Fly ash doped cement double-aggregate high-water-content material and preparation method thereof

Abstract

The invention belongs to the technical field of coal mine gob-side entry retaining and goaf filling, and particularly relates to a high-water-content material and a preparation method thereof.The high-water-content material is composed of a composition A, a composition B, an auxiliary material A and an auxiliary material B. The composition A is a mixture of fly ash and silica alumina; the composition B is sulphoaluminate cement and comprises any one or a combination of any two or more of 725 cement, 525 cement and 425 cement; the auxiliary material component A is a mixture of anhydrous calcium sulfate and magnesium aluminum silicate; and the auxiliary material B component is calcium hydroxide. By preparing the high-water-content material, the purposes of energy conservation and environmental protection are achieved, the economic benefit can be improved, and the problem of low utilization rate of the fly ash is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of goaf-side tunnel retention and goaf filling in coal mines, and in particular relates to a fly ash-cement-doped double-aggregate high-water material and a preparation method thereof. Background Art

[0002] Ultra-high-water and high-water materials consist of two materials, A and B. Material A is primarily composed of bauxite and gypsum, each refined separately, and supplemented with a composite super-retarding dispersant (also known as admixture AA). Material B is a blend of gypsum and lime, combined with a small amount of a composite accelerating setting agent (also known as admixture BB). When materials A and B are used in a 1:1 ratio, with a water volume of 95%-97%, the compressive strength of the ultra-high-water material can be adjusted based on the water volume and admixture formulation. The initial setting time can be adjusted between 8 and 90 minutes, and the 28-day strength can reach 0.66-1.50 MPa. A single slurry of the two main materials, A and B, can remain unset for 30-40 hours. Once mixed, the material rapidly hydrates and sets. Adjusting the admixture formulation can alter material properties, with a water-cement ratio as high as 11:1.

[0003] Existing high-water-density and ultra-high-water-density materials exhibit low strength in experiments. The setting time is short when the individual slurries are stirred separately, and the setting time is long after the A and B materials are mixed. This excessively long time to develop strength results in excessively low strength, ultimately preventing the high-water-density and even ultra-high-water-density materials from being truly put into production. Furthermore, due to the varying sources of experimental materials, different batches of products from the same manufacturer with the same formula can produce different experimental results. Furthermore, due to the wide variety of gypsum types in the B material, the use of different gypsum types can result in the high-water-density materials failing to develop sufficient strength.

[0004] Fly ash, also known as fly ash, is a clay-like solid mixture produced by high-temperature combustion in coal-fired boilers of thermal power plants. It is a gray-brown material with a specific surface area of ​​2500-7000cm 2 / g, the particle size is about (1-500μm), and they are generally spherical. In China, the chemical composition of most fly ash exists in this way: silicon dioxide, aluminum oxide, iron oxide, calcium oxide, etc. In addition, it also contains a small amount of magnesium, titanium, sulfur, potassium, sodium and other oxides. With the continuous development of my country's economy and society, its total emissions have shown an increasing trend year by year. If not properly treated, it will occupy a large amount of arable land and cause serious air pollution. At the same time, it will seep into the underground system due to the leaching effect, and its mud will be discharged into rivers and lakes, causing pollution and blockage of the river, directly affecting the growth of aquatic organisms and destroying the ecological balance. In order to solve the problem of fly ash pollution to the environment, improve its treatment efficiency, realize its resource utilization, and develop new functional materials are current research hotspots. Summary of the Invention

[0005] The purpose of the present invention is to provide a fly ash-cement-doped dual-aggregate high-water material and a preparation method thereof, so as to overcome the shortcomings of the existing technology, realize resource utilization of fly ash, solve the problem of environmental pollution, improve its treatment efficiency, and realize waste into treasure; solve the problem of low final strength of the existing high-water material or ultra-high-water material slurry after mixing and stirring; solve the problem of the single product of the existing high-water material or ultra-high-water material.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] One of the technical solutions: A dual-aggregate high-water material with fly ash doped with cement, consisting of composition A, composition B, auxiliary material A and auxiliary material B, wherein the component in composition A is a mixture of fly ash and silica alumina; composition B is sulfoaluminate cement, including any one of 725 cement, 525 cement or 425 cement or a combination of any two or more; auxiliary material A is a mixture of anhydrous calcium sulfate and magnesium aluminum silicate; auxiliary material B is calcium hydroxide.

[0008] Furthermore, the weight ratio of the composition A to the composition B is (3-2):1.

[0009] Furthermore, the weight ratio of the fly ash to silica alumina is 7:(6-3).

[0010] Furthermore, the fly ash particles are mainly composed of glass microspheres (spherical), spongy glass and unburned carbon particles, with a particle diameter ranging from 0.5 to 300 μm, a porosity of 50% to 80%, and a density of 1.9 to 2.9 g / cm 3 , bulk density 0.53~1.26g / cm 3 , specific surface area 800~19,500cm 2 / g, and has a high water requirement. Main components: SiO2 (40% to 65%), Al2O3 (15% to 30%), Fe2O3 (5% to 15%), with small amounts of CaO, MgO, SO3, etc.

[0011] Furthermore, the silica alumina density is 3.9-4.0 g / cm 3 , Mohs hardness 1 to 3, white, grayish white or brownish yellow, mainly composed of hydrated alumina minerals, the main component Al2O3 content is 60% to 85%, and the rest are Fe2O3, SiO2, TiO2 impurities.

[0012] Furthermore, the weight ratio of anhydrous calcium sulfate to material A in the auxiliary material A is 1:(8-5), and the weight ratio of magnesium aluminum silicate to material A is 1:16.

[0013] Furthermore, the weight ratio of the auxiliary material B to the composition B is 1:7.

[0014] Technical solution 2: A method for preparing a fly ash-doped cement dual-aggregate high-water material, specifically comprising the following steps: 1) mixing composition A and auxiliary material A to obtain mixture 1; mixing composition B and auxiliary material B to obtain mixture 2; 2) adding water to the mixture 1 and mixture 2 separately and mixing them, and adding them to the upper tank and lower tank of a double-layer laboratory mixer respectively. After stirring evenly, pulling out the partition of the upper tank to allow mixture 1 to enter the mixture 2 in the lower tank through the screen and continue mixing and stirring to obtain a mixture; 3) pouring the mixture into a mold, letting it stand, and then solidifying and demolding to obtain the fly ash-doped cement dual-aggregate high-water material.

[0015] Furthermore, in the mixture 1, the mass ratio of water to material A is 1.0-3.0; in the mixture 2, the mass ratio of water to material B is 1.0-3.0, and the temperature of the water is 12-28°C.

[0016] Furthermore, the specification model of the upper and lower double-layer laboratory stirrer is ZCX700, and the mesh aperture is 20 mesh-60 mesh and is replaceable.

[0017] The material reaction principle and performance support principle of the present invention are:

[0018] Reaction principle of the present invention:

[0019] Pozzolanic effect: The active components (SiO2, Al2O3) in fly ash react with Ca(OH)2 produced by cement hydration to form calcium silicate gel and aluminate hydrate, which improves the later strength.

[0020] Cement setting mechanism: Calcium sulfoaluminate cement undergoes a hydration reaction in the presence of gypsum to form ettringite, while releasing a large amount of heat. This reaction is the main driving force for setting and early strength.

[0021] Filling effect of calcium silicate gel and aluminum gel: Calcium silicate and calcium aluminosilicate are hydrated to generate hydrated calcium silicate gel and aluminum gel, which fill the pores between the ettringite skeleton and improve the density.

[0022] Physical filling effect: Fly ash particles fill the pores between cement particles and hydration products, further improving the density.

[0023] Performance Support Principle Analysis

[0024] 1. Formation and strengthening of ettringite skeleton

[0025] Sulphoaluminate cement-dominated rapid hydration

[0026] When the sulphoaluminate cement in composition B (such as 725 / 525 / 425 cement) reacts with water, its core mineral calcium sulphoaluminate (C4A3S) rapidly releases Al 3+ and SO4 2- , combined with anhydrous calcium sulfate (CaSO4) in auxiliary material A and calcium hydroxide (Ca(OH)2) in auxiliary material B to generate a large amount of ettringite (AFt, 3CaO·Al2O3·3CaSO4·32H2O).

[0027] Structural support: Ettringite is interwoven into a three-dimensional network skeleton with needle-shaped or columnar crystals, giving the material high early strength (1 hour strength can reach 0.5-1MPa).

[0028] High water content: Ettringite crystals contain 32 crystalline waters, which combine with free water adsorption to form a "sponge structure", achieving a volume water content of 90%-97% while maintaining mechanical stability.

[0029] Synergistic effect of excipient A

[0030] Anhydrous calcium sulfate: provides SO4 2- , regulate the formation rate and morphology of ettringite, and prevent flash solidification caused by the hydration of C3A alone.

[0031] Magnesium aluminum silicate: acts as a dispersant and retarder to optimize the rheological properties of the slurry, extend the construction time, and participate in the formation of gelled products (such as magnesium aluminum silicate gel) to fill the pores.

[0032] 2. Pozzolanic and filling effects of fly ash and silica alumina

[0033] Pozzolanic reaction of fly ash

[0034] The fly ash in composition A (containing active SiO2 and Al2O3) undergoes secondary hydration under the alkaline activation of Ca(OH)2 in auxiliary material B: SiO2+Ca(OH)2→CSH gel Al2O3+Ca(OH)2→CAH gel

[0035] Enhance later strength: The generated CSH and CAH gels fill the gaps in the ettringite skeleton and improve density (strength can reach over 10 MPa after 28 days).

[0036] Reduce porosity: The spherical particles of fly ash (particle size 0.5-300μm) optimize the particle grading through the micro-aggregate effect and reduce the proportion of capillary pores.

[0037] High temperature resistance and chemical stability of silica alumina

[0038] Bauxite component (Al2O360%-85%): forms a stable phase (such as diaspore) at high temperature, improving the refractoriness of the material (refractory ≥1780℃).

[0039] Synergistic with ettringite: The microcrystalline nucleus effect of silica alumina accelerates the directional growth of ettringite, while its high aluminum content inhibits the expansion damage caused by sulfate attack.

[0040] 3. Alkalinity Control and Regeneration Mechanism of Excipient B

[0041] Alkali activation of calcium hydroxide

[0042] Maintain a high pH environment: The Ca(OH)2 in auxiliary material B provides alkaline conditions (pH>12), continuously stimulating the pozzolanic activity of fly ash and silica alumina, and promoting long-term strength growth.

[0043] Dynamic repair ability: After the material is damaged by pressure, the unreacted Ca(OH)2 and free water will regenerate into ettringite, restoring some strength (regeneration strength characteristics).

[0044] 4. Synergistic Optimization of Dual Aggregate System

[0045] Coarse and fine aggregate gradation design

[0046] Coarse aggregate (silica alumina): Silica alumina particles with a particle size of 0.1-5 mm form the main skeleton and reduce slurry shrinkage.

[0047] Fine aggregate (fly ash): fills the gaps between coarse aggregates and forms a dense network at the "micron-nano" level together with ettringite, improving impermeability (chloride ion diffusion coefficient is reduced by 50%).

[0048] The performance of this high-water material is supported by the synergistic effect of multiple components: sulfoaluminate cement and auxiliary material A form an ettringite skeleton to provide early strength; fly ash and silica alumina optimize long-term performance through pozzolanic effect and filling effect; the alkaline environment of auxiliary material B stimulates activity and achieves self-repair.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1) By adding various auxiliary materials such as magnesium aluminum silicate and calcium hydroxide to the main material, the hydration time of the single slurry can be changed, and the initial setting time of the mixed slurry can be controlled within 2-30 minutes. At the same time, the initial setting time of the mixed slurry can be adjusted as needed, solving the problem of the single product of existing high-water-content materials or ultra-high-water-content materials;

[0051] 2) By designing the proportion of ingredients, the final strength can be greatly improved to 4-12MPa, and up to 15MPa, solving the problem of low final strength after mixing and stirring the existing high-water-content material or ultra-high-water-content material slurry;

[0052] 3) The fly ash is utilized as a resource, the problem of environmental pollution is solved, its processing efficiency is improved, waste is turned into treasure, and its resource utilization is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a curve diagram of the strength change of the sample of Example 1 of the present invention within 28 days of demolding. DETAILED DESCRIPTION

[0054] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0055] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the specific embodiments required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some implementation methods of the present invention. For ordinary technicians in this field, other specific embodiments can be obtained based on these specific embodiments without paying any creative work.

[0056] The components of the embodiments of the present invention generally described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the specific embodiments is not intended to limit the scope of the claimed invention, but is merely representative of selected embodiments of the present invention.

[0057] The double-layer laboratory agitator used in Examples 1-4 below is model ZCX700, manufactured by Shandong Xihao Machinery Equipment Co., Ltd. The mesh size is 20-60 mesh and is replaceable. The fly ash used is from a power plant, and its chemical composition and physical properties meet relevant standards. The fly ash particles are mainly composed of spherical glass microspheres, spongy glass, and unburned carbon particles, with a particle diameter ranging from 0.5 to 300 μm and a porosity of 50% to 80%. The density is 1.9 to 2.9 g / cm 3, bulk density 0.53~1.26g / cm 3 , specific surface area 800~19,500cm 2 / g, main components: SiO2 (40% ~ 65%), Al2O3 (15% ~ 30%), Fe2O3 (5% ~ 15%), containing a small amount of CaO, MgO, SO3 and other impurities.

[0058] Silica alumina particles are hard and have a density of 3.9-4.0 g / cm 3 , Mohs hardness 1-3, white, off-white or brownish yellow (due to iron impurities). Mainly composed of hydrated aluminum oxide minerals, such as diaspore (Al2O3·H2O) and gibbsite (Al2O3·3H2O), the main component Al2O3 content is 60%-85%, with impurities such as Fe2O3, SiO2, TiO2, etc.

[0059] The addition of fly ash can improve the strength and durability of high-water materials while reducing costs. Sulphoaluminate cement, including 725 cement, 525 cement or 425 cement, are all commercially available products of Xingfen Building Materials Company.

[0060] Example 1

[0061] A method for preparing a fly ash-cement mixed dual-aggregate high-water material comprises the following steps:

[0062] 1) Composition A and auxiliary material A are mixed to obtain mixture 1; composition B and auxiliary material B are mixed to obtain mixture 2; composition A comprises a mixture of fly ash and silicate; composition B comprises 725 sulphoaluminate cement; auxiliary material A comprises a mixture of anhydrous calcium sulfate and magnesium aluminum silicate; auxiliary material B comprises calcium hydroxide; the weights of composition A and composition B are 130 g and 65 g, respectively. The weights of fly ash and bauxite in composition A are 70 g and 60 g, respectively. The weight of magnesium aluminum silicate is 8.125 g. The weight of anhydrous calcium sulfate is 16.25 g. The weight of calcium hydroxide is 65 / 7 g.

[0063] 2) Mixture 1 and mixture 2 were separately mixed with water. In mixture 1, the mass ratio of water to material A was 1.0; in mixture 2, the mass ratio of water to material B was 3.0. The water temperature was 23° C. Mixture 1 and mixture 2 were respectively added to the upper and lower tanks of a double-layer laboratory stirrer. After stirring evenly, the partition of the upper tank was removed to allow mixture 1 to enter mixture 2 in the lower tank through the screen and continue mixing and stirring to obtain a mixture.

[0064] 3) Pour the mixture into a mold, let it stand, and solidify before demolding to obtain a fly ash-cement dual-aggregate high-water-density material sample. During the molding process, vibration or compaction can be used to increase the density and strength of the high-water-density material.

[0065] The prepared high-water material samples were subjected to compressive strength tests to ensure that they met the requirements of relevant standards. Durability tests were carried out, including performance evaluations such as impermeability and resistance to freeze-thaw cycles. The construction performance of the high-water material was tested, including the determination of indicators such as the fluidity of the slurry and the setting time. Under standard laboratory test conditions (water-cement ratio of 1.5:1), the strength growth of the high-water material is as follows: the compressive strength can reach 2.1MPa within 2 hours. The compressive strength can reach 5.6MPa after 24 hours. The compressive strength can reach 10.36MPa after 7 days. The compressive strength can reach 10.82MPa after 28 days. This shows that the strength in 1 day reaches more than 50% of the final strength, and the strength in 7 days can reach more than 90% of the final strength.

[0066] Example 2

[0067] A method for preparing a fly ash-cement mixed dual-aggregate high-water material comprises the following steps:

[0068] 1) Composition A and auxiliary material A are mixed to obtain mixture 1; composition B and auxiliary material B are mixed to obtain mixture 2; composition A comprises a mixture of fly ash and silica alumina; composition B comprises a mixture of 525 sulphoaluminate cement and 425 sulphoaluminate cement in a ratio of 1:1; auxiliary material A comprises a mixture of anhydrous calcium sulfate and magnesium aluminum silicate; auxiliary material B comprises calcium hydroxide; the weights of composition A and composition B are 195 g and 65 g, respectively. The weights of fly ash and bauxite in composition A are 105 g and 90 g, respectively. The weight of magnesium aluminum silicate is 12.1875 g. The weight of anhydrous calcium sulfate is 24.375 g. The weight of calcium hydroxide is 65 / 7 (g).

[0069] 2) Mixture 1 and mixture 2 were separately mixed with water. In mixture 1, the mass ratio of water to material A was 3.0; in mixture 2, the mass ratio of water to material B was 1.0. The water temperature was 26° C. Mixture 1 and mixture 2 were respectively added to the upper and lower tanks of a double-layer laboratory stirrer. After stirring evenly, the partition of the upper tank was removed to allow mixture 1 to enter mixture 2 in the lower tank through the screen and continue mixing and stirring to obtain a mixture.

[0070] 3) Pour the mixture into a mold, let it stand, and solidify before demolding to obtain a fly ash-cement dual-aggregate high-water-density material sample. During the molding process, vibration or compaction can be used to increase the density and strength of the high-water-density material.

[0071] The prepared high-water-content materials were subjected to compressive strength tests to ensure that they met the requirements of relevant standards. Durability tests were conducted, including performance evaluations such as impermeability and resistance to freeze-thaw cycles. The construction performance of high-water-content materials was tested, including the determination of indicators such as the fluidity of the slurry and the setting time. Under standard laboratory test conditions (water-cement ratio of 1.5:1), the strength growth of high-water-content materials is as follows: the compressive strength can reach 1.6MPa within 2 hours. The compressive strength can reach 4.2MPa after 24 hours. The compressive strength can reach 9.73MPa after 7 days. The compressive strength can reach 10.05MPa after 28 days. This shows that the strength in 1 day reaches more than 50% of the final strength, and the strength in 7 days can reach more than 90% of the final strength.

[0072] Example 3

[0073] A method for preparing a fly ash-cement mixed dual-aggregate high-water material comprises the following steps:

[0074] 1) Composition A and auxiliary material A are mixed to obtain mixture 1; composition B and auxiliary material B are mixed to obtain mixture 2; composition A comprises a mixture of fly ash and silica alumina; composition B comprises a mixture of 525 sulphoaluminate cement and 425 sulphoaluminate cement in a ratio of 1:1; auxiliary material A comprises a mixture of anhydrous calcium sulfate and magnesium aluminum silicate; auxiliary material B comprises calcium hydroxide; the weights of composition A and composition B are 130 g and 65 g, respectively. The weights of fly ash and bauxite in composition A are 91 g and 39 g, respectively. The weight of magnesium aluminum silicate is 8.125 g. The weight of anhydrous calcium sulfate is 16.25 g. The weight of calcium hydroxide is 65 / 7 g.

[0075] 2) Mixture 1 and mixture 2 were separately mixed with water. In mixture 1, the mass ratio of water to material A was 2.0; in mixture 2, the mass ratio of water to material B was 2.0. The water temperature was 20° C. Mixture 1 and mixture 2 were respectively added to the upper and lower tanks of a double-layer laboratory stirrer. After stirring evenly, the partition of the upper tank was removed to allow mixture 1 to enter mixture 2 in the lower tank through the screen and continue mixing and stirring to obtain a mixture;

[0076] The mixture is poured into a mold, allowed to stand, and solidified before demoulding to obtain a fly ash-cement mixed dual aggregate high-water-density material sample. During the molding process, the density and strength of the high-water-density material can be improved by vibration or compaction.

[0077] The prepared high-water-content materials are subjected to compressive strength tests to ensure that they meet the requirements of relevant standards. Durability tests are carried out, including performance evaluations such as impermeability and resistance to freeze-thaw cycles. The construction performance of high-water-content materials is tested, including the determination of indicators such as the fluidity of the slurry and the setting time. Under standard laboratory test conditions (water-cement ratio of 1.5:1), the strength growth of high-water-content materials is as follows: the compressive strength can reach 1.8MPa within 2 hours. The compressive strength can reach 5.0MPa after 24 hours. The compressive strength can reach 9.78MPa after 7 days. The compressive strength can reach 9.98MPa after 28 days. This shows that the strength in 1 day reaches more than 50% of the final strength, and the strength in 7 days can reach more than 90% of the final strength.

[0078] Example 4

[0079] A method for preparing a fly ash-cement mixed dual-aggregate high-water material comprises the following steps:

[0080] 1) Composition A and auxiliary material A are mixed to obtain mixture 1; composition B and auxiliary material B are mixed to obtain mixture 2; composition A comprises a mixture of fly ash and silica alumina; composition B comprises a mixture of 525 sulphoaluminate cement and 425 sulphoaluminate cement in a ratio of 1:1; auxiliary material A comprises a mixture of anhydrous calcium sulfate and magnesium aluminum silicate; auxiliary material B comprises calcium hydroxide; the weights of composition A and composition B are 130 g and 65 g, respectively. The weights of fly ash and bauxite in composition A are 70 g and 60 g, respectively. The weight of magnesium aluminum silicate is 8.125 g. The weight of anhydrous calcium sulfate is 26 g. The weight of calcium hydroxide is 65 / 7 (g).

[0081] 2) Mixture 1 and mixture 2 were separately mixed with water. In mixture 1, the mass ratio of water to material A was 1.6; in mixture 2, the mass ratio of water to material B was 2.4. The water temperature was 13° C. Mixture 1 and mixture 2 were respectively added to the upper and lower tanks of a double-layer laboratory stirrer. After stirring evenly, the partition of the upper tank was removed to allow mixture 1 to enter mixture 2 in the lower tank through the screen and continue mixing and stirring to obtain a mixture.

[0082] 3) Pour the mixture into a mold, let it stand, and solidify before demolding to obtain a fly ash-cement dual-aggregate high-water-density material sample. During the molding process, vibration or compaction can be used to increase the density and strength of the high-water-density material.

[0083] The prepared high-water-content materials were subjected to compressive strength tests to ensure that they met the requirements of relevant standards. Durability tests were conducted, including performance evaluations such as impermeability and resistance to freeze-thaw cycles. The construction performance of high-water-content materials was tested, including the determination of indicators such as the fluidity of the slurry and the setting time. Under standard laboratory test conditions (water-cement ratio of 1.5:1), the strength growth of high-water-content materials is as follows: the compressive strength can reach 2.0MPa within 2 hours. The compressive strength can reach 4.9MPa after 24 hours. The compressive strength can reach 19.54MPa after 7 days. The compressive strength can reach 10.51MPa after 28 days. This shows that the strength in 1 day reaches more than 50% of the final strength, and the strength in 7 days can reach more than 90% of the final strength.

[0084] Comparative Example

[0085] A commercially available high-water-density material consists of two ingredients, A and B. Material A is primarily composed of bauxite and gypsum, each refined independently, and supplemented with a composite super-retarding dispersant (also known as admixture AA). Material B is a blend of gypsum and lime, combined with a small amount of a composite accelerating setting agent (also known as admixture BB). When materials A and B are used in a 1:1 ratio, and the water volume is between 95% and 97%, the compressive strength of the super-high-water-density material can be adjusted based on the water volume and admixture formulation. The initial setting time can be adjusted between 8 and 90 minutes, and its 28-day strength can reach 0.66-1.50 MPa. A single slurry of the two main ingredients, A and B, can remain unset for 30-40 hours. After mixing, the material rapidly hydrates and solidifies. Adjusting the admixture formulation can alter the material's properties, with a water-cement ratio as high as 11:1.

[0086] The following is a comparative table of performance tests of the high-quality water obtained in Examples 1-4 of the present invention and the comparative example, see Table 1.

[0087] Table 1

[0088]

[0089] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A fly ash mixed with cement double aggregate high water material, characterized in that: It is composed of composition A, composition B, auxiliary material A and auxiliary material B, wherein: The components in composition A are a mixture of fly ash and silica alumina; Composition B is sulphoaluminate cement, comprising any one of 725 cement, 525 cement or 425 cement, or a combination of any two or more thereof; The auxiliary material component A is a mixture of anhydrous calcium sulfate and magnesium aluminum silicate; The auxiliary material B component is calcium hydroxide.

2. The fly ash-cement-doped dual-aggregate high-water material according to claim 1, characterized in that: The weight ratio of the composition A to the composition B is (3-2):

1.

3. The fly ash-cement-doped dual-aggregate high-water material according to claim 1, characterized in that: The weight ratio of the fly ash to silica alumina is 7:(6-3).

4. The fly ash-cement-doped dual-aggregate high-water material according to claim 1, characterized in that: The fly ash particles are mainly composed of spherical glass beads, sponge-like glass and unburned carbon particles, with a particle diameter range of 0.5 to 300 μm, a porosity of 50% to 80%, and a density of 1.9 to 2.9 g / cm 3 , bulk density 0.53~1.26g / cm 3 , specific surface area 800~19,500cm 2 / g, the main components are: SiO2 40%~65%, Al2O3 15%~30%, Fe2O3 5%~15%, containing a small amount of CaO, MgO, SO3 impurities.

5. The fly ash-cement-doped dual-aggregate high-water material according to claim 1, characterized in that: The silica alumina density is 3.9-4.0 g / cm 3 , Mohs hardness 1 to 3, white, grayish white or brownish yellow, mainly composed of hydrated alumina minerals, the main component Al2O3 content is 60% to 85%, and the rest are Fe2O3, SiO2, TiO2 impurities.

6. The fly ash-cement-doped dual-aggregate high-water material according to claim 1, characterized in that: The weight ratio of anhydrous calcium sulfate to material A in the auxiliary material A is 1:8-5, and the weight ratio of magnesium aluminum silicate to material A is 1:

16.

7. The fly ash-cement-doped dual-aggregate high-water material according to claim 1, characterized in that: The weight ratio of the auxiliary material B to the composition B is 1:

7.

8. The method for preparing the fly ash-cement-doped dual-aggregate high-water material according to any one of claims 1 to 7, characterized in that: The specific steps include: 1) Mixing composition A and auxiliary material A to obtain mixture 1; mixing composition B and auxiliary material B to obtain mixture 2; 2) Adding water to the mixture 1 and mixture 2 separately, mixing them, and adding them to the upper tank and lower tank of a double-layer laboratory mixer respectively. After stirring evenly, pulling out the partition of the upper tank to allow mixture 1 to enter the mixture 2 in the lower tank through a screen and continue mixing and stirring to obtain a mixture; 3) Pour the mixture into a mold, let it stand, and after solidification and demolding, obtain a fly ash-cement-doped dual-aggregate high-water material.

9. The method for preparing a fly ash-cement-doped dual-aggregate high-water material according to claim 8, characterized in that: In the first mixture, the mass ratio of water to material A is 1.0-3.0; in the second mixture, the mass ratio of water to material B is 1.0-3.0, and the temperature of water is 12-28°C.

10. The method for preparing a fly ash-cement-doped dual-aggregate high-water material according to claim 8, characterized in that: The specification model of the upper and lower double-layer laboratory stirrer is ZCX700, and the screen aperture is 20 mesh-60 mesh and is replaceable.

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