and the horizontal cross-sectional dimensions of the beam-column joint are related as follows: P = kP0 / m, m = 1 when W ∈ (0, 600], L ∈ (0, 600], m = 2 when W ∈ (600, 900], L ∈ (600, 900], m = 4 when W ∈ (900, 1200], L ∈ (900, 1200]); where P is the jet pressure, k is a reference coefficient, and k depends on the beam-column reinforcement ratio and environmental conditions. Temperature and humidity, and the type of concrete admixture are pre-calibrated, with a value range of 0.7 to 1.3; P0 is the reference pressure, with a value range of 12 MPa to 20 MPa; m is the number of grouting jet points; W and L are the cross-sectional dimensions, with units of mm; the high-strength grout is made primarily of cement-based materials, with a standard cubic compressive strength of not less than 80 MPa, and its water-cement ratio satisfies the following formula: (W3 / B3) = (W1+W2) / (B1+B2), where: W1, W2, and W3 represent the design values ​​of the water content of the beam and slab concrete in the core area of ​​each volume node, the water content of the high-strength grout, and the overall water content after jet reinforcement, respectively; B1, B2, and B3 represent the design values ​​of the amount of cementitious material used in the beam and slab concrete in the core area of ​​each volume node, the amount of cementitious material used in the high-strength grout, and the amount of overall cementitious material used after jet reinforcement, respectively.

[0038] In this embodiment, the high-strength grout is a cement-based material. The concrete grade difference between the beams and columns of the frame structure is within 6 grades, expressed by concrete grade as follows: beams and slabs C30, columns C45 and above; beams and slabs C35, columns C45 and above; beams and slabs C40, columns C50 and above. Grouting points within the beam-column joints are arranged symmetrically and evenly. Large cross-section joints with a cross-sectional dimension >900mm use a four-point diagonally symmetrical hole arrangement; medium cross-section joints with a cross-sectional dimension of 600-900mm use a two-point opposing hole arrangement; and small cross-section joints with a cross-sectional dimension ≤600mm use a single-point central hole arrangement.

[0039] 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 construction method for a frame structure based on concrete grout jet reinforcement during the plastic stage, wherein the frame structure based on grout jet reinforcement nodes during the plastic stage consists of ordinary concrete columns (1), ordinary concrete beams (2-1), ordinary concrete floor slabs (2-2), and concrete grout jet reinforced beam-column nodes (3), wherein the concrete of the beam-column nodes is prepared using high-strength grout high-pressure jet reinforcement technology during the plastic stage, and the number of jet points of the high-strength grout in the core area of ​​the beam-column nodes can be single-point or multi-point, characterized in that, Includes the following steps: Step 1: Pour ordinary concrete column (1) up to the bottom elevation of ordinary concrete beam (2-1); Step 2: Pour ordinary concrete beams (2-1) and ordinary concrete floor slabs (2-2). Use concrete of the same grade as the beams and slabs to pour the core area of ​​the beam-column joints. Pour the concrete to the top elevation of the floor slab. At the same time, start the grouting equipment to prepare high-strength grout according to the designed high-strength grout mix ratio. Step 3: During the plastic stage of the concrete in the core area of ​​the beam-column joint, a high-pressure jet grouting pump is used to inject the high-strength grout into the core area of ​​the beam-column joint through the grouting pipe at a certain rotation speed and lifting speed, forming a concrete grout jet-reinforced beam-column joint (3); Step 3 is repeated for all beam-column joint core areas to complete the construction of the frame structure.

2. The construction method for a frame structure based on concrete grout jet reinforcement during the plastic stage, as described in claim 1, is characterized in that: The high-pressure jet pressure and the number of jet points and the horizontal cross-sectional dimensions of the beam-column joint are related as follows: P=kP0 / m, m=1 when W∈(0,600], L∈(0,600], m=2 when W∈(600,900], L∈(600,900], m=4 when W∈(900,1200], L∈(900,1200]; In the formula: P is the jet pressure, k is the reference coefficient, which is pre-calibrated according to the reinforcement ratio of beam and column steel bars, ambient temperature and humidity, and type of concrete admixture, with a value range of 0.7 to 1.3; P0 is the reference pressure, with a value range of 12MPa to 20MPa; m is the number of grouting jet points, and W and L are the cross-sectional dimensions, with the unit being mm; the high-strength grout is made of cement-based materials as the main material, with a standard cubic compressive strength of not less than 80MPa, and its water-cement ratio satisfies the relationship: (W3 / B3) = (W1+W2) / (B1+B2), where: W1, W2, and W3 represent the design values ​​of the water content of the beam and slab concrete in the core area of ​​each volume node, the water content of the high-strength grout, and the overall water content after jet reinforcement, respectively; B1, B2, and B3 represent the design values ​​of the amount of cementitious material used in the beam and slab concrete in the core area of ​​each volume node, the amount of cementitious material used in the high-strength grout, and the amount of overall cementitious material after jet reinforcement, respectively.

3. The construction method for a frame structure based on concrete grout jet reinforcement during the plastic stage, as described in claim 1, is characterized in that: In step three, the number of grouting points is determined according to the cross-sectional dimensions of the beam-column joint. Small cross-section joints are grouted using a single-point grouting at the center, while medium and large cross-section joints are grouted using a multi-point symmetrical and uniformly distributed hole grouting. The rotational speed and lifting speed of the grouting pipe satisfy the following relationship: μ / γ=d, where: γ is the rotational speed, μ is the lifting speed, and d is the injection effect width; In step three, different cross-sectional nodes are matched with specific jet pressures. The larger the cross-sectional size and the more grouting points, the jet pressure at a single point is adaptively reduced according to the formula P=kP0 / m to avoid concrete segregation and hollow defects. In step three, the grouting process is completed within 60 minutes after the concrete is poured. After the grouting is completed, it is allowed to set and does not require secondary vibration. It achieves self-compacting fusion by relying on the impact force of the grout jet and the thixotropic properties of the concrete.

4. A construction method for a frame structure based on concrete grout jet reinforcement during the plastic stage, as described in claim 1, characterized in that: The high-strength grout is a cement-based material; the concrete grade difference between the beams and columns of the frame structure is within 6 grade differences, expressed by concrete grade as follows: beams and slabs C30, columns C45 and above; beams and slabs C35, columns C45 and above; beams and slabs C40, columns C50 and above; the grouting points in the beam-column joints are arranged symmetrically and evenly; large cross-section joints with a cross-sectional size > 900mm adopt a four-point diagonal symmetrical hole arrangement, medium cross-section joints with a cross-sectional size of 600-900mm adopt a two-point opposing hole arrangement, and small cross-section joints with a cross-sectional size ≤ 600mm adopt a central single-point hole arrangement.

5. The construction method for a frame structure based on concrete slurry jet reinforcement during the plastic stage, as described in claim 1, is characterized in that: The plasticity stage of the concrete in the core area of ​​the beam-column joint refers to the state in which the concrete is thixotropic within 1 hour after the concrete is poured, and its slump is not less than 100mm.

6. A construction method for a frame structure based on concrete slurry jet reinforcement during the plastic stage, as described in claim 3, is characterized in that: In step two, the mix proportion of high-strength grout is determined by iterative calculation based on the target strength of the node concrete and the overall water-cement ratio formula. After molding, the overall compressive strength of the core area of ​​the node is not lower than the compressive strength of the ordinary concrete column (1).

7. A construction method for a frame structure based on concrete grout jet reinforcement during the plastic stage, as described in claim 5, characterized in that: In step two, after the concrete pouring and vibration of the core area of ​​the node and ordinary concrete beams and slabs are completed, the concrete slump is monitored in real time to ensure that the slump is ≥100mm and to lock in the construction window during the plastic period.

8. A construction method for a frame structure based on concrete grout jet reinforcement during the plastic stage, as described in claim 7, characterized in that: In step three, the output pressure adjustment accuracy of the high-pressure jet grouting pump is ≤ ±0.2MPa, and the lifting speed and rotation speed of the grouting pipe are precisely controlled by frequency conversion to adapt to different spray width requirements.

9. A construction method for a frame structure based on concrete grout jet reinforcement during the plastic stage, as described in claim 1, characterized in that: The pulping equipment adopts a high-speed forced pulping machine with a pulping speed of not less than 800 r / min and a pulping and mixing time of not less than 3 min to ensure that the high-strength slurry is homogeneous, free of lumps, and has uniform fluidity. A filter device is installed at the discharge port of the pulping equipment; at the same time, a filter device is also installed at the inlet of the grouting pipe.

10. A construction method for a frame structure based on concrete grout jet reinforcement during the plastic stage, as described in claim 9, characterized in that: The filter device consists of a filter top cover (4), a pressure gauge interface (5), a replaceable filter screen (6), and a filter bottom cover (7). The filter top cover (4), the replaceable filter screen (6), and the filter bottom cover (7) are connected in sequence by a fender or thread. The feed inlet (8) is located outside the filter bottom cover (7), and the feed direction is opposite to the direction of gravity. The discharge outlet (9) is located outside the filter top cover (4). The filter top cover (4) is equipped with a pressure gauge interface (5).

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