Still water filling composite cementing material for tunnel surrounding rock reinforcement, preparation method and application

Abstract

The invention discloses a still water filling composite cementitious material for tunnel surrounding rock reinforcement, a preparation method and application, the cementitious material comprises 80-95 parts of a matrix component, 10-20 parts of an early strength component, 10-20 parts of an additive and 10-20 parts of a solvent; the early strength component is prepared from 5 to 20 parts of amorphous calcium aluminate mineral and anhydrous gypsum CaSO4; the admixture is prepared from the following components in parts by weight: 0.1 to 0.8 part of a retarder, 0.1 to 0.3 part of a high-performance water reducing agent, 0.02 to 0.06 part of a thickening water-retaining agent and 0.1 to 0.5 part of an underwater anti-dispersion flocculant; 25 to 40 parts of a solvent; the method comprises the following steps: weighing the mass of each component raw material in parts by weight, and uniformly mixing the matrix component, the early strength component and the additive component to obtain a premixed dry material; adding a solvent into the premixed dry material, and uniformly stirring to obtain mixed slurry; the grouting reinforcement material is high in fluidity in a normal-temperature or high-temperature (20-40 DEG C) environment, the early strength is quickly improved, and the later strength is low in loss.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel surrounding rock reinforcement, and particularly relates to a hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement, a preparation method and an application thereof. Background Art

[0002] In on-site engineering applications, materials such as ordinary Portland cement, cement-sodium silicate, and sulfoaluminate cement are still favored. However, the available operation time of these existing materials can last up to 10 hours at most and about 1 minute at least. If the time is too short, it is easy to block the mixer, and if the time is too long, it is difficult to form early strength in a static water environment; there are problems of fast setting, high early strength, high loss, or slow setting, low early strength, low loss. For the existing situation of simultaneously meeting slow setting, high early strength, and high loss, the prior art cannot achieve it. Moreover, the existing reinforcement materials are mainly Portland cement, cement-sodium silicate, sulfoaluminate cement, and oil well cement. Under the continuous action of high temperature, the rapid hydration of the reinforcement materials leads to the disordered precipitation and wrong overlapping of a large number of hydration products. At the same time, the increase in temperature causes the transformation of low-density AFt to high-density AFm, resulting in more rough pores in the system, thus causing a loss of the final strength.

[0003] Chinese Patent CN114477931A discloses a foamed aluminate cement-based thermal pipeline waterproof plugging and sealing material and its preparation. The plugging material of this patent includes: 57-82 parts of clay clinker, 25-45 parts of bauxite clinker, 10-15 parts of cementitious material, 5-10 parts of silica fume, 0.5-2.5 parts of water reducer, 0.5-1.5 parts of calcium peroxide, 0.3-0.65 parts of foam stabilizer, 0.2-0.4 parts of retarder, and 20-35 parts of water. Among them, aluminate cement and silica fume enhance the early strength, and clay clinker and bauxite clinker enhance the bonding performance of the material. Although this material has good impermeability and plugging performance, its curing time is very fast, which is not conducive to construction. Chinese Patent CN113651590B discloses a building plugging composite material and its use method. It uses a water-based epoxy curing agent to enhance the bonding performance and durability of the material in a humid environment, and uses rubber particles to replace traditional sand materials to provide elasticity and reduce the curing shrinkage of the material. However, the flexural strength of this material is insufficient and its heat resistance also needs to be improved.

[0004] Aiming at the difficulty in unifying the available operation time, early strength, and strength stability of tunnel surrounding rock reinforcement materials in a static water environment at high temperature (20°C - 40°C), the present invention provides a composite cementitious material, a preparation method and an application for a high-temperature static water environment, so as to solve the problem that the prior art cannot simultaneously meet the requirements of a long available operation time, high early strength, and high strength stability. Summary of the Invention

[0005] The object of the invention is to provide a hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement, a preparation method and an application, so as to solve the problem that the prior art cannot simultaneously meet the requirements of long operable time, high early strength and high strength stability.

[0006] The present invention is realized as follows. A hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement includes a matrix component, an early strength component, an admixture and a solvent.

[0007] The matrix component is 80 - 95 parts.

[0008] The early strength component includes 5 - 20 parts of amorphous calcium aluminate mineral and anhydrous gypsum CaSO4.

[0009] The admixture includes 0.1 - 0.8 part of retarder, 0.1 - 0.3 part of high-performance water reducer, 0.02 - 0.06 part of thickening and water-retaining agent, and 0.1 - 1 part of underwater anti-dispersion flocculant.

[0010] The solvent is 25 - 40 parts.

[0011] In the present invention, the addition of a small amount of a mixture of amorphous calcium aluminate mineral and anhydrous gypsum can quickly induce the formation of calcium sulfoaluminate hydrate products, promote the setting of the slurry, and enhance the early strength of the slurry. The addition of a retarder, a high-performance water reducer and an underwater anti-dispersion flocculant enables the slurry to have a large fluidity and operable time during underwater grouting, and also has a certain underwater anti-dispersion performance, which can improve the stone formation rate of the slurry underwater. The present invention proposes a method for modifying the mineral phase of the hydration products in traditional silicate cement grouting materials. By adding amorphous calcium aluminate mineral, the hydration products of the slurry are mainly calcium sulfoaluminate phase in the early stage and mainly calcium silicate gel phase in the later stage, so as to achieve rapid increase of early strength and low loss of later strength of the grouting reinforcement material in normal temperature or high temperature (20°C - 40°C) environment.

[0012] A further technical solution of the present invention is that the mass ratio of the amorphous calcium aluminate mineral to anhydrous gypsum CaSO4 is 55 - 60:40 - 45.

[0013] A further technical solution of the present invention is that the content of amorphous mineral in the amorphous calcium aluminate mineral is ≥95%.

[0014] The amorphous mineral includes SiO2 with a content of ≤5wt%, Al2O3 with a content of ≥42wt%, CaO with a content of ≥48wt%, MgO with a content of ≤1wt% and Fe2O3 with a content of ≤1wt%.

[0015] A further technical solution of the present invention is that the retarder is tartaric acid, the high-performance water reducer is polycarboxylate powder water reducer, the thickening and water-retaining agent is cellulose ether with a viscosity of 40,000, and the underwater anti-dispersion flocculant is type IV flocculant.

[0016] A further technical solution of the present invention is that the solvent is water.

[0017] A further technical solution of the present invention is that the matrix component is ordinary Portland cement.

[0018] The present invention also provides a preparation method of a composite cementitious material.

[0019] The preparation method includes the following steps:

[0020] S1. Weigh the mass of each component raw material described in any one of claims 1-6 by weight parts and set aside.

[0021] S2. Mix the matrix component, early strength component, and admixture component evenly to obtain a pre-mixed dry material.

[0022] S3. Add the solvent to the pre-mixed dry material and mix evenly. First, stir at a speed of 120-140 r / min for 100-120 s, and then stir at a speed of 270-290 r / min for 100-120 s to obtain a mixed slurry, that is, the composite cementitious material.

[0023] Advantages of the present invention: In the present invention, the addition of a small amount of the mixture of amorphous calcium aluminate minerals and anhydrous gypsum can quickly induce the formation of calcium sulfoaluminate hydrate products, promote the setting of the slurry, and improve the early strength of the slurry; the addition of a retarder, a high-performance water reducer, and an underwater anti-dispersion flocculant enables the slurry to have a large fluidity and operable time during underwater grouting, and also has a certain underwater anti-dispersion performance, which can improve the stone formation rate of the slurry underwater; the present invention proposes a method for modifying the mineral phase of the hydration products in traditional Portland cement grouting materials. By adding amorphous calcium aluminate minerals and anhydrous gypsum, the early formation of calcium sulfoaluminate hydrate and calcium aluminate hydrate phases in the slurry hydration products is regulated, and the hydration calcium silicate gel phase is still the main phase in the later stage, realizing the rapid increase of the early strength and low loss of the later strength of the grouting reinforcement material in normal temperature or high temperature (20°C - 40°C) environments. Description of the Drawings

[0024] Figure 1 is a flowchart of a preparation method of a hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement provided by the present invention.

[0025] Figure 2 is an application diagram provided by the present invention. Detailed Embodiments

[0026] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0027] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essential meanings. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope for the implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0028] A hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement, comprising a matrix component, an early strength component, an admixture, and a solvent.

[0029] The matrix component is 80 - 95 parts.

[0030] The early strength component includes 5 - 20 parts of amorphous calcium aluminate mineral and anhydrous gypsum CaSO4.

[0031] The admixture includes 0.1 - 0.8 part of a retarder, 0.1 - 0.3 part of a high-performance water reducer, 0.02 - 0.06 part of a thickening and water-retaining agent, and 0.1 - 1 part of an underwater anti-dispersion flocculant.

[0032] The solvent is 25 - 40 parts.

[0033] In the present invention, the addition of a small amount of a mixture of amorphous calcium aluminate mineral and anhydrous gypsum can quickly induce the formation of hydrated calcium sulfoaluminate products, promote the setting of the slurry, and enhance the early strength of the slurry. The combined addition of a retarder, a high-performance water reducer, and an underwater anti-dispersion flocculant enables the slurry to have a large fluidity and an operable time during underwater grouting, and also has a certain underwater anti-dispersion performance, which can improve the stone formation rate of the slurry underwater. The present invention proposes a method for modifying the mineral phase of the hydrated products in traditional silicate cement grouting materials. By adding amorphous calcium aluminate mineral, the hydrated products of the slurry are mainly calcium sulfoaluminate phase in the early stage and mainly calcium silicate gel phase in the later stage, realizing the rapid increase of the early strength and low loss of the later strength of the grouting reinforcement material in normal temperature or high temperature (20°C - 40°C) environments.

[0034] The mass ratio of the amorphous calcium aluminate mineral to anhydrous gypsum CaSO4 is 55 - 60:40 - 45.

[0035] The content of amorphous minerals in the amorphous calcium aluminate mineral is ≥95%;

[0036] The amorphous minerals include SiO2 with a content of ≤5wt%, Al2O3 with a content of ≥42wt%, CaO with a content of ≥48wt%, MgO with a content of ≤1wt%, and Fe2O3 with a content of ≤1wt%.

[0037] The retarder is tartaric acid, the high - performance water - reducing agent is a polycarboxylate powder water - reducing agent, the thickening and water - retaining agent is a cellulose ether with a viscosity of 40,000, and the underwater anti - dispersion flocculant is a type IV flocculant.

[0038] The solvent is water.

[0039] The matrix component is ordinary Portland cement (OPC).

[0040] Aiming at the problems that the early strength of the current traditional Portland cement slurry is low and the setting time is relatively long, the incorporation of a mixture of amorphous calcium aluminate mineral and anhydrous gypsum can quickly induce the formation of calcium sulfoaluminate hydrate products, promote the setting of the slurry, and improve the early strength of the slurry; aiming at the problems that the setting time of the current traditional Portland cement slurry is relatively long, and the setting of sulfoaluminate cement slurry and cement - water glass double slurry is too fast (especially in high - temperature environments), a retarder is incorporated to regulate the dissolution - precipitation process of early hydration products to achieve controllable setting time of the slurry; aiming at the poor fluidity of the slurry, a high - performance water - reducing agent is incorporated to produce a steric hindrance effect on cement particles to achieve the purpose of dispersion and improve the fluidity of the slurry; aiming at the poor stability and low stone formation rate of the slurry underwater, cellulose ether and an underwater anti - dispersion agent are incorporated to increase the viscosity of the cement paste and improve the stone formation rate of the slurry in a static water environment; aiming at the problems that the material strength of the current quick - setting and quick - hardening cement slurry shows reverse shrinkage or large loss rate in the later stage at normal temperature or high temperature (20°C - 40°C), a method for modifying the mineral phase of hydration products in traditional Portland cement grouting materials is proposed. By incorporating amorphous calcium aluminate mineral, the hydration products of the slurry are mainly calcium sulfoaluminate phase in the early stage and mainly calcium silicate gel phase in the later stage, realizing rapid increase in early strength and low loss in later strength of the grouting reinforcement material.

[0041] Examples 1 - 13:

[0042] Examples 1 - 13 of the present invention provide a static - water filling composite cementitious material for tunnel surrounding rock reinforcement, and the raw materials in each example are shown in Table 1;

[0043] Table 1 Raw material ratios of Examples 1 - 13

[0044] Ordinary Portland cement Early strength component Retarder High-performance water reducer Anti-underwater dispersant Cellulose ether Water 1 95 5 0.2 0.2 0 0.04 40 2 90 10 0.4 0.2 0 0.04 40 3 85 15 0.6 0.2 0 0.04 40 4 80 20 0.8 0.2 0 0.04 40 5 80 20 0.5 0.3 0 0.01 30 6 95 5 0.2 0.3 0 0.01 30 7 95 5 0.3 0.1 0 0.01 30 8 95 5 0.15 0.3 0 0.02 30 9 90 10 0.3 0.2 0 0.02 30 10 85 15 0.5 0.3 0 0.02 35 11 90 10 0.5 0.15 0 0.08 35 12 90 10 0.4 0.2 0.1 0.04 40 13 90 10 0.4 0.2 0.5 0.04 40

[0045] In Table 1, the early strength component is C 12 A7 + CaSO4; the retarding agent is tartaric acid; the high-performance water reducing agent is a polycarboxylate powder water reducing agent; the underwater anti-dispersant is a type IV flocculant;

[0046] C 12 A7 is dodecacalcium heptaaluminate, i.e., amorphous calcium aluminate.

[0047] The above-mentioned preparation method for preparing a static water filling composite cementitious material, as Figure 1 described, comprises the following steps:

[0048] S1. Weigh the mass of each component raw material described in Table 1 by weight parts and reserve;

[0049] S2. Mix the matrix component (OPC), the early strength component, and the admixture components (retarding agent, high-performance water reducing agent, flocculant, and cellulose ether) evenly to obtain a pre-mixed dry material;

[0050] S3. Add a solvent to the pre-mixed dry material and mix evenly. First, stir at a speed of 140 r / min for 120 s, and then stir at a speed of 285 r / min for 120 s to obtain a mixed slurry, i.e., the composite cementitious material.

[0051] Perform performance tests on the composite cementitious materials in Examples 1-11, including fluidity tests at normal temperature and high temperature and uniaxial compressive strength tests of the slurry stone bodies at 1 d, 7 d, and 28 d. The results are shown in Tables 2 and 3. Perform anti-dispersion performance tests on the composite gel materials in Examples 12-13 at normal temperature and high temperature, and the results are shown in Table 4;

[0052] Table 2 Application example data at 20 °C environment

[0053] Initial fluidity / mm 40min fluidity / mm 1d strength / MPa 7d strength / MPa 28d strength / MPa Example 1 267 242 10.5 53.8 66.6 Example 2 282 278 20.6 55.5 70.6 Example 3 302 278 39.1 64.7 80.2 Example 4 294 282 40.8 69.2 63.5 Example 5 318 280 46.5 70.6 77.8 Example 6 310 280 36.7 75.1 85.6 Example 7 310 302 37.5 73.8 82.2 Example 8 308 275 39.7 75.8 86.2 Example 9 281 265 35.8 70.9 84.4 Example 10 292 284 42.8 68.9 76.8 Example 11 280 276 33.5 62.3 75.5

[0054] Table 3 Application example data at 40 °C environment

[0055]

[0056]

[0057] Table 4 Anti-dispersion performance at 20 °C and 40 °C environments

[0058]

[0059] As can be seen from Tables 1, 2, 3, and 4, in the present invention, no matter how the dosage of the preparation raw materials changes or the temperature changes, it will affect the fluidity, compressive strength, strength loss rate, and water-land strength ratio of the grouting material.

[0060] As can be seen from the results in Tables 2 and 3, the initial fluidity of the material of the present invention ranges from 287 to 318 mm, and the fluidity at 40 min ranges from 206 to 302 mm. Taking Example 5 as an example, both the initial fluidity and the fluidity at 40 min are above 280 mm, indicating that the material has excellent fluidity performance.

[0061] As can be seen from the results in Tables 2 and 3, the 1-day strength of the material of the present invention ranges from 10.5 to 46.5 MPa at 20°C, and the 1-day strength ranges from 30.8 to 71.9 MPa at 40°C. Taking Example 5 as an example, the 1-day compressive strengths at 20°C and 40°C can reach 46.5 MPa and 60.6 MPa respectively, indicating that the material has high early strength.

[0062] As can be seen from the results in Tables 2 and 3, for the materials of Examples 1-11, there is no loss in the 28-day compressive strength at 40°C compared to that at 20°C, and the strength growth rate remains between 0.15% and 26.65%. Especially for Example 10, the strength growth rate reaches 26.65%, indicating that the material has no loss at high temperature and good high-temperature stability.

[0063] As can be seen from the results in Table 4, the water-land strength ratios of the material at 20°C and 40°C both exceed 80%, indicating that the material has excellent underwater anti-dispersion performance.

[0064] As can be seen from Examples 1 to 13, the material of the present invention can achieve the unity of the fluidity, early strength, and strength stability of the surrounding rock reinforcement material, and can be used for the reinforcement of broken surrounding rock in a static water environment at high temperature (20°C - 40°C) in tunnels, such as Figure 2 shown, and its process is the same as that of ordinary cement grouting.

[0065] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement, characterized in that Comprising the following parts by mass of matrix components, early strength components, admixtures and solvents, The matrix components are 80 to 95 parts; The early strength components include 5 to 20 parts of amorphous calcium aluminate minerals and anhydrous gypsum CaSO4; The admixtures include 0.1 to 0.8 part of retarder, 0.1 to 0.3 part of high-performance water reducer, 0.02 to 0.06 part of thickening and water-retaining agent, and 0.1 to 1 part of underwater anti-dispersion flocculant; The solvent is 25 to 40 parts.

2. The hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement according to claim 1, wherein The mass ratio of amorphous calcium aluminate minerals to anhydrous gypsum CaSO4 is 55 to 60:40 to 45.

3. A hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement according to claim 1, characterized in that, The content of amorphous minerals in the amorphous calcium aluminate minerals is ≥95%; The amorphous minerals include SiO2 with a content of ≤5wt%, Al2O3 with a content of ≥42wt%, CaO with a content of ≥48wt%, MgO with a content of ≤1wt% and Fe2O3 with a content of ≤1wt%.

4. A hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement according to claim 1, characterized in that, The retarder is tartaric acid, the high-performance water reducer is polycarboxylic acid powder water reducer, the thickening and water-retaining agent is 40,000 viscosity cellulose ether, and the underwater anti-dispersion flocculant is type IV flocculant.

5. A hydrostatic filling composite gelling material for tunnel surrounding rock reinforcement according to claim 1, characterized in that, The solvent is water.

6. The hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement according to claim 1, characterized in that, The matrix components are ordinary portland cement.

7. A preparation method of a composite cementitious material according to any one of claims 1-6, characterized in that, The preparation method includes the following steps: S1. Weigh the masses of each component raw material according to parts by weight and set aside; S2. Mix the matrix components, early strength components and admixture components evenly to obtain a pre-mixed dry material; S3. Add the solvent to the pre-mixed dry material and mix evenly. First, stir at a speed of 120 to 140 r / min for 100 to 120 s, and then stir at a speed of 270 to 290 r / min for 100 to 120 s to obtain a mixed slurry, that is, the composite cementitious material.

8. The preparation method of a hydrostatic filling composite cementitious material for tunnel surrounding rock reinforcement according to claim 7, characterized in that In S3, add the solvent to the pre-mixed dry material and mix evenly. First, stir at 140 r / min for 120 s, and then stir at 285 r / min for 120 s to obtain a mixed slurry, that is, the composite cementitious material.

9. A composite cementitious material for hydrostatic filling in tunnel surrounding rock reinforcement, characterized in that, The composite cementitious material is prepared by the preparation method according to claim 7 or 8.

10. Use of the composite cementitious material according to claim 9, characterized in that, The composite gel material is used for reinforcing the broken surrounding rock of a tunnel in an environment with a temperature of 20°C - 40°C.

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