All-solid-waste cementing material for high-performance fluid-state solidified soil and preparation method of all-solid-waste cementing material

Abstract

The invention relates to the technical field of waste cementing materials, and discloses an all-solid waste cementing material for high-performance fluid-state solidified soil and a preparation method. The all-solid waste cementing material is prepared from the following raw materials in parts by weight: 56 to 70 parts of slag powder, 24 to 38 parts of steel slag powder, 12 to 25 parts of Portland cement clinker, 1 to 4 parts of modified cellulose, 4 to 8 parts of fly ash, 6 to 8 parts of aluminum sulfate and 2.5 to 3.3 parts of desulfurized gypsum powder. The modified cellulose contains carboxyl, imino, a large number of phenolic hydroxyl groups and other groups, can play a role in dispersing the Portland cement clinker, the slag powder, the steel slag powder and the fly ash, is beneficial to improving the mechanical property and the compressive strength of the cementing material, and is excellent in water resistance; the prepared all-solid waste cementing material has good practical application in the aspects of fluid-state solidified soil and the like.

Description

Technical Field

[0001] This invention relates to the field of waste cementitious materials technology, specifically to a fully solid waste cementitious material and its preparation method for use in high-performance fluidized solidified soil. Background Technology

[0002] Solid waste cementitious materials are mainly made from industrial waste such as slag powder and fly ash, as well as construction waste, as aggregates, and sulfates, gypsum, water glass, etc. are added as activators. The resulting building materials take into account both resource recycling and performance adaptability. They can solve the environmental problems of solid waste storage and replace traditional cementitious materials in specific scenarios. They have economic, environmental, and technological value and are widely used in fluidized solidified soil, concrete, and other fields.

[0003] Cellulose is environmentally friendly, inexpensive, and readily available. It can be used as a water-reducing agent, flocculant, and dispersant, and has important applications in solid waste cementitious materials, cement concrete, and other building materials. Patent CN112430022B discloses a foamed underground filling cementitious material for ultrafine tailings and its preparation method. Using steel slag, blast furnace slag, fly ash, gypsum, hydroxypropyl methylcellulose ether, sodium dodecyl sulfonate, and other raw materials, the prepared underground filling cementitious material exhibits good mechanical strength and other properties. However, this patent does not improve the water resistance and other properties of the cementitious material, which is detrimental to its practical application in fluidized solidified soil and other applications. Summary of the Invention

[0004] This invention solves the problems of low strength and poor water resistance of solid waste cementitious materials.

[0005] The technical solution of the present invention is: a solid waste cementitious material and its preparation method. The raw materials of the solid waste cementitious material include: 56-70 parts by weight of slag powder, 24-38 parts by weight of steel slag powder, 12-25 parts by weight of silicate cement clinker, 1-4 parts by weight of modified cellulose, 4-8 parts by weight of fly ash, 6-8 parts by weight of aluminum sulfate, and 2.5-3.3 parts by weight of desulfurized gypsum powder.

[0006] The preparation method of all-solid waste cementitious materials is as follows: (1) Add carboxymethyl cellulose, 4-dimethylaminopyridine and dicyclohexylcarbodiimide to dimethyl sulfoxide, stir and then add resveratrol. After the reaction, pour the solution into ethanol, filter and wash the filter cake with ethanol, and dry to obtain resveratrol-based cellulose.

[0007] (2) Add resveratrol-based cellulose and alkylamine to N,N-dimethylformamide, stir and react, pour the solution into ethanol, filter, wash the filter cake with ethanol, and dry to obtain modified cellulose.

[0008] (3) Add water, slag powder, steel slag powder, silicate cement clinker, modified cellulose and fly ash to the mixer, stir and disperse, add aluminum sulfate and desulfurized gypsum powder, stir, pour the material into the mold, demold after molding, and cure to obtain solid waste cementitious material.

[0009] Furthermore, the reaction in (1) is carried out at 20-30℃ for 18-36 hours.

[0010] Furthermore, in (1), the amount of carboxymethyl cellulose is 100 parts by weight, 4-dimethylaminopyridine is 0.6-2.3 parts by weight, dicyclohexylcarbodiimide is 7-26 parts by weight, and resveratrol is 8-30 parts by weight.

[0011] Furthermore, the reaction in (2) is carried out at 35-60℃ for 12-24h.

[0012] Furthermore, in (2), the amount of resveratrol-based cellulose is 100 parts by weight and the amount of alkylamine is 7-35 parts by weight.

[0013] Furthermore, the molecular formula of alkylamines is NH2-C. a H 2a+1 , where a is 12-18.

[0014] Furthermore, in (3), the stirring and dispersion time is 40-60 min, and the stirring time is 2-3 min.

[0015] Furthermore, (3) the temperature during maintenance is 20-25℃, the relative humidity is 90-95%, and the maintenance time is 7-28 days.

[0016] Furthermore, all-solid waste cementitious materials are applied to high-performance fluidized solidified soil.

[0017] The beneficial technical effects of this invention are as follows: This invention utilizes resveratrol and carboxymethyl cellulose for esterification, followed by addition reaction of alkenyl groups with the primary amines of alkylamines (generating imino groups) to obtain modified cellulose. This modified cellulose is used as a binder and dispersant. Slag powder, steel slag powder, silicate cement clinker, fly ash, etc., are used as the matrix of solid waste cementitious materials. Aluminum sulfate and desulfurized gypsum powder are used as activators. The mixture is blended, cemented, cured, and then a solid waste cementitious material is obtained.

[0018] The modified cellulose of this invention contains carboxyl, imino, and a large number of phenolic hydroxyl groups, which can disperse silicate cement clinker, slag powder, steel slag powder, and fly ash, thus improving the mechanical properties of cementitious materials. Cellulose itself has a certain reinforcing effect, and the introduction of multiple rigid benzene rings, under the synergistic effect, improves the mechanical properties and compressive strength of cementitious materials.

[0019] The modified cellulose of this invention contains hydrophobic benzene rings and alkyl long chains, which can reduce the hydrophilicity of carboxymethyl cellulose, thereby maintaining the low water absorption of the all-solid waste cementitious material. It still maintains high compressive strength after soaking in water and has excellent water resistance. The prepared all-solid waste cementitious material has good practical applications in fluidized solidified soil, concrete, marine cement, refractory materials, wall materials, and lightweight building materials. Attached Figure Description

[0020] Figure 1 This is the infrared spectrum of the modified cellulose from Example 1. Detailed Implementation

[0021] The present invention will be described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments. Example 1:

[0022] (1) Add 200g of carboxymethyl cellulose (CMC carboxymethyl cellulose from Guangzhou Yiming Chemical Co., Ltd., the same below), 2.4g of 4-dimethylaminopyridine, and 27g of dicyclohexylcarbodiimide to 3L of dimethyl sulfoxide. After stirring, add 30g of resveratrol (CAS No. 501-36-0). Stir the reaction at 20℃ for 24h. Pour the solution into ethanol, filter, wash the filter cake with ethanol, and dry to obtain resveratrol-based cellulose.

[0023] (2) Add 200g of resveratrol-based cellulose and 34g of hexadecylamine to 3.5L N,N-dimethylformamide, stir and react at 35℃ for 24h, pour the solution into ethanol, filter, wash the filter cake with ethanol, and dry to obtain modified cellulose. Figure 1 1422-1461 cm⁻¹ in the infrared spectrum -1 These are characteristic peaks of the benzene ring skeleton, 1744-1780 cm⁻¹ -1 The absorption peaks are at the -C=O- group of the carboxyl and ester groups, indicating that the hydroxyl groups of resveratrol and the carboxyl groups of cellulose undergo esterification to form ester groups, 2931-2889 cm⁻¹. -1 The absorption peaks of the alkyl chain (-CH2, -CH3) indicate that the alkenyl group undergoes an addition reaction with the primary amine of the alkylamine, introducing a long alkyl chain.

[0024] (3) Add 4.7L water, 6.3kg slag powder, 3.8kg steel slag powder, 1.6kg silicate cement clinker, 300g modified cellulose, and 400g fly ash to the mixer and stir and disperse for 40 minutes. Add 800g aluminum sulfate and 270g desulfurized gypsum powder and stir for 2 minutes. Pour the material into the mold, demold after molding, and cure for 7 days at 90% relative humidity and 20℃ to obtain the all-solid waste cementitious material.

[0025] Example 2:

[0026] (1) Add 200g of carboxymethyl cellulose, 1.2g of 4-dimethylaminopyridine and 14g of dicyclohexylcarbodiimide to 3L of dimethyl sulfoxide, stir and then add 16g of resveratrol. Stir and react at 30℃ for 18h. Pour the solution into ethanol, filter and wash the filter cake with ethanol, and dry to obtain resveratrol-based cellulose.

[0027] (2) Add 200g of resveratrol-based cellulose and 14g of octadecylamine to 3L of N,N-dimethylformamide, stir and react at 40℃ for 12h, pour the solution into ethanol, filter, wash the filter cake with ethanol, and dry to obtain modified cellulose.

[0028] (3) Add 4.4L water, 5.9kg slag powder, 3.3kg steel slag powder, 1.2kg silicate cement clinker, 400g modified cellulose and 560g fly ash to the mixer and stir and disperse for 40min. Add 800g aluminum sulfate and 290g desulfurized gypsum powder and stir for 2min. Pour the material into the mold, demold after molding, and cure at 90% relative humidity and 20℃ for 14 days to obtain all-solid waste cementitious material.

[0029] Example 3:

[0030] (1) Add 200g carboxymethyl cellulose, 4.6g 4-dimethylaminopyridine and 52g dicyclohexylcarbodiimide to 3.5L dimethyl sulfoxide, stir and then add 60g resveratrol. Stir and react at 20℃ for 36h. Pour the solution into ethanol, filter and wash the filter cake with ethanol, dry and obtain resveratrol-based cellulose.

[0031] (2) Add 200g of resveratrol-based cellulose and 70g of dodecylamine to 4L of N,N-dimethylformamide, stir and react at 60℃ for 12h, pour the solution into ethanol, filter, wash the filter cake with ethanol, and dry to obtain modified cellulose.

[0032] (3) Add 4.7L water, 7kg slag powder, 2.4kg steel slag powder, 2.1kg silicate cement clinker, 200g modified cellulose, and 800g fly ash to the mixer and stir and disperse for 60min. Add 600g aluminum sulfate and 330g desulfurized gypsum powder and stir for 3min. Pour the material into the mold, demold after molding, and cure at 95% relative humidity and 25℃ for 28 days to obtain all-solid waste cementitious material.

[0033] Example 4:

[0034] (1) Add 200g carboxymethyl cellulose, 3.5g 4-dimethylaminopyridine and 40g dicyclohexylcarbodiimide to 3.5L dimethyl sulfoxide, stir and then add 45g resveratrol. Stir and react at 25℃ for 36h. Pour the solution into ethanol, filter and wash the filter cake with ethanol, dry and obtain resveratrol-based cellulose.

[0035] (2) Add 200g of resveratrol-based cellulose and 56g of hexadecylamine to 3.5L N,N-dimethylformamide, stir and react at 45℃ for 24h, pour the solution into ethanol, filter, wash the filter cake with ethanol, and dry to obtain modified cellulose.

[0036] (3) Add 4.8L water, 5.6kg slag powder, 2.8kg steel slag powder, 2.5kg silicate cement clinker, 100g modified cellulose and 730g fly ash to the mixer and stir and disperse for 60min. Add 760g aluminum sulfate and 250g desulfurized gypsum powder and stir for 3min. Pour the material into the mold, demold after molding, and cure at 90% relative humidity and 20℃ for 28 days to obtain the solid waste cementitious material.

[0037] Comparative Example 1: (1) Add 4.7L water, 6.3kg slag powder, 3.8kg steel slag powder, 1.6kg silicate cement clinker, 300g carboxymethyl cellulose, and 400g fly ash to the mixer and stir and disperse for 40min. Add 800g aluminum sulfate and 270g desulfurized gypsum powder and stir for 2min. Pour the material into the mold, demold after molding, and cure for 7 days at 90% relative humidity and 20℃ to obtain the all-solid waste cementitious material.

[0038] Comparative Example 2: (1) Add 4.7L water, 6.3kg slag powder, 3.8kg steel slag powder, 1.6kg silicate cement clinker, 300g resveratrol-based cellulose (prepared from Example 1), and 400g fly ash to the mixer, stir and disperse for 40min, add 800g aluminum sulfate and 270g desulfurized gypsum powder, stir for 2min, pour the material into the mold, demold after molding, and cure for 7 days at 90% relative humidity and 20℃ to obtain all-solid waste cementitious material.

[0039] Comparative Example 3: (1) Add 200g of resveratrol-based cellulose (prepared from Example 1) and 34g of ethylamine to 3.5L N,N-dimethylformamide, stir and react at 35°C for 24h, pour the solution into ethanol, filter, wash the filter cake with ethanol, and dry to obtain modified cellulose.

[0040] (2) Add 4.7L water, 6.3kg slag powder, 3.8kg steel slag powder, 1.6kg silicate cement clinker, 300g modified cellulose, and 400g fly ash to the mixer and stir and disperse for 40min. Add 800g aluminum sulfate and 270g desulfurized gypsum powder and stir for 2min. Pour the material into the mold, demold after molding, and cure for 7 days at 90% relative humidity and 20℃ to obtain the all-solid waste cementitious material.

[0041] Comparative Example 4: (1) Add 200g of carboxymethyl cellulose, 2.4g of 4-dimethylaminopyridine and 27g of dicyclohexylcarbodiimide to 3L of dimethyl sulfoxide, stir and then add 30g of hydroxyethyl acrylate. Stir and react at 20℃ for 24h. Pour the solution into ethanol, filter and wash the filter cake with ethanol, dry and obtain acrylate-based cellulose.

[0042] (2) Add 200g of acrylate-based cellulose and 34g of hexadecylamine to 3.5L N,N-dimethylformamide, stir and react at 35℃ for 24h, pour the solution into ethanol, filter, wash the filter cake with ethanol, and dry to obtain modified cellulose.

[0043] (3) Add 4.7L water, 6.3kg slag powder, 3.8kg steel slag powder, 1.6kg silicate cement clinker, 300g modified cellulose, and 400g fly ash to the mixer and stir and disperse for 40 minutes. Add 800g aluminum sulfate and 270g desulfurized gypsum powder and stir for 2 minutes. Pour the material into the mold, demold after molding, and cure for 7 days at 90% relative humidity and 20℃ to obtain the all-solid waste cementitious material.

[0044] The compressive strength P was tested according to standard GB / T 17671-2021. The solid waste cementitious material was immersed in water for 72 hours, then removed, the surface moisture was wiped dry, and the compressive strength P was tested again. 水 And calculate the compressive strength retention rate.

[0045] Table 1 Performance Tests

[0046] After testing, compared with the comparative examples, the all-solid-waste cementitious material of Example 1, as an auxiliary binder and dispersant, contains carboxyl, imino, and a large number of phenolic hydroxyl groups, which can disperse silicate cement clinker, slag powder, steel slag powder, and fly ash, thus improving the mechanical properties of the cementitious material. Furthermore, the presence of cellulose itself provides reinforcement, and the introduction of multiple rigid benzene rings synergistically enhances the mechanical properties and compressive strength of the cementitious material. The hydrophobic benzene rings and alkyl long chains of cellulose reduce the hydrophilicity of carboxymethyl cellulose, thereby maintaining the low water absorption of the all-solid-waste cementitious material. Even after soaking in water, it retains high compressive strength and excellent water resistance. Examples 2-4, with the addition of different proportions of silicate cement clinker, steel slag powder, fly ash, and modified cellulose, also exhibited excellent mechanical properties and water resistance in the all-solid-waste cementitious materials.

[0047] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on the present invention without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A solid waste cementitious material, characterized in that, The raw materials of the all-solid waste cementitious material include: 56-70 parts by weight of slag powder, 24-38 parts by weight of steel slag powder, 12-25 parts by weight of silicate cement clinker, 1-4 parts by weight of modified cellulose, 4-8 parts by weight of fly ash, 6-8 parts by weight of aluminum sulfate, and 2.5-3.3 parts by weight of desulfurized gypsum powder.

2. A method for preparing the all-solid waste cementitious material as described in claim 1, characterized in that, The preparation method is as follows: (1) Add carboxymethyl cellulose, 4-dimethylaminopyridine and dicyclohexylcarbodiimide to dimethyl sulfoxide, stir and then add resveratrol. After the reaction, pour the solution into ethanol, filter, wash the filter cake, and dry to obtain resveratrol-based cellulose. (2) Add resveratrol-based cellulose and alkylamine to N,N-dimethylformamide, stir and react, pour the solution into ethanol, filter, wash the filter cake, and dry to obtain modified cellulose; (3) Add water, slag powder, steel slag powder, silicate cement clinker, modified cellulose and fly ash to the mixer, stir and disperse, add aluminum sulfate and desulfurized gypsum powder, stir, pour the material into the mold, demold after molding, and cure to obtain solid waste cementitious material.

3. The method for preparing the all-solid waste cementitious material according to claim 2, characterized in that, The reaction in (1) is carried out at 20-30℃ for 18-36 hours.

4. The method for preparing the all-solid waste cementitious material according to claim 2, characterized in that, In (1), the amount of carboxymethyl cellulose is 100 parts by weight, 4-dimethylaminopyridine is 0.6-2.3 parts by weight, dicyclohexylcarbodiimide is 7-26 parts by weight, and resveratrol is 8-30 parts by weight.

5. The method for preparing the all-solid waste cementitious material according to claim 2, characterized in that, The reaction in (2) is carried out at 35-60℃ for 12-24 hours.

6. The method for preparing the all-solid waste cementitious material according to claim 2, characterized in that, The amount of resveratrol-based cellulose used in (2) is 100 parts by weight and the amount of alkylamine is 7-35 parts by weight.

7. The method for preparing the all-solid waste cementitious material according to claim 6, characterized in that, The molecular formula of the alkylamine is NH2-C. a H 2a+1 , where a is 12-18.

8. The method for preparing the all-solid waste cementitious material according to claim 2, characterized in that, The stirring and dispersing time in (3) is 40-60 min, and the stirring time is 2-3 min.

9. The method for preparing the all-solid waste cementitious material according to claim 2, characterized in that, The temperature during curing in (3) is 20-25℃, the relative humidity is 90-95%, and the curing time is 7-28 days.

10. The application of a solid waste cementitious material obtained by the preparation method according to any one of claims 2-9 in high-performance fluidized solidified soil.

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