Method for preparing alkali-activated slag solidified engineering slag soil and application and design method of formula thereof

Abstract

The present application relates to a kind of alkali-activated slag solidified engineering slag soil preparation method and application and its formula design method, belong to building material and resource utilization technical field, the design method calculates the blast furnace slag, sodium hydroxide, water glass and additional water needed to solidify different engineering slag soil;The preparation method comprises: according to formula quantity, engineering slag soil and blast furnace slag are mixed uniformly, to obtain dry material;According to formula quantity, sodium hydroxide, water glass and additional water are mixed uniformly, to obtain alkali-activator solution;Dry material and alkali-activator solution are mixed uniformly, to obtain alkali-activated slag solidified engineering slag soil.Compared with prior art, the present application takes alkali-activated slag solidified engineering slag soil as object, and proposes its formula rapid design method, which can directly calculate feasible formula according to the basic performance of engineering slag soil and the product performance requirement, avoid complex test debugging work, and then time and cost can be saved.

Description

Technical Field

[0001] This invention relates to the field of building materials and resource utilization technology, specifically to a method for preparing alkali-activated slag solidification engineering waste soil and its application, as well as a method for designing its formulation. Background Technology

[0002] In recent years, with the advancement of urbanization, underground space has been extensively developed and utilized, leading to a large number of construction projects such as underground buildings and subway tunnels, generating a significant amount of construction waste. The main component of construction waste is soil, including various types of clay, silt, and sand. Construction waste is characterized by its wide range of sources, complex composition, and significant regional variations. Specifically, the amount of construction waste generated exceeds 2 billion tons annually, far exceeding the city's own absorption capacity. Transporting construction waste to surrounding areas for landfill is not only costly, energy-intensive, and results in high carbon emissions, but also easily leads to soil erosion and environmental pollution. Therefore, it is necessary to utilize construction waste as a resource to "turn waste into treasure." The main directions for the resource utilization of construction waste include roadbed / foundation construction, preparation of building materials (including non-fired bricks, ceramsite, solidified soil, fluidized bed backfill, sintered bricks, etc.), and preparation of planting soil.

[0003] Among numerous technologies for the resource utilization of construction waste, the technology of preparing building materials from construction waste has high added value. For example, patents ZL201711382031.8 and ZL202010211686.4 disclose methods for preparing non-fired bricks using tunnel boring machine (TBM) waste and geopolymers; patent ZL202011202657.8 discloses a method for solidifying high-viscosity waste soil for use as backfill; and patent ZL201911422938.1 discloses a composite material of construction waste soil for 3D printing, its preparation method, and its application. This model, which uses construction waste soil as the main raw material and enhances its physical and mechanical properties with the help of a cementing material to produce various forms of products, can effectively utilize construction waste soil as a resource. However, in actual production, different types of construction waste products have different requirements for workability and mechanical properties (which can be simplified to different requirements for fluidity and compressive strength). For example, cast-in-place non-fired bricks require a fluidity greater than 160 mm and a compressive strength of 10 MPa to 20 MPa; fluid backfill material made from construction waste requires a fluidity of over 200 mm and a compressive strength of around 2 MPa; and 3D printing ink materials made from construction waste have extremely high fluidity requirements, approximately 160 to 180 mm. However, construction waste typically originates from different regions and at different excavation depths, resulting in complex composition and variable properties. This makes existing formulas prone to failure, necessitating the development of new formulas. The development of new formulas requires extensive testing and experimentation, a problem that has not yet been researched and resolved. Summary of the Invention

[0004] The purpose of this invention is to overcome at least one of the defects in the existing technology mentioned above by providing a method for preparing alkali-activated slag-solidified engineering waste soil, its application, and a method for designing its formulation. The formulation design targets alkali-activated slag-solidified engineering waste soil, whose main raw materials are engineering waste soil (including foundation pit soil, shield tunneling waste soil, road waste soil, etc.), blast furnace slag, sodium hydroxide (industrial flaky caustic soda), water glass (industrial purity or analytical purity is acceptable), and tap water. The objective of this invention is to quickly calculate the mixing formulation of the above raw materials so that the mixed product meets certain requirements for fluidity and compressive strength.

[0005] In other words, the design method of this invention is applicable to situations where engineering waste soil is used as raw material and alkali-activated slag is used as cementing material. It can provide a simple and convenient calculation method for the formulation of various types of products (including non-fired bricks, fluid fillers, 3D printing materials, etc.), thus avoiding complicated testing and debugging work, greatly improving the production efficiency of engineering waste soil resource utilization, and has great application potential.

[0006] This invention uses alkali-activated blast furnace slag as a cementing material because it has high application potential. Compared with traditional cement, lime, and other solidifying agents, it has better solidification effect and lower carbon emissions. Blast furnace slag is a common industrial solid waste with high pozzolanic activity, which can be used as a precursor for alkali activation. Under the catalysis of alkali activators (commonly used alkali activators are mainly water glass and sodium hydroxide), geopolymers are generated. Geopolymers have excellent mechanical properties and durability, making them a very promising building material and a high-quality, low-carbon cementing material.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] One of the objectives of this invention is to design a formula for alkali-activated slag solidification engineering slag soil, wherein the alkali-activated slag includes blast furnace slag and an alkali activator, and the alkali activator includes sodium hydroxide, water glass and added water;

[0009] The method for designing this formula includes the following steps:

[0010] Step 1: Measure the clay content (m) of the construction waste soil. C / m S , plastic limit w p Liquid limit w l and plasticity index I P ;

[0011] Step 2: Preset the required flowability F and compressive strength f according to the product type and application scenario. C ;

[0012] Step 3: Preset the mass ratio of blast furnace slag to engineering slag, i.e., the clay ratio B / S, and record it as m. B / m S If there is no clay ratio B / S at this time, then the clay ratio B / S is preset, based on the clay ratio B / S and the clay content m. C / m S Make a judgment if m C / (m S +m B )<0.37, with I L Calculate using (F) = (F - 140.16) / 64.32; if m C / (m S +m B )≥0.37, with I L The calculation is performed using (F) = (F - 104.95) / 85.56;

[0013] Step 4, using w B (F) = (F + 290.33) / 950 Calculate the water content w required to achieve the preset fluidity F in step two. B (F);

[0014] Step 5: The 7-day, 28-day, or 60-day compressive strength of the designed alkali-activated solidification engineering waste soil is recorded as f. C According to f C The value is used to calculate the water-cement ratio wc / B;

[0015] f C =317.28 / 11.82 (wc / B) 7-day compressive strength

[0016] f C =182.37 / 4.94 (wc / B) 28-day compressive strength

[0017] f C =202.93 / 5.14 (wc / B) 60-day compressive strength

[0018] Step Six: Based on the designed alkali concentration and modulus of the alkali-activated slag, and the I calculated in Steps Three, Four, and Five... L (F), w B (F) and wc / B, then calculate the clay ratio B / S of the alkali-activated slag solidification engineering slag soil according to the following formula, as well as the relative mass relationship of engineering slag soil, blast furnace slag, sodium hydroxide, water glass and added water;

[0019] I L (F)=[(m W +m WG *k3) / m S -wB (F)*(B / S)-w P ] / I P

[0020] B / S = m B / m S

[0021] w C / B=(m W +m WG *k3) / m B

[0022] Na2O%=(m SH *31 / 40+m WG *k1) / m B* 100%

[0023] Modulus = (m WG *k2 / 60) / (m SH / 80+m SH *k1 / 62)

[0024] Where k1 is the mass fraction of Na2O in the water glass; k2 is the mass fraction of SiO2 in the water glass; k3 is the mass fraction of water in the water glass; m SH m represents the mass of sodium hydroxide. B For blast furnace slag quality; m S For the quality of construction waste; m W For the mass of added water, m WG For water glass quality; w p Plastic limit of construction waste, %; I P The plasticity index of construction waste soil;

[0025] Step 7: Calculate the actual B / S ratio based on Step 6, and then check the m value in Step 4 accordingly. C / (m S +m B If the relationship between 0.37 and 0.37 is not correctly determined, it needs to be re-determined, and the formula needs to be recalculated starting from step four until it is correctly determined.

[0026] Step 8: Based on the calculations in Steps 1 to 7, obtain the clay-to-soil ratio (B / S) and water-to-cement ratio (wc / B) for alkali-activated slag-solidified engineering slag soil, as well as the relative mass relationships of engineering slag soil, blast furnace slag, sodium hydroxide, water glass, and added water. Then, calculate the required mass of engineering slag soil, blast furnace slag, sodium hydroxide, water glass, and added water based on the total amount of materials required for actual production. The formula calculated according to the above steps is for reference only and may have slight differences in fluidity and compressive strength compared to the actual prepared alkali-activated slag-solidified engineering slag soil. Fine-tuning can be made according to actual conditions.

[0027] Furthermore, the clay content m of the engineering waste soil C / m S The gradation curve of the engineering waste soil is obtained by measuring the moisture content using national standard SY / T5163–2018, or by using the moisture method specified in national standard GBT50123-2019, or by using a laser particle size analyzer. The proportion of fine particles with a particle size less than 0.002 mm in the engineering waste soil is taken as the clay content (m) of the engineering waste soil. C / m S Specifically, the clay content (m) of the tested engineering waste soil was determined. C / m S Specifically, according to the national standard SY / T 5163–2018, clay mineral analysis was performed on the engineering waste soil using an XRD diffractometer to analyze the clay mineral content (i.e., the proportion of clay minerals such as kaolinite, illite, montmorillonite, and chlorite) in the waste soil. This is the method for obtaining accurate values; the clay content m of the engineering waste soil... C / m S Alternatively, the gradation curve of the engineering waste soil can be obtained according to the moisture method specified in national standard GB / T50123-2019, or by using a laser particle size analyzer. The proportion of fine particles with a particle size less than 0.002 mm in the engineering waste soil can be approximated as the clay content (m) of the engineering waste soil. C / m S use.

[0028] Furthermore, according to the national standard GB / T 50123-2019, the plastic limit (w) of engineering waste soil was tested. p Liquid limit w l and plasticity index I P .

[0029] Furthermore, the construction waste soil comes from the excavated soil generated during the earthwork process of building foundation engineering, underground construction engineering, road engineering subgrade, subway shield tunnel or underground pipe gallery engineering.

[0030] Furthermore, the particle size of the engineering waste soil should be ≤2mm, and coarse particles larger than 2mm, such as gravel and coarse sand, should be avoided as much as possible to prevent inaccurate calculation results.

[0031] Furthermore, the alkali concentration (Na2O%) in the designed alkali-activated slag is 5%-10%, and the modulus is 0.5-1.5. Preferably, the alkali concentration (Na2O%) in the designed alkali-activated slag is 6%-8%, and the modulus is 0.8-1.2.

[0032] Specifically, the accuracy of the formulation design method is relatively high when the alkali concentration (Na2O%) is in the range of 6%-8% and the modulus is in the range of 0.8-1.2. Simultaneously increasing both the alkali concentration (Na2O%) and the modulus can effectively improve the compressive strength of alkali-activated slag-solidified engineering soil, while having a relatively small impact on fluidity. Therefore, when the required compressive strength design value of the product is high, and the B / S ratio obtained by the method calculated in this invention is too high, the design value of B / S can be reduced, the water-cement ratio can be recalculated, and then the strength of the alkali-activated solidified engineering soil can be improved by increasing the alkali concentration (Na2O%) and the modulus.

[0033] Furthermore, according to the above-mentioned formula involved in the method proposed by the present invention, the formulation parameters (such as the clay-cement ratio and water-cement ratio) of the alkali-activated slag solidification engineering slag soil can be designed first, and then the fluidity and compressive strength of this formulation can be calculated to achieve the prediction and control of product performance.

[0034] Furthermore, the fluidity mentioned refers to the fluidity obtained by the table test, and the test method can be carried out with reference to the industry standard "Standard for Test Methods of Basic Performance of Building Mortar" JGJ70-2009.

[0035] The second objective of this invention is to provide a method for preparing alkali-activated solidified slag engineering waste soil. The formula of this alkali-activated solidified slag engineering waste soil is obtained using the above-mentioned design method, and the preparation method includes the following steps:

[0036] According to the formula, the engineering waste soil and blast furnace slag are mixed evenly to obtain dry material;

[0037] According to the formula, sodium hydroxide, water glass and added water are mixed evenly to obtain an alkaline activator solution;

[0038] The dry materials and alkali activator solution are mixed evenly to obtain alkali-activated slag solidification engineering waste soil. At this point, the fluidity of the alkali-activated slag solidification engineering waste soil can be tested as needed. This alkali-activated slag solidification engineering waste soil is mainly used as a building material.

[0039] The third objective of this invention is to apply the alkali-activated slag solidified engineering slag obtained by the preparation method described above to non-fired bricks and non-fired blocks that simultaneously require both fluidity and strength.

[0040] The fourth objective of this invention is to apply an alkali-activated slag solidification engineering slag obtained by the preparation method described above to a fluidized backfill material that simultaneously requires both fluidity and strength.

[0041] The fifth objective of this invention is to apply an alkali-activated slag solidification engineering slag obtained by the preparation method described above to a 3D printing ink material that simultaneously requires both fluidity and strength.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] 1) This invention takes alkali-activated slag solidified engineering waste soil as a new material and proposes a rapid design method for its formulation. This new method can directly calculate feasible formulations based on the basic properties of engineering waste soil and the performance requirements of the product, which can avoid complicated test and debugging work, thereby saving time and costs. The design method of this invention is original.

[0044] 2) The raw materials used in this invention come from construction and industrial waste, including construction waste and blast furnace slag. The high-quality resource utilization of construction waste is a current challenge for the construction industry. This invention provides support for the technology of resource utilization of construction waste and preparation of high-quality building materials.

[0045] 3) This invention takes into account the complexity and regional differences of engineering waste soil, and solves the problem that the composition and properties of engineering waste soil will affect the effect of its solidified product. It utilizes the properties of engineering waste soil itself to achieve rapid formula design, which is lacking in the existing technology.

[0046] 4) This invention can provide reasonable formula design based on the actual performance requirements of the product. That is, the formula can be designed based on the requirements. The main custom requirements are the two most basic properties of flowability and compressive strength, so it has better application potential. Attached Figure Description

[0047] Figure 1 The present invention relates to a method for designing slag soil formulations for alkali-activated slag solidification engineering.

[0048] Figure 2 Alkali-activated slag engineering slag non-fired bricks obtained in Example 1.

[0049] Figure 3 The alkali-activated slag engineering waste 3D printing ink material obtained in Example 3. Detailed Implementation

[0050] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments. All materials and reagents used in the embodiments were purchased commercially.

[0051] Example 1

[0052] 1) A certain shield tunneling slag was obtained and used as raw material. After drying and crushing, powder with a particle size of less than 2 mm was obtained. XRD clay mineral testing showed that its clay content was 39.06%, and its plastic limit was 22.5% and plasticity index was 12.0. The alkali concentration of the alkali-activated slag used was preset to be 6.0% and the modulus was 1.0.

[0053] 2) Prepare alkali-activated slag solidification engineering slag non-fired bricks with strength grades of MU10, MU20 and MU30 respectively, that is, the compressive strength after 28 days can reach 10MPa, 20MPa and 30MPa respectively. In order to meet the needs of convenient casting in the production process, the fluidity is required to be >160mm. Here, the fluidity is pre-set to reach 180mm.

[0054] 3) According to Figure 1 The calculation process yielded the parameters B / S (cement ratio) and wc / B (water-cement ratio) as shown in Table 1. Since the calculated formula parameters are quite complex (i.e., the calculated values ​​of B / S and wc / B are infinite decimals, making them inconvenient for practical use), a simple optimization was performed. (Based on the calculated B / S and wc / B, they were rounded to the nearest rational number for ease of use. The optimized parameters were then substituted into the formula to ensure that the fluidity and strength still met the requirements; this process is called optimization). Based on the optimized parameters, the fluidity and compressive strength of the alkali-activated slag solidification engineering slag were predicted. It was found that the predicted values ​​met the requirements, as shown in Table 1.

[0055] 4) Calculate the required mass of engineering waste soil, blast furnace slag, sodium hydroxide, water glass and water according to the designed formula parameters, and weigh them for later use.

[0056] 5) According to the formula, mix the engineering slag and blast furnace slag evenly to obtain dry material; according to the formula, mix sodium hydroxide, water glass, and added water evenly to obtain alkali activator solution; mix the dry material and alkali activator solution evenly to obtain alkali-activated slag-solidified engineering slag. The fluidity of the fresh alkali-activated slag-solidified engineering slag was tested, and the fluidity of the mixture met the preset requirements. The remaining alkali-activated slag-solidified engineering slag was cast into standard specimens and cured under standard conditions for 28 days. Subsequently, its compressive strength was tested, and the predicted compressive strength and the measured compressive strength were not significantly different (as shown in Table 1), and the measured compressive strength still met the initial performance requirements.

[0057] 6) The alkali-activated slag solidification engineering slag non-fired bricks produced can be used for masonry, such as... Figure 2 As shown.

[0058] 7) In this embodiment, the material's flowability and compressive strength both meet expectations well. If discrepancies arise in subsequent implementations, it may be due to experimental errors during the preparation process. This method allows for a certain degree of error between predicted and actual values. When the errors in flowability or compressive strength are significant, the preset parameters can be adjusted appropriately (generally, B / S can be increased and wc / B decreased), and the formulation parameters can be recalculated before re-preparing the alkali-activated slag solidification engineering slag soil.

[0059] Table 1. Formulation design parameters and test results in Example 1

[0060]

[0061]

[0062] Example 2

[0063] 1) A certain engineering waste soil raw material was obtained, and after drying and crushing, powder with a particle size of less than 0.6 mm was obtained. XRD clay mineral testing showed that its clay content was about 50%, and its plastic limit was 25.3% and its plasticity index was 30.4. The alkali concentration of the alkali-activated slag used was preset to be 6.0% and the modulus was 1.0.

[0064] 2) Prepare high-flowability backfill material with a 7-day compressive strength greater than 2.0 MPa. To meet the working performance requirements during use, the flowability is required to be >200 mm.

[0065] 3) According to Figure 1 The calculation process yielded a clay-cement ratio (B / S) of 0.371 and a water-cement ratio (wc / B) of 1.96. Based on these results, a clay-cement ratio (B / S) of 0.4 was selected. To meet the requirement of fluidity >200mm, the following calculation was performed again... Figure 1 The calculation process yielded a water-cement ratio of 1.9, with a predicted flowability of 203 mm and a predicted 7-day compressive strength of 2.9 MPa, which met the initial design requirements.

[0066] 4) Calculate the required mass of engineering waste soil, blast furnace slag, sodium hydroxide, water glass and water according to the formula parameters designed in the previous steps, and weigh them for later use.

[0067] 5) According to the formula, mix the engineering slag and blast furnace slag evenly to obtain dry material; according to the formula, mix sodium hydroxide, water glass and added water evenly to obtain alkali activator solution; mix the dry material and alkali activator solution evenly to obtain alkali-activated slag-solidified engineering slag. The fluidity of the fresh alkali-activated slag-solidified engineering slag was tested, and the actual fluidity was measured to be 197 mm, with an error of 3% compared to the predicted value, indicating a small error and basically meeting the requirements. The remaining alkali-activated slag-solidified engineering slag was cast into standard specimens and cured under standard conditions for 7 days. Its compressive strength was then tested, and the measured compressive strength was 2.86 MPa, with an error of 1.4% compared to the predicted value, indicating a small error, and the measured compressive strength meets the initial performance requirements.

[0068] Example 3

[0069] 1) A certain engineering waste soil raw material was obtained, which was dried and crushed to obtain powder with a particle size of less than 0.6 mm. XRD clay mineral testing showed that its clay content was approximately 66.7%, and its plastic limit was 30.6%, plasticity index was 18.2. The alkali concentration of the alkali-activated slag used was preset to be 6.0%, the modulus was 1.0, and the clay-cement ratio was preset to be 0.4.

[0070] 2) Prepare ink materials for 3D printing. The ink material should have a flowability of 170mm to 190mm and a 7-day compressive strength greater than 5.0MPa. To meet the working performance requirements, the ink material should be designed with a flowability of about 180mm.

[0071] 3) According to Figure 1 The calculation process is followed. Since the clay-cement ratio B / S is fixed at 0.4, in order to simultaneously meet the requirements of fluidity and 7-day compressive strength, the water-cement ratio can be calculated to be 1.65. At this time, the predicted fluidity is about 179mm and the predicted 7-day compressive strength is 5.39MPa, which can simultaneously meet the initial design requirements.

[0072] 4) Calculate the required mass of engineering waste soil, blast furnace slag, sodium hydroxide, water glass and water according to the formula parameters designed in the previous steps, and weigh them for later use.

[0073] 5) According to the formula, mix the engineering waste soil and blast furnace slag evenly to obtain dry material; according to the formula, mix sodium hydroxide, water glass, and added water evenly to obtain alkali activator solution; mix the dry material and alkali activator solution evenly to obtain alkali-activated slag-solidified engineering waste soil. A flowability test was conducted on the fresh alkali-activated slag-solidified engineering waste soil, and its actual flowability was measured to be 177 mm, with an error of 1.1% compared to the predicted value, indicating that the error is small and basically meets the requirements. In actual 3D printing work, the printing effect was found to be good, as shown in the attached figure. Figure 3As shown, the remaining mixture in the printing ink material was cast into standard specimens, cured for 7 days under standard conditions, and their compressive strength was tested. The measured compressive strength was 5.05 MPa, with an error of 6.7% compared to the predicted value. The error was small, and the measured compressive strength met the initial performance requirements.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for designing a slag formulation for alkali-activated blast furnace slag solidification engineering, wherein the alkali-activated blast furnace slag comprises blast furnace slag and an alkali activator, and the alkali activator comprises sodium hydroxide, water glass, and added water, characterized in that, The method for designing this formula includes the following steps: Step 1: Measure the clay content of the construction waste soil. m C / m S Plastic Limit w p Liquid limit w l and plasticity index I P ; Step 2: Preset the required liquidity based on product type and application scenario. F With compressive strength f C ; Step 3: Preset the mass ratio of blast furnace slag to engineering slag, i.e., the clay ratio B / S, and record it as... m B / m S If there is no clay ratio B / S at this time, then the clay ratio B / S is preset, based on the clay ratio B / S and clay content. m C / m S calculate m C / ( m S + m B The value of ) is used to determine if m C / ( m S + m B ) < 0.37, with I L ( F )=( F Calculate using -140.16) / 64.32; if m C / ( m S + m B )≥0.37, with I L ( F )=( F The calculation is performed using -104.95) / 85.56; Step 4, with w B ( F )=( F The calculation of +290.33) / 950 yields the liquidity target set in step two. F Required moisture content w B ( F ); Step 5: The 7-day, 28-day, or 60-day compressive strength of the designed alkali-activated solidification engineering waste soil is... f C ,according to f C Use the value to calculate the water-cement ratio wc / B ; f C =317.28 / 11.82 (wc / B) 7-day compressive strength f C =182.37 / 4.94 (wc / B) 28-day compressive strength f C =202.93 / 5.14 (wc / B) 60-day compressive strength Step Six: Based on the designed alkali concentration and modulus of the alkali-activated slag, and the calculations obtained in Steps Three, Four, and Five... I L ( F ), w B ( F )and wc / B Then, calculate the clay ratio B / S of the alkali-activated slag solidification engineering slag soil according to the following formula, as well as the relative mass relationship of engineering slag soil, blast furnace slag, sodium hydroxide, water glass, and added water; I L ( F )=[( m W + m WG * k 3) / m S - w B ( F )*(B / S)- w P ] / I P B / S= m B / m S w C / B=( m W + m WG * k 3) / m B Na2O%=( m SH *31 / 40+ m WG * k 1) / m B *100% Modulus=( m WG * k 2 / 60) / ( m SH / 80+ m SH * k 1 / 62) in, k 1 represents the mass fraction of Na2O in water glass; k 2 represents the mass fraction of SiO2 in the water glass; k 3 represents the water mass fraction in the water glass; m SH This refers to the mass of sodium hydroxide. m B For the quality of blast furnace slag; m S For the quality of construction waste; m W For the quality of the added water, m WG For water glass quality; w p The plastic limit for construction waste is %; I P The plasticity index of construction waste soil; Step 7: Calculate the actual B / S ratio based on Step 6, and then review the results in Step 3 accordingly. m C / ( m S + m B If the relationship between 0.37 and 0.37 is not correctly determined, it needs to be re-determined, and the formula needs to be recalculated starting from step three until it is correctly determined. Step 8: Calculate the clay-to-soil ratio (B / S) and water-to-cement ratio of the slag in the alkali-activated slag solidification project based on steps 1 to 7. wc / B After determining the relative mass relationships of engineering waste soil, blast furnace slag, sodium hydroxide, water glass, and added water, the required mass of engineering waste soil, blast furnace slag, sodium hydroxide, water glass, and added water is calculated based on the total amount of materials required for actual production.

2. The design method for an alkali-activated slag solidification engineering slag soil formulation according to claim 1, characterized in that, The clay content of the engineering waste soil m C / m S The gradation curve of the engineering waste soil is obtained by measuring the moisture content according to national standard SY / T 5163–2018, or by using the moisture method specified in national standard GBT50123-2019, or by using a laser particle size analyzer. The proportion of fine particles with a particle size less than 0.002 mm in the engineering waste soil is taken as the clay content of the engineering waste soil. m C / m S .

3. The design method for an alkali-activated slag solidification engineering slag soil formulation according to claim 1, characterized in that, The construction waste soil comes from the excavated soil generated during the excavation of foundations for building projects, underground construction projects, or roadbeds for road projects.

4. The design method for an alkali-activated slag solidification engineering slag soil formulation according to claim 1, characterized in that, The particle size of the engineering waste soil is ≤2mm.

5. The design method for an alkali-activated slag solidification engineering slag soil formulation according to claim 1, characterized in that, The designed alkali concentration (Na2O%) in the alkali-activated slag is 5%-10%, and the modulus is 0.5-1.

5.

6. The design method for an alkali-activated slag solidification engineering slag soil formulation according to claim 1, characterized in that, The designed alkali concentration (Na2O%) in the alkali-activated slag is 6%-8%, and the modulus is 0.8-1.

2.

7. A method for preparing alkali-activated solidified slag engineering waste soil, characterized in that, The formulation for alkali-activated slag solidification engineering waste soil is obtained by the design method described in any one of claims 1-6, and the preparation method includes the following steps: According to the formula, the engineering waste soil and blast furnace slag are mixed evenly to obtain dry material; According to the formula, sodium hydroxide, water glass and added water are mixed evenly to obtain an alkaline activator solution; Mix the dry material and the alkali activator solution evenly to obtain the alkali-activated slag solidification engineering slag soil.

8. The application of alkali-activated slag solidified engineering slag obtained by the preparation method as described in claim 7 in non-fired blocks.

9. The application of alkali-activated slag solidified engineering slag obtained by the preparation method as described in claim 7 in fluidized backfill material.

10. The application of alkali-activated slag solidified engineering waste soil obtained by the preparation method as described in claim 7 in 3D printing ink materials.

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