A full-solid-waste alkali-activated cementitious material and a preparation method thereof

Abstract

This invention discloses an all-solid-waste alkali-activated cementitious material and its preparation method, relating to the field of building materials technology. The cementitious material, by weight, comprises the following components: 300-400 parts blast furnace slag, 150-350 parts glass powder, 30-200 parts red brick powder, 40-70 parts desulfurized gypsum, 160-260 parts alkali activator, 10-30 parts sodium sulfate, 30-40 parts sodium tripolyphosphate, 0.4-5 parts silane coupling agent, and 200-400 parts water. This invention utilizes various industrial wastes such as blast furnace slag, glass powder, red brick powder, and desulfurized gypsum to prepare an all-solid-waste alkali-activated cementitious material. It possesses excellent mechanical properties, outstanding durability, and strong environmental adaptability, improving the utilization rate of industrial solid waste, reducing the use of traditional cementitious materials such as cement, lowering resource dependence and production costs, and promoting the low-carbon transformation of building materials.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and in particular to a solid waste alkali-activated cementitious material and its preparation method. Background Technology

[0002] With the rapid development of the construction industry, the demand for cement, as a major cementitious material, continues to grow. However, the cement production process consumes a large amount of non-renewable resources and is energy-intensive, polluting, and emits large amounts of CO2, causing serious environmental impact. Statistics show that the construction industry accounts for approximately 33% of global CO2 emissions, with cement production accounting for as much as 40.69%. Every ton of cement produced emits approximately 0.98 tons of CO2, exacerbating the greenhouse effect. At the same time, the large amounts of solid waste generated in industrial production, such as blast furnace slag, waste glass, waste bricks, and desulfurization gypsum, if not properly disposed of, will occupy land, pollute water bodies and soil, and harm the ecological environment.

[0003] Alkali-activated materials, as a potential cement alternative, have attracted widespread attention due to their advantages such as low permeability, high strength, corrosion resistance, and dense microstructure. They utilize industrial solid waste rich in silica and aluminum to react under alkaline conditions, forming products with cementing properties. This not only disposes of large amounts of solid waste but also significantly reduces resource consumption and environmental pollution associated with traditional cement production. Therefore, developing alkali-activated cementitious materials using all-solid-waste as raw materials is of great significance for promoting the green and low-carbon transformation of the building materials industry and developing a circular economy. Summary of the Invention

[0004] The purpose of this invention is to provide an all-solid-waste alkali-activated cementitious material and its preparation method, thereby improving the utilization rate of industrial solid waste, reducing the use of traditional cementitious materials such as cement, reducing resource dependence and production costs, and promoting the low-carbon transformation of building materials.

[0005] To achieve the above objectives, the present invention provides an all-solid waste alkali-activated cementitious material, comprising the following components by weight: 300-400 parts blast furnace slag, 150-350 parts glass powder, 30-200 parts red brick powder, 40-70 parts desulfurized gypsum, 160-260 parts alkali activator, 10-30 parts sodium sulfate, 30-40 parts sodium tripolyphosphate, 0.4-5 parts silane coupling agent, and 200-400 parts water.

[0006] Preferably, the blast furnace slag is S95 grade blast furnace slag with a density of 2.88 g / cm³. 3 Specific surface area is 421 m² 2 / kg. In this invention, blast furnace slag rapidly deagglomerates under the action of an alkaline activator, releasing Ca. 2+ [SiO4] 4- and [AlO4] 5-Active ions generate calcium-(aluminum)-silicon-hydrate gel, namely C-(A)-SH gel, which constitutes the main strength framework of the solid waste alkali-activated cementitious material.

[0007] Preferably, the glass powder contains 68.57% SiO2 and 0.78% Al2O3; the red brick powder contains 59.34% SiO2 and 17.79% Al2O3. In this invention, the glass powder primarily serves as a silicon source supplement. Its high proportion of amorphous SiO2 dissolves under the action of an alkali activator, releasing reactive silicate species. These species react synergistically with the dissolved components of blast furnace slag and red brick powder, promoting the formation of a cementitious product primarily composed of silicate gel. This improves the early structure establishment rate of the slurry, enhances matrix density, and further improves the long-term mechanical and impermeability durability of the material. The red brick powder primarily functions as a micro-filler and a partial active supplement. The fine particles of the red brick powder effectively fill the voids in the mixture, improving the density and structural uniformity of the alkali-activated cementitious material from solid waste, thereby improving impermeability and durability.

[0008] Preferably, the desulfurized gypsum is a hemihydrate desulfurized gypsum with a density of 2.53 g / cm³. 3 Specific surface area is 259m² 2 / kg, with a median particle size of 15.6μm. In this invention, the desulfurized gypsum provides sulfate ions, promoting the reaction of calcium and aluminum ions with sulfate ions in the system to generate sulfoaluminate hydration products such as ettringite, thereby accelerating the development of early strength; on the other hand, the desulfurized gypsum can also regulate the reaction rate and setting time.

[0009] Preferably, the alkali activator is a composite alkali activator, comprising, by weight: 10-30 parts sodium hydroxide and 150-200 parts water glass; the modulus of the alkali activator is in the range of 1.2-1.6. In this invention, the alkali activator activates and promotes the dissolution of active components (such as silicon and aluminum) in the waste. Under highly alkaline conditions, these active components rapidly release reactive substances, thereby forming silicate and aluminosilicate gels, constructing the skeletal structure of the all-solid waste alkali-activated cementitious material, improving early strength and overall durability.

[0010] Preferably, the sodium hydroxide is solid sodium hydroxide granules; the mass fraction of sodium hydroxide in the solid sodium hydroxide granules is ≥96%, and the density is 2.13 g / cm³. 3 The solubility is 1090 g / L; the initial modulus of the water glass is 3.3, and the solid content is 35.5%. In this invention, sodium hydroxide primarily provides a highly alkaline environment, thereby promoting the rapid dissolution of active silicon and aluminum elements in waste materials such as blast furnace slag, glass powder, and red brick powder. The main function of water glass is to provide a sufficient silicon source.

[0011] Preferably, the sodium sulfate is anhydrous sodium sulfate granules; the anhydrous sodium sulfate granules contain ≥99% sodium sulfate by mass, ≤0.005% water-insoluble matter, and have a density of 2.68 g / mL; the sodium tripolyphosphate is solid sodium tripolyphosphate granules; the solid sodium tripolyphosphate granules contain ≤0.05% water-insoluble matter; and the silane coupling agent is KH-560. In this invention, sodium sulfate assists the alkali activator by releasing sulfate ions, accelerating the dissolution of active silicon and aluminum elements in the system, and promoting the rapid formation of silicate and aluminosilicate gels, thereby significantly improving early strength. Sodium tripolyphosphate improves fluidity and workability, and also optimizes the microstructure and mechanical properties of the all-solid waste alkali-activated cementitious material by regulating the hydration process. KH-560 hydrolyzes in a strongly alkaline environment and condenses and anchors with glass powder or red brick powder and the surface of the reactive gel to form an organosilicon modified layer, thereby reducing the hydrophilicity of the pore wall and the capillary water absorption driving force, weakening the migration and salting-out deposition of alkali metal ions and sulfates in the pore liquid to the surface. At the same time, it improves impermeability and volume stability through the microscopic "pore sealing-reducing connectivity" effect, and plays a certain buffering and homogenizing role in the early dissolution-polymerization process.

[0012] This invention also provides a method for preparing an all-solid waste alkali-activated cementitious material, which includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, passed through a 600-mesh sieve, and pretreated with acetic acid to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum. S2. Weigh 10-30 parts by weight of solid sodium hydroxide granules and 150-200 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand and cool at room temperature for 24 hours to obtain the alkali activator. S3. By weight, weigh 300-400 parts blast furnace slag, 150-350 parts glass powder, 30-200 parts red brick powder, 40-70 parts desulfurized gypsum, 160-260 parts alkali activator, 10-30 parts sodium sulfate, 30-40 parts sodium tripolyphosphate, 0.4-5 parts silane coupling agent and 200-400 parts water; S4. Mix 300-400 parts of blast furnace slag, 150-350 parts of glass powder, 30-200 parts of red brick powder and 40-70 parts of desulfurized gypsum for 3 minutes to obtain a mixed dry material. S5. Mix 160-260 parts of alkali activator, 10-30 parts of sodium sulfate, 30-40 parts of sodium tripolyphosphate, 0.4-5 parts of silane coupling agent and 200-400 parts of water evenly, then pour the mixture into the dry mixture and stir for 2 minutes to obtain a uniform alkali-activated slurry. S6. Inject the alkali-activated slurry into the mold, vibrate to compact it, and cover it with a film. After 24 hours, remove the mold and cure to obtain the solid waste alkali-activated cementitious material.

[0013] In this invention, calcination during the preparation of glass powder is performed to effectively remove adsorbed water and residual organic impurities from the glass powder surface, improve the powder surface state, and reduce agglomeration tendency, thereby increasing the effective solubility and reaction participation of the glass powder in an alkaline environment, which in turn helps to improve the overall reactivity of the system. Calcination before using desulfurized gypsum is to further remove adsorbed water and potentially residual crystal water from the desulfurized gypsum, and to regulate the composition of the calcium sulfate phase, thereby reducing SO42-. 2- The dissolution and supply are more uniform and controllable in the initial stage of mixing, which is conducive to the early formation of ettringite and the adjustment of setting time.

[0014] Preferably, the acetic acid pretreatment in S1 involves immersing red brick powder, after passing through a 600-mesh sieve, in an acetic acid solution with a concentration of 0.5 mol / L to 2.0 mol / L at a solid-liquid ratio of 1 g:(5-20) mL for 0.5 h to 24 h, followed by filtration, washing, and drying. In this invention, the acetic acid pretreatment dissolves and removes impurities from the surface of the red brick powder. Simultaneously, the acid washing treatment improves the surface condition of the particles and increases the exposure of active sites, promoting the dissolution and reaction participation of the active aluminum-silicon components in the red brick powder in an alkaline environment. This allows them to play an auxiliary role in gel formation and microstructure densification, in addition to their filling effect.

[0015] Preferably, the curing temperature in S6 is 20±2℃ and the humidity is ≥95%; the curing is carried out in a standard curing chamber and the curing is carried out until the specified test age.

[0016] In summary, the all-solid waste alkali-activated cementitious material and its preparation method provided by this invention have the following advantages compared with traditional technologies: (1) The present invention utilizes a variety of industrial wastes such as blast furnace slag, glass powder, red brick powder and desulfurized gypsum to prepare a solid waste alkali-activated cementitious material, which improves the utilization rate of industrial solid waste, reduces the use of traditional cementitious materials such as cement, reduces resource dependence and production costs, promotes the low-carbon transformation of building materials, and achieves the goals of energy conservation, emission reduction and green environmental protection.

[0017] (2) In this invention, the alkaline activator combined with sodium sulfate to assist in activation significantly improves the activity of the raw materials, promotes hydration and silicate gel formation, thereby greatly improving early strength and long-term durability; sodium tripolyphosphate, as a dispersant, effectively improves the uniformity and flowability of the raw material mixture, reduces the water-cement ratio requirement, and enhances the construction performance; the silane coupling agent hydrolyzes in the alkaline system and condenses and anchors with the particle surface to form an organosilicon modified layer, which reduces the hydrophilicity of the pore wall and the driving force of capillary migration, thereby inhibiting the enrichment of migratory alkali / salt to the surface and the risk of efflorescence and salt precipitation, and is conducive to improving the impermeability and durability of the material; by making full use of waste resources, not only is the production cost reduced, but also the goals of energy conservation, emission reduction and green environmental protection are achieved.

[0018] The technical method of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a flowchart of the method for preparing all-solid waste alkali-activated cementitious materials according to the present invention. Detailed Implementation

[0020] The technical method of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0022] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0023] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0024] The specific implementation examples are as follows: Example 1 A solid waste alkali-activated cementitious material, by weight, comprises the following components: 360 parts blast furnace slag, 324 parts glass powder, 36 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560, and 267 parts water.

[0025] The blast furnace slag is S95 grade blast furnace slag with a density of 2.88 g / cm³. 3 Specific surface area is 421 m² 2 / kg; the glass powder contains 68.57% SiO2 and 0.78% Al2O3; the red brick powder contains 59.34% SiO2 and 17.79% Al2O3; the desulfurized gypsum is hemihydrate desulfurized gypsum with a density of 2.53 g / cm³. 3 Specific surface area is 259m² 2 / kg, median particle size is 15.6μm; sodium hydroxide is solid sodium hydroxide particles, wherein the mass fraction of sodium hydroxide is ≥96%, and the density is 2.13g / cm³. 3 The solubility is 1090 g / L; the initial modulus of water glass is 3.3, and the solid content is 35.5%; the sodium sulfate is anhydrous sodium sulfate granules, with a sodium sulfate mass fraction ≥99%, water-insoluble matter ≤0.005%, and a density of 2.68 g / mL; the sodium tripolyphosphate is solid sodium tripolyphosphate granules, with a water-insoluble matter content ≤0.05%, and a content of 56% as P2O5.

[0026] A method for preparing an all-solid waste alkali-activated cementitious material, such as Figure 1 As shown, it includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, and passed through a 600-mesh sieve, then soaked in a 1.0 mol / L acetic acid solution at a solid-liquid ratio of 1g:10mL for 12 hours, followed by solid-liquid separation, washing with water and filtering until the pH of the filtrate is 7, then dried at 90℃ to constant weight, and passed through a 600-mesh sieve to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum.

[0027] S2. Weigh 30 parts by weight of solid sodium hydroxide granules and 164 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand at room temperature for 24 hours to eliminate the exothermic effect, thus obtaining the alkali activator.

[0028] S3. Weigh out 360 parts by weight of blast furnace slag, 324 parts by weight of glass powder, 36 parts by weight of red brick powder, 43.2 parts by weight of desulfurized gypsum, 196.7 parts by weight of alkali activator, 12.7 parts by weight of sodium sulfate, 38.2 parts by weight of sodium tripolyphosphate, 1.2 parts by weight of KH-560 and 267 parts by weight of water.

[0029] S4. Pour 360 parts of blast furnace slag, 324 parts of glass powder, 36 parts of red brick powder and 43.2 parts of desulfurized gypsum into a mixer and mix for 3 minutes to obtain a mixed dry material.

[0030] S5. Mix 196.7 parts of alkali activator, 12.7 parts of sodium sulfate, 38.2 parts of sodium tripolyphosphate, 1.2 parts of KH-560 and 267 parts of water evenly, then pour the mixture into the dry mixture and continue mixing in a mixer for 2 minutes to obtain a uniform alkali-activated slurry.

[0031] S6. Pour the alkali-activated slurry into the mold, vibrate to compact it, cover the surface with a film to obtain a molded test block. After 24 hours, remove the mold to obtain the test block. Finally, cure it in a standard curing chamber with a temperature of 20±2℃ and a humidity of ≥95% until the specified test age to obtain the finished product, namely the all-solid waste alkali-activated cementitious material.

[0032] Example 2 A solid waste alkali-activated cementitious material, by weight, comprises the following components: 360 parts blast furnace slag, 288 parts glass powder, 72 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560, and 267 parts water.

[0033] The blast furnace slag, glass powder, red brick powder, desulfurized gypsum, alkali activator, sodium sulfate, and sodium tripolyphosphate used in this embodiment are consistent with the corresponding technical indicators specified in Example 1.

[0034] A method for preparing an all-solid waste alkali-activated cementitious material includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, and passed through a 600-mesh sieve, then soaked in a 1.0 mol / L acetic acid solution at a solid-liquid ratio of 1g:10mL for 12 hours, followed by solid-liquid separation, washing with water and filtering until the pH of the filtrate is 7, then dried at 90℃ to constant weight, and passed through a 600-mesh sieve to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum.

[0035] S2. Weigh 30 parts by weight of solid sodium hydroxide granules and 164 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand at room temperature for 24 hours to eliminate the exothermic effect, thus obtaining the alkali activator.

[0036] S3. Weigh out 360 parts by weight of blast furnace slag, 288 parts by weight of glass powder, 72 parts by weight of red brick powder, 43.2 parts by weight of desulfurized gypsum, 196.7 parts by weight of alkali activator, 12.7 parts by weight of sodium sulfate, 38.2 parts by weight of sodium tripolyphosphate, 1.2 parts by weight of KH-560 and 267 parts by weight of water.

[0037] S4. Pour 360 parts of blast furnace slag, 288 parts of glass powder, 72 parts of red brick powder and 43.2 parts of desulfurized gypsum into a mixer and mix for 3 minutes to obtain a mixed dry material.

[0038] S5. Mix 196.7 parts of alkali activator, 12.7 parts of sodium sulfate, 38.2 parts of sodium tripolyphosphate, 1.2 parts of KH-560 and 267 parts of water evenly, then pour the mixture into the dry mixture and continue mixing in a mixer for 2 minutes to obtain a uniform alkali-activated slurry.

[0039] S6. Pour the alkali-activated slurry into the mold, vibrate it to make it dense, cover the surface with a film, remove the mold after 24 hours, and cure it in a standard curing chamber with a temperature of 20±2℃ and a humidity of ≥95% until the specified test age to obtain the all-solid waste alkali-activated cementitious material.

[0040] Example 3 A solid waste alkali-activated cementitious material, by weight, comprises the following components: 360 parts blast furnace slag, 252 parts glass powder, 108 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560, and 267 parts water.

[0041] The blast furnace slag, glass powder, red brick powder, desulfurized gypsum, alkali activator, sodium sulfate, and sodium tripolyphosphate used in this embodiment are consistent with the corresponding technical indicators specified in Example 1.

[0042] A method for preparing an all-solid waste alkali-activated cementitious material includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, and passed through a 600-mesh sieve, then soaked in a 1.0 mol / L acetic acid solution at a solid-liquid ratio of 1g:10mL for 12 hours, followed by solid-liquid separation, washing with water and filtering until the pH of the filtrate is 7, then dried at 90℃ to constant weight, and passed through a 600-mesh sieve to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum.

[0043] S2. Weigh 30 parts by weight of solid sodium hydroxide granules and 164 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand at room temperature for 24 hours to eliminate the exothermic effect, thus obtaining the alkali activator.

[0044] S3. Weigh out 360 parts by weight of blast furnace slag, 252 parts by weight of glass powder, 108 parts by weight of red brick powder, 43.2 parts by weight of desulfurized gypsum, 196.7 parts by weight of alkali activator, 12.7 parts by weight of sodium sulfate, 38.2 parts by weight of sodium tripolyphosphate, 1.2 parts by weight of KH-560 and 267 parts by weight of water.

[0045] S4. Pour 360 parts of blast furnace slag, 252 parts of glass powder, 108 parts of red brick powder and 43.2 parts of desulfurized gypsum into a mixer and mix for 3 minutes to obtain a mixed dry material.

[0046] S5. Mix 196.7 parts of alkali activator, 12.7 parts of sodium sulfate, 38.2 parts of sodium tripolyphosphate, 1.2 parts of KH-560 and 267 parts of water evenly, then pour the mixture into the dry mixture and continue mixing in a mixer for 2 minutes to obtain a uniform alkali-activated slurry.

[0047] S6. Pour the alkali-activated slurry into the mold, vibrate it to make it dense, cover the surface with a film, remove the mold after 24 hours, and cure it in a standard curing chamber with a temperature of 20±2℃ and a humidity of ≥95% until the specified test age to obtain the all-solid waste alkali-activated cementitious material.

[0048] Example 4 A solid waste alkali-activated cementitious material, by weight, comprises the following components: 360 parts blast furnace slag, 216 parts glass powder, 144 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560, and 267 parts water.

[0049] The blast furnace slag, glass powder, red brick powder, desulfurized gypsum, alkali activator, sodium sulfate, and sodium tripolyphosphate used in this embodiment are consistent with the corresponding technical indicators specified in Example 1.

[0050] A method for preparing an all-solid waste alkali-activated cementitious material includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, and passed through a 600-mesh sieve, then soaked in a 1.0 mol / L acetic acid solution at a solid-liquid ratio of 1g:10mL for 12 hours, followed by solid-liquid separation, washing with water and filtering until the pH of the filtrate is 7, then dried at 90℃ to constant weight, and passed through a 600-mesh sieve to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum.

[0051] S2. Weigh 30 parts by weight of solid sodium hydroxide granules and 164 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand at room temperature for 24 hours to eliminate the exothermic effect, thus obtaining the alkali activator.

[0052] S3. Weigh out 360 parts by weight of blast furnace slag, 216 parts by weight of glass powder, 144 parts by weight of red brick powder, 43.2 parts by weight of desulfurized gypsum, 196.7 parts by weight of alkali activator, 12.7 parts by weight of sodium sulfate, 38.2 parts by weight of sodium tripolyphosphate, 1.2 parts by weight of KH-560 and 267 parts by weight of water.

[0053] S4. Pour 360 parts of blast furnace slag, 216 parts of glass powder, 144 parts of red brick powder and 43.2 parts of desulfurized gypsum into a mixer and mix for 3 minutes to obtain a mixed dry material.

[0054] S5. Mix 196.7 parts of alkali activator, 12.7 parts of sodium sulfate, 38.2 parts of sodium tripolyphosphate, 1.2 parts of KH-560 and 267 parts of water evenly, then pour the mixture into the dry mixture and continue mixing in a mixer for 2 minutes to obtain a uniform alkali-activated slurry.

[0055] S6. Pour the alkali-activated slurry into the mold, vibrate it to make it dense, cover the surface with a film, remove the mold after 24 hours, and cure it in a standard curing chamber with a temperature of 20±2℃ and a humidity of ≥95% until the specified test age to obtain the all-solid waste alkali-activated cementitious material.

[0056] Example 5 A solid waste alkali-activated cementitious material, by weight, comprises the following components: 360 parts blast furnace slag, 180 parts glass powder, 180 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560, and 267 parts water.

[0057] The blast furnace slag, glass powder, red brick powder, desulfurized gypsum, alkali activator, sodium sulfate, and sodium tripolyphosphate used in this embodiment are consistent with the corresponding technical indicators specified in Example 1.

[0058] A method for preparing an all-solid waste alkali-activated cementitious material includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, and passed through a 600-mesh sieve, then soaked in a 1.0 mol / L acetic acid solution at a solid-liquid ratio of 1g:10mL for 12 hours, followed by solid-liquid separation, washing with water and filtering until the pH of the filtrate is 7, then dried at 90℃ to constant weight, and passed through a 600-mesh sieve to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum.

[0059] S2. Weigh 30 parts by weight of solid sodium hydroxide granules and 164 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand at room temperature for 24 hours to eliminate the exothermic effect, thus obtaining the alkali activator.

[0060] S3. Weigh out 360 parts by weight of blast furnace slag, 180 parts by weight of glass powder, 180 parts by weight of red brick powder, 43.2 parts by weight of desulfurized gypsum, 196.7 parts by weight of alkali activator, 12.7 parts by weight of sodium sulfate, 38.2 parts by weight of sodium tripolyphosphate, 1.2 parts by weight of KH-560 and 267 parts by weight of water.

[0061] S4. Pour 360 parts of blast furnace slag, 180 parts of glass powder, 180 parts of red brick powder and 43.2 parts of desulfurized gypsum into a mixer and mix for 3 minutes to obtain a mixed dry material.

[0062] S5. Mix 196.7 parts of alkali activator, 12.7 parts of sodium sulfate, 38.2 parts of sodium tripolyphosphate, 1.2 parts of KH-560 and 267 parts of water evenly, then pour the mixture into the dry mixture and continue mixing in a mixer for 2 minutes to obtain a uniform alkali-activated slurry.

[0063] S6. Pour the alkali-activated slurry into the mold, vibrate it to make it dense, cover the surface with a film, remove the mold after 24 hours, and cure it in a standard curing chamber with a temperature of 20±2℃ and a humidity of ≥95% until the specified test age to obtain the all-solid waste alkali-activated cementitious material.

[0064] Example 6 A solid waste alkali-activated cementitious material, by weight, comprises the following components: 360 parts blast furnace slag, 216 parts glass powder, 144 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560, and 305.3 parts water.

[0065] The blast furnace slag, glass powder, red brick powder, desulfurized gypsum, alkali activator, sodium sulfate, and sodium tripolyphosphate used in this embodiment are consistent with the corresponding technical indicators specified in Example 1.

[0066] A method for preparing an all-solid waste alkali-activated cementitious material includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, and passed through a 600-mesh sieve, then soaked in a 1.0 mol / L acetic acid solution at a solid-liquid ratio of 1g:10mL for 12 hours, followed by solid-liquid separation, washing with water and filtering until the pH of the filtrate is 7, then dried at 90℃ to constant weight, and passed through a 600-mesh sieve to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum.

[0067] S2. Weigh 30 parts by weight of solid sodium hydroxide granules and 164 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand at room temperature for 24 hours to eliminate the exothermic effect, thus obtaining the alkali activator.

[0068] S3. Weigh out 360 parts by weight of blast furnace slag, 216 parts by weight of glass powder, 144 parts by weight of red brick powder, 43.2 parts by weight of desulfurized gypsum, 196.7 parts by weight of alkali activator, 12.7 parts by weight of sodium sulfate, 38.2 parts by weight of sodium tripolyphosphate, 1.2 parts by weight of KH-560 and 305.3 parts by weight of water.

[0069] S4. Pour 360 parts of blast furnace slag, 216 parts of glass powder, 144 parts of red brick powder and 43.2 parts of desulfurized gypsum into a mixer and mix for 3 minutes to obtain a mixed dry material.

[0070] S5. Mix 196.7 parts of alkali activator, 12.7 parts of sodium sulfate, 38.2 parts of sodium tripolyphosphate, 1.2 parts of KH-560 and 305.3 parts of water evenly, then pour the mixture into the dry mixture and continue mixing in a mixer for 2 minutes to obtain a uniform alkali-activated slurry.

[0071] S6. Pour the alkali-activated slurry into the mold, vibrate it to make it dense, cover the surface with a film, remove the mold after 24 hours, and cure it in a standard curing chamber with a temperature of 20±2℃ and a humidity of ≥95% until the specified test age to obtain the all-solid waste alkali-activated cementitious material.

[0072] Example 7 A solid waste alkali-activated cementitious material, by weight, comprises the following components: 360 parts blast furnace slag, 216 parts glass powder, 144 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560, and 343.4 parts water.

[0073] The blast furnace slag, glass powder, red brick powder, desulfurized gypsum, alkali activator, sodium sulfate, and sodium tripolyphosphate used in this embodiment are consistent with the corresponding technical indicators specified in Example 1.

[0074] A method for preparing an all-solid waste alkali-activated cementitious material includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, and passed through a 600-mesh sieve, then soaked in a 1.0 mol / L acetic acid solution at a solid-liquid ratio of 1g:10mL for 12 hours, followed by solid-liquid separation, washing with water and filtering until the pH of the filtrate is 7, then dried at 90℃ to constant weight, and passed through a 600-mesh sieve to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum.

[0075] S2. Weigh 30 parts by weight of solid sodium hydroxide granules and 164 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand at room temperature for 24 hours to eliminate the exothermic effect, thus obtaining the alkali activator.

[0076] S3. By weight, weigh 360 parts blast furnace slag, 216 parts glass powder, 144 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560 and 343.4 parts water.

[0077] S4. Pour 360 parts of blast furnace slag, 216 parts of glass powder, 144 parts of red brick powder and 43.2 parts of desulfurized gypsum into a mixer and mix for 3 minutes to obtain a mixed dry material.

[0078] S5. Mix 196.7 parts of alkali activator, 12.7 parts of sodium sulfate, 38.2 parts of sodium tripolyphosphate, 1.2 parts of KH-560 and 343.4 parts of water evenly, then pour the mixture into the dry mixture and continue mixing in a mixer for 2 minutes to obtain a uniform alkali-activated slurry.

[0079] S6. Pour the alkali-activated slurry into the mold, vibrate it to make it dense, cover the surface with a film, remove the mold after 24 hours, and cure it in a standard curing chamber with a temperature of 20±2℃ and a humidity of ≥95% until the specified test age to obtain the all-solid waste alkali-activated cementitious material.

[0080] Example 8 A solid waste alkali-activated cementitious material, by weight, comprises the following components: 360 parts blast furnace slag, 216 parts glass powder, 144 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 17.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560, and 267 parts water.

[0081] The blast furnace slag, glass powder, red brick powder, desulfurized gypsum, alkali activator, sodium sulfate, and sodium tripolyphosphate used in this embodiment are consistent with the corresponding technical indicators specified in Example 1.

[0082] A method for preparing an all-solid waste alkali-activated cementitious material includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, and passed through a 600-mesh sieve, then soaked in a 1.0 mol / L acetic acid solution at a solid-liquid ratio of 1g:10mL for 12 hours, followed by solid-liquid separation, washing with water and filtering until the pH of the filtrate is 7, then dried at 90℃ to constant weight, and passed through a 600-mesh sieve to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum.

[0083] S2. Weigh 15 parts by weight of solid sodium hydroxide granules and 164 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, let stand at room temperature for 24 hours to eliminate the exothermic effect, and obtain the alkali activator.

[0084] S3. Weigh out 360 parts by weight of blast furnace slag, 216 parts by weight of glass powder, 144 parts by weight of red brick powder, 43.2 parts by weight of desulfurized gypsum, 196.7 parts by weight of alkali activator, 17.7 parts by weight of sodium sulfate, 38.2 parts by weight of sodium tripolyphosphate, 1.2 parts by weight of KH-560 and 267 parts by weight of water.

[0085] S4. Pour 360 parts of blast furnace slag, 216 parts of glass powder, 144 parts of red brick powder and 43.2 parts of desulfurized gypsum into a mixer and mix for 3 minutes to obtain a mixed dry material.

[0086] S5. Mix 196.7 parts of alkali activator, 17.7 parts of sodium sulfate, 38.2 parts of sodium tripolyphosphate, 1.2 parts of KH-560 and 267 parts of water evenly, then pour the mixture into the dry mixture and continue mixing in a mixer for 2 minutes to obtain a uniform alkali-activated slurry.

[0087] S6. Pour the alkali-activated slurry into the mold, vibrate it to make it dense, cover the surface with a film, remove the mold after 24 hours, and cure it in a standard curing chamber with a temperature of 20±2℃ and a humidity of ≥95% until the specified test age to obtain the all-solid waste alkali-activated cementitious material.

[0088] Comparative Example 1 A solid waste alkali-activated cementitious material, by weight, comprises the following components: 360 parts blast furnace slag, 288 parts glass powder, 72 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560 silane coupling agent, and 267 parts water.

[0089] The blast furnace slag, glass powder, red brick powder, desulfurized gypsum, alkali activator, sodium sulfate, and sodium tripolyphosphate used in this comparative example are consistent with the corresponding technical indicators specified in Example 1.

[0090] A method for preparing an all-solid waste alkali-activated cementitious material includes the following steps: S1. The waste glass is washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; the waste red bricks are crushed, ground, impurity removed, dried, and passed through a 600-mesh sieve to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum.

[0091] S2. Weigh 30 parts by weight of solid sodium hydroxide granules and 164 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand at room temperature for 24 hours to eliminate the exothermic effect, thus obtaining the alkali activator.

[0092] S3. By weight, weigh 360 parts blast furnace slag, 288 parts glass powder, 72 parts red brick powder, 43.2 parts desulfurized gypsum, 196.7 parts alkali activator, 12.7 parts sodium sulfate, 38.2 parts sodium tripolyphosphate, 1.2 parts KH-560 silane coupling agent and 267 parts water.

[0093] S4. Pour 360 parts of blast furnace slag, 288 parts of glass powder, 72 parts of red brick powder and 43.2 parts of desulfurized gypsum into a mixer and mix for 3 minutes to obtain a mixed dry material.

[0094] S5. Mix 196.7 parts of alkali activator, 12.7 parts of sodium sulfate, 38.2 parts of sodium tripolyphosphate, 1.2 parts of KH-560 silane coupling agent and 267 parts of water evenly, then pour the mixture into the dry mixture and continue stirring in a mixer for 2 minutes to obtain a uniform alkali-activated slurry.

[0095] S6. Pour the alkali-activated slurry into the mold, vibrate it to make it dense, cover the surface with a film, remove the mold after 24 hours, and cure it in a standard curing chamber with a temperature of 20±2℃ and a humidity of ≥95% until the specified test age to obtain the all-solid waste alkali-activated cementitious material.

[0096] Table 1 shows the flowability, 28-day compressive strength, and flexural strength test results of each solid waste alkali-activated cementitious material in Examples 1-8 and Comparative Example 1.

[0097] Table 1. Results of flowability, 28-day compressive strength, and flexural strength tests of various solid waste alkali-activated cementitious materials in the examples and comparative examples.

[0098] As can be seen from Table 1, within the proportion range of this invention: (1) when the amount of blast furnace slag and glass powder is relatively high and the amount of red brick powder is relatively low, the compressive strength and flexural strength of the hardened cementitious material generally show an increasing trend, indicating that the slag-glass powder composite precursor is more conducive to forming higher mechanical properties; (2) as the water-cement ratio increases, the fluidity of the mixture increases accordingly, but the mechanical strength tends to decrease to a certain extent, indicating that there is a trade-off between "workability improvement" and "strength maintenance" in this system; (3) when the modulus of the activator is in the range of 1.2-1.4, the fluidity change is more sensitive, while the 28-day strength fluctuation is relatively limited, indicating that the modulus range has a relatively mild effect on strength; therefore, considering both construction fluidity and mechanical properties, it is preferable to control the water-cement ratio in the range of 0.35-0.40 and use a higher proportion of blast furnace slag and glass powder to obtain a solid waste alkali activated cementitious material that takes into account both workability and strength level. Compared with Comparative Example 1, which did not pretreat the red brick powder with acetic acid, Example 1, which used the acetic acid pretreatment of red brick powder according to the present invention, under the same proportions and curing conditions, showed that the flowability of the mixture increased from 182 mm to 213 mm, the 28-day compressive strength increased from 35.2 MPa to 68.6 MPa, and the 28-day flexural strength increased from 6.1 MPa to 12.7 MPa. These results indicate that acetic acid pretreatment helps improve the surface condition of red brick powder and promotes the participation of its active components in the reaction under alkaline conditions, thereby improving mechanical properties while ensuring workability.

[0099] This invention, based on alkali activation technology, produces an all-solid waste alkali-activated cementitious material from various industrial wastes such as blast furnace slag, glass powder, red brick powder, and desulfurized gypsum. This material exhibits excellent mechanical properties, outstanding durability, and strong environmental adaptability. Furthermore, the preparation method for this all-solid waste alkali-activated cementitious material is simple, with low production costs. The production process eliminates the need for the high-temperature calcination process required for traditional cement production, reducing energy consumption by over 50% and eliminating CO2 emissions from limestone decomposition. The carbon footprint per ton of material can be reduced by 0.6-0.9 tons. In summary, this invention demonstrates significant advantages in performance, cost, and environmental protection, and has great potential for widespread application.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical methods of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical methods of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical methods to deviate from the spirit and scope of the technical methods of the present invention.

Claims

1. A solid waste alkali-activated cementitious material, characterized in that, By weight, it includes the following components: 300-400 parts blast furnace slag, 150-350 parts glass powder, 30-200 parts red brick powder, 40-70 parts desulfurized gypsum, 160-260 parts alkali activator, 10-30 parts sodium sulfate, 30-40 parts sodium tripolyphosphate, 0.4-5 parts silane coupling agent, and 200-400 parts water.

2. The all-solid waste alkali-activated cementitious material according to claim 1, characterized in that, The blast furnace slag is S95 grade blast furnace slag with a density of 2.88 g / cm³. 3 Specific surface area is 421 m² 2 / kg.

3. The all-solid waste alkali-activated cementitious material according to claim 1, characterized in that, The glass powder contains 68.57% SiO2 and 0.78% Al2O3; the red brick powder contains 59.34% SiO2 and 17.79% Al2O3.

4. The all-solid waste alkali-activated cementitious material according to claim 1, characterized in that, The desulfurized gypsum is a hemihydrate desulfurized gypsum with a density of 2.53 g / cm³. 3 Specific surface area is 259m² 2 / kg, with a median particle size of 15.6μm.

5. The all-solid waste alkali-activated cementitious material according to claim 1, characterized in that, The alkali activator is a composite alkali activator, comprising, by weight, 10-30 parts sodium hydroxide and 150-200 parts water glass; the modulus of the alkali activator is in the range of 1.2-1.

6.

6. The all-solid waste alkali-activated cementitious material according to claim 5, characterized in that, The sodium hydroxide is solid sodium hydroxide granules; the mass fraction of sodium hydroxide in the solid sodium hydroxide granules is ≥96%, and the density is 2.13 g / cm³. 3 The solubility is 1090 g / L; the initial modulus of the water glass is 3.3, and the solid content is 35.5%.

7. The all-solid waste alkali-activated cementitious material according to claim 1, characterized in that, The sodium sulfate is anhydrous sodium sulfate granules; the anhydrous sodium sulfate granules contain ≥99% sodium sulfate by mass, ≤0.005% water-insoluble matter, and have a density of 2.68 g / mL; the sodium tripolyphosphate is solid sodium tripolyphosphate granules; the solid sodium tripolyphosphate granules contain ≤0.05% water-insoluble matter; the silane coupling agent is KH-560.

8. A method for preparing an all-solid waste alkali-activated cementitious material, characterized in that, The preparation of the all-solid waste alkali-activated cementitious material according to any one of claims 1-7 includes the following steps: S1. Waste glass is sequentially washed, dried, ball-milled, passed through a 1250-mesh sieve, and calcined at 400℃ for 4 hours to obtain glass powder; waste red bricks are sequentially crushed, ground, impurity removed, dried, passed through a 600-mesh sieve, and pretreated with acetic acid to obtain red brick powder; the desulfurized gypsum to be treated is calcined at 180℃ for 4 hours to obtain desulfurized gypsum. S2. Weigh 10-30 parts by weight of solid sodium hydroxide granules and 150-200 parts by weight of water glass, mix and stir until the solid sodium hydroxide granules are completely dissolved, and let stand and cool at room temperature for 24 hours to obtain the alkali activator. S3. By weight, weigh 300-400 parts blast furnace slag, 150-350 parts glass powder, 30-200 parts red brick powder, 40-70 parts desulfurized gypsum, 160-260 parts alkali activator, 10-30 parts sodium sulfate, 30-40 parts sodium tripolyphosphate, 0.4-5 parts silane coupling agent and 200-400 parts water; S4. Mix 300-400 parts of blast furnace slag, 150-350 parts of glass powder, 30-200 parts of red brick powder and 40-70 parts of desulfurized gypsum for 3 minutes to obtain a mixed dry material. S5. Mix 160-260 parts of alkali activator, 10-30 parts of sodium sulfate, 30-40 parts of sodium tripolyphosphate, 0.4-5 parts of silane coupling agent and 200-400 parts of water evenly, then pour the mixture into the dry mixture and stir for 2 minutes to obtain a uniform alkali-activated slurry. S6. Inject the alkali-activated slurry into the mold, vibrate to compact it, and cover it with a film. After 24 hours, remove the mold and cure to obtain the solid waste alkali-activated cementitious material.

9. The method for preparing an all-solid waste alkali-activated cementitious material according to claim 8, characterized in that, The acetic acid pretreatment described in S1 involves soaking red brick powder that has passed through a 600-mesh sieve in an acetic acid solution with a concentration of 0.5 mol / L to 2.0 mol / L at a solid-liquid ratio of 1 g: (5-20) mL for 0.5 h to 24 h, followed by filtration, washing, and drying.

10. The method for preparing an all-solid waste alkali-activated cementitious material according to claim 8, characterized in that, The curing temperature described in S6 is 20±2℃, and the humidity is ≥95%; the curing is carried out in a standard curing chamber and is performed until the specified test age.

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