Nano-composite polyurethane secondary permeation intelligent response type water shutoff consolidation grouting material and preparation method thereof

Abstract

The invention discloses a nano-composite polyurethane secondary permeation intelligent response type water plugging consolidation grouting material and a preparation method thereof, and belongs to the technical field of underground engineering anti-seepage reinforcement grouting materials. The nano composite polyurethane secondary permeation intelligent response type water shutoff consolidation grouting material is prepared from the following components in parts by volume: 1 part of slurry framework liquid and 1.5 to 2 parts of mixed liquid of a nano polyurethane cross-linking liquid component A and a nano polyurethane cross-linking liquid component B, wherein the volume ratio of the nano polyurethane cross-linking liquid component A to the nano polyurethane cross-linking liquid component B is 1: 1. The grouting material disclosed by the invention has the characteristics of nano-scale infiltration capacity, adjustable dynamic mechanical property and environmental response curing, through the synergistic effect of nano particle enhancement and a polyurethane network, the anti-permeability and durability of a sand layer difficult to permeate are remarkably improved, and the grouting material is suitable for efficient water plugging and reinforcement of projects such as water conservancy, tunnels and mines.

Description

Technical Field

[0001] This invention belongs to the technical field of underground engineering seepage prevention and reinforcement grouting materials, specifically relating to a nano-composite polyurethane secondary permeation intelligent responsive water plugging and consolidation grouting material and its preparation method. Background Technology

[0002] Poorly permeable sand layers, a common type of unfavorable geological formation, are characterized by low compressibility, easy liquefaction, lack of cohesion, and extremely poor stability. Under the influence of factors such as groundwater recharge, seepage, changes in in-situ stress, and engineering excavation, these layers are highly susceptible to serious problems such as landslides, groundwater depletion, and even casualties. Therefore, effective consolidation and seepage prevention of poorly permeable sand layers are critical issues that urgently need to be addressed in underground engineering construction.

[0003] Currently, grouting is a commonly used consolidation and treatment method for poorly permeable strata such as silty fine sand, aiming to achieve hydraulic sealing and formation reinforcement. Existing grouting materials are mainly divided into two categories: inorganic and organic. Common inorganic grouting materials, such as cement-based materials, have the advantages of low price and wide availability. However, when treating dense silty fine sand layers, conventional high-pressure cement fracturing grouting can only form a limited consolidation zone near the grout vein, and cannot effectively reinforce the area outside the grout vein, thus limiting the reinforcement range.

[0004] Organic chemical grouting materials, such as traditional polyurethane and epoxy resins, while possessing good penetration and diffusion properties and having some applications in engineering practice, also have significant drawbacks. On the one hand, these materials are costly, increasing the economic burden of engineering construction; on the other hand, some chemical materials pose safety issues, such as containing volatile organic compounds (VOCs), which present potential threats to the health of construction workers and the environment.

[0005] Furthermore, existing grouting materials lack intelligent response and self-regulation capabilities when facing complex and ever-changing engineering environments. For example, under different temperature, pressure, and pH conditions, the curing time and performance of the materials are difficult to control precisely, failing to meet the stability and reliability requirements of engineering projects for grouting effects.

[0006] In recent years, nanotechnology has demonstrated enormous application potential in the field of materials science. However, the combination of nanotechnology with polyurethane grouting materials to develop novel grouting materials with nanoscale permeability, adjustable dynamic mechanical properties, and environmentally responsive curing characteristics has not yet been fully researched and applied in existing technologies. Therefore, there is an urgent need to develop a grouting material with high permeability, good injectability, reasonable cost, and intelligent responsiveness to meet the practical needs of treating difficult-to-permeable sand layers. Summary of the Invention

[0007] Addressing the limitations of existing grouting materials in the treatment of difficult-to-permeable sand layers, such as the limited reinforcement range of inorganic materials, the high cost and insufficient safety of organic materials, and the lack of intelligent response characteristics, this invention aims to provide a nano-composite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material and its preparation method. By introducing nanotechnology and intelligent response mechanisms, combined with the synergistic effect of organic and inorganic materials, efficient water blocking and reinforcement of difficult-to-permeable sand layers can be achieved, providing an innovative solution for water blocking and seepage prevention engineering construction under complex geological conditions.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] One of the technical solutions of this invention is to provide a nano-composite polyurethane secondary permeation intelligent responsive water plugging and consolidation grouting material, which, by volume, comprises: 1 part of grout skeleton liquid, and 1.5 to 2 parts of a mixture of nano-polyurethane crosslinking liquid component A and nano-polyurethane crosslinking liquid component B; wherein, the volume ratio of nano-polyurethane crosslinking liquid component A to nano-polyurethane crosslinking liquid component B is 1:(0.8 to 1.2).

[0010] By weight, the slurry skeleton liquid comprises 45-55 parts cement and 45-55 parts water; component A of the nano-polyurethane crosslinking liquid comprises 90-95 parts polyether-type polyurethane prepolymer, 5-10 parts nano-SiO2 and 0.5-1 parts catalyst; component B of the nano-polyurethane crosslinking liquid comprises 80-90 parts chain extender, 10-20 parts curing agent and 5-8 parts expansion agent.

[0011] This invention utilizes a nanocomposite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material, designed synergistically with organic and inorganic components to form a "rigid skeleton-elastic permeation" two-phase system. Cement slurry is used as the grout vein skeleton fluid, providing rigid support and an alkaline environment; nanocomposite polyurethane is used as the permeation crosslinking fluid, leveraging the reinforcing effect of nanoparticles and the elasticity of polyurethane to achieve secondary permeation and intelligent response. During grouting reinforcement, the grout vein skeleton fluid achieves initial consolidation of the sand layer within a small area during low-pressure permeation, while the nanocomposite polyurethane crosslinking fluid continues to permeate and diffuse into the surrounding sand layer through channels outside the grout vein. Through the synergistic effect of nanoparticles and polyurethane, micropores are filled and an organic-inorganic interpenetrating network structure is formed, significantly improving the material's mechanical properties and impermeability.

[0012] Preferably, the cement has a fineness of not less than 1000 mesh.

[0013] Optionally, the catalyst is dibutyltin dilaurate.

[0014] Optionally, the chain extender is a polyol.

[0015] Optionally, the polyol is polyethylene glycol.

[0016] Optionally, the curing agent is diethylenetriamine.

[0017] Optionally, the expanding agent is montmorillonite.

[0018] The second technical solution of this invention provides a method for preparing the above-mentioned nanocomposite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material, comprising the following steps:

[0019] First, the slurry skeleton liquid, the nano-polyurethane crosslinking liquid component A, and the nano-polyurethane crosslinking liquid component B are prepared according to the weight parts of the raw materials; then, the three are mixed according to the volume usage to obtain the nano-composite polyurethane secondary permeation intelligent response water plugging and consolidation grouting material.

[0020] Preferably, the mixing order is to first mix the nano-polyurethane crosslinking liquid component A with the nano-polyurethane crosslinking liquid component B, and then add the slurry skeleton liquid.

[0021] The third technical solution of the present invention provides an application of the above-mentioned nanocomposite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material in the reinforcement and seepage prevention of difficult-to-permeable sand layers.

[0022] The beneficial technical effects of the present invention are as follows:

[0023] (1) Nano-reinforcement and synergistic effect: Nano-SiO2 is uniformly dispersed in the polyurethane network, forming a tight interfacial bond with cement hydration products, which enhances the compressive strength and impermeability of the material. The small size effect and surface activity of nanoparticles improve the material's ability to fill micropores.

[0024] (2) Adjustable dynamic mechanical properties: By adjusting the ratio of polyether-type polyurethane prepolymer, chain extender and curing agent, as well as the content of nanoparticles, the material can adapt to the mechanical requirements of different engineering environments. At the same time, the flexibility and deformation resistance of the material are significantly improved, enabling it to better cope with the dynamic changes of the formation.

[0025] (3) Environmental Response Curing Characteristics: This material has intelligent response characteristics, and its curing time can be adjusted by regulating the pH value or temperature of the environment. In acidic or alkaline environments, the material can automatically adjust the reaction rate to achieve precise curing control and meet the grouting requirements under different construction conditions.

[0026] (4) Environmental protection and durability: The material of this invention has no solvent evaporation, meets environmental protection requirements, and does not pollute groundwater. At the same time, the introduction of nanoparticles improves the material's anti-aging and anti-corrosion properties, giving it good durability and enabling it to adapt to long-term underground engineering environments.

[0027] (5) Secondary infiltration and diffusion: The nano-composite polyurethane crosslinking liquid has low viscosity and high permeability, which can achieve secondary infiltration, increase the grouting diffusion radius, effectively seal the pores and cracks in the difficult-to-permeable sand layer, and improve the overall stability and impermeability of the formation. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0029] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0030] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0031] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0032] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0033] Example 1

[0034] Preparation of nanocomposite polyurethane secondary permeation smart responsive water-blocking and consolidation grouting material:

[0035] (1) Preparation of slurry skeleton liquid: Take 50 parts by weight of PI 52.5 ultrafine cement with a fineness of more than 1000 mesh and 50 parts by weight of water, and mix them evenly with a mortar mixer to obtain slurry skeleton liquid for later use.

[0036] (2) Preparation of component A of nano-polyurethane crosslinking liquid: Take 90 parts by weight of polyether-type polyurethane prepolymer, 10 parts by weight of nano-SiO2 with a particle size of 20nm and 0.5 parts by weight of dibutyltin dilaurate catalyst, put them into a high-speed disperser and stir at 1000rpm for 10 minutes to mix evenly to obtain component A of nano-polyurethane crosslinking liquid for later use.

[0037] (3) Preparation of component B of nano-polyurethane crosslinking liquid: Take 80 parts by weight of polyethylene glycol, 20 parts by weight of diethylenetriamine curing agent and 5 parts by weight of montmorillonite expansion agent, and ultrasonically disperse them for 5 minutes. Stir evenly to obtain component B of nano-polyurethane crosslinking liquid for later use.

[0038] (4) Mix component A of nano-polyurethane crosslinking liquid and component B of nano-polyurethane crosslinking liquid at a volume ratio of 1:1 to obtain a mixture. Then mix the slurry skeleton liquid with the mixture at a volume ratio of 1:1.5. Stir at a low speed of 300r / min for 2 minutes, and then stir at a high speed of 800r / min for 1 minute to obtain the nano-composite polyurethane secondary permeation intelligent response water plugging and consolidation grouting composite material.

[0039] Example 2

[0040] Preparation of nanocomposite polyurethane secondary permeation smart responsive water-blocking and consolidation grouting material:

[0041] (1) Preparation of slurry skeleton liquid: Take 50 parts by weight of PI 52.5 ultrafine cement with a fineness of more than 1000 mesh and 50 parts by weight of water, and mix them evenly with a mortar mixer to obtain slurry skeleton liquid for later use.

[0042] (2) Preparation of component A of nano-polyurethane crosslinking liquid: Take 92 parts by weight of polyether-type polyurethane prepolymer, 8 parts by weight of nano-SiO2 with a particle size of 30nm and 0.7 parts by weight of dibutyltin dilaurate catalyst, put them into a high-speed disperser and stir at 1000rpm for 10 minutes to mix evenly to obtain component A of nano-polyurethane crosslinking liquid for later use.

[0043] (3) Preparation of component B of nano-polyurethane crosslinking liquid: Take 85 parts by weight of polyethylene glycol, 15 parts by weight of diethylenetriamine curing agent and 6 parts by weight of montmorillonite expansion agent, ultrasonically disperse for 5 minutes, stir evenly to obtain component B of nano-polyurethane crosslinking liquid, and set aside.

[0044] (4) Mix component A of nano-polyurethane crosslinking liquid and component B of nano-polyurethane crosslinking liquid at a volume ratio of 1:1 to obtain a mixture. Then mix the slurry skeleton liquid with the mixture at a volume ratio of 1:1.8. Stir at a low speed of 300r / min for 2 minutes, and then stir at a high speed of 800r / min for 1 minute to obtain a nano-composite polyurethane secondary permeation intelligent response water plugging and consolidation grouting composite material.

[0045] Example 3

[0046] Preparation of nanocomposite polyurethane secondary permeation smart responsive water-blocking and consolidation grouting material:

[0047] (1) Preparation of slurry skeleton liquid: Take 50 parts by weight of PI52.5 ultrafine cement with a fineness of more than 1000 mesh and 50 parts by weight of water, and mix them evenly with a mortar mixer to obtain slurry skeleton liquid for later use.

[0048] (2) Preparation of component A of nano-polyurethane crosslinking liquid: Take 95 parts by weight of polyether-type polyurethane prepolymer, 5 parts by weight of nano-SiO2 with a particle size of 50nm and 1 part by weight of dibutyltin dilaurate catalyst, put them into a high-speed disperser and stir at 1000rpm for 10 minutes to mix evenly to obtain component A of nano-polyurethane crosslinking liquid for later use.

[0049] (3) Preparation of component B of nano-polyurethane crosslinking liquid: Take 90 parts by weight of polyethylene glycol, 10 parts by weight of diethylenetriamine curing agent and 8 parts by weight of montmorillonite expansion agent, ultrasonically disperse for 5 minutes, stir evenly to obtain component B of nano-polyurethane crosslinking liquid, and set aside.

[0050] (4) Mix the nano-polyurethane crosslinking liquid component A and nano-polyurethane crosslinking liquid component B at a volume ratio of 1:1 to obtain a mixture. Then mix the slurry skeleton liquid with the mixture at a volume ratio of 1:2. Stir at low speed for 2 minutes and then stir at high speed for 1 minute to obtain the nano-composite polyurethane secondary penetration intelligent response water plugging and consolidation grouting composite material.

[0051] Comparative Example 1

[0052] Compared with Example 1, the difference is that only the slurry skeleton liquid is used, and the nano-polyurethane crosslinking liquid component A and nano-polyurethane crosslinking liquid component B are not added. Everything else is the same as Example 1.

[0053] Comparative Example 2

[0054] Compared with Example 1, the difference is that no slurry skeleton liquid is added, and only nano-polyurethane crosslinking liquid component A and nano-polyurethane crosslinking liquid component B are used. Everything else is the same as in Example 1.

[0055] The grouting materials prepared in Examples 1-3 and Comparative Examples 1-2 are mixed before use and injected into the impermeable sand layer through a two-liquid grouting device during field application.

[0056] Under the conditions of grouting pressure of 0.1 MPa and dynamic water flow velocity of 0.5 m / s, the performance of the grouting materials prepared in Examples 1-3 and Comparative Examples 1-2 was measured and compared.

[0057] Viscosity was tested using a rotational viscometer (e.g., NDJ-8S type, rotor No. 3). During testing, the sample was placed in a constant temperature water bath at 25±0.5℃ for 30 minutes, stirred at 60 r / min, and the viscosity value was recorded after the reading stabilized for 2 minutes. The measurement was repeated three times, and the average value was taken to ensure that the data error did not exceed 5%.

[0058] Gelation time: The viscosity change of the material was monitored using a rotational viscometer. The grouting material was mixed according to the formula and immediately poured into the sample cup. It was stirred at 100 r / min, and the viscosity change over time was recorded in real time. The gelation time was defined as the time interval when the viscosity suddenly increased to 10 times the initial value. The test temperature was controlled at 25±1℃.

[0059] Compressive strength: Prepare cylindrical specimens with a diameter of 50 mm and a height of 100 mm. Use an electro-hydraulic servo pressure testing machine to apply load at a rate of 0.5–0.8 MPa / s until the specimen fails. Record the failure load and calculate the compressive strength of the specimen, in MPa. The compressive strength value is taken as the arithmetic mean of the test results of three specimens, accurate to 0.1 MPa.

[0060] The material retention rate was calculated by using the circular tube flushing method. The cured grouting material specimen was placed in a transparent circular tube to simulate a dynamic water environment. The water flow rate was controlled by a water pump, and the erosion was continuously flushed for a certain period of time. The lost material was collected, dried, weighed, and the retention rate was calculated to evaluate the erosion resistance of the material in flowing water.

[0061] The permeability of the material was tested using a constant head permeability test apparatus. The prepared grouting material was cured and formed into a cylindrical standard specimen, which was then installed in the permeameter. A stable head difference was applied across the specimen to maintain a stable water flow through it. The amount of water passing through the specimen within a certain time was measured, and Darcy's law was used to calculate the material's permeability coefficient.

[0062] The test results are shown in Table 1 below.

[0063] Table 1. Performance test results of the grouting materials prepared in Examples 1-3 and Comparative Examples 1-3

[0064]

[0065] Table 1 shows that the synergistic effect of the nanocomposite polyurethane crosslinking liquid and the grout skeleton liquid has a significant impact on the material properties. Materials without the nanocomposite polyurethane crosslinking liquid exhibit poor compressive strength and permeability; materials without the grout skeleton liquid show low solidification strength and unsatisfactory retention rate. Compared with common polyurethane grouting materials on the market, the nanocomposite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material of this invention has significant advantages in compressive strength, permeability, and retention rate, and can better adapt to different engineering needs.

[0066] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A nano-composite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material, characterized in that, The components, by volume, include: 1 part of slurry skeleton liquid, and 1.5 to 2 parts of a mixture of nano-polyurethane crosslinking liquid component A and nano-polyurethane crosslinking liquid component B; wherein the volume ratio of nano-polyurethane crosslinking liquid component A to nano-polyurethane crosslinking liquid component B is 1:(0.8 to 1.2). By weight, the slurry skeleton liquid comprises 45-55 parts cement and 45-55 parts water; component A of the nano-polyurethane crosslinking liquid comprises 90-95 parts polyether-type polyurethane prepolymer, 5-10 parts nano-SiO2 and 0.5-1 parts catalyst; component B of the nano-polyurethane crosslinking liquid comprises 80-90 parts chain extender, 10-20 parts curing agent and 5-8 parts expansion agent.

2. The nano-composite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material according to claim 1, characterized in that, The fineness of the cement is not less than 1000 mesh.

3. The nano-composite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material according to claim 1, characterized in that, The catalyst is dibutyltin dilaurate.

4. The nano-composite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material according to claim 1, characterized in that, The chain extender is a polyol.

5. The nano-composite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material according to claim 4, characterized in that, The polyol is polyethylene glycol.

6. The nano-composite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material according to claim 1, characterized in that, The curing agent is diethylenetriamine.

7. The nano-composite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material according to claim 1, characterized in that, The expanding agent is montmorillonite.

8. A method for preparing the nanocomposite polyurethane secondary permeation smart responsive water-blocking and consolidation grouting material according to any one of claims 1 to 7, characterized in that, Includes the following steps: First, the slurry skeleton liquid, the nano-polyurethane crosslinking liquid component A, and the nano-polyurethane crosslinking liquid component B are prepared according to the weight parts of the raw materials; then, the three are mixed according to the volume usage to obtain the nano-composite polyurethane secondary permeation intelligent response water plugging and consolidation grouting material.

9. The preparation method according to claim 8, characterized in that, The mixing sequence is as follows: first, the nano-polyurethane crosslinking liquid component A is mixed with the nano-polyurethane crosslinking liquid component B, and then the slurry skeleton liquid is added.

10. The application of the nanocomposite polyurethane secondary permeation intelligent responsive water-blocking and consolidation grouting material according to any one of claims 1 to 7 in the reinforcement and seepage prevention of difficult-to-permeable sand layers.

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