Grouting material for low negative temperature construction and preparation method and application thereof

Abstract

The application relates to the technical field of cement-based building materials, in particular to a grouting material for low-negative-temperature construction and a preparation method and application thereof. Ordinary Portland cement is used as a main cementing material, an amorphous calcium aluminate mineral and an anhydrite are used as a fast-hardening agent, superfine mineral admixtures and a synergist are added as active components, the low-negative-temperature mechanical strength of the grouting material is improved, the open time of the grouting material is ensured, the utilization rate of industrial solid wastes is improved, the product cost is reduced, a water reducing agent, a retarder, a dispersant and a thickening agent are added to adjust the grouting construction effect.

Description

Technical Field

[0001] This invention relates to the field of cement-based building materials technology, and in particular to a grouting material for low-temperature construction, its preparation method, and its application. Background Technology

[0002] Grouting technology involves preparing a slurry from one or more materials, which is then pumped into fractured aquifers or soft, loose strata to solidify and bond, thus achieving water plugging or reinforcement. This technology is applied not only in underground engineering but also in surface engineering, particularly in tunnel transportation, foundation reinforcement, hydraulic engineering leak sealing, and mine restoration. Currently, single-component ordinary cement grouting is prone to bleeding and segregation, shrinks in volume after hardening, and has poor mechanical properties, making it difficult to meet anti-seepage requirements. Ordinary cement-water glass two-component grouting materials exhibit significant linear shrinkage, severely affecting the long-term stability of the grouting effect. Furthermore, its chemical structure is unstable; under contact with flowing water, a large amount of sodium ions dissolve, causing the hardened body to pulverize, reducing its consolidation strength, and the dissolved sodium ions also pollute water resources.

[0003] Currently, cement-based grouting technology is mainly used in normal temperature construction environments. It can prepare multifunctional cement-based grouting materials, such as early-strength type (CN115385638A, CN114436604A, CN116332543A), strong impermeability (CN202111245699), anti-dispersion type (CN114605102A), and low viscosity type (CN116655317A). Under normal temperature conditions, it is relatively easy to achieve the above functions. Patent CN116835947A invented a high-temperature and high-efficiency water-blocking grouting material. However, the development of cement-based grouting materials under low-temperature conditions is still blank. Although the existing technology CN116854438A discloses an ultra-low temperature grout for wind power steel-concrete towers, which can be constructed at -20℃, it is suitable for wind power foundation installation. The grout has no fluidity and uses a large amount of highly active cement, resulting in high cost. Summary of the Invention

[0004] Based on the problems of existing technologies, this invention provides a grouting material for low-temperature construction, its preparation method, and its application. Specifically, this invention uses ordinary silicate cement as the main cementing material, combined with amorphous calcium aluminate minerals and anhydrite as fast-setting agents, and discloses the specific preparation process of amorphous calcium aluminate. Ultrafine mineral admixtures and synergists are added as active components to jointly improve the low-temperature mechanical strength of the grouting material while ensuring its open time, improving the utilization rate of industrial solid waste, and reducing product costs. Water-reducing agents, retarders, anti-dispersants, and thickeners are added to adjust the grouting construction effect.

[0005] Specifically, the grouting material for low negative temperature construction of the present invention is composed of solid phase material and liquid phase material in a mass ratio of (9-12):3;

[0006] The solid material is composed of the following raw materials in parts by weight: 50-70 parts ordinary silicate cement, 1-15 parts rapid-setting agent, 1-20 parts ultrafine mineral admixture, 0.1-5 parts synergist, 0.01-0.2 parts water-reducing agent, 0.02-0.5 parts retarder, 0.01-0.2 parts anti-dispersing agent, and 0.01-0.2 parts thickener. The rapid-setting agent is a mixture of amorphous calcium aluminate mineral and anhydrite in a mass ratio of (7-7.5):(2.5-3.5). The ultrafine mineral admixture is a mixture of mineral powder and calcined coal gangue in a mass ratio of (6-6.5):(3.5-4.5). The synergist is a mixture of ultrafine alumina slag powder and rice husk ash in a mass ratio of 10:(1-3). The anti-dispersant is a mixture of modified polyacrylamide obtained by grafting starch, initiator and polyacrylamide, followed by washing and drying, and sodium tartrate and sodium tripolyphosphate in a mass ratio of (1-3):(0.8-1):(0.3-0.5).

[0007] The liquid phase material is a mixture of methanol, ethylene glycol and water in a mass ratio of 1:3:(6-10).

[0008] Preferably, the solid material is composed of the following raw materials in parts by weight: 50-70 parts of ordinary silicate cement, 10-15 parts of rapid hardening agent, 10-20 parts of ultrafine mineral admixture, 1-5 parts of synergist, 0.1-0.2 parts of water-reducing agent, 0.2-0.5 parts of retarder, 0.1-0.2 parts of anti-dispersing agent, and 0.1-0.2 parts of thickener.

[0009] Preferably, the ordinary silicate cement is P·O42.5 cement.

[0010] Preferably, the specific surface area of ​​the fast-setting agent is 800-850 cm². 2 / g.

[0011] Preferably, the preparation process of the amorphous calcium aluminate mineral is as follows: CaO and Al₂O₃ are uniformly mixed at a mass ratio of 1:0.9-1.2, calcined at 1500-1700℃, then the molten liquid phase is cooled to 1180-1200℃ by compressed air, then cooled to room temperature with water, and finally ground to a particle size of 450-500 cm⁻¹. 2 / g, that is, you get it.

[0012] Preferably, the mineral powder is S95 grade mineral powder.

[0013] Preferably, the calcined coal gangue is calcined at a temperature of 800-850℃, and the ultrafine mineral admixture has a specific surface area of ​​1000 cm². 2 / g.

[0014] Preferably, the preparation process of the ultrafine alumina slag powder is as follows: grinding the alumina slag powder to a specific surface area of ​​700-800 cm². 2 / g, that is, you get it.

[0015] Preferably, the water-reducing agent is a polycarboxylate water-reducing agent.

[0016] Preferably, the retarder is at least one of sodium gluconate, sucrose, tartaric acid, and boric acid.

[0017] Preferably, the initiator is persulfate.

[0018] Preferably, the thickener is a cellulose ether.

[0019] This invention also relates to a method for preparing the above-mentioned grouting material for low-temperature construction, specifically including the following steps:

[0020] 1) Weigh each raw material according to its weight.

[0021] 2) Mix the raw materials to obtain liquid-phase materials and solid-phase materials respectively.

[0022] 3) Mix the liquid phase material and the solid phase material evenly to obtain the final product.

[0023] This invention also relates to the application of the aforementioned low-temperature grouting material, specifically, its use for grouting and reinforcing tunnel cracks. More preferably, the low-temperature environment is -20 to -30°C.

[0024] This invention has the following technical advantages:

[0025] 1) This invention uses ordinary silicate cement as the main cementing material and adds a large amount of industrial solid waste as an auxiliary cementing material, thereby reducing costs and making use of waste;

[0026] 2) This invention uses fast-setting agents, ultrafine mineral admixtures and synergists to improve the mechanical properties of grouting materials under low negative temperature conditions, and adjusts the composition of active raw materials to ensure the construction performance and open time of the grouting materials;

[0027] 3) By adjusting the anti-dispersant formulation and combining it with a thickener, this invention achieves thickening and anti-dispersion capabilities suitable for grouting materials under low negative temperature conditions, ensuring that the grouting material does not segregate during the flow and seepage process in the cracks, maintains good workability, and exhibits normal development of mechanical strength;

[0028] 4) This invention uses methanol and ethylene glycol to modify water to obtain a liquid phase material, which can fully ensure that the cement hydration reaction can be triggered and the reaction can be sustained even at -30℃.

[0029] 5) The grouting material of the present invention has good fluidity and mechanical properties at -20 to -30℃, and no heat preservation measures are required. Detailed Implementation

[0030] To characterize the technical effect of this invention, grouting materials were prepared and their properties were tested. The flowability testing environment temperature was set to -25℃. The specimens were cured to a specified age before compressive and flexural strength tests were performed. -1d represents 1 day of curing at -25℃, -3d represents 3 days of curing at -25℃, and -7d+21d represents 7 days of curing at -25℃ followed by 21 days of curing under standard conditions.

[0031] The raw materials used include ordinary Portland cement (P·O42.5 cement) and a rapid-hardening agent with a specific surface area of ​​800 cm². 2 / g, the preparation process of amorphous calcium aluminate mineral is as follows: CaO and Al2O3 are uniformly mixed at a mass ratio of 1:1.1, calcined at 1700℃, then the molten liquid phase is cooled to 1200℃ by compressed air, and then cooled to room temperature by water, and ground to 490cm³. 2 / g, that is, the mineral powder is S95 grade mineral powder, and the specific surface area of ​​the ultrafine mineral admixture is 1000cm². 2 / g, specific surface area of ​​ultrafine alumina slag powder 780cm² 2 / g, the water-reducing agent is polycarboxylate powder water-reducing agent, the retarder is sodium gluconate, and the thickener is hydroxyethyl cellulose ether.

[0032] Example 1

[0033] The grouting material for low negative temperature construction is composed of solid phase material and liquid phase material in a mass ratio of 11:3.

[0034] The solid material is composed of the following raw materials in parts by weight: 65 parts ordinary silicate cement, 11 parts rapid hardening agent, 15 parts ultrafine mineral admixture, 3 parts synergist, 0.15 parts water-reducing agent, 0.2 parts retarder, 0.1 parts anti-dispersing agent, and 0.12 parts thickener. The rapid hardening agent is a mixture of amorphous calcium aluminate mineral and anhydrite in a mass ratio of 7.5:2.5. The ultrafine mineral admixture is a mixture of mineral powder and calcined coal gangue in a mass ratio of 6:4. The synergist is a mixture of ultrafine alumina slag powder and rice husk ash in a mass ratio of 10:2. The anti-dispersing agent is a mixture of modified polyacrylamide obtained by grafting starch, initiator and polyacrylamide, followed by washing and drying, and sodium tartrate and sodium tripolyphosphate in a mass ratio of 1:0.8:0.4.

[0035] The liquid phase material is a mixture of methanol, ethylene glycol and water in a mass ratio of 1:3:10.

[0036] Tests showed that at -25℃, the initial fluidity of the slurry was 380 mm, the fluidity at 30 min was 300 mm, the workability was good, the compressive strength at -1d was 30.7 MPa, the compressive strength at -3d was 48.5 MPa, the compressive strength at -7+21d was 85.7 MPa, and the flexural strength at -7+21d was 9.2 MPa.

[0037] Example 2

[0038] The grouting material for low-temperature construction is composed of solid and liquid phase materials in a mass ratio of 10:3.

[0039] The solid material is composed of the following raw materials in parts by weight: 55 parts ordinary silicate cement, 15 parts rapid-hardening agent, 16 parts ultrafine mineral admixture, 2 parts synergist, 0.14 parts water-reducing agent, 0.3 parts retarder, 0.2 parts anti-dispersing agent, and 0.1 parts thickener. The rapid-hardening agent is a mixture of amorphous calcium aluminate mineral and anhydrite in a mass ratio of 7:3. The ultrafine mineral admixture is a mixture of mineral powder and calcined coal gangue in a mass ratio of 6.5:3.5. The synergist is a mixture of ultrafine alumina slag powder and rice husk ash in a mass ratio of 10:3. The anti-dispersing agent is a mixture of modified polyacrylamide obtained by grafting starch, initiator and polyacrylamide, followed by washing and drying, and sodium tartrate and sodium tripolyphosphate in a mass ratio of 3:1:0.3.

[0040] The liquid phase material is a mixture of methanol, ethylene glycol and water in a mass ratio of 1:3:8.

[0041] Tests showed that at -25℃, the initial fluidity of the slurry was 360 mm, the fluidity at 30 min was 310 mm, the workability was good, the compressive strength at -1d was 28.5 MPa, the compressive strength at -3d was 46.3 MPa, the compressive strength at -7+21d was 82.4 MPa, and the flexural strength at -7+21d was 8.9 MPa.

[0042] Comparative Example 1

[0043] The grouting material is composed of solid phase material and liquid phase material in a mass ratio of 10:3;

[0044] The solid material is composed of the following raw materials in parts by weight: 55 parts ordinary silicate cement, 15 parts rapid-hardening agent, 16 parts ultrafine mineral admixture, 2 parts synergist, 0.14 parts water-reducing agent, 0.3 parts retarder, 0.2 parts anti-dispersing agent, and 0.1 parts thickener. The rapid-hardening agent is a mixture of C3A and anhydrite in a mass ratio of 7:3. The ultrafine mineral admixture is a mixture of fly ash and mineral powder in a mass ratio of 6.5:3.5. The synergist is a mixture of ultrafine alumina slag powder and rice husk ash in a mass ratio of 10:3. The anti-dispersing agent is a mixture of modified polyacrylamide obtained by grafting starch, initiator and polyacrylamide, followed by washing and drying, and sodium tartrate and sodium tripolyphosphate in a mass ratio of 3:1:0.3.

[0045] The liquid phase material is a mixture of methanol, ethylene glycol and water in a mass ratio of 1:3:8.

[0046] Tests showed that at -25℃, the initial fluidity of the slurry was 330 mm, the fluidity at 30 min was 260 mm, the workability was good, the compressive strength at -1d was 12.5 MPa, the compressive strength at -3d was 18.6 MPa, the compressive strength at -7+21d was 43.1 MPa, and the flexural strength at -7+21d was 3.8 MPa.

[0047] Comparative Example 2

[0048] The grouting material is composed of solid phase material and liquid phase material in a mass ratio of 10:3;

[0049] The solid material is composed of the following raw materials in parts by weight: 55 parts ordinary silicate cement, 15 parts sulfoaluminate cement, 16 parts ultrafine mineral admixture, 2 parts calcium nitrate, 0.14 parts water-reducing agent, 0.3 parts retarder, 0.2 parts anti-dispersant agent, and 0.1 parts thickener. The ultrafine mineral admixture is a mixture of mineral powder and calcined coal gangue in a mass ratio of 6.5:3.5. The anti-dispersant agent is a mixture of modified polyacrylamide obtained by grafting starch, initiator and polyacrylamide, followed by washing and drying, and sodium tartrate and sodium tripolyphosphate in a mass ratio of 3:1:0.3.

[0050] The liquid phase material is a mixture of methanol, ethylene glycol and water in a mass ratio of 1:3:8.

[0051] Tests showed that at -25℃, the initial fluidity of the slurry was 270 mm, it had no fluidity after 30 min, the compressive strength was 7.3 MPa at -1 day, 8.4 MPa at -3 days, 16.6 MPa at -7+21 days, and 2.1 MPa at -7+21 days.

[0052] Comparative Example 3

[0053] The grouting material is composed of solid phase material and liquid phase material in a mass ratio of 10:3;

[0054] The solid material is composed of the following raw materials in parts by weight: 55 parts ordinary silicate cement, 15 parts rapid-hardening agent, 16 parts ultrafine mineral admixture, 2 parts synergist, 0.14 parts water-reducing agent, 0.3 parts retarder, 0.2 parts anti-dispersing agent, and 0.1 parts thickener. The rapid-hardening agent is a mixture of amorphous calcium aluminate mineral and anhydrite in a mass ratio of 7:3. The ultrafine mineral admixture is a mixture of fly ash and silica fume in a mass ratio of 6.5:3.5. The synergist is ultrafine alumina slag powder. The anti-dispersing agent is a mixture of modified polyacrylamide obtained by grafting starch, initiator and polyacrylamide, followed by washing and drying, and sodium tartrate and sodium tripolyphosphate in a mass ratio of 3:1:0.3.

[0055] The liquid phase material is a mixture of methanol, ethylene glycol and water in a mass ratio of 1:3:8.

[0056] Tests showed that at -25℃, the initial fluidity of the slurry was 200 mm, with some caking and slight bleeding. After 30 minutes, there was no fluidity. The compressive strength was 17.5 MPa at -1 day, 22.0 MPa at -3 days, 36.2 MPa at -7+21 days, and 3.3 MPa at -7+21 days.

[0057] Comparative Example 4

[0058] The grouting material is composed of solid phase material and liquid phase material in a mass ratio of 10:3;

[0059] The solid material is composed of the following raw materials in parts by weight: 55 parts ordinary silicate cement, 15 parts rapid hardening agent, 16 parts ultrafine mineral admixture, 2 parts synergist, 0.14 parts water-reducing agent, 0.3 parts retarder, 0.2 parts anti-dispersing agent, and 0.1 parts thickener. The rapid hardening agent is a mixture of amorphous calcium aluminate mineral and anhydrite in a mass ratio of 7:3. The ultrafine mineral admixture is ultrafine fly ash. The synergist is metakaolin. The anti-dispersing agent is a mixture of modified polyacrylamide obtained by grafting starch, initiator and polyacrylamide, followed by washing and drying, and polyether polyol in a mass ratio of 3:1.

[0060] The liquid phase material is a mixture of methanol, ethylene glycol and water in a mass ratio of 1:3:8.

[0061] Tests showed that at -25℃, the initial fluidity of the slurry was 150 mm, it had no fluidity after 30 min, the compressive strength was 14.1 MPa at -1 day, 18.4 MPa at -3 days, 22.6 MPa at -7+21 days, and 2.3 MPa at -7+21 days.

[0062] Comparative Example 5

[0063] The grouting material is composed of solid phase material and liquid phase material in a mass ratio of 10:3;

[0064] The solid material is composed of the following raw materials in parts by weight: 55 parts ordinary silicate cement, 15 parts rapid-hardening agent, 16 parts ultrafine mineral admixture, 2 parts synergist, 0.14 parts water-reducing agent, 0.3 parts retarder, 0.2 parts anti-dispersing agent, and 0.1 parts thickener. The rapid-hardening agent is a mixture of amorphous calcium aluminate mineral and anhydrite in a mass ratio of 7:3. The ultrafine mineral admixture is a mixture of mineral powder and calcined coal gangue in a mass ratio of 6.5:3.5. The synergist is a mixture of ultrafine alumina slag powder and rice husk ash in a mass ratio of 10:3. The anti-dispersing agent is a mixture of modified polyacrylamide obtained by grafting starch, initiator and polyacrylamide, followed by washing and drying, and sodium tartrate and sodium tripolyphosphate in a mass ratio of 3:1:0.3.

[0065] The liquid phase material is water.

[0066] Tests showed that at -25℃, the initial fluidity of the slurry was 180 mm, it had no fluidity after 30 min, the compressive strength was 7.1 MPa at -1 day, 19.9 MPa at -3 days, 30.1 MPa at -7+21 days, and 3.4 MPa at -7+21 days.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A grouting material for low-temperature construction, characterized in that, It is composed of solid and liquid phase materials in a mass ratio of (9-12):3; The solid material is composed of the following raw materials in parts by weight: 50-70 parts ordinary silicate cement, 1-15 parts rapid-setting agent, 1-20 parts ultrafine mineral admixture, 0.1-5 parts synergist, 0.01-0.2 parts water-reducing agent, 0.02-0.5 parts retarder, 0.01-0.2 parts anti-dispersing agent, and 0.01-0.2 parts thickener. The rapid-setting agent is a mixture of amorphous calcium aluminate mineral and anhydrite in a mass ratio of (7-7.5):(2.5-3.5). The fine mineral admixture is a mixture of mineral powder and calcined coal gangue in a mass ratio of (6-6.5):(3.5-4.5). The synergist is a mixture of ultrafine alumina slag powder and rice husk ash in a mass ratio of 10:(1-3). The anti-dispersant is a mixture of modified polyacrylamide obtained by grafting starch, initiator and polyacrylamide, followed by washing and drying, and sodium tartrate and sodium tripolyphosphate in a mass ratio of (1-3):(0.8-1):(0.3-0.5). The liquid phase material is a mixture of methanol, ethylene glycol and water in a mass ratio of 1:3:(6-10).

2. The grouting material for low-temperature construction according to claim 1, characterized in that, The solid material is composed of the following raw materials in parts by weight: 50-70 parts of ordinary silicate cement, 10-15 parts of rapid hardening agent, 10-20 parts of ultrafine mineral admixture, 1-5 parts of synergist, 0.1-0.2 parts of water-reducing agent, 0.2-0.5 parts of retarder, 0.1-0.2 parts of anti-dispersing agent, and 0.1-0.2 parts of thickener.

3. The grouting material for low-temperature construction according to claim 1, characterized in that, The ordinary silicate cement is P·O42.5 cement.

4. The grouting material for low-temperature construction according to claim 1, characterized in that, The rapid-hardening agent has a specific surface area of ​​800-850 cm². 2 / g, the preparation process of the amorphous calcium aluminate mineral is as follows: CaO and Al2O3 are uniformly mixed at a mass ratio of 1:0.9-1.2, calcined at 1500-1700℃, then the molten liquid phase is cooled to 1180-1200℃ by compressed air, then cooled to room temperature by water, and ground to 450-500 cm³. 2 / g, that is, you get it.

5. The grouting material for low-temperature construction according to claim 1, characterized in that, The mineral powder is S95 grade mineral powder.

6. The grouting material for low-temperature construction according to claim 1, characterized in that, The calcined coal gangue is calcined at a temperature of 800-850℃, and the ultrafine mineral admixture has a specific surface area of ​​1000 cm². 2 / g.

7. The grouting material for low-temperature construction according to claim 1, characterized in that, The preparation process of the ultrafine alumina slag powder is as follows: grinding the alumina slag powder to a specific surface area of ​​700-800 cm². 2 / g, that is, you get it.

8. The grouting material for low-temperature construction according to claim 1, characterized in that, The water-reducing agent is a polycarboxylate water-reducing agent, the retarder is at least one of sodium gluconate, sucrose, tartaric acid, and boric acid, the initiator is persulfate, and the thickener is cellulose ether.

9. The method for preparing the low-temperature grouting material for construction according to any one of claims 1-8, characterized in that, Includes the following steps: 1) Weigh each raw material according to its weight. 2) Mix the raw materials to obtain liquid-phase materials and solid-phase materials respectively. 3) Mix the liquid phase material and the solid phase material evenly to obtain the final product.

10. The application of the low-temperature grouting material according to any one of claims 1-8, characterized in that, It was used for grouting reinforcement of tunnel cracks.