Design and preparation method of mineral powder-based high-strength grouting material

Abstract

The invention discloses a design and preparation method of a mineral powder-based high-strength grouting material, which comprises the following steps: designing the mix proportion of the mineral powder-based high-strength grouting material by using a closest packing model-MAA model, and obtaining an ideal packing curve corresponding to the closest packing of a solid mixture of the mineral powder-based high-strength grouting material according to a formula I, and obtaining the volume ratio of the corresponding solid mixture when the stacking curve of the solid mixture is closest to the ideal stacking curve by adopting a formula II, and converting the volume ratio into the mass ratio of the raw materials in the grouting material, namely the optimal mixing ratio of the grouting material. The invention designs and develops the grouting material which takes the mineral powder as an auxiliary cementing material, has ultrahigh strength, good fluidity and low cost, can be applied to foundation reinforcement, equipment installation, reinforcement embedding, structure repair, seepage prevention and leakage stoppage and the like in constructional engineering, and prolongs the service life of structural parts.

Description

Technical Field

[0001] The present invention belongs to the technical field of grouting materials, and particularly relates to a design and preparation method of a mineral powder-based high-strength grouting material. Background Art

[0002] Traditional grouting materials usually use a large amount of cement, having the disadvantages of high energy consumption, high cost and low strength. With the continuous progress of construction technology and the increasing demand for high-performance building materials, developing grouting materials with higher strength, better durability and more environmental protection has become an important development direction. The new grouting materials not only need to meet the requirements of engineering structures, but also should have the advantages of convenient construction, good crack resistance and long-term stability.

[0003] As a by-product of the iron and steel industry, mineral powder contains a large amount of active SiO2, and has significant potential for preparing high-performance grouting materials. The fineness and pozzolanic activity of mineral powder enable it to fill pores in cement-based materials, improve the density, and participate in the hydration reaction to generate more cementitious products, thereby enhancing the strength and durability of the grouting material. It is an ideal supplementary cementitious material.

[0004] Compared with traditional cement-based materials, mineral powder has a lower heat release, which can effectively reduce the shrinkage and cracking caused by temperature rise during the grouting process. In addition, using mineral powder to prepare grouting materials can not only realize the resource utilization of industrial waste, reduce environmental pollution, but also reduce production costs, having significant economic and environmental benefits. However, developing grouting materials with ultra-high strength, good fluidity and low cost using mineral powder as a supplementary cementitious material is still a major technical challenge. Summary of the Invention

[0005] The main object of the present invention is to provide a design method of a mineral powder-based high-strength grouting material, using the most closely packed model - the MAA model to design the mix proportion of the mineral powder-based high-strength grouting material, and to design and develop a grouting material that uses mineral powder as a supplementary cementitious material and simultaneously has ultra-high strength, good fluidity and low cost.

[0006] Another object of the present invention is to provide a preparation method of the mineral powder-based high-strength grouting material, and the obtained grouting material can be applied to aspects such as foundation reinforcement, equipment installation, steel bar embedding, structural repair and anti-seepage plugging in construction projects.

[0007] To achieve the above objects, the present invention adopts the following technical solutions:

[0008] The present invention provides a design method of a mineral powder-based high-strength grouting material, using the most closely packed model - the MAA model to design the mix proportion of the mineral powder-based high-strength grouting material, including the following steps:

[0009] (1) obtaining an ideal packing curve corresponding to the most dense packing of the solid mixture of the mineral powder-based high-strength grouting material according to formula 1, wherein the solid mixture comprises cement, silica fume, mineral powder and quartz sand;

[0010] (2) using formula 2 to obtain the solid mixture volume ratio corresponding to the closest stacking curve of the solid mixture to the ideal stacking curve obtained in step (1), and converting it into the mass ratio of each raw material in the grouting material, which is the optimal grouting material mix ratio;

[0011] In step (1), formula 1 is:

[0012]

[0013] In formula 1, P(D) is the volume fraction of particles smaller than particle size D in the solid mixture; D is the particle size of the solid particles; D max is the maximum particle size in the solid mixture; D min is the minimum particle size in the solid mixture; q is the distribution modulus, which is 0.25;

[0014] In step (2), formula 2 is:

[0015]

[0016] Where S S is the residual sum of squares; P mix is the mixing ratio between raw materials; P tar It is the ideal ratio calculated according to the model.

[0017] Preferably, the mineral powder-based high-strength grouting material further includes a water reducer, a defoamer, steel fiber, and water. The optimal grouting material ratio is shown in the following table:

[0018] Cement Silica fume Ground granulated blast-furnace slag Quartz sand Water Water reducer Defoamer Steel fiber Weight percentage 25.6％ 0.6％ 20.5％ 39.6％ 8.6％ 0.42％ 0.08％ 4.6％

[0019] Preferably, the cement is Portland cement with a strength of 52.5.

[0020] Preferably, the silicon content of the silica fume is 94%.

[0021] Preferably, the mineral powder is S95 mineral powder.

[0022] Preferably, the gradation of the quartz sand is 40-70 mesh.

[0023] More preferably, the water reducer is a solid polycarboxylic acid water reducer with a water reduction rate of 25%.

[0024] More preferably, the defoaming agent is a polyether defoaming agent.

[0025] More preferably, the fiber is a copper-plated steel fiber with a diameter of 0.2 mm and a length of 16 mm.

[0026] The present invention also provides a preparation method of a mineral powder-based high-strength grouting material, comprising the following steps:

[0027] (1) Weigh each component of the grouting material according to the optimal grouting material mix ratio obtained by the design method of the mineral powder-based high-strength grouting material.

[0028] (2) Pour cement, silica fume, mineral powder, quartz sand, water reducer, and defoamer into a mixing pan and slowly stir for 3 minutes to mix evenly.

[0029] (3) Pour water into the mixing pan and quickly stir for 2 minutes, then slowly stir for 3 minutes. During the slow stirring process, slowly add steel fibers and continue to quickly stir for 1 minute to obtain the product.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] (1) In the present invention, mineral powder is used to replace part of the cement, and the grouting material mix ratio is optimized by the most closely packed model. The mineral powder not only has a filling effect but also can produce a pozzolanic reaction and a nucleation effect. The incorporation of the mineral powder not only reduces the amount of cement used, reduces production costs and carbon emissions, but also promotes the hydration reaction of cement, increases the density of the grouting material system, endows the grouting material with ultra-high strength and excellent fluidity, has a fast early strength development and a high late strength, the compressive strength can reach 78 MPa at 3 d and 149 MPa at 28 d, realizing significant economic and environmental benefits of the grouting material and being conducive to the sustainable development of building materials.

[0032] (2) In the present invention, the performance is further optimized by adding a water reducer and a defoamer to the grouting material. The water reducer can effectively disperse cement particles, reduce the water consumption, and at the same time maintain the fluidity of the grouting material, which not only makes the construction more convenient but also greatly improves the strength of the grouting material. The defoamer can significantly reduce the generation of internal bubbles in the grouting material, make the grouting material more dense and uniform, thereby improving its mechanical properties and durability, and ensuring the stability and reliability of the project quality.

[0033] (3) By incorporating an appropriate amount of steel fibers into the grouting material in the present invention, the problems commonly found in ordinary grouting materials, such as poor flexural performance, insufficient toughness, and easy generation of cracks, are significantly improved. The addition of steel fibers can change the fracture behavior of the grouting material, not only endowing the grouting material with higher tensile and flexural strengths but also significantly enhancing its toughness and durability, enabling the grouting material to have excellent mechanical properties and better meeting the requirements of modern civil engineering for high-strength and high-toughness materials, thereby extending the service life of structural members. Description of the Drawings

[0034] Figure 1It is the particle size distribution curve of the solid mixture of the mineral powder-based high-strength grouting material and the ideal packing curve corresponding to the closest packing in the embodiment. Detailed implementation manners

[0035] To more fully understand and demonstrate the technical solutions, objectives, and advantages of the present invention, the technical effects produced by the present invention will be further described in detail and completely below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. It should be noted that for those of ordinary skill in the art, other embodiments obtained without departing from the concept of the present invention all fall within the protection scope of the present invention.

[0036] Example 1

[0037] This example proposes a design method for a mineral powder-based high-strength grouting material. Based on the theory of particle close packing and using the MAA model to design the grouting material mix ratio, the specific steps are as follows:

[0038] First, use a laser particle size analyzer to measure the particle size distributions of cement, silica fume, mineral powder, and quartz sand respectively. According to Formula 1, obtain the ideal packing curve corresponding to the closest packing of the grouting material solid mixture, as Figure 1 shown; then adopt Formula 2, and adjust the proportion of each material in the mixture according to the optimization algorithm of the least squares method. When the deviation value between the ideal packing curve and the fitting curve is the smallest, obtain the volume ratio of cement, silica fume, mineral powder, and quartz sand, and convert it into the mass ratio of each raw material, that is, the optimal grouting material mix ratio.

[0039] Formula 1 is as follows:

[0040]

[0041] In the formula, P(D) is the volume fraction of the solid mixture less than the particle size D; D is the solid particle size; D max is the maximum particle size in the solid mixture; D min is the minimum particle size in the solid mixture; q is the distribution modulus, and its value is 0.25;

[0042] Formula 2 is as follows:

[0043]

[0044] In the formula, S S is the sum of squared residuals; P mix is the mixing ratio between raw materials; P tar is the ideal ratio calculated according to the model.

[0045] According to the theory of closest packing, calculate the optimal mix ratio of the grouting material, as shown in Table 1.

[0046] Table 1

[0047] Cement Silica fume Ground granulated blast-furnace slag Quartz sand Water Water reducer Defoamer Steel fiber Weight percentage 25.6％ 0.6％ 20.5％ 39.6％ 8.6％ 0.42％ 0.08％ 4.6％

[0048] Example 2

[0049] This example proposes a design method for mineral powder-based high-strength grouting material. The difference is that steel fibers are removed on the basis of Example 1, and the dosages of other materials are the same as those in Example 1, as shown in Table 2.

[0050] Table 2

[0051] Cement Silica fume Ground granulated blast-furnace slag Water Quartz sand Water reducer Defoamer Weight percentage 26.8％ 0.63％ 21.5％ 9.0％ 41.55％ 0.44％ 0.08％

[0052] Comparative Example 1

[0053] The difference between this comparative example and Example 1 is that all mineral powder is replaced with cement on the basis of Example 1, and the dosages of other materials are the same as those in Example 1.

[0054] Table 3

[0055] Cement Silica fume Quartz sand Water Water reducer Defoamer Steel fiber Weight percentage 46.1％ 0.6％ 39.6％ 8.6％ 0.42％ 0.08％ 4.6％

[0056] Comparative Example 2

[0057] This comparative example prepares steel slag-based two-component high-strength grouting material according to the preparation method described in the application number CN113636820B. By testing the performance of the grouting materials prepared in Examples 1 and 2 and Comparative Examples 1 and 2, the indexes of fluidity, 3d and 28d strength, and bleeding rate are shown in Table 4.

[0058] Table 4

[0059]

[0060] The replacement ratios of cement in Examples 1 and 2 reach 44.4%, greatly saving the cement consumption. At the same time, the fluidity, compressive strength, and bleeding rate of the grouting materials in Examples 1 and 2 all meet the standards, achieving significant economic and environmental benefits.

[0061] The 3d compressive strength and flexural strength of the grouting material in Example 1 are 78MPa and 23MPa respectively, and the 28d compressive strength and flexural strength are 149MPa and 24MPa respectively. The 3d compressive strength and flexural strength of the grouting material in Comparative Example 1 are 65MPa and 20MPa respectively, and the 28d compressive strength and flexural strength are 129MPa and 22MPa respectively. The mechanical properties of Example 1 are significantly improved compared with those of Comparative Example 1, proving that replacing part of the cement with mineral powder and using the most compact packing theory for mix proportion design can not only optimize the particle gradation, but also produce pozzolanic reaction, increase the hydration products, fill the pores, and densify the slurry structure, which is beneficial to enhancing the mechanical properties of the grouting material.

[0062] The 28-day compressive strengths of the grouting materials in Examples 1 and 2 were 149 MPa and 90 MPa respectively, which were increased by 98.1% and 19.7% compared with the steel slag-based two-component high-strength grouting material (Comparative Example 2). It can be seen that the mechanical properties of the grouting materials in Examples 1 and 2 are significantly higher than those of the grouting materials in the prior art.

[0063] The 3-day compressive strength and flexural strength of the grouting material in Example 1 were 78 MPa and 23 MPa respectively, and the 28-day compressive strength and flexural strength were 149 MPa and 24 MPa respectively. The 3-day compressive strength and flexural strength of the grouting material in Example 2 were 45 MPa and 6 MPa respectively, and the 28-day compressive strength and flexural strength were 90 MPa and 7 MPa respectively. The mechanical properties of Example 1 were significantly improved compared with those of Example 2, which proves that the incorporation of steel fibers can further greatly improve the compressive strength and flexural strength of the grouting material, and is beneficial to enhancing the toughness and durability of the grouting material.

[0064] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A design method for a mineral powder-based high-strength grouting material, characterized in that Design the mix proportion of the mineral powder-based high-strength grouting material using the closest packing model - the MAA model, including the following steps: (1) Obtain the ideal packing curve corresponding to the closest packing of the solid mixture of the mineral powder-based high-strength grouting material according to Formula 1, where the solid mixture includes cement, silica fume, mineral powder, and quartz sand; (2) Use Formula 2 to obtain the volume ratio of the solid mixture corresponding to when the packing curve of the solid mixture is closest to the ideal packing curve obtained in step (1), and convert it to the mass ratio of each raw material in the grouting material, which is the best mix proportion of the grouting material; In step (1), Formula 1 is: In Equation 1, P(D) is the volume fraction of particles smaller than particle size D in the solid mixture; D is the particle size of solid particles; D max is the maximum particle size in the solid mixture; D min is the minimum particle size in the solid mixture; q is the distribution modulus, with a value of 0.25; In step (2), Formula 2 is: where S S is the sum of squared residuals; P mix is the mixing ratio between raw materials; P tar is the ideal mixing ratio calculated according to the model.

2. The design method of the ore powder-based high-strength grouting material according to claim 1, characterized in that, The mineral powder-based high-strength grouting material also includes a water reducer, an antifoaming agent, steel fibers, and water. The best mix proportion of the grouting material is shown in the following table: 。 3. The design method of the ore powder-based high-strength grouting material according to claim 1, characterized in that, The cement is Portland cement with a strength of 52.

5.

4. The design method of the ore powder-based high-strength grouting material according to claim 1, characterized in that, The silica fume has a silicon content of 94%.

5. The design method of the ore powder-based high-strength grouting material according to claim 1, characterized in that, The mineral powder is S95 mineral powder.

6. The design method of the ore powder-based high-strength grouting material according to claim 1, characterized in that, The quartz sand has a particle size distribution of 40 - 70 mesh.

7. According to the design method of the mineral powder-based high-strength grouting material described in claim 2, characterized in that The water reducer is a solid polycarboxylate water reducer with a water reduction rate of 25%; And / or the antifoaming agent is a polyether antifoaming agent; And / or the steel fibers are copper-plated steel fibers with a diameter of 0.2 mm and a length of 16 mm.

8. A preparation method of a mineral powder-based high-strength grouting material, characterized in that, It includes the following steps: (1) Obtain the best mix proportion of the mineral powder-based high-strength grouting material according to the design method of the mineral powder-based high-strength grouting material described in any one of claims 1 to 7, and weigh each component of the mineral powder-based high-strength grouting material; (2) Slowly stir the cement, silica fume, mineral powder, quartz sand, water reducer, and antifoaming agent for 3 minutes to mix evenly; (3) Add water to the mixture obtained in step (2) and quickly stir for 2 minutes, then slowly stir for 3 minutes. During the slow stirring process, slowly add the steel fibers and continue to quickly stir for 1 minute to obtain it.

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