Solid waste concrete and preparation method thereof

Abstract

The present application relates to the field of concrete technology, and specifically discloses a solid waste concrete and a preparation method thereof. The mixture of the solid waste concrete includes the following components in parts by weight: 300-320 parts of cement, 80-100 parts of solid waste mineral admixture, 1150-1250 parts of coarse aggregate, 580-620 parts of iron-loaded machine-made sand, 200-240 parts of modified mineral wool fiber, 156-160 parts of water, and 3.8-4.2 parts of polycarboxylate water reducer. The present application uses modified mineral wool fiber and loads iron sulfate in clay brick machine-made sand to obtain iron-loaded machine-made sand, so that the water-reducing effect of the polycarboxylate water reducer can be more fully exerted, and the water absorption rate of the machine-made sand is reduced, so that the slurry of the concrete mixture has better fluidity, which is beneficial to the construction of the concrete mixture.

Description

Technical Field

[0001] The present application relates to the field of concrete technology, and more specifically, to a solid waste concrete and a preparation method thereof. Background Art

[0002] Solid waste, also known as solid waste (or simply solid waste), refers to solid and semi-solid waste materials generated by humans in production, consumption, daily life, and other activities. Traditional methods of solid waste disposal, such as landfill or incineration, can cause environmental pollution. Therefore, more environmentally friendly methods are needed for solid waste disposal. Currently, processing solid waste as raw material for concrete production is a promising disposal method.

[0003] In related art, a solid waste concrete mix includes the following components by weight: 300 kg of cement, 80 kg of solid waste mineral admixture, 1150 kg of coarse aggregate, 780 kg of manufactured sand, 156 kg of water, and 3.8 kg of polycarboxylate superplasticizer. The solid waste mineral admixture is fly ash, and the manufactured sand is the product of crushing discarded clay bricks.

[0004] Regarding the above-mentioned related technologies, the inventors believe that the material of clay bricks easily absorbs water and has a strong adsorption effect on polycarboxylate water-reducing agents, which makes it difficult for polycarboxylate water-reducing agents to fully exert their water-reducing effect, thereby reducing the free water in the cement slurry. Therefore, the above-mentioned concrete mixture is prone to insufficient slurry fluidity, which is not conducive to the construction of the concrete mixture. Summary of the Invention

[0005] In the related art, concrete mixtures are prone to insufficient slurry fluidity, which is not conducive to the construction of the concrete mixture. In order to improve this defect, the present application provides a solid waste concrete and a preparation method thereof.

[0006] In a first aspect, the present application provides a solid waste concrete, which adopts the following technical solution:

[0007] A solid waste concrete, wherein the mixture of the solid waste concrete comprises the following components in parts by weight: 300-320 parts of cement, 80-100 parts of solid waste mineral admixture, 1150-1250 parts of coarse aggregate, 580-620 parts of iron-loaded machine-made sand, 200-240 parts of modified mineral wool fibers, 156-160 parts of water, and 3.8-4.2 parts of a polycarboxylate water-reducing agent, wherein the modified mineral wool fibers are mineral wool fibers having an acrylic polymer grafted on their surfaces, the iron-loaded machine-made sand is obtained by immersing clay brick machine-made sand in a machine-made sand modifying liquid and then drying it, and the solute in the machine-made sand modifying liquid comprises ferric sulfate.

[0008] By adopting the above technical solution, the present application replaces part of the machine-made sand with modified mineral wool fiber, and loads iron sulfate in the clay brick machine-made sand to obtain iron-loaded machine-made sand. In the concrete mixture of the present application, the polyacrylic acid group on the surface of the modified mineral wool fiber has a similar structure to the main chain of the polycarboxylate water-reducer. Both carry a large number of carboxyl groups, and the amount of modified mineral wool fiber used is much greater than the amount of polycarboxylate water-reducer used. Therefore, the modified mineral wool fiber is more easily adsorbed on the surface of the machine-made sand than the polycarboxylate water-reducer, thereby occupying the adsorption sites on the surface of the machine-made sand, reducing the probability of adsorption between the polycarboxylate water-reducer and the machine-made sand, and allowing the water-reducing effect of the polycarboxylate water-reducer to be more fully exerted. At the same time, the iron sulfate in the iron-loaded machine-made sand can react with the calcium hydroxide in the concrete mixture to produce iron hydroxide and calcium sulfate. The iron hydroxide and calcium sulfate can play a certain filling role in the pore structure of the machine-made sand, and the calcium sulfate can further participate in the formation of calcium aluminate, which helps to reduce the water absorption rate of the machine-made sand. Since the water-reducing effect of the polycarboxylate water-reducing agent can be more fully exerted and the water absorption rate of the machine-made sand is reduced, the slurry in the concrete mixture of the present application has good fluidity, which is beneficial to the construction of the concrete mixture.

[0009] Preferably, the solid waste mineral admixture is fly ash with a free calcium oxide content of 6-10%.

[0010] By adopting the above technical solution, the present application optimizes the free calcium oxide content of fly ash. The free calcium oxide in fly ash hydrates rapidly, generating calcium hydroxide faster than cement, thereby increasing the calcium hydroxide content in the cement slurry during the initial hydration phase. Increasing the calcium hydroxide content promotes the conversion of ferric sulfate in iron-loaded manufactured sand to ferric hydroxide, thereby helping to reduce the water absorption of the manufactured sand and improving the fluidity of the slurry in the concrete mixture.

[0011] Preferably, the modified mineral wool fiber is prepared according to the following method:

[0012] (1) washing the mineral wool fiber and drying it for later use; mixing ethanol, water and vinyl triethoxysilane to obtain a silane modified solution for later use; adding acrylic acid to water to obtain a monomer dispersion for later use;

[0013] (2) mixing the mineral wool fiber with the silane modification liquid, stirring and heating at 65°C for 4 hours, and then filtering and drying to obtain the vinyl modified fiber;

[0014] (3) The vinyl modified fiber, monomer dispersion and initiator are mixed, heated at 80° C. for 5 h, and then filtered and dried to obtain modified mineral wool fiber.

[0015] By adopting the above technical solution, the present application first uses a silane coupling agent to graft-modify the mineral wool fiber, grafting vinyl onto the surface of the mineral wool fiber, and then under the action of an initiator, heating to copolymerize acrylic acid and vinyl to obtain a modified mineral wool fiber with polyacrylic acid groups grafted on the surface.

[0016] Preferably, the molar ratio of acrylic acid to vinyltriethoxysilane is (4-8):1.

[0017] By adopting the above technical solution, the molar ratio between acrylic acid and silane coupling agent is optimized, which is beneficial to improving the adsorption effect of the polyacrylic acid group on the surface of the modified mineral wool fiber on the machine-made sand.

[0018] Preferably, the iron-loaded machine-made sand is prepared according to the following method:

[0019] (1) crushing and screening discarded clay bricks to obtain clay brick machine-made sand; adding ferric sulfate to water to obtain machine-made sand modified liquid;

[0020] (2) Clay brick machine-made sand and machine-made sand modifying liquid are mixed in a weight ratio of 1:4, and after standing for a period of time, the machine-made sand obtained by filtration is filtered and dried to obtain iron-loaded machine-made sand.

[0021] By adopting the above technical solution, the present application adds clay brick machine-made sand into machine-made sand modifying liquid for immersion, allows the clay brick machine-made sand to absorb a certain amount of iron salt by standing, and then filters and dries to obtain iron-loaded machine-made sand.

[0022] Preferably, the mass fraction of ferric sulfate in the machine-made sand modifying fluid is 6-8%.

[0023] By adopting the above technical solution, this application optimizes the mass fraction of iron sulfate in the sand-modifying fluid. Since the sand will carry away some of the sand-modifying fluid during filtration and recovery, increasing the mass fraction of iron sulfate in the sand-modifying fluid can increase the total amount of iron sulfate carried by the sand, facilitating a full reaction between the iron sulfate and calcium hydroxide, thereby improving the sealing effect on the sand's pore structure and reducing its water absorption.

[0024] Preferably, when preparing the machine-made sand modifying fluid, methoxy polyether and iron salt are added into water and dissolved.

[0025] By adopting the above technical solution, the side chain structure of methoxy polyether is similar to that of polycarboxylate water-reducing agent, and it can replace the side chain of polycarboxylate water-reducing agent to adsorb with machine-made sand, which helps to reduce the adsorption of machine-made sand on polycarboxylate water-reducing agent, thereby improving the fluidity of concrete slurry.

[0026] Preferably, the average molecular weight of the methoxy polyether is 600-1000.

[0027] By adopting the above technical solution, the molecular weight range of methoxy polyether is optimized, which is beneficial to improving the adsorption effect of clay bricks on methoxy polyether.

[0028] Preferably, the amount of the methoxy polyether is 3.2-4.8% by weight of the clay brick machine-made sand.

[0029] By adopting the above technical solution, the dosage of methoxy polyether is optimized, which helps to make the clay brick machine-made sand fully adsorb the methoxy polyether, thereby reducing the adsorption amount of the clay brick machine-made sand on the polycarboxylate water reducer.

[0030] In a second aspect, the present application provides a method for preparing solid waste concrete, which adopts the following technical solution.

[0031] A method for preparing solid waste concrete comprises the following steps:

[0032] (1) mixing cement, solid waste mineral admixture, coarse aggregate, iron-loaded machine-made sand, and modified mineral wool fiber to obtain a dry material; mixing a polycarboxylate water reducer and water to obtain a water reducer solution;

[0033] (2) dry-mixing the dry materials, then adding the water-reducing agent solution to the dry materials and continuing to stir to obtain a concrete mixture;

[0034] (3) The concrete mixture is poured into a mold for curing, and solid waste concrete is obtained after reaching a specified age.

[0035] By adopting the above technical solution, the present application first prepares dry material and water reducer solution separately, then mixes the dry material and water reducer solution and further stirs them to obtain a concrete mixture, and then uses the obtained concrete mixture to prepare solid waste concrete.

[0036] In summary, this application has the following beneficial effects:

[0037] 1. This application replaces part of the machine-made sand in the related art with modified mineral wool fiber, and loads iron sulfate in the clay brick machine-made sand to obtain iron-loaded machine-made sand, so that the water-reducing effect of the polycarboxylic acid water-reducing agent can be more fully exerted, and the water absorption rate of the machine-made sand is reduced. Therefore, the slurry in the concrete mixture of this application has good fluidity, which is conducive to the construction of the concrete mixture.

[0038] 2. In this application, fly ash with a free calcium oxide content of 6-10% is preferably used as the solid waste mineral admixture. Free calcium oxide is beneficial to promote the conversion of iron sulfate in iron-loaded machine-made sand to iron hydroxide, thereby helping to reduce the water absorption rate of machine-made sand and improve the fluidity of the slurry in the concrete mixture. DETAILED DESCRIPTION

[0039] The present application is further described in detail below with reference to the Examples, Preparation Examples and Comparative Examples. The raw materials involved in the present application can all be obtained commercially.

[0040] Preparation example of modified mineral wool fiber

[0041] The following is an explanation using Preparation Example 1.

[0042] Preparation Example 1

[0043] In this preparation example, the modified mineral wool fiber was prepared according to the following method:

[0044] (1) washing the mineral wool fibers and drying them for later use; mixing ethanol, water, and vinyltriethoxysilane to obtain a silane-modified solution for later use; adding acrylic acid to water to obtain a monomer dispersion solution having a mass fraction of 20% acrylic acid for later use; in this step, the weight ratio of ethanol to water is 1:2, the mass fraction of vinyltriethoxysilane in the silane-modified solution is 5%, and the molar ratio of acrylic acid to vinyltriethoxysilane (hereinafter referred to as the monomer molar ratio) is 1.5:1;

[0045] (2) mixing the mineral wool fiber with the silane modification liquid, stirring and heating at 60°C for 3 hours, and then filtering and drying to obtain the vinyl modified fiber;

[0046] (3) The vinyl modified fiber, monomer dispersion and initiator are mixed, heated at 80° C. for 5 h, and then filtered and dried to obtain modified mineral wool fiber.

[0047] As shown in Table 1, the difference between Preparation Examples 1-5 is the different molar ratios of monomers.

[0048] Table 1 Monomer molar ratio

[0049] sample Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Preparation Example 5 Monomer molar ratio 1.5:1 2.5:1 4:1 6:1 8:1

[0050] Preparation example of iron-loaded machine-made sand

[0051] The following is an illustration of Preparation Example 6.

[0052] Preparation Example 6

[0053] In this preparation example, iron-loaded machine-made sand was prepared according to the following method:

[0054] (1) crushing and screening discarded clay bricks to obtain clay brick machine-made sand; adding ferric sulfate to water to obtain a machine-made sand modification liquid with a mass fraction of ferric sulfate of 4%;

[0055] (2) Clay brick machine-made sand and machine-made sand modifying liquid were mixed in a weight ratio of 1:4, allowed to stand for 6 hours, and then filtered. The machine-made sand obtained by filtration was dried to obtain iron-loaded machine-made sand that met the requirements of GB / T 14684-2022 Construction Sand for Zone 2 machine-made sand.

[0056] As shown in Table 2, the difference between Preparation Examples 6-10 is the different mass fractions of iron sulfate in the machine-made sand modifying liquid.

[0057] Table 2 Mass fraction of ferrous sulfate

[0058] sample Preparation Example 6 Preparation Example 7 Preparation Example 8 Preparation Example 9 Preparation Example 10 Iron sulfate mass fraction / % 4 5 6 7 8

[0059] Preparation Example 11

[0060] The difference between this preparation example and preparation example 10 is that when preparing the iron salt aqueous solution, methoxy polyether and iron salt are added into water together for dissolution, the average molecular weight of methoxy polyether is 1200, and the amount of methoxy polyether used is 1.6% of the weight of clay brick machine-made sand.

[0061] As shown in Table 3, the difference between Preparation Examples 11-15 is that the average molecular weight of the methoxy polyether is different.

[0062] Table 3 Average molecular weight of methoxy polyether

[0063]

[0064] As shown in Table 4, the difference between Preparation Examples 15-19 is that the percentage of the amount of methoxy polyether used in the weight of the clay brick machine-made sand (hereinafter referred to as the methoxy polyether ratio) is different.

[0065] Table 4 Proportion of methoxy polyether

[0066] sample Preparation Example 15 Preparation Example 16 Preparation Example 17 Preparation Example 18 Preparation Example 19 Methoxy polyether ratio 1.6 2.4 3.2 4.0 4.8

[0067] Example

[0068] Examples 1-5

[0069] The following description will be made using Example 1 as an example.

[0070] Example 1

[0071] In this example, the solid waste concrete mixture is composed of the following raw materials: 300 kg of cement, 80 kg of solid waste mineral admixture, 1150 kg of coarse aggregate, 580 kg of iron-loaded machine-made sand from Preparation Example 6, 200 kg of modified mineral wool fiber from Preparation Example 1, 156 kg of water, and 3.8 kg of polycarboxylate water reducer. The cement is P.O5 2.5 Portland cement, the solid waste mineral admixture is fly ash with a free calcium oxide content of 2%, and the coarse aggregate is 5-31.5 mm continuously graded natural crushed stone. The polycarboxylate water reducer is tested according to the test method described in "GB8076-2008 Concrete Admixtures" and has a water reduction rate of 31.7% when added at a concentration of 1% of the base cement weight. In this example, the solid waste concrete is prepared according to the following steps:

[0072] (1) mixing cement, solid waste mineral admixture, coarse aggregate, iron-loaded machine-made sand, and modified mineral wool fiber to obtain a dry material; mixing a polycarboxylate water reducer and water to obtain a water reducer solution;

[0073] (2) dry-mixing the dry materials, then adding the water-reducing agent solution to the dry materials and continuing to stir to obtain a concrete mixture;

[0074] (3) The concrete mixture is poured into a mold for curing, and solid waste concrete is obtained after reaching a specified age.

[0075] As shown in Table 5, the differences between Examples 1-5 are mainly due to the different raw material ratios of the solid waste concrete mixture.

[0076] Table 5 Raw material ratio of solid waste concrete mixture

[0077]

[0078] Examples 6-10

[0079] As shown in Table 6, the difference between Examples 6-10 and Example 5 is that the free calcium oxide content of the fly ash is different.

[0080] Table 6 Free calcium oxide content

[0081] sample Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Free calcium oxide content / % 2 3 4 6 8 10

[0082] Examples 11-14

[0083] As shown in Table 7, Examples 11-14 differ from Example 10 in that the preparation examples of the modified mineral wool fibers are different.

[0084] Table 7 Preparation example of modified mineral wool fiber

[0085] sample Preparation Example Example 10 Preparation Example 1 Example 11 Preparation Example 2 Example 12 Preparation Example 3 Example 13 Preparation Example 4 Example 14 Preparation Example 5

[0086] Examples 14-27

[0087] As shown in Table 8, the difference between Examples 14-27 is that the preparation examples of iron-loaded machine-made sand are different.

[0088] Table 8 Preparation example of iron-loaded machine-made sand

[0089] sample Preparation Example sample Preparation Example Example 14 Preparation Example 6 Example 21 Preparation Example 13 Example 15 Preparation Example 7 Example 22 Preparation Example 14 Example 16 Preparation Example 8 Example 23 Preparation Example 15 Example 17 Preparation Example 9 Example 24 Preparation Example 16 Example 18 Preparation Example 10 Example 25 Preparation Example 17 Example 19 Preparation Example 11 Example 26 Preparation Example 18 Example 20 Preparation Example 12 Example 27 Preparation Example 19

[0090] Comparative Example

[0091] Comparative Example 1

[0092] This example provides a solid waste concrete mixture composed of the following raw materials: 300 kg of cement, 80 kg of solid waste mineral admixture, 1150 kg of coarse aggregate, 780 kg of machine-made sand, 156 kg of water, and 3.8 kg of polycarboxylate water reducer. The cement is PO52.5 Portland cement, the solid waste mineral admixture is fly ash with a free calcium oxide content of 2%, the coarse aggregate is 5-31.5 mm continuously graded natural crushed stone, and the machine-made sand is the crushed product of discarded clay bricks, the source of which is the same as in Preparation Example 6. The polycarboxylate water reducer was tested according to the test method described in "GB8076-2008 Concrete Admixtures." When added at a concentration of 1% by weight of the base cement, the water reduction rate was 31.7%.

[0093] In this embodiment, solid waste concrete is prepared according to the following steps:

[0094] (1) mixing cement, solid waste mineral admixture, coarse aggregate, and machine-made sand to obtain a dry material; mixing a polycarboxylate water reducer and water to obtain a water reducer solution;

[0095] (2) dry-mixing the dry materials, then adding the water-reducing agent solution to the dry materials and continuing to stir to obtain a concrete mixture;

[0096] (3) The concrete mixture is poured into a mold for curing, and solid waste concrete is obtained after reaching a specified age.

[0097] Comparative Example 2

[0098] The difference between this comparative example and Example 1 is that the modified mineral wool fiber is replaced by iron-loaded machine-made sand.

[0099] Comparative Example 3

[0100] The difference between this comparative example and Example 1 is that the iron-loaded machine-made sand is replaced by the machine-made sand of Comparative Example 1.

[0101] Performance testing methods

[0102] Referring to the method described in "GB / T 50080-2016 Standard for Test Methods for Performance of Ordinary Concrete Mixtures", the expansion of the concrete mixtures of Examples 1-27 and Comparative Examples 1-3 was tested, and then the ratio of the expansion of the concrete of Examples 1-27 and Comparative Examples 1-3 to the expansion of the concrete of Comparative Example 1 was calculated. This ratio was defined as the relative expansion. The results are shown in Table 9.

[0103] Table 9 Relative expansion

[0104] sample Relative expansion / % sample Relative expansion / % Example 1 112.4 Example 16 125.6 Example 2 113.5 Example 17 126.3 Example 3 113.8 Example 18 126.8 Example 4 114.6 Example 19 128.5 Example 5 115.2 Example 20 129.9 Example 6 115.7 Example 21 130.5 Example 7 116.5 Example 22 131.2 Example 8 117.9 Example 23 131.7 Example 9 119.2 Example 24 132.6 Example 10 119.8 Example 25 133.8 Example 11 120.7 Example 26 135.1 Example 12 121.5 Example 27 136.4 Example 13 122.8 Comparative Example 1 100.0 Example 14 124.4 Comparative Example 2 102.7 Example 15 124.9 Comparative Example 3 104.4

[0105] Combining Examples 1-5 and Comparative Example 1 and Table 9, it can be seen that the relative expansions measured in Examples 1-5 are all greater than those in Comparative Example 1, indicating that the solid waste concrete of the present application has high fluidity and relatively better construction performance.

[0106] Combining Example 1 with Comparative Examples 2-3 and Table 9, it can be seen that when modified mineral wool fibers and iron-loaded machine-made sand are not used together, the resulting concrete mixture has poor slurry fluidity, indicating that the modified mineral wool fibers and iron-loaded machine-made sand have a synergistic effect in improving the slurry fluidity of the concrete mixture. This is speculated to be because, although iron-loaded machine-made sand was used in Comparative Example 2, the polycarboxylate superplasticizer still readily adsorbed on the machine-made sand surface in the absence of modified mineral wool fibers. Although modified mineral wool fibers were used in Comparative Example 3, the absence of iron-loaded machine-made sand made it difficult to fully inhibit water absorption by the machine-made sand.

[0107] Combining Example 5 and Examples 6-10 with Table 9, it can be seen that as the free calcium oxide content of the fly ash increases, the relative expansion gradually increases. When the free calcium oxide content of the fly ash is 6-10%, the relative expansion is larger, indicating that the slurry fluidity of the concrete mixture is better within this range.

[0108] Combining Examples 10-14 with Table 9, it can be seen that increasing the amount of acrylic acid can improve the fluidity of the concrete mixture to a certain extent. When the molar ratio of acrylic acid to vinyltriethoxysilane is (4-8):1, the fluidity of the concrete mixture is better.

[0109] From Examples 14-18 and Table 9, it can be seen that increasing the concentration of ferric sulfate can improve the fluidity of the concrete mixture to a certain extent. When the mass fraction of ferric sulfate in the iron salt modifying liquid is 6-8%, the total amount of ferric sulfate carried by the machine-made sand is high, which is conducive to the full reaction of ferric sulfate with calcium hydroxide, thereby improving the sealing effect of the pore structure of the machine-made sand and reducing the water absorption rate of the machine-made sand. As a result, the fluidity of the concrete mixture is better.

[0110] Combining Examples 19-23, Example 18, and Table 9, it can be seen that the addition of methoxy polyether to the iron salt-modified liquid during the preparation of iron-loaded manufactured sand improves the fluidity of the concrete mixture slurry. This indicates that the methoxy polyether can replace the side chains of the polycarboxylate superplasticizer and adsorb to the manufactured sand, helping to reduce the adsorption of the polycarboxylate superplasticizer by the manufactured sand. When the average molecular weight of the methoxy polyether is 600-1000, the concrete mixture slurry has better fluidity.

[0111] It can be seen from Examples 23-27 and Table 9 that when the amount of methoxy polyether is 3.2-4.8% by weight of the clay brick machine-made sand, the slurry fluidity of the concrete mixture is better.

[0112] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A solid waste concrete, characterized in that: The solid waste concrete mixture comprises the following components in parts by weight: 300-320 parts of cement, 80-100 parts of solid waste mineral admixture, 1150-1250 parts of coarse aggregate, 580-620 parts of iron-loaded machine-made sand, 200-240 parts of modified mineral wool fibers, 156-160 parts of water, and 3.8-4.2 parts of a polycarboxylate superplasticizer, wherein the modified mineral wool fibers are mineral wool fibers having an acrylic polymer grafted on their surfaces, and the iron-loaded machine-made sand is obtained by immersing clay brick machine-made sand in a machine-made sand modifying solution and then drying it, wherein the solute in the machine-made sand modifying solution comprises ferric sulfate; The modified mineral wool fiber is prepared according to the following method: (1) Washing and drying the mineral wool fibers for later use; mixing ethanol, water, and vinyl triethoxysilane to obtain a silane-modified solution for later use; adding acrylic acid to water to obtain a monomer dispersion for later use; the molar ratio of acrylic acid to vinyl triethoxysilane is (4-8):1; (2) Mixing the mineral wool fiber with the silane modification liquid, stirring and heating at 65°C for 4 hours, and then filtering and drying to obtain vinyl modified fiber; (3) The vinyl modified fiber, monomer dispersion and initiator are mixed, heated at 80°C for 5 hours, and then filtered and dried to obtain modified mineral wool fiber.

2. The solid waste concrete according to claim 1, characterized in that The solid waste mineral admixture is fly ash with a free calcium oxide content of 6-10%.

3. The solid waste concrete according to claim 1, characterized in that The iron-loaded machine-made sand is prepared according to the following method: (1) Crushing and screening the discarded clay bricks to obtain clay brick machine-made sand; adding ferric sulfate into water to obtain machine-made sand modification liquid; (2) Mix the clay brick machine-made sand and the machine-made sand modifying liquid in a weight ratio of 1:4, let it stand for a period of time, and then filter it. Dry the machine-made sand obtained by filtration to obtain iron-loaded machine-made sand.

4. The solid waste concrete according to claim 3, characterized in that The mass fraction of ferric sulfate in the machine-made sand modifying liquid is 6-8%.

5. The solid waste concrete according to claim 3, characterized in that: When preparing the machine-made sand modifying fluid, methoxy polyether and iron salt are added into water and dissolved.

6. The solid waste concrete according to claim 5, characterized in that The average molecular weight of the methoxy polyether is 600-1000.

7. The solid waste concrete according to claim 6, characterized in that The dosage of the methoxy polyether is 3.2-4.8% of the weight of the clay brick machine-made sand.

8. The method for preparing solid waste concrete according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Cement, solid waste mineral admixture, coarse aggregate, iron-loaded machine-made sand, and modified mineral wool fiber are mixed to obtain a dry material; polycarboxylate water reducer and water are mixed to obtain a water reducer solution; (2) Dry mix the dry materials, then add the water reducer solution to the dry materials and continue stirring to obtain a concrete mixture; (3) The concrete mixture is poured into a mold for curing, and solid waste concrete is obtained after reaching a specified age.

Images