Fiber-reinforced tailing sand cement-based grouting material and preparation method thereof

Abstract

The invention provides a fiber-reinforced tailing sand cement-based grouting material and a preparation method thereof, and belongs to the technical field of grouting materials. The concrete is prepared from the following raw materials in parts by weight: 800-820 parts of a cementing material, 80-120 parts of solid waste aggregate, 70-90 parts of a mineral admixture, 1-3 parts of reinforced fibers and 500 parts of water. The preparation method comprises the following steps: weighing the raw materials in parts by weight, and controlling the mass ratio of the raw materials to water; mixing cement, iron tailing sand, fly ash and short-cut basalt fiber, and placing the mixture in water to obtain a mixed material; and putting the mixed material into a JJ-5 cement mortar stirrer, and uniformly stirring to obtain the fiber-reinforced tailing sand cement-based grouting material. According to the invention, the basalt fiber, the iron tailing sand and the fly ash are compounded to prepare the grouting material with high fluidity, strong diffusivity, high compressive and flexural strength and crack resistance, efficient utilization of solid wastes is realized, and the carbon emission is reduced while the preparation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of grouting materials, and particularly to a fiber-reinforced tailings sand cement-based grouting material and a preparation method thereof. Background Art

[0002] As a main technical means for geological disaster control, geotechnical engineering reinforcement and tailings reservoir seepage control, the material properties of grouting technology directly affect the engineering safety and economy. In the construction of the initial dam of a tailings reservoir, rockfill dams are widely used due to their advantages such as simple structure and low cost. However, their seepage problems and long-term stability need to be repaired and reinforced by high-performance grouting materials.

[0003] The commonly used grouting materials in engineering are mainly pure cement-based and chemical grouting materials. Although pure cement-based grouting materials have a wide range of sources, their rheological properties are insufficient. Due to the short setting time and poor fluidity retention ability of the cement system, it is difficult to effectively diffuse and fill in complex fracture environments, affecting the grouting uniformity. At the same time, the mechanical properties of pure cement-based grouting materials have certain limitations. Their flexural strength is low and toughness is poor, and cracks are easily generated due to the deformation of the base material, resulting in the failure of anti-seepage. Moreover, there are also environmental problems. Due to the large amount of cement used and the failure to utilize solid waste, not only the cost is high, but also the accumulation pollution of industrial waste residues such as tailings sand and fly ash is aggravated.

[0004] In addition, although chemical grouting materials have good adhesion and durability, they are prone to solvent volatilization and toxic substance residues, resulting in a high risk of environmental pollution. At the same time, the curing process is difficult to control, severely limiting their application in large-scale projects such as water conservancy and mines.

[0005] In addition, the comprehensive utilization rate of industrial solid waste by existing grouting materials is low. At present, the annual emissions of mine tailings sand and fly ash are huge. Long-term stacking not only occupies land, but also has safety hazards such as dam collapse and dust. At the same time, traditional materials have not effectively disposed of such waste, which does not conform to the development trend of green building materials. Summary of the Invention

[0006] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a fiber-reinforced tailings sand cement-based grouting material and a preparation method thereof. By compounding basalt fiber, iron tailings sand and fly ash, a grouting material with high fluidity, strong diffusion ability, high compressive and flexural strength and crack resistance is prepared, realizing the efficient utilization of solid waste, reducing the preparation cost and reducing the carbon emissions at the same time.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A fiber-reinforced tailings sand cement-based grouting material is composed of the following raw materials in parts by weight: 800-820 parts of a cementitious material, 80-120 parts of a solid waste aggregate, 70-90 parts of a mineral admixture, 1-3 parts of reinforcing fibers, and 500 parts of water.

[0009] Preferably, the cementitious material is cement, and the cement is ordinary Portland cement with a strength of not less than 42.5, and the particle size is 400-1000 mesh.

[0010] Preferably, the solid waste aggregate is iron tailings sand, and the pretreatment process of the tailings sand is as follows: The iron tailings sand is washed with tap water, and the number of washing times is not less than 3 times; then the washed iron tailings sand is placed in an electrothermal blast drying oven and dried at 200°C for 6-8 h; then it is sieved by a ZBSX-92A type shock vibrating sieve machine to obtain iron tailings sand with a particle size > 100 mesh.

[0011] Preferably, the working cycle of the shock vibrating sieve machine is 10 min, and the screening process is reciprocated at intervals of 5-10 s for not less than 3 cycles.

[0012] Preferably, the mineral admixture is fly ash, and the fly ash includes Class C fly ash from burning lignite or sub-bituminous coal and high-calcium fly ash, and the particle size of the fly ash is 400-600 mesh.

[0013] Preferably, the reinforcing fiber is chopped basalt fiber, and the length of the chopped basalt fiber is 6 mm, and the single filament diameter < 15 μm.

[0014] The present invention also provides a preparation method of the above-mentioned fiber-reinforced tailings sand cement-based grouting material, which includes the following steps: Weigh the raw materials according to parts by weight, and control the mass ratio of the raw materials to water to be 1:0.3-0.6; then mix the cement, iron tailings sand, fly ash, and chopped basalt fiber and place them in water to obtain a mixed material; place the mixed material in a JJ-5 cement mortar mixer and stir evenly to obtain the fiber-reinforced tailings sand cement-based grouting material.

[0015] Preferably, the stirring speed of the cement mortar mixer is 130-290 r / min, and the stirring time is 240 s.

[0016] According to the specific embodiments provided by the present invention, the following technical effects of the present invention are disclosed:

[0017] (1) By incorporating chopped basalt fibers as an admixture, the present invention improves the crack resistance of the grouting material, prevents the expansion of cracks in the specimens, enhances the interfacial strength and density between the material and the surrounding materials, and endows the grouting material with a relatively high flexural strength. Compared with the grouting material without fibers, the 28-day flexural strength is increased by 10.5%, and the crack resistance is significantly improved, meeting the long-term stability requirements under complex stress environments.

[0018] (2) The iron tailings sand provided by the present invention serves as an aggregate to provide a skeleton support, and the active components of fly ash delay the hydration reaction, enabling the flowability of the grouting material to reach 163 - 165 mm, the initial setting time to be extended to 352 - 361 min, and the final setting time to be 475 - 477 min, which is significantly better than that of traditional pure cement-based grouting materials. Thus, it ensures that the grouting material has good diffusion ability and filling effect in cracks, and improves the grouting uniformity and anti-seepage performance.

[0019] (3) The present invention replaces part of the cement with 80 - 120 parts of iron tailings sand and 70 - 90 parts of fly ash. Each batch of materials can consume 150 - 210 parts of industrial waste residue, reducing the cement consumption. It not only reduces the raw material cost, but also solves the problems of tailings sand stacking pollution and fly ash resource utilization, meeting the construction requirements of "waste-free cities". Compared with pure cement-based grouting materials, the preparation cost and carbon emissions are significantly reduced.

[0020] (4) By compounding basalt fibers, iron tailings sand and fly ash, the present invention prepares a grouting material with high fluidity, strong diffusion ability, high compressive and flexural strengths and crack resistance, realizing the efficient utilization of solid waste, reducing the preparation cost and carbon emissions at the same time. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 It is a flow chart of the preparation method of a fiber-reinforced tailings sand cement-based grouting material of the present invention. Detailed Embodiments

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, rather than all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] In order to make the above-mentioned objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] As Figure 1 shown, the present invention provides a preparation method of a fiber-reinforced tailings sand cement-based grouting material, including the following steps:

[0026] Step 100: Weigh the raw materials according to parts by weight, and control the mass ratio of the raw materials to water to be 1:0.3 - 0.6;

[0027] Step 200: Mix cement, iron tailings sand, fly ash, and chopped basalt fibers and place them in water to obtain a mixed material;

[0028] Step 300: Place the mixed material in a JJ-5 cement mortar mixer and stir evenly to obtain a fiber-reinforced tailings sand cement-based grouting material.

[0029] Among them, the stirring speed of the above cement mortar mixer is 130 - 290 r / min, and the stirring time is 240 s.

[0030] In addition, the above raw materials are composed of the following raw materials by weight: 800 - 820 parts of cementitious materials, 80 - 120 parts of solid waste aggregates, 70 - 90 parts of mineral admixtures, 1 - 3 parts of reinforcing fibers, and 500 parts of water.

[0031] Specifically, the cementitious material is cement, and the cement is ordinary Portland cement with a strength of not less than 42.5, and the particle size is 400 - 1000 mesh. The solid waste aggregate is iron tailings sand, and the pretreatment process of the tailings sand is as follows: Wash the iron tailings sand with tap water, and the number of washing times is not less than 3 times; then place the washed iron tailings sand in an electrothermal blast drying oven and dry it at 200°C for 6 - 8 h; then screen it through a ZBSX-92A type shock vibrating sieve machine, with a working cycle of 10 min, reciprocating at intervals of 5 - 10 s for not less than 3 cycles of screening to obtain iron tailings sand with a particle size > 100 mesh.

[0032] The mineral admixture is fly ash, and the fly ash includes Class C fly ash from burning lignite or sub-bituminous coal, high-calcium fly ash, and the particle size of the fly ash is 400 - 600 mesh. The reinforcing fiber is chopped basalt fiber, and the length of the chopped basalt fiber is 6 mm, and the single filament diameter < 15 μm.

[0033] The technical solution of the present invention will be further elaborated below through specific embodiments.

[0034] Example 1

[0035] In this embodiment, the fiber-reinforced tailings sand cement-based grouting material is composed of the following raw materials by weight: 818 parts of cement, 85 parts of iron tailings sand, 75 parts of fly ash, 1.5 parts of chopped basalt fiber, and 500 parts of water.

[0036] Among them, the treatment process of the above iron tailings sand is as follows: Wash the iron tailings sand 3 times with tap water to fully remove impurities in the tailings sand; then place it in an electrothermal blast drying oven at 200 °C for 8 hours to ensure drying, and then place it in a ZBSX-92A type - shock standard vibrating sieve machine, set the working cycle to 10 minutes, reciprocate for 3 cycles at intervals of 10 seconds for full separation, and obtain iron tailings sand with a particle size > 100 mesh.

[0037] In addition, this embodiment also provides a preparation method for the above fiber-reinforced tailings sand cement-based grouting material, including: weighing the raw materials according to the weight parts of this embodiment, and the mass ratio of the raw materials to water is 1:0.5; then mixing the raw materials and placing them in water to obtain a mixed material; finally, placing the mixed material in a JJ-5 cement mortar mixer and stirring for 240 s at a stirring speed of 250 r / min to obtain the fiber-reinforced tailings sand cement-based grouting material.

[0038] Example 2

[0039] In this embodiment, the fiber-reinforced tailings sand cement-based grouting material is composed of the following raw materials by weight: 818 parts of cement, 90 parts of iron tailings sand, 80 parts of fly ash, 2 parts of chopped basalt fiber, and 500 parts of water.

[0040] Among them, the treatment process of the above iron tailings sand is as follows: Wash the iron tailings sand 3 times with tap water to fully remove impurities in the tailings sand; then place it in an electrothermal blast drying oven at 200 °C for 8 hours to ensure drying, and then place it in a ZBSX-92A type - shock standard vibrating sieve machine, set the working cycle to 10 minutes, reciprocate for 3 cycles at intervals of 10 seconds for full separation, and obtain iron tailings sand with a particle size > 100 mesh.

[0041] In addition, this embodiment also provides a preparation method for the above fiber-reinforced tailings sand cement-based grouting material, including: weighing the raw materials according to the weight parts of this embodiment, and the mass ratio of the raw materials to water is 1:0.5; then mixing the raw materials and placing them in water to obtain a mixed material; finally, placing the mixed material in a JJ-5 cement mortar mixer and stirring for 240 s at a stirring speed of 250 r / min to obtain the fiber-reinforced tailings sand cement-based grouting material.

[0042] Comparative Example 1

[0043] The difference from Example 1 is that the raw materials do not include chopped basalt fiber, and the remaining raw material composition and preparation method are the same as those in Example 1.

[0044] Comparative Example 2

[0045] The difference from Example 1 is that the raw materials do not include iron tailings sand, and the remaining raw material composition and preparation method are the same as those in Example 1.

[0046] Comparative Example 3

[0047] The difference from Example 1 is that the raw materials do not include chopped basalt fibers and iron tailings sand, and the remaining raw material composition and preparation method are the same as those in Example 1.

[0048] Comparative Example 4

[0049] The difference from Example 1 is that the raw materials do not include chopped basalt fibers, iron tailings sand and fly ash, and the remaining raw material composition and preparation method are the same as those in Example 1.

[0050] Based on the above Examples 1-2 and Comparative Examples 1-4, the fiber-reinforced tailings sand cement-based grouting materials prepared correspondingly were subjected to performance tests, and the performance test results are shown in Table 1, where Table 1 is:

[0051] Table 1 Comparison of Material Performance Test Results

[0052]

[0053] As can be seen from Table 1, the fiber-reinforced tailings sand cement-based grouting materials prepared in the above Examples 1-2 and Comparative Examples 1-4 all meet the basic performance requirements of grouting materials.

[0054] In addition, comparing the performance test results, in Comparative Example 1, chopped basalt fibers were not added, and its flexural strength and crack resistance were significantly lower than those in Examples 1-2, highlighting that basalt fibers enhance the internal structure of the material through the bridging effect, effectively improving the flexural strength and crack resistance, and verifying the irreplaceability of fibers in improving the mechanical properties and toughness of the material. At the same time, in Comparative Example 2, iron tailings sand was lacking, and its fluidity and spreading ability were significantly lower than those in Examples 1-2, indicating that iron tailings sand, as a solid waste aggregate, can optimize the particle gradation of the slurry, improve the fluidity and spreading ability, and ensure full filling of the grouting material in the cracks. On the contrary, in Comparative Example 3, fly ash was not incorporated, resulting in defects in the utilization of solid waste and cost control. In Examples 1-2, by incorporating fly ash, not only the resource utilization of solid waste was realized, but also the hydration process of the cementitious material was regulated, improving the setting time and environmental protection benefits, reflecting the dual value of fly ash in green low-carbon and performance optimization. The performance of Comparative Example 4 was lower than that of Examples 1-2, confirming that the proportionate compounding of cement, iron tailings sand, fly ash and chopped basalt fibers, through the synergistic effect of "fiber reinforcement-solid waste filling-cementitious regulation", jointly improved the fluidity, compressive and flexural strength, crack resistance and environmental protection of the grouting material.

[0055] Therefore, by adopting the above-mentioned fiber-reinforced tailings sand cement-based grouting material and its preparation method, through the compounding of basalt fiber, iron tailings sand and fly ash, a grouting material with high fluidity, strong diffusion ability, high compressive and flexural strengths and crack resistance is prepared, realizing the efficient utilization of solid waste, reducing the preparation cost and reducing the carbon emission at the same time.

[0056] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same and similar parts among the various embodiments, reference can be made to each other.

[0057] Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The descriptions of the above embodiments are only used to help understand the method of the present invention and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. A fiber-reinforced tailings sand cement-based grouting material, characterized in that, It is composed of the following raw materials in parts by weight: 800 - 820 parts of cementitious material, 80 - 120 parts of solid waste aggregate, 70 - 90 parts of mineral admixture, 1 - 3 parts of reinforcing fiber, and 500 parts of water.

2. The fiber-reinforced tailings sand cement-based grouting material according to claim 1, wherein The cementitious material is cement, and the cement is ordinary Portland cement with a strength of not less than 42.5, and the particle size is 400 - 1000 mesh.

3. The fiber-reinforced tailings sand cement-based grouting material according to claim 1, characterized in that, The solid waste aggregate is iron tailings sand, and the pretreatment process of the tailings sand is as follows: The iron tailings sand is washed with tap water, and the number of washing times is not less than 3 times; then the washed iron tailings sand is placed in an electrothermal blast drying oven and dried at 200 °C for 6 - 8 h; then it is screened by a ZBSX-92A type shock vibrating sieve machine to obtain iron tailings sand with a particle size > 100 mesh.

4. The fiber-reinforced tailings sand cement-based grouting material according to claim 3, wherein, The working cycle of the shock vibrating sieve machine is 10 min, and the screening process of not less than 3 cycles is reciprocated at intervals of 5 - 10 s.

5. A fiber-reinforced tailings sand cement-based grouting material according to claim 1, characterized in that, The mineral admixture is fly ash, and the fly ash includes Class C fly ash from burning lignite or sub-bituminous coal and high-calcium fly ash, and the particle size of the fly ash is 400 - 600 mesh.

6. The fiber-reinforced tailings sand cement-based grouting material according to claim 1, characterized in that, The reinforcing fiber is chopped basalt fiber, and the length of the chopped basalt fiber is 6 mm, and the single filament diameter < 15 μm.

7. A preparation method of the fiber-reinforced tailings sand cement-based grouting material according to any one of claims 1 to 6, characterized in that, It includes the following steps: Weigh the raw materials according to parts by weight, and control the mass ratio of the raw materials to water to be 1:0.3 - 0.6; then mix the cement, iron tailings sand, fly ash, and chopped basalt fiber and place them in water to obtain a mixed material; place the mixed material in a JJ-5 cement mortar mixer and stir evenly to obtain a fiber-reinforced tailings sand cement-based grouting material.

8. The preparation method of a fiber-reinforced tailings sand cement-based grouting material according to claim 7, characterized in that, The stirring speed of the cement mortar mixer is 130 - 290 r / min, and the stirring time is 240 s.

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