A slag-based non-fired building material and a method for preparing the same

Abstract

This invention provides a non-fired building material based on construction waste, comprising the following components by mass: 90-120 parts of construction waste, 7-16 parts of a five-dimensional composite system, and 12-20 parts of water; wherein the five-dimensional composite system comprises the following components by mass: 4-8 parts of a composite activator, 1-3 parts of reinforcing fibers, 2-5 parts of a functional modifier, 0.4-1.6 parts of attapulgite, and 0.05-0.2 parts of a surfactant. This invention constructs a five-dimensional synergistic strengthening mechanism of "activation-reinforcement-modification-regulation-dispersion." The surfactant, as the dispersion dimension, ensures uniform component distribution; the attapulgite, as the regulation dimension, stabilizes the reaction environment; the composite activator, as the activation dimension, lays the foundation for strength; the fibers, as the reinforcement dimension, compensate for matrix brittleness; and the functional modifier, as the modification dimension, improves durability.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization and green building materials. Specifically, it relates to a slag-based non-fired building material and its preparation method; more specifically, it relates to a five-dimensional reinforced ultra-high utilization rate slag-based non-fired brick and its preparation method. Background Technology

[0002] With the continuous acceleration of urbanization and the expansion of engineering construction scale, the annual discharge of construction waste is showing a surge. Traditional methods of waste disposal mainly involve stockpiling and landfilling, which not only occupy a large amount of land resources but also easily cause prominent environmental problems such as dust pollution and soil erosion. Against this backdrop, the resource utilization technology of non-fired bricks has gradually become a research hotspot in the field of construction waste resource utilization due to its advantages such as low carbon emissions, environmental friendliness, and low energy consumption. However, the technology still faces multiple bottlenecks in practical applications, mainly in the following five aspects: (1) The contradiction between solid waste utilization rate and material performance is prominent: In existing patented technologies, the amount of engineering slag is mostly in the range of 50%-70%. While pursuing high content, it is often difficult to achieve synergistic improvement of strength and toughness. It generally has the inherent defect of "strong but brittle, tough but weak", which limits its application in high-performance scenarios such as load-bearing structural components; (2) The multi-component dispersion is uneven and the microstructure is difficult to control: In the process of material preparation, functional components such as nanomaterials, natural clay, and reinforcing fibers are prone to agglomeration, resulting in uneven distribution in the matrix, which in turn causes significant differences in microstructure. (2) The material properties fluctuate greatly, with the coefficient of variation generally exceeding 10%, which seriously affects the consistency and reliability of the product; (3) The multiphase interface bonding performance is poor, and the mechanical transfer efficiency is limited: the interfacial bonding force between the matrix and the reinforcing phases such as fibers, nanoparticles, and clay is weak, and there are obvious gaps in the interface transition zone. Under the load, it is difficult to achieve effective stress transfer, which weakens the overall mechanical properties and long-term durability of the composite material; (4) Insufficient adaptability to complex working conditions: the existing technology has poor applicability to inferior slag soil with high organic matter and high salt content. At the same time, under extreme environmental conditions such as low temperature and humidity, the material curing process is easily disturbed, leading to performance degradation, which makes it difficult to meet the usage requirements of diverse engineering environments. Summary of the Invention

[0003] To address the above problems, the present invention aims to provide a non-fired building material based on slag and its preparation method.

[0004] A non-fired building material based on slag soil comprises the following components by mass: 90-120 parts of engineering slag soil, 7-16 parts of a five-dimensional composite system, and 12-20 parts of water; wherein the five-dimensional composite system comprises the following components by mass: 4-8 parts of a composite activator, 1-3 parts of reinforcing fiber, 2-5 parts of a functional modifier, 0.4-1.6 parts of attapulgite, and 0.05-0.2 parts of a surfactant.

[0005] Preferably, the composition includes the following components by mass: 100-110 parts of engineering waste soil, 9-13 parts of a five-dimensional composite system, and 14-16 parts of water; wherein the five-dimensional composite system includes: a composite activator, reinforcing fibers, a functional modifier, attapulgite, and a surfactant.

[0006] Preferably, the composite activator includes one or more of inorganic alkali, slag powder, and metakaolin; wherein the inorganic alkali includes one or more of sodium hydroxide and potassium hydroxide.

[0007] Preferably, the composite activator comprises the following components by mass parts: 2-4 parts of inorganic alkali; 1-3 parts of slag powder; 1-3 parts of metakaolin; wherein the inorganic alkali comprises the following components by mass parts: 3-6 parts of sodium hydroxide; 1 part of potassium hydroxide.

[0008] Preferably, the functional modifier includes one or more of graphene quantum dots, biomineralizing bacteria, and nano-calcium carbonate.

[0009] Preferably, the functional modifier comprises the following components in parts by mass: 0.05-0.1 parts graphene quantum dots; 0.5-1 parts Bacillus pasteurellii; and 1.45-3.95 parts nano-calcium carbonate.

[0010] Preferably, the attapulgite clay is activated by calcination at 270-360℃ for 3-5 hours and / or modified with 3%-5% silane coupling agent.

[0011] Preferably, the surfactant includes one or more of the following: nonionic hydrophobic modified polyethylene glycol PEG-6000, Tween 80, and fatty alcohol polyoxyethylene ether AEO-9.

[0012] Preferably, the moisture content of the engineering waste soil is ≤20% or / and the organic matter content is ≤10%.

[0013] This invention also provides a method for preparing a slag-based non-fired building material, characterized in that the method for preparing the slag-based non-fired building material as described in any of the above-mentioned methods includes the following steps:

[0014] Step S1: Raw material pretreatment, wherein the raw materials include one or more of the following: engineering waste soil, attapulgite soil, and surfactants;

[0015] Step S2: Add pretreated engineering waste soil, composite activator, and nano calcium carbonate to the mortar mixer and dry mix for 5-8 minutes; then add pretreated attapulgite soil and continue dry mixing for 3-5 minutes; finally add reinforcing fibers and dry mix for 3-5 minutes.

[0016] Step S3: Five-dimensional fusion of wet materials, wherein the wet materials include functional modifiers and aqueous solutions containing surfactants. After mixing the wet materials, add the dry materials and stir for 8-12 minutes, controlling the moisture content to 12%-16%.

[0017] Step S4, Compression molding: Bidirectional static pressure molding, pressure 10-20MPa, holding pressure for 40s;

[0018] Step S5: Activate at room temperature (20-25℃) for 6-8 hours, then accelerate curing at medium temperature (40-50℃) for 12-16 hours, and finally stabilize curing at low temperature (15-20℃) for 24-36 hours to obtain the finished non-fired brick.

[0019] The beneficial effects of this invention, which provides a non-fired building material based on slag and its preparation method, are as follows: Compared with existing technologies, this invention breaks through the limitations of existing single / three-dimensional optimization, constructing a five-dimensional closed loop of "activation (chemical basis) - enhancement (mechanical support) - modification (performance optimization) - regulation (process stability) - dispersion (uniformity assurance)," with each dimension supporting the others. Specifically, the dispersion dimension ensures the uniform distribution of the activation, enhancement, modification, and regulation components, avoiding local failures; the regulation dimension optimizes the rheological properties of the system, providing a stable reaction environment for the other four-dimensional mechanisms; the activation dimension improves the reaction conversion rate, enhancing the effects of enhancement and modification; the enhancement dimension alleviates the internal stress caused by modification and regulation, ensuring structural stability; and the modification dimension improves interfacial bonding and durability, extending the service life of other dimensions. The non-fired brick slag material prepared by this invention has a slag content ≥85%, a compressive strength of 20-30 MPa, a flexural strength ≥4.0 MPa, a water absorption rate ≤6%, and a freeze-thaw strength loss ≤15%, with comprehensive performance far exceeding existing technologies. Meanwhile, the molding cycle is shortened by 5%-10%, the process error tolerance is increased by 11.8%, it can handle complex engineering waste soil with organic matter ≤10%, it is suitable for low temperature and humid environments, requires no new equipment, and the cost remains basically the same. It effectively solves the technical problem that existing technologies only focus on single or three-dimensional performance optimization, resulting in many limitations in their use.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 Flowchart of the preparation process for non-fired building materials based on slag soil;

[0023] Figure 2 The image shows the compressive strength test results of the unfired bricks prepared in Example 1. Detailed Implementation

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] Please see Figure 1 and Figure 2 A non-fired building material based on construction waste comprises the following components by weight: 90-120 parts of construction waste, 7-16 parts of a five-dimensional composite system, and 12-20 parts of water. The five-dimensional composite system comprises the following components by weight: 4-8 parts of a composite activator, 1-3 parts of reinforcing fibers, 2-5 parts of a functional modifier, 0.4-1.6 parts of attapulgite, and 0.05-0.2 parts of a surfactant. These five components form a five-dimensional synergistic mechanism of "activation-reinforcement-modification-regulation-dispersion." More specifically, the preferred proportions are 100-110 parts of construction waste, 9-13 parts of the five-dimensional composite system, and 14-16 parts of water.

[0026] As a specific embodiment of the present invention, the engineering waste soil has a moisture content of ≤20% and an organic matter content of ≤10%, and is used to provide a reaction matrix for the five-dimensional mechanism.

[0027] In one specific embodiment of the present invention, the composite activator includes one or more of inorganic alkali, slag powder, and metakaolin. The inorganic alkali includes one or more of sodium hydroxide and potassium hydroxide.

[0028] In some feasible embodiments, the composite activator comprises the following components by mass parts: 2-4 parts inorganic alkali; 1-3 parts slag powder; and 1-3 parts metakaolin. The inorganic alkali comprises the following components by mass parts: 3-6 parts sodium hydroxide; and 1 part potassium hydroxide.

[0029] In any feasible embodiment, the composite activator is obtained by compounding inorganic alkali, slag powder, and metakaolin in a mass ratio of 2:1:1; wherein the inorganic alkali is obtained by mixing sodium hydroxide and potassium hydroxide in a mass ratio of 3:1. Specifically, the inorganic alkali is used to provide a highly alkaline environment with a pH ≥ 13. The slag powder and metakaolin synergistically catalyze the dissociative polymerization of silicon and aluminum, resulting in a geopolymer reaction conversion rate ≥ 90%, laying the chemical foundation for strength.

[0030] In one specific embodiment of the present invention, the reinforcing fiber is silane coupling agent modified basalt fiber. The preparation process of the modified basalt fiber is as follows: the basalt fiber is washed with acetone, dried at 105°C, then immersed in an alcohol / water (9:1) solution (pH 3-5) containing 0.5%-2% silane coupling agent, treated at room temperature to 70°C for 5-30 minutes, rinsed, and dried and cured at 105-120°C to complete the modification. The length of the reinforcing fiber is 6-12 mm, and the tensile strength is ≥3500 MPa. The reinforcing fiber is used to construct a microscopic mechanical support network, achieving crack bridging and improving toughness.

[0031] As a specific embodiment of the present invention, the surfactant includes one or more of nonionic hydrophobic modified polyethylene glycol PEG-6000, Tween 80, and fatty alcohol polyoxyethylene ether AEO-9.

[0032] In some feasible embodiments, the surfactant is preferably a nonionic hydrophobically modified polyethylene glycol PEG-6000 (molecular weight 6000, hydrophobicity 30%), with Tween 80 and AEO-9 as alternatives. The surfactant is used to reduce interfacial tension and solve the problem of multi-component agglomeration.

[0033] As a specific embodiment of the present invention, the functional modifier includes one or more of graphene quantum dots, biomineralizing bacteria, and nano-calcium carbonate, wherein the biomineralizing bacteria includes Bacillus pasteurellii with a bacterial concentration ≥10. 8 CFU / mL.

[0034] In some feasible embodiments, the functional modifier includes graphene quantum dots, biomineralizing bacteria and nano-calcium carbonate in a mass ratio of 1:10:39, wherein the biomineralizing bacteria is Bacillus pasteurellii.

[0035] In any feasible embodiment, the functional modifier is composed of graphene quantum dots (0.05-0.1 parts), biomineralizing bacteria (0.5-1 parts), and nano-calcium carbonate (1.45-3.95 parts). The functional modifier is used to achieve multi-scale matrix densification, pore sealing, and improved durability.

[0036] As a specific embodiment of the present invention, attapulgite is activated by calcination at 270-360℃ for 3-5 hours and / or modified with 3%-5% silane coupling agent. In any feasible embodiment, the preparation process of modified attapulgite can be as follows: attapulgite is crushed and ground through a 200-mesh sieve, calcined at a constant temperature of 270-360℃ for 3-5 hours, cooled in the furnace, and then 0.3%-0.5% by mass of an ethanol-water solution of silane coupling agent (solid-liquid ratio 1:3-1:5) is added. The mixture is stirred and impregnated at 40-50℃ for 30-60 minutes, filtered, and dried at 80-105℃ until the moisture content is ≤1%. The modified attapulgite is then obtained by grinding and breaking it down.

[0037] In some feasible embodiments, attapulgite is successively activated by calcination at 270-360°C for 3-5 hours and modified with 3%-5% silane coupling agent.

[0038] In any feasible embodiment, attapulgite is successively activated by calcination at 270°C for 3 hours and modified with 3%-5% silane coupling agent to optimize rheological properties and process stability, making it suitable for complex engineering waste and extreme environments.

[0039] This invention provides a non-fired building material based on slag soil. It achieves five-dimensional reinforcement through the synergistic interaction of these components: a composite activator as the activation dimension, reinforcing fibers as the reinforcement dimension, a functional modifier as the modification dimension, attapulgite as the regulation dimension, and a surfactant as the dispersion dimension. Specifically, this invention overcomes the limitations of existing single / three-dimensional optimization methods by constructing a five-dimensional closed loop: "Activation (chemical basis) - Reinforcement (mechanical support) - Modification (performance optimization) - Regulation (process stability) - Dispersion (uniformity assurance)," with each dimension mutually supporting the others. Specifically, the dispersion dimension ensures the uniform distribution of the activation, reinforcement, modification, and regulation components, avoiding localized failures; the regulation dimension optimizes the system's rheological properties, providing a stable reaction environment for the other four-dimensional mechanisms; the activation dimension improves reaction conversion rate, enhancing the effects of reinforcement and modification; the reinforcement dimension alleviates internal stress caused by modification and regulation, ensuring structural stability; and the modification dimension improves interfacial bonding and durability, extending the service life of the other dimensions. The non-fired brick slag prepared by this invention has an admixture content of ≥85%, a compressive strength of 20-30 MPa, a flexural strength of ≥4.0 MPa, a water absorption rate of ≤6%, and a freeze-thaw strength loss of ≤15%, with comprehensive performance far exceeding existing technologies. Simultaneously, the molding cycle is shortened by 5%-10%, the process error tolerance is increased by 11.8%, it can handle complex engineering slag with organic matter ≤10%, it is suitable for low-temperature and humid environments, requires no additional equipment, and maintains a relatively stable cost. This effectively solves the technical problem that existing technologies only focus on single or three-dimensional performance optimization, leading to numerous limitations in application.

[0040] This invention also provides a method for preparing a slag-based non-fired building material, used to prepare any of the slag-based non-fired building materials described above. Please refer to [link to relevant documentation]. Figure 1 and Figure 2 This includes the following steps:

[0041] Step S1: Raw material pretreatment, wherein the raw materials include one or more of the following: engineering waste soil, attapulgite soil, and surfactant.

[0042] In any feasible embodiment, the pretreatment process for construction waste soil is as follows: the construction waste soil is first dried, and then screened to remove impurities. When the organic matter content is >5%, it is treated with 1% hydrogen peroxide to remove excessive organic matter from the construction waste soil and purify it to improve its engineering performance.

[0043] In any feasible embodiment, the pretreatment process of attapulgite is as follows: first, it is activated by calcination at 270°C for 3 hours, and then modified with 3%-5% silane coupling agent. The silane coupling agent can be γ-(methacryloyloxy)propyltrimethoxysilane or γ-aminopropyltriethoxysilane.

[0044] In any feasible embodiment, the surfactant pretreatment involves mixing a solid surfactant into water, then heating at 60°C and stirring for 5-8 minutes until the solid surfactant is completely dissolved.

[0045] Step S2: Five-dimensional pretreatment of dry materials, wherein the dry materials include one or more of the following: engineering waste soil, composite activator, nano calcium carbonate, attapulgite, and reinforcing fibers.

[0046] In some feasible embodiments, the five-dimensional pretreatment process of dry materials includes: adding pretreated engineering waste soil, composite activator, and nano-calcium carbonate to a mortar mixer and dry mixing for 5-8 minutes; then adding pretreated attapulgite soil and continuing to dry mix for 3-5 minutes; and finally adding reinforcing fibers and dry mixing for 3-5 minutes.

[0047] Step S3: Five-dimensional fusion of wet materials, wherein the wet materials include functional modifiers and aqueous solutions containing surfactants. After mixing the wet materials, add the dry materials and stir for 8-12 minutes, controlling the moisture content to 12%-16%.

[0048] In some feasible embodiments, the wet material five-dimensional fusion process includes: first, mixing an aqueous solution containing surfactant with graphene quantum dots and biomineralizing agents, and ultrasonically dispersing for 10-15 minutes; then gradually adding the ultrasonically mixed solution to the dry material and stirring for 8-12 minutes, controlling the water content to 12%-16%.

[0049] Step S4, Compression molding: Bidirectional static pressure molding, pressure 10-20MPa, holding pressure for 40s.

[0050] Step S5, Gradient Curing: First, activate at room temperature (20-25℃) for 6-8 hours, then accelerate curing at medium temperature (40-50℃) for 12-16 hours, and finally stabilize curing at low temperature (15-20℃) for 24-36 hours to obtain the finished non-fired bricks. Test their compressive strength, flexural strength, water absorption, and frost resistance.

[0051] Example 1

[0052] A non-fired building material based on construction waste comprises the following components by weight: 105 parts of construction waste, 12 parts of a five-dimensional composite system, and 15 parts of water. The five-dimensional composite system comprises the following components by weight: 5.5 parts of a composite activator, 2.0 parts of reinforcing fiber, 3.5 parts of a functional modifier, 0.825 parts of attapulgite (15% activator), and 0.12 parts of nonionic hydrophobic modified polyethylene glycol PEG-6000. More specifically, the functional modifier comprises the following components by weight: 0.07 parts of graphene quantum dots; 0.7 parts of Bacillus pasteurellii; and 2.73 parts of nano-calcium carbonate.

[0053] The preparation method of this slag-based non-fired building material includes the following steps:

[0054] Step S1: Raw material pretreatment, wherein the raw materials include: engineering waste soil, attapulgite, and surfactant. The engineering waste soil is first dried, then screened to remove impurities. When the organic matter content is >5%, it is treated with 1% hydrogen peroxide. The attapulgite pretreatment process is as follows: first, it is activated by calcination at 270℃ for 3 hours, then modified with 3%-5% silane coupling agent. The surfactant pretreatment process is as follows: the solid surfactant is mixed into water, then heated at 60℃ and stirred for 6 minutes until the solid surfactant is completely dissolved.

[0055] Step S2: Add pretreated engineering waste soil, composite activator, and nano calcium carbonate to the mortar mixer and dry mix for 6 minutes; then add pretreated attapulgite soil and continue dry mixing for 3 minutes; finally add reinforcing fibers and dry mix for 4 minutes.

[0056] Step S3: First, mix the aqueous solution containing surfactant with graphene quantum dots and biomineralizing bacteria, and then ultrasonically disperse for 10 minutes; then gradually add the ultrasonically dispersed solution to the dry material and stir for 10 minutes, controlling the water content to 14%.

[0057] Step S4, Compression molding: Bidirectional static pressure molding, pressure 15MPa, holding pressure for 40s.

[0058] Step S5: First, activate at room temperature (25℃) for 7 hours, then accelerate curing at medium temperature (40℃) for 14 hours, and finally stabilize curing at low temperature (15℃) for 30 hours to obtain the finished non-fired bricks. Then, test their compressive strength, flexural strength, water absorption rate, and frost resistance.

[0059] Example 2: Increasing the amount of attapulgite soil added

[0060] A non-fired building material based on construction waste comprises the following components by weight: 105 parts of construction waste, 12 parts of a five-dimensional composite system, and 15 parts of water. The five-dimensional composite system comprises the following components by weight: 5.5 parts of a composite activator, 2.0 parts of reinforcing fiber, 3.5 parts of a functional modifier, 1.1 parts of attapulgite (20% activator), and 0.12 parts of nonionic hydrophobic modified polyethylene glycol PEG-6000. More specifically, the functional modifier comprises the following components by weight: 0.07 parts of graphene quantum dots; 0.7 parts of Bacillus pasteurellii; and 2.73 parts of nano-calcium carbonate.

[0061] The preparation method of this slag-based non-fired building material includes the following steps:

[0062] Step S1: Raw material pretreatment, wherein the raw materials include: engineering waste soil, attapulgite, and surfactant. The engineering waste soil is first dried, then screened to remove impurities. When the organic matter content is >5%, it is treated with 1% hydrogen peroxide. The attapulgite pretreatment process is as follows: first, it is activated by calcination at 270℃ for 3 hours, then modified with 3%-5% silane coupling agent. The surfactant pretreatment process is as follows: the solid surfactant is mixed into water, then heated at 60℃ and stirred for 6 minutes until the solid surfactant is completely dissolved.

[0063] Step S2: Add pretreated engineering waste soil, composite activator, and nano calcium carbonate to the mortar mixer and dry mix for 6 minutes; then add pretreated attapulgite soil and continue dry mixing for 5 minutes; finally add reinforcing fibers and dry mix for 5 minutes.

[0064] Step S3: First, mix the aqueous solution containing surfactant with graphene quantum dots and biomineralizing bacteria, and then ultrasonically disperse for 10 minutes; then gradually add the ultrasonically dispersed solution to the dry material and stir for 10 minutes, controlling the water content to 14%.

[0065] Step S4, Compression molding: Bidirectional static pressure molding, pressure 15MPa, holding pressure for 40s.

[0066] Step S5: First, activate at room temperature (25℃) for 7 hours, then accelerate curing at medium temperature (40℃) for 14 hours, and finally stabilize curing at low temperature (15℃) for 30 hours to obtain the finished non-fired bricks. Then, test their compressive strength, flexural strength, water absorption rate, and frost resistance.

[0067] Example 3: Surfactant Substitution

[0068] A non-fired building material based on construction waste comprises the following components by weight: 105 parts of construction waste, 12 parts of a five-dimensional composite system, and 15 parts of water. The five-dimensional composite system comprises the following components by weight: 5.5 parts of a composite activator, 2.0 parts of reinforcing fiber, 3.5 parts of a functional modifier, 0.825 parts of attapulgite (15% activator), and 0.12 parts of Tween-80 (HLB=15.0). More specifically, the functional modifier comprises the following components by weight: 0.07 parts of graphene quantum dots; 0.7 parts of Bacillus pasteurellii; and 2.73 parts of nano-calcium carbonate.

[0069] The preparation method of this slag-based non-fired building material includes the following steps:

[0070] Step S1: Raw material pretreatment, wherein the raw materials include: engineering waste soil, attapulgite, and surfactant. The engineering waste soil is first dried, then screened to remove impurities. When the organic matter content is >5%, it is treated with 1% hydrogen peroxide. The attapulgite pretreatment process is as follows: first, it is activated by calcination at 270℃ for 3 hours, then modified with 3%-5% silane coupling agent. The surfactant pretreatment process is as follows: the solid surfactant is mixed into water, then heated at 50℃ and stirred for 6 minutes until the solid surfactant is completely dissolved.

[0071] Step S2: Add pretreated engineering waste soil, composite activator, and nano calcium carbonate to the mortar mixer and dry mix for 6 minutes; then add pretreated attapulgite soil and continue dry mixing for 3 minutes; finally add reinforcing fibers and dry mix for 4 minutes.

[0072] Step S3: First, mix the aqueous solution containing surfactant with graphene quantum dots and biomineralizing bacteria, and then ultrasonically disperse for 10 minutes; then gradually add the ultrasonically dispersed solution to the dry material and stir for 10 minutes, controlling the water content to 14%.

[0073] Step S4, Compression molding: Bidirectional static pressure molding, pressure 15MPa, holding pressure for 40s.

[0074] Step S5: First, activate at room temperature (25℃) for 7 hours, then accelerate curing at medium temperature (40℃) for 14 hours, and finally stabilize curing at low temperature (15℃) for 30 hours to obtain the finished non-fired bricks. Then, test their compressive strength, flexural strength, water absorption rate, and frost resistance.

[0075] Example 4: Functional Modifier Adjustment

[0076] A non-fired building material based on construction waste comprises the following components by weight: 105 parts of construction waste, 12 parts of a five-dimensional composite system, and 15 parts of water. The five-dimensional composite system comprises the following components by weight: 5.5 parts of a composite activator, 2.0 parts of reinforcing fiber, 3.5 parts of a functional modifier, 0.825 parts of attapulgite (15% activator), and 0.12 parts of nonionic hydrophobic modified polyethylene glycol PEG-6000. More specifically, the functional modifier comprises the following components by weight: 0.1 parts of graphene quantum dots; 0.6 parts of Bacillus pasteurellii; and 2.8 parts of nano-calcium carbonate.

[0077] The preparation method of this slag-based non-fired building material includes the following steps:

[0078] Step S1: Raw material pretreatment, wherein the raw materials include: engineering waste soil, attapulgite, and surfactant. The engineering waste soil is first dried, then screened to remove impurities. When the organic matter content is >5%, it is treated with 1% hydrogen peroxide. The attapulgite pretreatment process is as follows: first, it is activated by calcination at 270℃ for 3 hours, then modified with 3%-5% silane coupling agent. The surfactant pretreatment process is as follows: the solid surfactant is mixed into water, then heated at 60℃ and stirred for 6 minutes until the solid surfactant is completely dissolved.

[0079] Step S2: Add pretreated engineering waste soil, composite activator, and nano calcium carbonate to the mortar mixer and dry mix for 6 minutes; then add pretreated attapulgite soil and continue dry mixing for 3 minutes; finally add reinforcing fibers and dry mix for 4 minutes.

[0080] Step S3: First, mix the aqueous solution containing surfactant with graphene quantum dots and biomineralizing bacteria, and then ultrasonically disperse for 12 minutes; then gradually add the ultrasonically dispersed solution to the dry material and stir for 10 minutes, controlling the water content to 14%.

[0081] Step S4, Compression molding: Bidirectional static pressure molding, pressure 15MPa, holding pressure for 40s.

[0082] Step S5: First, activate at room temperature (25℃) for 7 hours, then accelerate curing at medium temperature (40℃) for 14 hours, and finally stabilize curing at low temperature (15℃) for 30 hours to obtain the finished non-fired bricks. Then, test their compressive strength, flexural strength, water absorption rate, and frost resistance.

[0083] Example 5: Adjustment of Construction Waste

[0084] A non-fired building material based on construction waste comprises the following components by weight: 105 parts of construction waste, 13 parts of a five-dimensional composite system, and 15 parts of water. The five-dimensional composite system comprises the following components by weight: 6 parts of a composite activator, 2.2 parts of reinforcing fiber, 3.8 parts of a functional modifier, 0.9 parts of attapulgite (15% activator), and 0.15 parts of nonionic hydrophobic modified polyethylene glycol PEG-6000. More specifically, the functional modifier comprises the following components by weight: 0.07 parts of graphene quantum dots; 0.7 parts of Bacillus pasteurellii; and 2.73 parts of nano-calcium carbonate.

[0085] The preparation method of this slag-based non-fired building material includes the following steps:

[0086] Step S1: Raw material pretreatment, wherein the raw materials include: engineering waste soil, attapulgite, and surfactant. The engineering waste soil is first dried and then screened to remove impurities. The organic matter content of this engineering waste soil is 9.5%. It is treated with 1% hydrogen peroxide for 40 minutes, and then the salt content of the engineering waste soil is adjusted to 0.8%. The attapulgite pretreatment process is as follows: first, it is activated by calcination at 270℃ for 3 hours, and then modified with 3%-5% silane coupling agent. The surfactant pretreatment process is as follows: the solid surfactant is mixed into water, then heated at 60℃ and stirred for 6 minutes until the solid surfactant is completely dissolved.

[0087] Step S2: Add pretreated engineering waste soil, composite activator, and nano calcium carbonate to the mortar mixer and dry mix for 6 minutes; then add pretreated attapulgite soil and continue dry mixing for 4 minutes; finally add reinforcing fibers and dry mix for 4 minutes.

[0088] Step S3: First, mix the aqueous solution containing surfactant with graphene quantum dots and biomineralizing bacteria, and then ultrasonically disperse for 10 minutes; then gradually add the ultrasonically dispersed solution to the dry material and stir for 10 minutes, controlling the water content to 14%.

[0089] Step S4, Compression molding: Bidirectional static pressure molding, pressure 15MPa, holding pressure for 40s.

[0090] Step S5: First, activate at room temperature (25℃) for 7 hours, then accelerate curing at medium temperature (40℃) for 14 hours, and finally stabilize curing at low temperature (15℃) for 30 hours to obtain the finished non-fired bricks. Then, test their compressive strength, flexural strength, water absorption rate, and frost resistance.

[0091] Performance index test results

[0092] compressive strength MPa 26.8 25.5 26.2 29.7 24.8 Flexural strength MPa 4.9 4.6 4.8 5.0 4.5 Water absorption rate % 4.3 4.8 4.5 4.2 4.7 Freeze resistance (50 freeze-thaw cycles) Strength loss rate % 2.4 2.8 2.6 1.8 2.7 Component aggregation rate (nano-components) % 3.5 4.8 3.7 3.2 4.2 Intensity variation coefficient % 2.3 2.6 2.4 2.2 2.5

[0093] Comparative analysis of data from different implementation examples

[0094] (1) Effect of attapulgite content (Example 1 vs Example 2)

[0095] Increasing the attapulgite content from 15% to 20% of the activator resulted in a 4.9% decrease in compressive strength (26.8→25.5MPa) and a 10.4% increase in water absorption (4.3→4.8%). This is because excessive attapulgite tends to agglomerate (agglomeration rate increased from 3.5%→4.8%), which compromises the compactness of the matrix.

[0096] Conclusion: The optimal dosage of attapulgite is 10%-15% of the total mass of the activator; excessive dosage will weaken the five-dimensional synergistic effect.

[0097] (2) Effect of surfactant substitution (Example 1 vs. Example 3):

[0098] After replacing PEG-6000 with Tween-80, the various properties remained basically stable (compressive strength decreased by only 1.6%, and freeze-thaw loss increased by 0.2 percentage points), and the agglomeration rate was controlled at 3.7%.

[0099] Conclusion: Nonionic surfactants (such as PEG-6000 and Tween 80) are all suitable for this system, with high process tolerance, providing multiple options for industrial production.

[0100] (3) Effect of functional modifier optimization (Example 1 vs Example 4):

[0101] Increasing the graphene quantum dot content from 0.07 parts to 0.1 parts resulted in a 10.8% increase in compressive strength (26.8 → 29.7 MPa), a 0.6 percentage point decrease in freeze-thaw resistance loss, and a more significant nano-strengthening effect.

[0102] Conclusion: Reasonable fine-tuning of nano-components in functional modifiers can further improve performance. The formulation range of this invention has room for optimization and can be adapted to different performance requirement scenarios.

[0103] (4) Impact of complex spoil compatibility (Example 1 vs. Example 5):

[0104] For complex slag soil with 9.5% organic matter and 0.8% salt content, the performance decreased (compressive strength 26.8→24.8MPa), and the coefficient of variation of strength was controlled at 2.5%.

[0105] The solution adopted in this application significantly improves the adaptability of complex slag soil by synergistically combining the adsorption of impurities by attapulgite soil, the dispersion of surfactants, and the efficient reaction of composite activators, breaking through the upper limit of organic matter tolerance in existing technologies (5%→10%).

[0106] (III) Analysis of Core Performance Advantages

[0107] Strength synergy: The compressive strength of all five embodiments is ≥24MPa, the flexural strength is ≥4.0MPa, and the strength ratio (compressive / flexural) is stable at 5.4-5.6, demonstrating the synergistic advantage of "high strength + high toughness" and solving the defect of "strong but brittle" in the existing technology;

[0108] Durability and stability: Water absorption rate ≤4.8%, freeze-thaw strength loss ≤2.8%, far superior to the existing technology's 15% water absorption rate and 25% freeze-thaw loss, suitable for extreme environments such as low temperature and humidity;

[0109] Process stability: The coefficient of variation of strength is ≤2.6% and the agglomeration rate of components is ≤4.8%, which proves that the five-dimensional strengthening mechanism (especially the dispersion dimension) effectively solves the problem of uneven dispersion of multiple components and has strong consistency in industrial production.

[0110] Cost controllability: Even for complex slag and soil (Example 5), only minor adjustments to the dosage of composite activator and surfactant are required, without the need for additional equipment, and the cost is the same as or 3%-5% lower than that of existing technologies.

[0111] (iv) Verification conclusions of the examples

[0112] The solution adopted in this invention achieves excellent performance under different component ratios, different types of slag, and different functional component substitution scenarios, verifying the flexibility and stability of the technical solution. The preferred embodiment (Example 1) has the best overall performance and can be used as a benchmark solution for industrial production. Examples 3 (surfactant substitution) and 4 (functional modifier optimization) can be flexibly adjusted according to raw material supply and performance requirements. Example 5 provides a feasible path for the resource utilization of complex slag.

[0113] The performance data of the five embodiments are significantly better than the prior art, which fully demonstrates the inventiveness and novelty of the present invention, especially the breakthroughs in "ultra-high solid waste utilization rate + multi-performance synergy + complex working condition adaptation".

[0114] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A slag-based non-fired construction material, characterized in that, It comprises the following components by weight: 90-120 parts of engineering waste soil, 9-16 parts of a five-dimensional composite system, and 12-20 parts of water; wherein the five-dimensional composite system comprises the following components by weight: 4-8 parts of composite activator, 1-3 parts of reinforcing fiber, 2-5 parts of functional modifier, 0.4-1.6 parts of attapulgite, and 0.05-0.2 parts of surfactant; The composite activator includes one or more of inorganic alkali, slag powder, and metakaolin; wherein the inorganic alkali includes one or more of sodium hydroxide and potassium hydroxide. The functional modifier includes one or more of graphene quantum dots, biomineralizing bacteria, and nano-calcium carbonate.

2. The slag-based non-burnt construction material according to claim 1, characterized in that, It includes the following components by mass: 100-110 parts of engineering waste soil, 9-13 parts of a five-dimensional composite system, and 14-16 parts of water; wherein, the five-dimensional composite system includes: a composite activator, reinforcing fibers, a functional modifier, attapulgite, and a surfactant.

3. The slag-based non-burnt construction material according to claim 2, characterized in that, The composite activator comprises the following components by mass: 2-4 parts inorganic alkali; 1-3 parts slag powder; 1-3 parts metakaolin; wherein the inorganic alkali comprises the following components by mass: 3-6 parts sodium hydroxide; 1 part potassium hydroxide.

4. The slag-based non-fired building material according to claim 3, characterized in that, The functional modifier comprises the following components in parts by mass: 0.05-0.1 parts graphene quantum dots; 0.5-1 parts Bacillus pasteurellii; and 1.45-3.95 parts nano-calcium carbonate.

5. The slag-based non-fired building material according to claim 4, characterized in that, The attapulgite clay is activated by calcination at 270-360℃ for 3-5 hours and / or modified with 3%-5% silane coupling agent.

6. The slag-based non-fired building material according to claim 5, characterized in that, The surfactant includes one or more of the following: nonionic hydrophobic modified polyethylene glycol PEG-6000, Tween 80, and fatty alcohol polyoxyethylene ether AEO-9.

7. The slag-based non-fired building material according to claim 6, characterized in that, The moisture content of the construction waste soil is ≤20% or / and the organic matter content is ≤10%.

8. A method for preparing a slag-based non-fired building material, characterized in that, The preparation of the slag-based non-fired building material as described in any one of claims 1-7 includes the following steps: Step S1: Raw material pretreatment, wherein the raw materials include one or more of the following: engineering waste soil, attapulgite soil, and surfactants; Step S2: Add pretreated engineering waste soil, composite activator, and nano calcium carbonate to the mortar mixer and dry mix for 5-8 minutes; then add pretreated attapulgite soil and continue dry mixing for 3-5 minutes; finally add reinforcing fibers and dry mix for 3-5 minutes. Step S3: Five-dimensional fusion of wet materials, wherein the wet materials include functional modifiers and aqueous solutions containing surfactants. After mixing the wet materials, add the dry materials and stir for 8-12 minutes, controlling the moisture content to 12%-16%. Step S4, Compression molding: Bidirectional static pressure molding, pressure 10-20MPa, holding pressure for 40s; Step S5: Activate at room temperature (20-25℃) for 6-8 hours, then accelerate curing at medium temperature (40-50℃) for 12-16 hours, and finally stabilize curing at low temperature (15-20℃) for 24-36 hours to obtain the finished non-fired brick.

Images