Low-carbon, high-density shotcrete de-elasticity agent, its preparation method, and application

Abstract

This invention discloses a low-carbon, high-density shotcrete admixture, its preparation method, and its application, relating to the field of concrete admixtures in building materials. The admixture comprises the following components by mass percentage: 53-73% rheological component, 15-25% thickening component, 10-18% early-strength component, and 0.5-4% setting regulator component. The rheological component includes manganese slag powder and silica fume, and the thickening component is tailings powder loaded with nano-modified cellulose ether. This invention increases the cohesiveness of shotcrete and improves the slurry encapsulation of concrete through the thickening component, increases the yield stress of concrete through the rheological component, and synergistically improves the adhesion and rapid hardening performance of the material after spraying by combining with the early-strength component, thereby reducing the rebound rate. Furthermore, the nanoparticles loaded on organic matter hydrate in the pores, directionally filling harmful pores, effectively improving the density and strength of shotcrete, achieving low-carbon, low-rebound, and high-density shotcrete.

Description

Technical Field

[0001] This invention relates to the field of concrete admixtures in building materials, specifically to a low-carbon, high-density shotcrete admixture and its preparation method. Background Technology

[0002] Shotcrete is a special type of concrete that uses compressed air to propel concrete at high speed onto a target surface using spraying machinery, allowing it to set and develop strength rapidly. Compared to cast-in-place concrete, machine-applied shotcrete offers advantages such as shorter setting time, easier construction, shorter construction period, and cost savings, and is widely used for shotcrete reinforcement in coal mine shafts, tunnels, culverts, and other engineering projects. However, when using shotcrete in tunnel engineering, its poor cohesion and the relatively smooth tunnel walls result in weak adhesion between the shotcrete and the wall, leading to a high rebound rate and a low pass rate for shotcrete.

[0003] Adding thickeners to concrete can improve its cohesiveness and reduce rebound rate. Existing thickeners are of two types: inorganic and organic. Inorganic thickeners are mainly used to reduce the thickness of the water film, increase the resistance to interparticle interaction, and improve the encapsulation of the paste. However, they have no significant effect on improving the binding viscosity between particles and aggregates, and their effect on reducing the rebound rate of shotcrete is limited. Organic thickeners are all branched, hydrophilic polymers with good particle adhesion. They achieve thickening and binding through water adsorption and aggregation, and the entanglement of long chains. However, the water aggregated by the polymer chains, after hydration or evaporation, can cause pores to enlarge, forming harmful pores, leading to increased concrete porosity and a significant decrease in strength. Currently, traditional thickeners all have significant shortcomings in reducing the rebound rate of shotcrete.

[0004] Therefore, it is necessary to develop a rebound reducer that can reduce the rebound rate of shotcrete and improve the density and strength of concrete. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a shotcrete rebound reducer that can reduce the rebound amount of shotcrete and improve the density and strength of concrete.

[0006] The technical solution of this invention is: a low-carbon, high-density shotcrete elasticity reducer, comprising the following components by mass percentage:

[0007] The rheological component is 53-73%, the thickening component is 15-25%, the early strength component is 10-18%, and the setting regulator component is 0.5-4%, with the sum of the mass percentages of the above components being 100%.

[0008] The rheological component includes manganese slag powder and silica fume, the thickening component is tailings powder loaded with nano-modified cellulose ether, the early strength component includes one or more of calcium formate, sodium sulfate, polyaluminum sulfate, lithium sulfate, aluminate cement, and sulfoaluminate cement, and the setting regulator component is one or more of sodium gluconate, sodium tripolyphosphate, boric acid, and citric acid.

[0009] Preferably, in the rheological component, the mass ratio of manganese slag powder to silica fume is 1.5–3.0:1, and the specific surface area of ​​the manganese slag powder is 600–800 m². 2 / kg, the specific surface area of ​​the silica fume is 15000-20000 m² / kg. 2 / kg.

[0010] The specific surface area of ​​the manganese slag powder in the above scheme is 600-800 m². 2 / kg, the purpose is that the manganese slag powder particles have a large specific surface area and an uneven surface, which can reduce the thickness of the water film layer on the particle surface, while increasing the relative resistance to movement between particles, thereby increasing the fluid yield stress and improving the wall adhesion performance of concrete slurry.

[0011] The specific surface area of ​​silica fume in the above scheme is 15,000-20,000 m². 2 The purpose of this is to fill the gaps between cement particles with fine silica fume, making the paste denser. In addition, silica fume has a large specific surface area and a large water demand. Due to the reaction of pozzolanic ash and the reduction of free water, the paste at the interface becomes denser, the Ca(OH)2 crystals are refined, the transition zone becomes thinner, and the bonding between the paste and the aggregate interface is increased.

[0012] Preferably, the tailings powder loaded with nano-modified cellulose ether is prepared by a method comprising the following steps:

[0013] S1. Prepare aqueous solutions of calcium nitrate and sodium metasilicate nonahydrate to obtain solutions A and B, respectively. Disperse the polyether macromonomer in water to form dispersion C. Dissolve the nonionic water-soluble cellulose ether in water to form solution D. Slowly and simultaneously add solutions A and B to dispersion C while stirring at a stirring rate of 300-500 rpm. When half of solutions A and B have been added, add solution D to dispersion C. Then stir at a high speed of 1200-2000 rpm until solutions A and B have been added simultaneously, to obtain a nano-modified cellulose ether solution.

[0014] S2. The tailings sand with a porous structure is crushed into tailings particles with a particle size of 0.5-2 mm and a pore size of 100-500 nm, wherein the tailings sand comes from one or more of copper tailings sand and iron tailings sand.

[0015] S3. Immerse the tailings particles obtained in step S2 in the nano-modified cellulose ether solution obtained in step S1 for 30–60 minutes. After immersion, dry, cool, and grind to a specific surface area of ​​50–150 m². 2 / g, yielding tailings powder loaded with nano-modified cellulose ether.

[0016] The tailings powder loaded with nano-modified cellulose ether prepared by the above scheme is a multifunctional thickening material with good dispersion, slow release, and directional pore filling. By loading porous tailings particles, the nano-cellulose ether achieves the effects of slow release and high dispersibility. High dispersibility can uniformly disperse organic matter into the powder, and slow release helps to alleviate the concentrated dissolution of long polymer chains and prevent local polymer chain aggregation and excessive entanglement. At the same time, excess nano-CSH crystal nuclei are pre-adsorbed with cellulose ether molecules. The nanoparticles will follow the movement of cellulose ether molecules and nucleate at the places where cellulose ether molecules encapsulate water, promoting the generation of hydration products and filling the pores after water hydration and evaporation, preventing the formation of harmful pores in some areas.

[0017] In the above scheme, the roles of each raw material are as follows: calcium nitrate + sodium metasilicate nonahydrate is used to prepare nano-CSH crystal nuclei; polyether macromonomer is used to disperse settled solid particles; cellulose ether is used to provide a carrier for nanoparticles, enabling nanoparticles to bind with cellulose ether molecules; and porous tailings particles are used to adsorb nano-modified cellulose ether, allowing it to be better dispersed in cement paste.

[0018] Furthermore, in step S1, the mass concentration of calcium nitrate in solution A is 20-30%, the mass concentration of sodium metasilicate nonahydrate aqueous solution is 20-30%, the mass concentration of polyether macromonomer in dispersion C is 5-15%, and the mass concentration of cellulose ether in solution D is 0.1-0.5%.

[0019] Furthermore, in step S1, the mass ratio of calcium nitrate: sodium metasilicate nonahydrate: polyether macromonomer: cellulose ether is 100: 100-150: 96-288: 1.2-5.0.

[0020] Furthermore, in step S1, the nonionic water-soluble cellulose ether is one or more of methyl cellulose ether, hydroxypropyl methyl cellulose ether, hydroxymethyl cellulose ether, and hydroxyethyl cellulose ether, with a molecular weight of 20,000-100,000. Too low a molecular weight results in poor thickening effect, while too high a molecular weight will cause excessive entanglement and coating of cement particles, reducing the strength of the concrete.

[0021] Furthermore, in step S1, the total time for adding solutions A and B is 2 to 4 hours.

[0022] Furthermore, in step S3, the drying temperature is 95–105°C and the drying time is 3–5 hours.

[0023] The present invention also provides a method for preparing the low-carbon high-density shotcrete de-elasticity agent as described above, wherein the rheological component, the thickening component, the early strength component, and the setting-regulating component are mixed to obtain the low-carbon high-density shotcrete de-elasticity agent.

[0024] This invention also provides the application of the elasticity-reducing agent for low-carbon, high-density shotcrete as described above, wherein the elasticity-reducing agent is added at a dosage that replaces 5% to 10% of the cement in the concrete. That is, the elasticity-reducing agent is added internally at a dosage of 5% to 10% of the total cement mass.

[0025] The beneficial effects of this invention are:

[0026] 1. By increasing the cohesiveness of shotcrete through thickening components and improving the slurry-like encapsulation of concrete, and by increasing the yield stress of concrete through rheological components, and by combining early strength components to synergistically improve the adhesion and fast-hardening properties of the material after spraying, the rebound rate is reduced and the thickness of a single spraying is increased; by hydrating nanoparticles loaded on organic matter in pores, harmful pores are directionally filled, effectively improving the density and strength of shotcrete, and achieving low-carbon, low-rebound, and high-density shotcrete.

[0027] 2. The elasticity reducer uses cellulose ether with a lower molecular weight to reduce the length of the polymer backbone and reduce the pores formed by water adsorption and aggregation. At the same time, the nanocrystal nuclei induce cement hydration during the evaporation of water around the thickener molecules to form a large amount of CSH gel to fill the structural pores, thereby achieving the directional filling of harmful pores, improving the density of hydration products, and eliminating the adverse effects of organic thickeners on concrete strength.

[0028] 3. The elasticity reducer uses porous tailings sand as an inorganic material. The porous water absorption and storage function of the particles enhances the rheological properties of the elasticity reducer, improves the initial pumping efficiency of concrete and the anti-sagging performance after spraying, and at the same time, the solid waste is reused to achieve green and low-carbon development.

[0029] 4. By loading nano-modified cellulose ether onto porous tailings sand, the thickener can be efficiently dispersed in the powder. At the same time, the nano-modified cellulose ether in the pores gradually dissolves and is released, reducing the concentration of thickener molecules in the liquid phase and their entanglement with cement particles. This helps to remove air bubbles and improve the hydration efficiency of cement particles during concrete mixing, thereby increasing the early-age strength of concrete.

[0030] 5. The addition of the elasticity-reducing agent of this invention can effectively improve the yield stress and plastic viscosity of shotcrete, with the yield stress reaching above 1321.2 Pa and the plastic viscosity reaching above 192.3 Pa·s; at the same time, it reduces the harmful porosity to below 2.5%; and improves the 1-day and 28-day compressive strength, with the 1-day compressive strength of C25 concrete reaching above 20.2 MPa and the 28-day compressive strength reaching above 37.8 MPa. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is further described below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Unless otherwise specified, the pharmaceuticals used in the following embodiments are commercially available products, and the methods used are conventional methods in the art.

[0032] In the rheological components, the specific surface area of ​​manganese slag powder is 600-800 m². 2 / kg, the specific surface area of ​​the silica fume is 15000-20000 m² / kg. 2 / kg

[0033] Among the thickening components, calcium nitrate, sodium metasilicate nonahydrate, polyether macromonomer, and cellulose ether are commercially available products. Specifically, the polyether macromonomer is isobutylene polyethylene glycol ether (HPEG) or isopentenyl polyethylene glycol ether (TPEG), which are commercially available products.

[0034] The early strength components include calcium formate, sodium sulfate, polyaluminum sulfate, lithium sulfate, aluminate cement, and sulfoaluminate cement, which are commercially available products.

[0035] The coagulation-regulating components, sodium gluconate, sodium tripolyphosphate, boric acid, and citric acid are commercially available products.

[0036] Example 1

[0037] This embodiment provides a low-carbon, high-density shotcrete elasticity reducer, comprising, by weight, 53 parts rheological component, 25 parts thickening component, 18 parts early-strength component, and 4 parts setting regulator. The rheological component is a mixture of manganese slag powder and silica fume in a 3:1 weight ratio; the thickening component is tailings powder loaded with nano-modified cellulose ether; the early-strength component is calcium formate; and the setting regulator is sodium tripolyphosphate.

[0038] The preparation steps of tailings powder loaded with nano-modified cellulose ether in this embodiment are as follows:

[0039] S1. Preparation of nano-modified cellulose ether: Calcium nitrate and sodium metasilicate nonahydrate were dissolved in distilled water to obtain a 20% calcium nitrate aqueous solution A and a 30% sodium metasilicate nonahydrate aqueous solution B. The polyether macromonomer (specifically HPEG in this example) was dispersed in water to prepare a dispersion C (5% by mass). Hydroxypropyl methylcellulose ether was dissolved in water to form a solution D (0.2% by mass). Then, 12g of solution A and 12g of solution B were slowly added to 46g of dispersion C by simultaneous dropwise addition over 2 hours (stirring at a low speed of 500 rpm for the first hour). After 1 hour of dropwise addition, 30g of cellulose ether aqueous solution D was added. After another hour of high-speed stirring (1500 rpm), solutions A and B were added simultaneously, and the nano-modified cellulose ether solution was obtained. Based on the specific dosages above, in this embodiment, the mass ratio of calcium nitrate: sodium metasilicate nonahydrate: polyether macromonomer: cellulose ether is 100:150:96:2.5.

[0040] S2. Porous copper tailings sand is crushed into particles with a pore size of 100-500 nm and a particle size of 0.5-2 mm.

[0041] S3. After soaking the tailings particles in a nano-modified cellulose ether solution for 30 minutes, remove them, dry them at 105℃ for 3 hours, cool them, and then grind them into powder using a ball mill, with a specific surface area of ​​50-150 m². 2 / g, tailings powder loaded with nano-modified cellulose ether was obtained.

[0042] Preparation method of low-carbon high-density shotcrete de-elasticity agent: simply mix the rheology component, thickening component, early strength component, and setting regulator component.

[0043] The elasticity reducer of Example 1 was added to the concrete as an internal admixture (replacing cement) at a dosage of 5%.

[0044] Example 2

[0045] This embodiment provides a low-carbon, high-density shotcrete elasticity reducer, comprising, by weight, 72.5 parts of rheological component, 15 parts of thickening component, 12 parts of early-strength component, and 0.5 parts of setting regulator. The rheological component is a mixture of manganese slag powder and silica fume in a 3:1 weight ratio; the thickening component is tailings powder loaded with nano-modified cellulose ether; the early-strength component is sodium sulfate; and the setting regulator is boric acid.

[0046] The preparation steps of tailings powder loaded with nano-modified cellulose ether in this embodiment are as follows:

[0047] S1. Preparation of nano-modified cellulose ether: Calcium nitrate and sodium metasilicate nonahydrate were dissolved in distilled water to obtain a 25% calcium nitrate aqueous solution A and a 25% sodium metasilicate nonahydrate aqueous solution B. The polyether macromonomer (specifically TPEG in this example) was dispersed in water to prepare a dispersion C (10% by mass). Hydroxypropyl methylcellulose ether was dissolved in water to form a solution D (0.4% by mass). Then, 12g of solution A and 12g of solution B were slowly added to 46g of dispersion C by simultaneous dropwise addition over 4 hours (stirring at a low speed of 500 rpm for the first 2 hours). After 2 hours of dropwise addition, 30g of cellulose ether aqueous solution D was added. After another 2 hours of high-speed stirring (1200 rpm), solutions A and B were added simultaneously, and the nano-modified cellulose ether solution was obtained. Based on the specific dosages above, in this embodiment, the mass ratio of calcium nitrate: sodium metasilicate nonahydrate: polyether macromonomer: cellulose ether is 100:100:153:4.0.

[0048] S2 porous iron tailings sand is crushed into particles with a pore size of 100-500 nm and a particle size of 0.5-2 mm.

[0049] S3 immerses tailings particles in a nano-modified cellulose ether solution for 30 minutes, then removes them, dries them at 105℃ for 3 hours, cools them, and grinds them into powder using a ball mill, with a specific surface area of ​​50–150 m². 2 / g, tailings powder loaded with nano-modified cellulose ether was obtained.

[0050] Preparation method of low-carbon high-density shotcrete de-elasticity agent: simply mix the rheology component, thickening component, early strength component, and setting regulator component.

[0051] The elasticity reducer of Example 2 was added to the concrete by means of internal admixture (replacing cement), with a dosage of 5%.

[0052] Example 3

[0053] This embodiment provides a low-carbon, high-density shotcrete elasticity reducer, comprising, by weight, 63 parts rheological component, 20 parts thickening component, 15 parts early-strength component, and 2 parts setting regulator. The rheological component is a mixture of manganese slag powder and silica fume in a 3:1 weight ratio; the thickening component is tailings powder loaded with nano-modified cellulose ether; the early-strength component is polyaluminum sulfate; and the setting regulator is citric acid.

[0054] The preparation steps of tailings powder loaded with nano-modified cellulose ether in this embodiment are as follows:

[0055] S1. Preparation of nano-modified cellulose ether: Calcium nitrate and sodium metasilicate nonahydrate were dissolved in distilled water to obtain a 25% calcium nitrate aqueous solution A and a 30% sodium metasilicate nonahydrate aqueous solution B. The polyether macromonomer (specifically TPEG in this example) was dispersed in water to prepare a dispersion C (15% by mass). Hydroxypropyl methylcellulose ether was dissolved in water to form a solution D (0.5% by mass). Then, 12g of solution A and 12g of solution B were slowly added to 46g of dispersion C by simultaneous dropwise addition over 3 hours (with low-speed stirring at 500 rpm for the first 1.5 hours). After 1.5 hours of dropwise addition, 30g of cellulose ether aqueous solution D was added, followed by high-speed stirring (2000 rpm) for another 1.5 hours to obtain the nano-modified cellulose ether solution. Based on the specific dosages above, in this embodiment, the mass ratio of calcium nitrate: sodium metasilicate nonahydrate: polyether macromonomer: cellulose ether is 100:120:230:5.0.

[0056] S2 porous copper tailings sand is crushed into particles with a pore size of 100-500 nm and a particle size of 0.5-2 mm.

[0057] S3 immerses tailings particles in a nano-modified cellulose ether solution for 30 minutes, then removes them, dries them at 105℃ for 3 hours, cools them, and grinds them into powder using a ball mill, with a specific surface area of ​​50–150 m². 2 / g, tailings powder loaded with nano-modified cellulose ether was obtained.

[0058] Preparation method of low-carbon high-density shotcrete de-elasticity agent: simply mix the rheology component, thickening component, early strength component, and setting regulator component.

[0059] The elasticity reducer of Example 4 was added to the concrete as an internal admixture (replacing cement) at a dosage of 5%.

[0060] Example 4

[0061] The low-carbon, high-density shotcrete de-elasticity agent in this embodiment is prepared in the same way as in Example 1, except that the dosage of the de-elasticity agent added to the concrete is 10%.

[0062] Performance testing

[0063] Comparative Example 1 uses C25 shotcrete as the baseline.

[0064] Comparative Example 2 was prepared according to the proportions of Example 3 (i.e., 63 parts rheological component, 20 parts thickening component, 15 parts early strength component, and 2 parts setting regulator component). The thickening component was not pre-adsorbed or loaded. Cellulose ether, nano-CSH nucleation early strength agent, and copper tailings powder raw material were directly mixed at a mass ratio of 1:140:800 to form the thickening component. The nano-nucleation early strength agent was CSH nucleation early strength agent from Jiangsu Aolaite New Material Co., Ltd.

[0065] Comparative Example 3 is HT-01, a product of Wuhan Yuanjin Building Materials Technology Co., Ltd.

[0066] The C25 shotcrete was prepared according to the examples and comparative examples as shown in Table 1 below.

[0067] Table 1. Mix proportions of C25 shotcrete (kg / m³) 3 )

[0068]

[0069] The following tests were conducted on the examples and comparative examples: 90-minute time loss, yield stress, plastic viscosity, sidewall rebound rate, arch rebound rate, single-shot thickness, 1-day compressive strength, 28-day compressive strength, and harmful porosity. Yield stress and plastic viscosity were measured using a Viskmat eBT2 rheometer in V mode, and harmful porosity was measured using an AutoPore IV9510 fully automatic mercury porosimeter manufactured by Mack. All other tests were conducted according to JGJ / T 372-2016 "Technical Specification for Application of Shotcrete". The test results are shown in Tables 2 and 3 below.

[0070] Table 2 Performance Test Results

[0071]

[0072] Table 3 Performance Test Results

[0073]

[0074] As shown in Table 2, the different components of the elasticity-reducing agent used in Examples 1, 2, and 3, compared with Comparative Example 1, effectively increase the yield stress and plastic viscosity of shotcrete, thereby improving the cohesiveness during pumping and the bonding performance during spraying, thus reducing the rebound rate. Simultaneously, it reduces harmful porosity and increases the 1-day and 28-day compressive strength. Comparing the test results of Examples 1, 2, and 3, it is evident that with the increase of the rheological component, the yield stress of shotcrete further increases, the rebound rate further decreases, and the strength at each age also improves. Comparing the test results of Examples 3 and 4, it is evident that the performance improvement is not significant after the elasticity-reducing agent dosage exceeds 5%. Comparing the test results of Example 3 and Comparative Example 2, it is evident that without pre-adsorption and dispersion treatment of the rheological component, it cannot specifically fill harmful pores, resulting in limited strength improvement. Comparing Example 3 and Comparative Example 3, the elasticity-reducing agent product of this invention has significant advantages in reducing rebound and improving strength.

[0075] Based on the above experimental results, this invention successfully formulated a shotcrete reducer that can lower the rebound rate and improve the density and strength of shotcrete by using the synergistic effect of thickening components, rheological components, early strength components and setting regulators. It can improve the slurry encapsulation and cohesiveness of concrete, improve the bonding performance of the material after spraying, thereby reducing the rebound rate and increasing the thickness of a single spraying. It can also directionally fill harmful pores, effectively improve the density and strength of shotcrete, and achieve low carbon, low rebound and high density shotcrete.

Claims

1. A low-carbon, high-density shotcrete de-elasticity agent, characterized in that, Includes the following components by mass percentage: The rheological components are 53-73%, the thickening components are 15-25%, the early strength components are 10-18%, and the setting-regulating components are 0.5-4%, with the sum of the mass percentages of the above components being 100%. The rheological component includes manganese slag powder and silica fume, the thickening component is tailings powder loaded with nano-modified cellulose ether, the early strength component includes one or more of calcium formate, sodium sulfate, polyaluminum sulfate, lithium sulfate, aluminate cement, and sulfoaluminate cement, and the setting regulator component is one or more of sodium gluconate, sodium tripolyphosphate, boric acid, and citric acid. The tailings powder loaded with nano-modified cellulose ether is prepared by a method comprising the following steps: S1. Prepare aqueous solutions of calcium nitrate and sodium metasilicate nonahydrate to obtain solutions A and B, respectively. Disperse the polyether macromonomer in water to form dispersion C. Dissolve the nonionic water-soluble cellulose ether in water to form solution D. Slowly and simultaneously add solutions A and B to dispersion C while stirring at a stirring rate of 300-500 rpm. When half of solutions A and B have been added, add solution D to dispersion C. Then stir at a high speed of 1200-2000 rpm until solutions A and B have been added simultaneously, to obtain a nano-modified cellulose ether solution. S2. The tailings sand with a porous structure is crushed into tailings particles with a particle size of 0.5-2 mm and a pore size of 100-500 nm, wherein the tailings sand comes from one or more of copper tailings sand and iron tailings sand. S3. Immerse the tailings particles obtained in step S2 in the nano-modified cellulose ether solution obtained in step S1 for 30–60 minutes. After immersion, dry, cool, and grind to a specific surface area of ​​50–150 m². 2 / g, yielding tailings powder loaded with nano-modified cellulose ether.

2. The low-carbon, high-density shotcrete reducer as described in claim 1, characterized in that, In the rheological component, the mass ratio of manganese slag powder to silica fume is 1.5–3:1, and the specific surface area of ​​the manganese slag powder is 600–800 m². 2 / kg, the specific surface area of ​​the silica fume is 15000-20000 m² 2 / kg.

3. The low-carbon, high-density shotcrete reducer as described in claim 1, characterized in that, In step S1, the mass concentration of calcium nitrate in solution A is 20-30%, the mass concentration of sodium metasilicate nonahydrate aqueous solution is 20-30%, the mass concentration of polyether macromonomer in dispersion C is 5-15%, and the mass concentration of cellulose ether in solution D is 0.1-0.5%.

4. The low-carbon, high-density shotcrete reducer as described in claim 3, characterized in that, In step S1, the mass ratio of calcium nitrate: sodium metasilicate nonahydrate: polyether macromonomer: cellulose ether is 100: 100~150: 96~288: 1.2~5.

0.

5. The low-carbon, high-density shotcrete reducer as described in claim 1, characterized in that, In step S1, the nonionic water-soluble cellulose ether is one or more of methylcellulose ether, hydroxypropyl methylcellulose ether, and hydroxyethylcellulose ether, with a molecular weight of 20,000-100,000.

6. The low-carbon, high-density shotcrete reducer as described in claim 1, characterized in that, In step S1, solutions A and B are added dropwise simultaneously over a period of 2–4 hours.

7. The low-carbon, high-density shotcrete reducer as described in claim 1, characterized in that, In step S3, the drying temperature is 95~105℃ and the drying time is 3~5h.

8. A method for preparing a low-carbon, high-density shotcrete de-elasticity agent as described in any one of claims 1 to 7, characterized in that, A low-carbon, high-density shotcrete reducer is obtained by mixing rheological components, thickening components, early-strength components, and setting-regulating components.

9. The application of a low-carbon, high-density shotcrete de-elasticity agent as described in any one of claims 1 to 7, characterized in that, The amount of the elasticity reducer is added to replace 5% to 10% of the cement in the concrete.

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