Two-component grouting system and grouting process

Abstract

The grouting system comprises a main grout supply pipeline and a plugging material supply pipeline, the plugging material supply pipeline is obliquely connected to the main grout supply pipeline, and a Y-shaped grouting pipe is formed; one end of the main slurry supply pipeline is a main slurry inlet, and the other end of the main slurry supply pipeline is a bi-component slurry outlet; the two-component grout outlet is connected with a grouting anchor rod, the grouting anchor rod is of a hollow structure, a plurality of grout outlet holes are formed in the side wall face of the grouting anchor rod, and two-component grout enters an anchor rod hole through the grout outlet holes for blocking; on the premise of not depending on a mechanical grout stopping device, self-adaptive plugging of cracks is achieved through a material response mechanism, functional plugging particles and grout are mixed in real time on site through physical isolation and sequential control modes before grouting, and the plugging risk caused by the fact that the functional plugging particles absorb water and expand in advance in a system is effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering reinforcement and support technology, specifically to a two-component grouting system and grouting process. Background Technology

[0002] In geotechnical engineering, grouting anchors (cables) are widely used in construction scenarios such as slope reinforcement, foundation pit support, tunnel surrounding rock stabilization, and underground structure water stopping. They achieve structural reinforcement and stability control by injecting cement-based grout into the anchor holes and surrounding cracks.

[0003] Existing grouting anchors have the following technical problems in fractured strata or highly permeable soil layers: 1. The method of preventing grout leakage relies on structural grout stoppers. Currently, physical grout stop structures (such as rubber rings, metal retaining rings, etc.) are mostly set at the front end or middle of the anchor. These components are easily affected by rock excavation disturbance and changes in ground stress, and lack active response characteristics. 2. Grout is prone to loss. In rock and soil masses with large variations in fracture width and complex structure, the grout is prone to "grout leakage" along the penetrating fractures, resulting in low grout utilization rate, uncontrollable reinforcement range, and in severe cases, affecting the anchoring effect and construction safety. 3. Difficulty in achieving effective sealing. Traditional grouts lack particle support and self-regulation functions, making it difficult to form a stable closed body in irregular or micro-fractures, resulting in poor sealing performance and long-term impermeability.

[0004] To address the issues of grout leakage along anchor holes or cracks and inadequate sealing during grouting, some projects have attempted to incorporate expansive granular materials into the grout, leveraging their hydration and expansion properties to enhance filling and sealing effects. However, these materials expand rapidly upon contact with water, and improper mixing methods or delivery locations can lead to premature expansion and blockage within pipelines or anchor bolt channels, affecting normal grouting operations. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a two-component grouting system and grouting process. By separating cement-based grout and sealing particles in the grouting channel, they are instantaneously mixed and injected synchronously before the grout is injected. This ensures that the particles and grout are evenly distributed and enter the fractured area to complete the sealing and bonding process. It aims to solve the technical problems of grout loss in fractured strata, low sealing efficiency, and premature expansion of sealing materials causing equipment blockage in traditional grouting processes, thereby improving the stability and reliability of grouting construction.

[0006] The technical solution of the present invention is as follows: In a first aspect of the invention, a two-component grouting system is provided, comprising a main grout supply pipeline and a sealing material supply pipeline, wherein the sealing material supply pipeline is obliquely connected to the main grout supply pipeline to form a Y-shaped grouting pipe; one end of the main grout supply pipeline is the main grout inlet, and the other end is the two-component grout outlet; the two-component grout outlet is connected to a grouting anchor rod, the grouting anchor rod having a hollow structure, and multiple grout outlet holes are provided on the side wall surface of the grouting anchor rod, through which the two-component grout enters the anchor rod hole for sealing.

[0007] In some embodiments of the present invention, the main slurry supply pipeline and the sealing material supply pipeline form an angle of 30° to 45°, and the distance between the sealing material outlet of the sealing material supply pipeline and the two-component slurry outlet of the main slurry supply pipeline is less than 1 meter. In some embodiments of the present invention, the sealing material inlet of the sealing material supply pipeline is connected to the sealing material storage chamber via a pneumatic vibrating feeder, and a valve is provided on the sealing material supply pipeline, the valve being located near the sealing material outlet. In some embodiments of the present invention, a grouting valve is provided at the two-component grout outlet of the main grout supply pipeline, and the grouting anchor is installed in the anchor hole through a gasket and a grout stop plug.

[0008] In some embodiments of the present invention, a spiral guide strip or guide rib is provided on the inner wall of the mixing area of ​​the main grout and the sealing material in the Y-shaped grouting pipe.

[0009] In some embodiments of the present invention, the sealing material is a functional sealing particle, the components of which include modified bentonite, superabsorbent polymer, mineral micro powder and cellulose composite material and quartz sand inert aggregate; the main grout is a cement-based grouting material. In a second aspect of the invention, a two-component grouting process is provided, implemented using the two-component grouting system described in the first aspect, comprising: The sealing material is introduced into the main slurry supply pipeline through the sealing material supply pipeline, and the sealing material is mixed with the main slurry in the main slurry supply pipeline; The mixed grout enters the anchor bolt and then enters the anchor bolt hole through the grout outlet on the anchor bolt to seal it. During the sealing process, the sealing material absorbs water and expands rapidly to form a high-strength cementitious body with the grout, which together fills the anchor bolt hole and the surrounding crack area.

[0010] In some embodiments of the present invention, the mixing ratio of the sealing material to the main slurry is: In some embodiments of the present invention, the sealing material is prepared into granules according to the following weight ratios: 45-50 parts by weight of modified bentonite; 5-10 parts by weight of superabsorbent polymer; 10-15 parts by weight of mineral micro powder and cellulose composite material; and 10-30 parts by weight of quartz sand inert aggregate.

[0011] In some embodiments of the present invention, the particle size of the sealing material is controlled between 0.3 mm and 2.5 mm, and the particle size of the inert quartz sand aggregate used is between 0.2 mm and 1.0 mm.

[0012] One or more technical solutions of the present invention have the following beneficial effects: (1) The two-component grouting system provided by the present invention uses a Y-type grouting pipe to introduce high-performance self-expanding particle sealing material into the main grout flow. Dynamic mixing is achieved without affecting the continuous supply of grout, which can realize the active sealing mechanism of grout and effectively suppress the risk of grout leakage. After contacting cement-based grout or pore water, the particles can quickly expand and form a flexible and deformable filler in the orifice and rock fissures. Together with the grout, they form a composite sealing layer of "expansion-cementation-interlocking", which significantly enhances the retention capacity of the grout and effectively prevents the grout from escaping into deep fissures or ineffective spaces.

[0013] (2) The two-component grouting system provided by this invention places the functional particle mixing section in an area no more than 1 meter away from the grouting hole, so that the mixed particle-grout system can be injected within 10 to 20 seconds, ensuring that the particle expansion process occurs in the target fracture zone, achieving precise control of the sealing reaction window, and ensuring stable pressure and directional filling. Compared with the passive sealing mode of traditional grouting of "escape first, solidify later", this invention realizes the active anti-escape mechanism of "trigger first, fill later", improving the grouting pressure stability by more than 20% and significantly improving the effective filling rate of grout, which is particularly suitable for high permeability strata or fractured sections.

[0014] (3) The two-component grouting system provided by this invention has a reasonable structural design, is easy to construct, and is adaptable to complex grouting environments. The entire anti-slurry-leakage two-component grouting system can be modularly integrated without replacing the original grouting pumping device. The particle supply system adopts a closed feeding and inclined tube injection method, which does not require an external pressure source, making installation simple and operation stable. The system is compatible with various slurry flow rates and concentrations, and is suitable for various complex geological conditions such as roadway reinforcement, water hazard sealing, slope grouting, and fracture zone treatment, with strong engineering adaptability.

[0015] (4) The two-component grouting process provided by this invention significantly improves the sealing quality and exhibits excellent long-term stability by using high-performance self-expanding particles as the sealing material. The sealing particles form a stable three-dimensional network cementitious body in the grout, possessing good shear resistance and compressive strength, and can maintain the sealing effect without degradation over a long period of time. The particle material is adapted to the alkaline grouting environment, is resistant to hydrolysis and shear, and the compressive strength of the sealing body is ≥3MPa, ensuring the structural stability of the sealing area and effectively extending the reinforcement life cycle. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the two-component grouting system of the present invention; Figure 2 This is a schematic diagram of the grouting process of the two-component grouting system of the present invention.

[0017] In the diagram: 1. Main grout supply pipeline; 101. Main grout inlet; 102. Two-component grout outlet; 2. Sealing material supply pipeline; 201. Sealing material inlet; 202. Sealing material outlet; 3. Pneumatic vibrating feeder; 4. Sealing material storage chamber; 5. Valve; 6. Grouting valve; 7. Gasket; 8. Grout stop plug; 9. Grouting anchor; 10. Anchor hole; 11. Sealing particles; 12. Rock mass; 13. Rock mass fissure. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Example 1 In a typical embodiment of the present invention, a two-component grouting system is proposed, such as... Figure 1 As shown, it includes a main grout supply pipeline 1 and a sealing material supply pipeline 2. The sealing material supply pipeline 2 is inclinedly connected to the main grout supply pipeline 1 to form a Y-shaped grouting pipe. One end of the main grout supply pipeline 1 is the main grout inlet 101, and the other end is the two-component grout outlet 102. The two-component grout outlet 102 is connected to the grouting anchor rod 9. The grouting anchor rod 9 has a hollow structure, and multiple grout outlet holes are provided on the side wall of the grouting anchor rod. The two-component grout enters the anchor rod hole through the grout outlet holes for sealing.

[0020] In this embodiment, the main slurry supply pipeline 1 and the sealing material supply pipeline 2 form an angle of 30° to 45°, and the distance between the sealing material outlet 202 of the sealing material supply pipeline 2 and the two-component slurry outlet 102 of the main slurry supply pipeline 1 is less than 1 meter.

[0021] Understandably, the preferred angle between the main grout supply pipeline and the sealing material supply pipeline is 30°~45°, which effectively guides particles in without causing flow field interference. The main grout is supplied by a conventional high-pressure grouting pump and enters the Y-shaped grouting pipe through the main grout supply pipeline. During the flow of the main grout, a local negative pressure zone is formed at the intersection of the inclined pipes, thereby automatically drawing the dry granular material into the grout flow system, avoiding the need for a separate pressurization unit. To prevent premature expansion of the sealing material particles after contact with the main grout, the distance between the sealing material introduction point and the area near the grouting hole is generally less than 1 meter, ensuring that injection is completed within 10~20 seconds after mixing, thereby controlling the expansion reaction window within the underground fissures and ensuring the effective sealing effect.

[0022] In this embodiment, the sealing material inlet 201 of the sealing material supply pipeline 2 is connected to the sealing material storage chamber 4 via a pneumatic vibrating feeder 3. A valve 5 is installed on the sealing material supply pipeline 2, and the valve 5 is located near the sealing material outlet 202. Furthermore, a spiral guide strip or guide rib is provided on the inner wall of the mixing area of ​​the main grout and sealing material in the Y-shaped grouting pipe.

[0023] Understandably, the dry functional plugging material granules are pre-stored in a sealed, dry plugging material storage chamber and quantitatively fed through a pneumatic vibratory feeder or a screw conveyor to prevent the granules from absorbing moisture and clumping. After being introduced into the slurry flow through the plugging material supply pipeline, the granules immediately enter a turbulent mixing zone located inside the pipeline. This mixing zone is equipped with spiral guide strips or turbulence ribs, which rely on the kinetic energy of the main slurry to fully disperse the granules and form a uniform mixture with the slurry. The entire structure has a consistent flow diameter along the entire flow path, without abrupt changes in size, avoiding pressure loss and flow velocity disturbance, and ensuring that the granules are uniformly distributed throughout the slurry flow without reducing the system grouting pressure.

[0024] In this embodiment, a grouting valve 6 is provided at the two-component grout outlet of the main grout supply pipeline 1, and the grouting anchor 9 is installed in the anchor hole 10 through a gasket 7 and a grout stop plug 8. The grouting volume and flow rate are controlled by the grouting valve 6, and the grout stop plug 8 prevents the grout from flowing out of the anchor hole.

[0025] In this embodiment, the sealing material is a functional sealing particle 11, the components of which include modified bentonite, superabsorbent polymer, mineral micro powder and cellulose composite material and quartz sand inert aggregate; the main grout is a cement-based grouting material.

[0026] Modified bentonite, as the main expansion substrate, possesses natural expansibility and good interfacial compatibility. Superabsorbent polymers (SAPs) can increase the reaction rate and expansion ratio; however, their dosage must be controlled to avoid adversely affecting the bonding strength. Mineral powder and cellulose composite materials enhance adhesion and anti-dispersion properties, and after expansion, they form a three-dimensional support structure, improving the overall sealing strength. Quartz sand inert aggregate provides skeletal support for the sealing particles, enhancing the material's shear, compressive, and rheological resistance. The main grout directly uses existing cement-based grouting materials.

[0027] The aforementioned functional plugging particles were used as plugging materials. The particle size of the plugging particles was controlled between 0.3 mm and 2.5 mm, exhibiting continuous gradation characteristics to improve adaptability to cracks of different sizes and filling efficiency. To enhance the stability of the plugging structure, 10% to 30% by mass of quartz sand particles with a particle size of 0.1 mm to 1.0 mm were mixed into the particle system to construct an interparticle support framework, thereby improving the material's compressive strength and erosion resistance.

[0028] The aforementioned plugging particles have the following advantages: 1. Expansion and stability: The sealing particles expand rapidly within 30-90 seconds after contact with free water or cement slurry, with a volume expansion rate of 500%-1000% of the original volume. After expansion, they form a flexible, structurally stable, and insoluble filler, enabling adaptive embedding and sealing of complex cracks. Quartz sand aggregate plays a role in resisting stress concentration and providing stable support during the expansion process, preventing structural damage or loss of the expanded body.

[0029] 2. Cementitious compatibility: The surface of the sealing particles undergoes hydrophilic modification treatment, exhibiting good interfacial activity and enabling them to form an interlocking structure with cement-based grouting materials. After grouting, they harden together with the grout within 6–12 hours to form a monolithic sealing cementitious body with a compressive strength ≥3MPa, providing excellent sealing and long-lasting anchoring performance.

[0030] 3. Good environmental adaptability: The sealing particles can exist stably in an alkaline grouting environment with pH=10 to 12 without degradation. They have good resistance to water seepage, shearing and chemical erosion, and are suitable for complex geological environments with high water content and obvious fracture development.

[0031] The two-component grouting system provided in this embodiment also includes an output and control system. This system directly adopts an existing structure and is mainly used for real-time regulation and monitoring of pressure, flow rate, time, and grout volume throughout the grouting process. It is a standard component in traditional grouting processes. The output and control system typically includes a high-pressure grouting pump, pressure gauge, flow meter, check valve, electrical control panel, and related monitoring modules. Operators can set the target grouting pressure and volume via the control panel. The system adjusts the pumping rate and output pressure in real time through closed-loop feedback to ensure stability and safety during the grouting process. Furthermore, the system also features automatic shutdown in case of abnormalities and overpressure alarm functions to prevent grout backflow, equipment damage, or construction accidents.

[0032] The two-component grouting system provided in this embodiment is also equipped with traditional equipment such as a grouting mixing device, a grout storage tank, and a grouting pump. Its main function is to prepare, temporarily store, and continuously and stably supply cement-based grout. This system typically uses a twin-shaft or single-shaft forced mixing device with high-speed stirring to uniformly mix cement, water, and necessary admixtures, producing a grout with good fluidity and suspension stability. After short-term buffering in the grout storage tank, it is pressurized and output by the grouting pump. The grouting pump type can be selected according to project requirements, such as a plunger pump, screw pump, or diaphragm pump, to achieve constant flow and continuous injection, meeting the basic construction requirements of the grouting process. This part of the system is a component of traditional grouting processes, with a mature structure and wide application. In this embodiment, it is used as a basic module, mainly serving the subsequent particle mixing and sealing functions.

[0033] The working principle of the two-component grouting system provided in this embodiment is as follows: Before grouting, complete the grout preparation, particle pre-loading, and inspection of the delivery module to ensure that all channels are well sealed and connected. During grouting, the cement-based grout is pressurized by the grouting pump and flows through the sealing material introduction point of the Y-shaped grouting pipe, automatically drawing in the sealing particles from the sealing material supply pipeline and mixing them rapidly. The mixing point is close to the grouting hole (usually less than 1m), and the injection is completed within 10-20 seconds, effectively preventing the particles from prematurely hydrating and expanding inside the pipe. After grouting, the particles and grout together fill the hole opening and fracture area. After absorbing water, the particles rapidly expand and form a high-strength cementitious body with the grout, achieving a dual sealing effect of "chemical reaction + physical filling," significantly enhancing the sealing effect of rock mass fractures and the integrity of the grout body.

[0034] The two-component grouting system provided in this embodiment ensures that the expanding particles and grout are uniformly mixed and enter the anchor bolt channel and surrounding fissure area synchronously with the fluid through the Y-shaped grouting pipe, thereby improving the integrity and anti-seepage stability of the sealing range. Without relying on mechanical grouting devices, it achieves adaptive sealing of fissures through a material response mechanism. Before grouting, physical isolation and timing control are used to ensure that the functional sealing particles and grout are mixed on-site in real time, effectively avoiding the risk of blockage caused by premature water absorption and expansion within the system.

[0035] Example 2 A typical embodiment of this invention provides a two-component grouting process, including: The sealing material is introduced into the main slurry supply pipeline through the sealing material supply pipeline, and the sealing material is mixed with the main slurry in the main slurry supply pipeline; The mixed grout enters the anchor bolt and then enters the anchor bolt hole through the grout outlet on the anchor bolt to seal it. During the sealing process, the sealing material absorbs water and expands rapidly to form a high-strength cementitious body with the grout, which together fills the anchor bolt hole and the surrounding crack area.

[0036] Specifically, during the grouting process, the mass of the sealing material added is 8-15% of the mass of the grout. Within this range, it ensures that the grout has good fluidity and stable pumping pressure, while allowing the sealing particles to be fully distributed and effectively expanded in the cracks, forming a uniform and dense filler. Preferably, the mass of the sealing material added is 10% of the mass of the grout.

[0037] In this embodiment, the sealing material is formulated into granules according to the following weight ratios: 45-50 parts by weight of modified bentonite; 5-10 parts by weight of superabsorbent polymer (SAP); 10-15 parts by weight of mineral micropowder and cellulose composite material; and 10-30 parts by weight of quartz sand inert aggregate. Preferably, 50 parts by weight of modified bentonite serves as the main expansion matrix, providing rapid water absorption and expansion, and basic sealing performance. 10 parts by weight of superabsorbent polymer (SAP) is used to enhance the initial rapid water absorption reaction and increase the volume expansion ratio. 15 parts by weight of mineral micropowder and cellulose composite material forms a three-dimensional skeleton structure during expansion, improving the support and anti-dispersion properties between particles. 25 parts by weight of quartz sand inert aggregate serves as a skeleton filler, improving the shear, compressive, and rheological resistance of the sealing body and preventing the expanded body from being dispersed.

[0038] Furthermore, the modified bentonite can be a sodium-based bentonite product coupled with an organosilane coupling agent, which can improve its water absorption rate and swelling stability. The highly absorbent polymer is preferably partially hydrolyzed sodium polyacrylate, which has a high water absorption ratio and good alkali resistance, making it suitable for cement-based slurry environments. The mixing ratio of the mineral powder and cellulose is 1:1; the mineral powder is preferably metakaolin powder, used to improve the density of the slurry; the cellulose is preferably sodium carboxymethyl cellulose (CMC), which enhances bonding and anti-dispersion properties; the inert quartz sand aggregate is preferably dried natural quartz sand with a particle size range of 0.2–1.0 mm, used to form a particle skeleton and improve the shear and rheological properties of the expanded body.

[0039] In this embodiment, the particle size of the sealing material is controlled between 0.3 mm and 2.5 mm, and the particle size of the inert quartz sand aggregate used is between 0.1 mm and 1.0 mm.

[0040] By controlling the particle size of the sealing particles to 0.3mm–2.5mm, which exhibit continuous gradation characteristics, the adaptability and filling efficiency to fractures of different sizes are improved. To enhance the stability of the sealing structure, 10%–30% by mass of quartz sand particles with a particle size of 0.1mm–1.0mm are blended into the particle system to construct an interparticle support framework, thereby improving the material's compressive strength and erosion resistance.

[0041] The two-component grouting process provided in this embodiment utilizes a main grout supply pipeline, a sealing material supply pipeline, and a Y-type ejector mixing structure to achieve stable, quantitative, and immediate introduction of functional self-expanding particles into cement-based grouting fluid without adding an independent pressure source, and completes efficient mixing near the grouting hole. This avoids the sealing failure problems caused by pressure loss or uneven mixing in traditional two-component systems, ensuring undiminished grout pressure, uniform particle distribution, and precise control of the mixing reaction window, effectively improving grouting sealing quality and injection efficiency.

[0042] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A two-component grouting system, characterized in that, It includes a main grout supply pipeline and a sealing material supply pipeline. The sealing material supply pipeline is inclinedly connected to the main grout supply pipeline to form a Y-shaped grouting pipe. One end of the main grout supply pipeline is the main grout inlet, and the other end is the two-component grout outlet. The two-component grout outlet is connected to the grouting anchor rod. The grouting anchor rod has a hollow structure and multiple grout outlet holes are provided on the side wall of the grouting anchor rod. The two-component grout enters the anchor rod hole through the grout outlet holes for sealing.

2. The two-component grouting system as described in claim 1, characterized in that, The main slurry supply pipeline and the sealing material supply pipeline form an angle of 30° to 45°, and the distance between the sealing material outlet of the sealing material supply pipeline and the two-component slurry outlet of the main slurry supply pipeline is less than 1 meter.

3. The two-component grouting system as described in claim 1, characterized in that, The sealing material inlet of the sealing material supply pipeline is connected to the sealing material storage chamber via a pneumatic vibrating feeder. A valve is installed on the sealing material supply pipeline, and the valve is located near the sealing material outlet.

4. The two-component grouting system as described in claim 1, characterized in that, A grouting valve is installed at the outlet of the two-component grout in the main grout supply pipeline, and the grouting anchor is installed in the anchor hole through a gasket and a grout stop plug.

5. The two-component grouting system as described in claim 1, characterized in that, Spiral guide strips or guide ribs are provided on the inner wall of the mixing area of ​​the main grout and sealing material inside the Y-shaped grouting pipe.

6. The two-component grouting system as described in claim 1, characterized in that, The sealing material uses functional sealing particles, which are composed of modified bentonite, superabsorbent polymer, mineral micro powder and cellulose composite material and quartz sand inert aggregate; the main grout uses cement-based grouting material.

7. A two-component grouting process, implemented using the two-component grouting system as described in any one of claims 1-6, characterized in that, include: The sealing material is introduced into the main slurry supply pipeline through the sealing material supply pipeline, and the sealing material is mixed with the main slurry in the main slurry supply pipeline; The mixed grout enters the anchor bolt and then enters the anchor bolt hole through the grout outlet on the anchor bolt to seal it. During the sealing process, the sealing material absorbs water and expands rapidly to form a high-strength cementitious body with the grout, which together fills the anchor bolt hole and the surrounding crack area.

8. The two-component grouting process as described in claim 7, characterized in that, During the grouting process, the mass of the sealing material added is 8-15% of the mass of the grouting liquid.

9. The two-component grouting process as described in claim 7, characterized in that, The sealing material is prepared into granules according to the following weight ratio: 45-50 parts by weight of modified bentonite; 5-10 parts by weight of superabsorbent polymer; 10-15 parts by weight of mineral powder and cellulose composite material; and 10-30 parts by weight of quartz sand inert aggregate.

10. The two-component grouting process as described in claim 7, characterized in that, The particle size of the sealing material is controlled between 0.3 mm and 2.5 mm, and the particle size of the inert quartz sand aggregate used is between 0.2 mm and 1.0 mm.

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