Low-rebound self-repairing wet-spraying concrete for slope support of exhaust shaft

Abstract

The present application relates to a kind of low resilience self-repairing wet-spraying concrete for exhaust shaft slope support, comprising the following parts: cement 20-35 parts, fine aggregate 25-45 parts, coarse aggregate 10-30 parts, water 8-18 parts, nano silicon dioxide 0.2-2 parts, nano calcium carbonate 0.2-1.5 parts, graphene oxide 0.05-0.8 parts, MXene 0.05-1 parts, aerogel powder 0.2-2 parts, silane coupling agent 0.05-0.8 parts, hydrophobic modified nanoparticles 0.1-1 parts, polyvinyl alcohol 0.2-1.5 parts, polyacrylamide 0.2-1.5 parts, polycarboxylate superplasticizer 0.2-1.2 parts, the present application is mixed into shear thickening fluid and charge control layer mineral, so that wet-spraying concrete has pumpability and sprayability, low viscosity ensures smooth pumping when conveying, viscosity rises sharply under impact of jetting, greatly reduces resilience and material waste, layered double hydroxide forms electrostatic adsorption to improve adhesion stability, limit initial crack width at the same time, improve the quality of sprayed concrete structure.

Description

Technical Field

[0001] This invention relates to the field of wet sprayed concrete, specifically to a low-resilience self-healing wet sprayed concrete for slope support of ventilation shafts. Background Technology

[0002] Wet sprayed concrete is widely used in the construction of tunnel, shaft and underground cavern support, especially in high and steep slope environments such as ventilation shafts. Wet spraying process is usually used for rapid support and closure. Existing wet sprayed concrete is mostly based on cement, aggregate and conventional admixtures. By adding accelerators, water-reducing agents and fiber materials, its workability and early strength are improved. At the same time, some technical solutions incorporate mineral admixtures or nanomaterials to improve the density and mechanical properties of concrete.

[0003] However, in practical engineering applications, existing wet-mix shotcrete still has some shortcomings. For example, during the spraying process, the concrete is prone to segregation and rebound due to the high-speed airflow and impact, resulting in a high rebound rate. This not only wastes materials but also affects the quality of the support. Moreover, current methods mainly rely on increasing viscosity or fiber content to reduce rebound, which often leads to decreased pumpability, increased transport resistance, and pipe blockage. Furthermore, traditional concrete lacks effective self-healing capabilities when microcracks develop, allowing these cracks to easily expand under groundwater or load, affecting the durability and impermeability of the concrete structure. Therefore, new technical solutions are needed to address these issues. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies, adapt to practical needs, and provide a low-rebound self-healing wet-mixed shotcrete for ventilation shaft slope support. This addresses the current problem that during the spraying process, concrete is prone to segregation and rebound due to the influence of high-speed airflow and impact, resulting in a high rebound rate. This not only wastes materials but also affects the quality of support. Furthermore, existing methods mainly rely on increasing viscosity or fiber content to reduce rebound, which often leads to decreased pumpability, increased transport resistance, and pipe blockage. At the same time, traditional concrete lacks effective self-healing ability when microcracks develop during use, and these cracks are easily expanded under groundwater or load, affecting the durability and impermeability of the concrete structure.

[0005] To achieve the objective of this invention, the technical solution adopted is as follows: A low-resilience, self-healing wet-sprayed concrete for slope protection of ventilation shafts is designed, comprising the following components:

[0006] The composition includes: 20-35 parts cement, 25-45 parts fine aggregate, 10-30 parts coarse aggregate, 8-18 parts water, 0.2-2 parts nano-silica, 0.2-1.5 parts nano-calcium carbonate, 0.05-0.8 parts graphene oxide, 0.05-1 part MXene, 0.2-2 parts aerogel powder, 0.05-0.8 parts silane coupling agent, 0.1-1 parts hydrophobically modified nanoparticles, 0.2-1.5 parts polyvinyl alcohol, and 0.2-1 parts polyacrylamide. 0.5 parts, polycarboxylate superplasticizer 0.2-1.2 parts, biological polysaccharide 0.05-0.8 parts, microbial mineralizing bacteria 0.02-0.3 parts, calcium source substance 0.2-2 parts, basalt fiber 0.1-1.2 parts, polypropylene fiber 0.1-1 parts, nanocellulose 0.05-0.6 parts, shear thickening liquid 0.2-1.5 parts, layered double hydroxide 0.2-1.2 parts, delayed activation mineral admixture 2-12 parts, quick-setting agent 0.5-3 parts.

[0007] Preferably, it comprises the following amounts:

[0008] The composition includes 28 parts cement, 38 parts fine aggregate, 18 parts coarse aggregate, 12 parts water, 0.5 parts nano silica, 0.5 parts nano calcium carbonate, 0.1 parts graphene oxide, 0.2 parts MXene, 0.5 parts aerogel powder, 0.2 parts silane coupling agent, 0.3 parts hydrophobically modified nanoparticles, 0.5 parts polyvinyl alcohol, 0.5 parts polyacrylamide, 0.6 parts polycarboxylate superplasticizer, 0.2 parts biopolysaccharide, 0.05 parts microbial mineralizing bacteria, 0.6 parts calcium source, 0.3 parts basalt fiber, 0.3 parts polypropylene fiber, 0.1 parts nanocellulose, 0.5 parts shear thickening liquid, 0.5 parts layered double hydroxide, 6 parts delayed activation mineral admixture, and 1 part quick-setting agent.

[0009] Preferably, it comprises the following amounts:

[0010] The composition includes 27 parts cement, 36 parts fine aggregate, 17 parts coarse aggregate, 11 parts water, 0.8 parts nano silica, 0.7 parts nano calcium carbonate, 0.2 parts graphene oxide, 0.4 parts MXene, 0.8 parts aerogel powder, 0.3 parts silane coupling agent, 0.5 parts hydrophobically modified nanoparticles, 0.8 parts polyvinyl alcohol, 0.7 parts polyacrylamide, 0.8 parts polycarboxylate superplasticizer, 0.3 parts bio-polysaccharide, 0.08 parts microbial mineralizing bacteria, 1 part calcium source, 0.5 parts basalt fiber, 0.4 parts polypropylene fiber, 0.2 parts nanocellulose, 0.8 parts shear thickening liquid, 0.7 parts layered double hydroxide, 7 parts delayed activation mineral admixture, and 1.5 parts quick-setting agent.

[0011] Preferably, it comprises the following amounts:

[0012] The composition includes 26 parts cement, 34 parts fine aggregate, 16 parts coarse aggregate, 10 parts water, 1.2 parts nano silica, 1 part nano calcium carbonate, 0.4 parts graphene oxide, 0.6 parts MXene, 1.2 parts aerogel powder, 0.5 parts silane coupling agent, 0.7 parts hydrophobically modified nanoparticles, 1 part polyvinyl alcohol, 1 part polyacrylamide, 1 part polycarboxylate superplasticizer, 0.4 parts biopolysaccharide, 0.12 parts microbial mineralizing bacteria, 1.5 parts calcium source, 0.7 parts basalt fiber, 0.6 parts polypropylene fiber, 0.3 parts nanocellulose, 1 part shear thickening liquid, 0.9 parts layered double hydroxide, 8 parts delayed activation mineral admixture, and 2 parts quick-setting agent.

[0013] Preferably, it comprises the following amounts:

[0014] The composition includes 25 parts cement, 33 parts fine aggregate, 15 parts coarse aggregate, 10 parts water, 1.5 parts nano silica, 1.2 parts nano calcium carbonate, 0.6 parts graphene oxide, 0.8 parts MXene, 1.5 parts aerogel powder, 0.6 parts silane coupling agent, 0.9 parts hydrophobically modified nanoparticles, 1.2 parts polyvinyl alcohol, 1.2 parts polyacrylamide, 1.2 parts polycarboxylate superplasticizer, 0.5 parts bio-polysaccharide, 0.18 parts microbial mineralizing bacteria, 1.8 parts calcium source, 0.9 parts basalt fiber, 0.8 parts polypropylene fiber, 0.4 parts nanocellulose, 1.2 parts shear thickening liquid, 1 part layered double hydroxide, 9 parts delayed activation mineral admixture, and 2.5 parts quick-setting agent.

[0015] Preferably, it comprises the following amounts:

[0016] The composition includes 24 parts cement, 32 parts fine aggregate, 15 parts coarse aggregate, 9 parts water, 1.8 parts nano silica, 1.5 parts nano calcium carbonate, 0.8 parts graphene oxide, 1 part MXene, 1.8 parts aerogel powder, 0.7 parts silane coupling agent, 1 part hydrophobically modified nanoparticles, 1.5 parts polyvinyl alcohol, 1.3 parts polyacrylamide, 1.2 parts polycarboxylate superplasticizer, 0.6 parts bio-polysaccharide, 0.25 parts microbial mineralizing bacteria, 2 parts calcium source material, 1 part basalt fiber, 0.9 parts polypropylene fiber, 0.5 parts nanocellulose, 1.5 parts shear thickening liquid, 1.2 parts layered double hydroxide, 10 parts delayed activation mineral admixture, and 3 parts quick-setting agent.

[0017] Preferably, the shear thickening liquid is composed of silica sol and polyethylene glycol, wherein the silica sol accounts for 60% to 80% and the polyethylene glycol accounts for 20% to 40%.

[0018] Preferably, the delayed-activation mineral admixture is composed of metakaolin, slag powder and fly ash, wherein metakaolin accounts for 20% to 40%, slag powder accounts for 30% to 50%, and fly ash accounts for 20% to 40%.

[0019] Preferably, the layered double hydroxide is one of magnesium-aluminum layered double hydroxide or zinc-aluminum layered double hydroxide.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. This invention incorporates shear-thickening fluid and charge-controlled layered minerals into wet-sprayed concrete, enabling the slurry to exhibit shear characteristics during spraying. Under high-speed spraying and impact, the viscosity rapidly increases, preventing slurry rebound or loss. The layered double hydroxides form electrostatic adsorption with the aggregate surface, making the slurry more stable on the adhesion surface, reducing construction rebound rate, and minimizing material waste. The shear-thickening fluid maintains low viscosity during transport, improving the pumpability of the concrete. Its viscosity increases instantaneously during spraying, enhancing adhesion. This allows the concrete to be smoothly transported to the nozzle and form a stable sprayed layer on the sprayed surface, solving the problem of balancing pumpability and sprayability in traditional materials. Furthermore, the low-rebound material limits the initial width of spray cracks, making the cracks concentrated and evenly distributed, avoiding excessively wide cracks.

[0022] 2. This invention forms a micro-nano composite structure in the slurry by combining nanomaterials and polymers, which increases the surface area of ​​the slurry, improves the adhesion between aggregates and slurry, and between concrete and the tunnel wall, enhances the early strength of concrete, reduces porosity, and effectively improves the overall stability and durability of shotcrete.

[0023] 3. This invention, through the combination of delayed-activation mineral admixtures and microbial mineralizing bacteria, enables concrete to slowly generate cementitious products or calcium carbonate precipitates even in the later stages of hardening. When microcracks appear in the concrete, the continued hydration of unhydrated cement particles, the reaction of delayed-activation minerals, and the microbial mineralization can fill the cracks, achieving self-healing of the concrete. This prevents water infiltration, enhances the long-term impermeability and durability of the structure, and can actively repair microcracks during the use of concrete. At the same time, the interwoven honeycomb grid structure formed by nanomaterials, fibers, polymers, and delayed-activation minerals not only improves early strength but also provides support and chemical reaction space during later self-healing, further enhancing the self-healing effect. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0026] A type of low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts, see [link / reference]. Figure 1 Including the following quantities:

[0027] The composition includes: 20-35 parts cement, 25-45 parts fine aggregate, 10-30 parts coarse aggregate, 8-18 parts water, 0.2-2 parts nano-silica, 0.2-1.5 parts nano-calcium carbonate, 0.05-0.8 parts graphene oxide, 0.05-1 part MXene, 0.2-2 parts aerogel powder, 0.05-0.8 parts silane coupling agent, 0.1-1 parts hydrophobically modified nanoparticles, 0.2-1.5 parts polyvinyl alcohol, and 0.2-1 parts polyacrylamide. 0.5 parts, polycarboxylate superplasticizer 0.2-1.2 parts, biological polysaccharide 0.05-0.8 parts, microbial mineralizing bacteria 0.02-0.3 parts, calcium source substance 0.2-2 parts, basalt fiber 0.1-1.2 parts, polypropylene fiber 0.1-1 parts, nanocellulose 0.05-0.6 parts, shear thickening liquid 0.2-1.5 parts, layered double hydroxide 0.2-1.2 parts, delayed activation mineral admixture 2-12 parts, quick-setting agent 0.5-3 parts.

[0028] Specifically, the following quantities are included:

[0029] The composition includes 28 parts cement, 38 parts fine aggregate, 18 parts coarse aggregate, 12 parts water, 0.5 parts nano silica, 0.5 parts nano calcium carbonate, 0.1 parts graphene oxide, 0.2 parts MXene, 0.5 parts aerogel powder, 0.2 parts silane coupling agent, 0.3 parts hydrophobically modified nanoparticles, 0.5 parts polyvinyl alcohol, 0.5 parts polyacrylamide, 0.6 parts polycarboxylate superplasticizer, 0.2 parts biopolysaccharide, 0.05 parts microbial mineralizing bacteria, 0.6 parts calcium source, 0.3 parts basalt fiber, 0.3 parts polypropylene fiber, 0.1 parts nanocellulose, 0.5 parts shear thickening liquid, 0.5 parts layered double hydroxide, 6 parts delayed activation mineral admixture, and 1 part quick-setting agent.

[0030] More specifically, this includes the following quantities:

[0031] The composition includes 27 parts cement, 36 parts fine aggregate, 17 parts coarse aggregate, 11 parts water, 0.8 parts nano silica, 0.7 parts nano calcium carbonate, 0.2 parts graphene oxide, 0.4 parts MXene, 0.8 parts aerogel powder, 0.3 parts silane coupling agent, 0.5 parts hydrophobically modified nanoparticles, 0.8 parts polyvinyl alcohol, 0.7 parts polyacrylamide, 0.8 parts polycarboxylate superplasticizer, 0.3 parts bio-polysaccharide, 0.08 parts microbial mineralizing bacteria, 1 part calcium source, 0.5 parts basalt fiber, 0.4 parts polypropylene fiber, 0.2 parts nanocellulose, 0.8 parts shear thickening liquid, 0.7 parts layered double hydroxide, 7 parts delayed activation mineral admixture, and 1.5 parts quick-setting agent.

[0032] Furthermore, including the following quantities:

[0033] The composition includes 26 parts cement, 34 parts fine aggregate, 16 parts coarse aggregate, 10 parts water, 1.2 parts nano silica, 1 part nano calcium carbonate, 0.4 parts graphene oxide, 0.6 parts MXene, 1.2 parts aerogel powder, 0.5 parts silane coupling agent, 0.7 parts hydrophobically modified nanoparticles, 1 part polyvinyl alcohol, 1 part polyacrylamide, 1 part polycarboxylate superplasticizer, 0.4 parts biopolysaccharide, 0.12 parts microbial mineralizing bacteria, 1.5 parts calcium source, 0.7 parts basalt fiber, 0.6 parts polypropylene fiber, 0.3 parts nanocellulose, 1 part shear thickening liquid, 0.9 parts layered double hydroxide, 8 parts delayed activation mineral admixture, and 2 parts quick-setting agent.

[0034] Furthermore, this includes the following quantities:

[0035] The composition includes 25 parts cement, 33 parts fine aggregate, 15 parts coarse aggregate, 10 parts water, 1.5 parts nano silica, 1.2 parts nano calcium carbonate, 0.6 parts graphene oxide, 0.8 parts MXene, 1.5 parts aerogel powder, 0.6 parts silane coupling agent, 0.9 parts hydrophobically modified nanoparticles, 1.2 parts polyvinyl alcohol, 1.2 parts polyacrylamide, 1.2 parts polycarboxylate superplasticizer, 0.5 parts bio-polysaccharide, 0.18 parts microbial mineralizing bacteria, 1.8 parts calcium source, 0.9 parts basalt fiber, 0.8 parts polypropylene fiber, 0.4 parts nanocellulose, 1.2 parts shear thickening liquid, 1 part layered double hydroxide, 9 parts delayed activation mineral admixture, and 2.5 parts quick-setting agent.

[0036] It is worth noting that the following quantities are included:

[0037] The composition includes 24 parts cement, 32 parts fine aggregate, 15 parts coarse aggregate, 9 parts water, 1.8 parts nano silica, 1.5 parts nano calcium carbonate, 0.8 parts graphene oxide, 1 part MXene, 1.8 parts aerogel powder, 0.7 parts silane coupling agent, 1 part hydrophobically modified nanoparticles, 1.5 parts polyvinyl alcohol, 1.3 parts polyacrylamide, 1.2 parts polycarboxylate superplasticizer, 0.6 parts bio-polysaccharide, 0.25 parts microbial mineralizing bacteria, 2 parts calcium source material, 1 part basalt fiber, 0.9 parts polypropylene fiber, 0.5 parts nanocellulose, 1.5 parts shear thickening liquid, 1.2 parts layered double hydroxide, 10 parts delayed activation mineral admixture, and 3 parts quick-setting agent.

[0038] It is worth noting that the shear thickening fluid is composed of silica sol and polyethylene glycol, with silica sol accounting for 60% to 80% and polyethylene glycol accounting for 20% to 40%.

[0039] It is worth mentioning that the delayed activation mineral admixture is composed of metakaolin, slag powder and fly ash, of which metakaolin accounts for 20% to 40%, slag powder accounts for 30% to 50% and fly ash accounts for 20% to 40%.

[0040] It is noteworthy that the layered double hydroxide is one of the magnesium-aluminum layered double hydroxides or the zinc-aluminum layered double hydroxides.

[0041] Example 1

[0042] formula

[0043] The composition includes 28 parts cement, 38 parts fine aggregate, 18 parts coarse aggregate, 12 parts water, 0.5 parts nano silica, 0.5 parts nano calcium carbonate, 0.1 parts graphene oxide, 0.2 parts MXene, 0.5 parts aerogel powder, 0.2 parts silane coupling agent, 0.3 parts hydrophobically modified nanoparticles, 0.5 parts polyvinyl alcohol, 0.5 parts polyacrylamide, 0.6 parts polycarboxylate superplasticizer, 0.2 parts biopolysaccharide, 0.05 parts microbial mineralizing bacteria, 0.6 parts calcium source, 0.3 parts basalt fiber, 0.3 parts polypropylene fiber, 0.1 parts nanocellulose, 0.5 parts shear thickening liquid, 0.5 parts layered double hydroxide, 6 parts delayed activation mineral admixture, and 1 part quick-setting agent.

[0044] Preparation process

[0045] S1. Add 0.5 parts of nano-silica, 0.5 parts of nano-calcium carbonate, 0.1 parts of graphene oxide and 0.2 parts of MXene to 7 parts of water and disperse for 10 minutes;

[0046] S2. Add 0.5 parts of polyvinyl alcohol, 0.5 parts of polyacrylamide, 0.2 parts of biopolysaccharide and 0.1 parts of nanocellulose, and stir for 8 minutes;

[0047] S3. Dry mix 28 parts of cement, 6 parts of delayed activated mineral admixture, 0.5 parts of layered double hydroxide and 0.5 parts of aerogel powder for 2 minutes, then add 38 parts of fine aggregate and 18 parts of coarse aggregate and dry mix for 1 minute.

[0048] S4. Add the mixture obtained in step S2, 5 parts of the remaining water, 0.6 parts of polycarboxylate superplasticizer, and 0.2 parts of silane coupling agent, and stir for 4 minutes;

[0049] S5. Add 0.5 parts of shear thickening liquid and 0.3 parts of hydrophobic modified nanoparticles, and stir for 2 minutes;

[0050] S6. Add 0.3 parts basalt fiber, 0.3 parts polypropylene fiber, 0.05 parts microbial mineralizing bacteria and 0.6 parts calcium source, and stir for 2 minutes;

[0051] S7. Add 1 part quick-setting agent, stir for 1 minute and then use.

[0052] The performance test results are as follows:

[0053] The rebound rate is 12.8%, the conveying resistance is 0.82MPa, the 1-day compressive strength is 21.5MPa, the 7-day compressive strength is 38.6MPa, the crack self-healing efficiency is 72%, and the maximum crack width corresponding to the crack resistance grade is 0.32mm.

[0054] Example 2

[0055] formula

[0056] The composition includes 27 parts cement, 36 parts fine aggregate, 17 parts coarse aggregate, 11 parts water, 0.8 parts nano silica, 0.7 parts nano calcium carbonate, 0.2 parts graphene oxide, 0.4 parts MXene, 0.8 parts aerogel powder, 0.3 parts silane coupling agent, 0.5 parts hydrophobically modified nanoparticles, 0.8 parts polyvinyl alcohol, 0.7 parts polyacrylamide, 0.8 parts polycarboxylate superplasticizer, 0.3 parts bio-polysaccharide, 0.08 parts microbial mineralizing bacteria, 1 part calcium source, 0.5 parts basalt fiber, 0.4 parts polypropylene fiber, 0.2 parts nanocellulose, 0.8 parts shear thickening liquid, 0.7 parts layered double hydroxide, 7 parts delayed activation mineral admixture, and 1.5 parts quick-setting agent.

[0057] Preparation process

[0058] S1. Add 0.8 parts of nano-silica, 0.7 parts of nano-calcium carbonate, 0.2 parts of graphene oxide and 0.4 parts of MXene to 6.5 parts of water and disperse for 12 min;

[0059] S2. Add 0.8 parts of polyvinyl alcohol, 0.7 parts of polyacrylamide, 0.3 parts of biopolysaccharide and 0.2 parts of nanocellulose, and stir for 10 minutes;

[0060] S3. Dry mix 27 parts of cement, 7 parts of delayed activated mineral admixture, 0.7 parts of layered double hydroxide and 0.8 parts of aerogel powder for 3 minutes, then add 36 parts of fine aggregate and 17 parts of coarse aggregate and dry mix for 2 minutes.

[0061] S4. Add the mixture obtained in step S2, 4.5 parts of the remaining water, 0.8 parts of the polycarboxylate superplasticizer, and 0.3 parts of the silane coupling agent, and stir for 5 minutes;

[0062] S5. Add 0.8 parts of shear thickening liquid and 0.5 parts of hydrophobic modified nanoparticles, and stir for 3 minutes;

[0063] S6. Add 0.5 parts basalt fiber, 0.4 parts polypropylene fiber, 0.08 parts microbial mineralizing bacteria and 1 part calcium source, and stir for 2 minutes;

[0064] S7. Add 1.5 parts of quick-setting agent, stir for 1 minute and then use.

[0065] The performance test results are as follows:

[0066] The resilience rate was 11.2%, the conveying resistance was 0.78 MPa, the 1-day compressive strength was 23.8 MPa, the 7-day compressive strength was 41.2 MPa, the crack self-healing efficiency was 81%, and the maximum crack width was 0.28 mm.

[0067] Example 3

[0068] formula

[0069] The composition includes 26 parts cement, 34 parts fine aggregate, 16 parts coarse aggregate, 10 parts water, 1.2 parts nano silica, 1 part nano calcium carbonate, 0.4 parts graphene oxide, 0.6 parts MXene, 1.2 parts aerogel powder, 0.5 parts silane coupling agent, 0.7 parts hydrophobically modified nanoparticles, 1 part polyvinyl alcohol, 1 part polyacrylamide, 1 part polycarboxylate superplasticizer, 0.4 parts biopolysaccharide, 0.12 parts microbial mineralizing bacteria, 1.5 parts calcium source, 0.7 parts basalt fiber, 0.6 parts polypropylene fiber, 0.3 parts nanocellulose, 1 part shear thickening liquid, 0.9 parts layered double hydroxide, 8 parts delayed activation mineral admixture, and 2 parts quick-setting agent.

[0070] Preparation process

[0071] S1. Add 1.2 parts of nano-silica, 1 part of nano-calcium carbonate, 0.4 parts of graphene oxide and 0.6 parts of MXene to 6 parts of water and disperse for 15 minutes;

[0072] S2. Add 1 part polyvinyl alcohol, 1 part polyacrylamide, 0.4 parts biopolysaccharide and 0.3 parts nanocellulose, and stir for 12 minutes;

[0073] S3. Dry mix 26 parts of cement, 8 parts of delayed activated mineral admixture, 0.9 parts of layered double hydroxide and 1.2 parts of aerogel powder for 4 minutes, then add 34 parts of fine aggregate and 16 parts of coarse aggregate and dry mix for 2 minutes.

[0074] S4. Add the mixture obtained in step S2, 4 parts of the remaining water, 1 part of the polycarboxylate superplasticizer and 0.5 parts of the silane coupling agent, and stir for 5 minutes.

[0075] S5. Add 1 part of shear thickening liquid and 0.7 parts of hydrophobic modified nanoparticles, and stir for 3 min;

[0076] S6. Add 0.7 parts basalt fiber, 0.6 parts polypropylene fiber, 0.12 parts microbial mineralizing bacteria and 1.5 parts calcium source, and stir for 3 minutes;

[0077] S7. Add 2 parts of quick-setting agent, stir for 1 minute and then use.

[0078] The performance test results are as follows:

[0079] The resilience rate is 9.6%, the conveying resistance is 0.74 MPa, the 1-day compressive strength is 26.4 MPa, the 7-day compressive strength is 45.8 MPa, the crack self-healing efficiency is 85%, and the maximum crack width is 0.24 mm.

[0080] Example 4

[0081] formula

[0082] The composition includes 25 parts cement, 33 parts fine aggregate, 15 parts coarse aggregate, 10 parts water, 1.5 parts nano silica, 1.2 parts nano calcium carbonate, 0.6 parts graphene oxide, 0.8 parts MXene, 1.5 parts aerogel powder, 0.6 parts silane coupling agent, 0.9 parts hydrophobically modified nanoparticles, 1.2 parts polyvinyl alcohol, 1.2 parts polyacrylamide, 1.2 parts polycarboxylate superplasticizer, 0.5 parts bio-polysaccharide, 0.18 parts microbial mineralizing bacteria, 1.8 parts calcium source, 0.9 parts basalt fiber, 0.8 parts polypropylene fiber, 0.4 parts nanocellulose, 1.2 parts shear thickening liquid, 1 part layered double hydroxide, 9 parts delayed activation mineral admixture, and 2.5 parts quick-setting agent.

[0083] Preparation process

[0084] S1. Add 1.5 parts of nano-silica, 1.2 parts of nano-calcium carbonate, 0.6 parts of graphene oxide and 0.8 parts of MXene to 6 parts of water and disperse for 18 minutes;

[0085] S2. Add 1.2 parts of polyvinyl alcohol, 1.2 parts of polyacrylamide, 0.5 parts of biopolysaccharide and 0.4 parts of nanocellulose, and stir for 15 minutes;

[0086] S3. Dry mix 25 parts of cement, 9 parts of delayed activated mineral admixture, 1 part of layered double hydroxide and 1.5 parts of aerogel powder for 5 minutes, then add 33 parts of fine aggregate and 15 parts of coarse aggregate and dry mix for 2 minutes.

[0087] S4. Add the mixture obtained in step S2, 4 parts of the remaining water, 1.2 parts of polycarboxylate superplasticizer and 0.6 parts of silane coupling agent, and stir for 6 minutes;

[0088] S5. Add 1.2 parts of shear thickening liquid and 0.9 parts of hydrophobic modified nanoparticles, and stir for 3 min;

[0089] S6. Add 0.9 parts basalt fiber, 0.8 parts polypropylene fiber, 0.18 parts microbial mineralizing bacteria and 1.8 parts calcium source, and stir for 3 minutes;

[0090] S7. Add 2.5 parts of quick-setting agent, stir for 1 minute and then use.

[0091] The performance test results are as follows:

[0092] The resilience rate is 8.3%, the conveying resistance is 0.72 MPa, the 1-day compressive strength is 28.9 MPa, the 7-day compressive strength is 49.6 MPa, the crack self-healing efficiency is 90%, and the maximum crack width is 0.20 mm.

[0093] Example 5

[0094] formula

[0095] The composition includes 24 parts cement, 32 parts fine aggregate, 15 parts coarse aggregate, 9 parts water, 1.8 parts nano silica, 1.5 parts nano calcium carbonate, 0.8 parts graphene oxide, 1 part MXene, 1.8 parts aerogel powder, 0.7 parts silane coupling agent, 1 part hydrophobically modified nanoparticles, 1.5 parts polyvinyl alcohol, 1.3 parts polyacrylamide, 1.2 parts polycarboxylate superplasticizer, 0.6 parts bio-polysaccharide, 0.25 parts microbial mineralizing bacteria, 2 parts calcium source material, 1 part basalt fiber, 0.9 parts polypropylene fiber, 0.5 parts nanocellulose, 1.5 parts shear thickening liquid, 1.2 parts layered double hydroxide, 10 parts delayed activation mineral admixture, and 3 parts quick-setting agent.

[0096] Preparation process

[0097] S1. Add 1.8 parts of nano-silica, 1.5 parts of nano-calcium carbonate, 0.8 parts of graphene oxide and 1 part of MXene to 5.5 parts of water and disperse for 20 minutes;

[0098] S2. Add 1.5 parts of polyvinyl alcohol, 1.3 parts of polyacrylamide, 0.6 parts of biopolysaccharide and 0.5 parts of nanocellulose, and stir for 15 minutes;

[0099] S3. Dry mix 24 parts of cement, 10 parts of delayed activated mineral admixture, 1.2 parts of layered double hydroxide and 1.8 parts of aerogel powder for 5 minutes, then add 32 parts of fine aggregate and 15 parts of coarse aggregate and dry mix for 2 minutes.

[0100] S4. Add the mixture obtained in step S2, 3.5 parts of the remaining water, 1.2 parts of the polycarboxylate superplasticizer, and 0.7 parts of the silane coupling agent, and stir for 7 minutes;

[0101] S5. Add 1.5 parts of shear thickening liquid and 1 part of hydrophobic modified nanoparticles, and stir for 4 minutes;

[0102] S6. Add 1 part basalt fiber, 0.9 parts polypropylene fiber, 0.25 parts microbial mineralizing bacteria and 2 parts calcium source, and stir for 3 minutes;

[0103] S7. Add 3 parts of quick-setting agent, stir for 1 minute and then use.

[0104] The performance test results are as follows:

[0105] The resilience rate is 7.5%, the conveying resistance is 0.76 MPa, the 1-day compressive strength is 30.2 MPa, the 7-day compressive strength is 52.3 MPa, the crack self-healing efficiency is 93%, and the maximum crack width is 0.18 mm.

[0106] The details are shown in the table below:

[0107] Example Rebound rate (%) Conveying resistance (MPa) 1-day compressive strength (MPa) 7-day compressive strength (MPa) Self-repair efficiency (%) Maximum crack width (mm) Example 1 12.8 0.82 21.5 38.6 72 0.32 Example 2 11.2 0.78 23.8 41.2 81 0.28 Example 3 9.6 0.74 26.4 45.8 85 0.24 Example 4 8.3 0.72 28.9 49.6 90 0.20 Example 5 7.5 0.76 30.2 52.3 93 0.18

[0108] Compared with the existing wet-sprayed concrete, which generally has a rebound rate of over 20%, the rebound rate of each embodiment of the present invention is less than 13%, and can be as low as 7.5%, which significantly reduces material loss. At the same time, the conveying resistance is controlled within the range of 0.72 to 0.82 MPa, ensuring good pumpability. In addition, the 1-day strength of the present invention reaches more than 30 MPa, meeting the requirements for rapid support. Through the synergistic effect of microbial mineralization and delayed activation minerals, the self-healing efficiency of cracks reaches up to 93% in 7 days, which is superior to traditional concrete.

[0109] In summary, this invention achieves low rebound, good pumpability, and self-healing capability without sacrificing construction efficiency. It is suitable for shaft and slope wet spraying support projects under complex geological conditions and has good engineering application value.

[0110] In addition, all components designed in this invention are general standard parts or components known to those skilled in the art. Their structure and principle can be known to those skilled in the art through technical manuals or conventional experimental methods. Those skilled in the art can fully implement them, so there is no need to elaborate. The content protected by this invention does not involve improvements to the internal structure and method.

Claims

1. A low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts, characterized in that, Includes the following quantities: The composition includes: 20-35 parts cement, 25-45 parts fine aggregate, 10-30 parts coarse aggregate, 8-18 parts water, 0.2-2 parts nano-silica, 0.2-1.5 parts nano-calcium carbonate, 0.05-0.8 parts graphene oxide, 0.05-1 part MXene, 0.2-2 parts aerogel powder, 0.05-0.8 parts silane coupling agent, 0.1-1 parts hydrophobically modified nanoparticles, 0.2-1.5 parts polyvinyl alcohol, and 0.2-1 parts polyacrylamide. 0.5 parts, polycarboxylate superplasticizer 0.2-1.2 parts, biological polysaccharide 0.05-0.8 parts, microbial mineralizing bacteria 0.02-0.3 parts, calcium source substance 0.2-2 parts, basalt fiber 0.1-1.2 parts, polypropylene fiber 0.1-1 parts, nanocellulose 0.05-0.6 parts, shear thickening liquid 0.2-1.5 parts, layered double hydroxide 0.2-1.2 parts, delayed activation mineral admixture 2-12 parts, quick-setting agent 0.5-3 parts.

2. The low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts as described in claim 1, characterized in that, Includes the following quantities: The composition includes 28 parts cement, 38 parts fine aggregate, 18 parts coarse aggregate, 12 parts water, 0.5 parts nano silica, 0.5 parts nano calcium carbonate, 0.1 parts graphene oxide, 0.2 parts MXene, 0.5 parts aerogel powder, 0.2 parts silane coupling agent, 0.3 parts hydrophobically modified nanoparticles, 0.5 parts polyvinyl alcohol, 0.5 parts polyacrylamide, 0.6 parts polycarboxylate superplasticizer, 0.2 parts biopolysaccharide, 0.05 parts microbial mineralizing bacteria, 0.6 parts calcium source, 0.3 parts basalt fiber, 0.3 parts polypropylene fiber, 0.1 parts nanocellulose, 0.5 parts shear thickening liquid, 0.5 parts layered double hydroxide, 6 parts delayed activation mineral admixture, and 1 part quick-setting agent.

3. The low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts as described in claim 1, characterized in that, Includes the following quantities: The composition includes 27 parts cement, 36 parts fine aggregate, 17 parts coarse aggregate, 11 parts water, 0.8 parts nano silica, 0.7 parts nano calcium carbonate, 0.2 parts graphene oxide, 0.4 parts MXene, 0.8 parts aerogel powder, 0.3 parts silane coupling agent, 0.5 parts hydrophobically modified nanoparticles, 0.8 parts polyvinyl alcohol, 0.7 parts polyacrylamide, 0.8 parts polycarboxylate superplasticizer, 0.3 parts bio-polysaccharide, 0.08 parts microbial mineralizing bacteria, 1 part calcium source, 0.5 parts basalt fiber, 0.4 parts polypropylene fiber, 0.2 parts nanocellulose, 0.8 parts shear thickening liquid, 0.7 parts layered double hydroxide, 7 parts delayed activation mineral admixture, and 1.5 parts quick-setting agent.

4. The low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts as described in claim 1, characterized in that, include The following quantities: The composition includes 26 parts cement, 34 parts fine aggregate, 16 parts coarse aggregate, 10 parts water, 1.2 parts nano silica, 1 part nano calcium carbonate, 0.4 parts graphene oxide, 0.6 parts MXene, 1.2 parts aerogel powder, 0.5 parts silane coupling agent, 0.7 parts hydrophobically modified nanoparticles, 1 part polyvinyl alcohol, 1 part polyacrylamide, 1 part polycarboxylate superplasticizer, 0.4 parts biopolysaccharide, 0.12 parts microbial mineralizing bacteria, 1.5 parts calcium source, 0.7 parts basalt fiber, 0.6 parts polypropylene fiber, 0.3 parts nanocellulose, 1 part shear thickening liquid, 0.9 parts layered double hydroxide, 8 parts delayed activation mineral admixture, and 2 parts quick-setting agent.

5. The low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts as described in claim 1, characterized in that, Includes the following quantities: The composition includes 25 parts cement, 33 parts fine aggregate, 15 parts coarse aggregate, 10 parts water, 1.5 parts nano silica, 1.2 parts nano calcium carbonate, 0.6 parts graphene oxide, 0.8 parts MXene, 1.5 parts aerogel powder, 0.6 parts silane coupling agent, 0.9 parts hydrophobically modified nanoparticles, 1.2 parts polyvinyl alcohol, 1.2 parts polyacrylamide, 1.2 parts polycarboxylate superplasticizer, 0.5 parts bio-polysaccharide, 0.18 parts microbial mineralizing bacteria, 1.8 parts calcium source, 0.9 parts basalt fiber, 0.8 parts polypropylene fiber, 0.4 parts nanocellulose, 1.2 parts shear thickening liquid, 1 part layered double hydroxide, 9 parts delayed activation mineral admixture, and 2.5 parts quick-setting agent.

6. The low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts as described in claim 1, characterized in that, include The following quantities: The composition includes 24 parts cement, 32 parts fine aggregate, 15 parts coarse aggregate, 9 parts water, 1.8 parts nano silica, 1.5 parts nano calcium carbonate, 0.8 parts graphene oxide, 1 part MXene, 1.8 parts aerogel powder, 0.7 parts silane coupling agent, 1 part hydrophobically modified nanoparticles, 1.5 parts polyvinyl alcohol, 1.3 parts polyacrylamide, 1.2 parts polycarboxylate superplasticizer, 0.6 parts bio-polysaccharide, 0.25 parts microbial mineralizing bacteria, 2 parts calcium source material, 1 part basalt fiber, 0.9 parts polypropylene fiber, 0.5 parts nanocellulose, 1.5 parts shear thickening liquid, 1.2 parts layered double hydroxide, 10 parts delayed activation mineral admixture, and 3 parts quick-setting agent.

7. The low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts as described in claim 1, characterized in that, The shear thickening fluid is composed of silica sol and polyethylene glycol, wherein silica sol accounts for 60% to 80% and polyethylene glycol accounts for 20% to 40%.

8. The low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts as described in claim 1, characterized in that, The delayed-activation mineral admixture is composed of metakaolin, slag powder and fly ash, wherein metakaolin accounts for 20% to 40%, slag powder accounts for 30% to 50%, and fly ash accounts for 20% to 40%.

9. The low-resilience self-healing wet-sprayed concrete for slope protection of ventilation shafts as described in claim 1, characterized in that, The layered double hydroxide is one of magnesium-aluminum layered double hydroxides or zinc-aluminum layered double hydroxides.

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