A Physical Enhancement Method and Its Application of Geopolymer Sinter-Free Artificial Aggregate Based on Fresh Density

Abstract

The present invention discloses a physical enhancement method and its application of geopolymer non-sintered artificial aggregate based on fresh density, including introducing the concept of fresh density and proposing a performance optimization method based on fresh density. This method conducts fresh density tests on fresh particles produced by disk granulation, and selects the solid precursor formula corresponding to the highest fresh density value for granulation and curing, thereby preparing high-strength geopolymer non-sintered artificial aggregates with a low reaction degree. The optimization method of the present invention can not only significantly improve the strength of geopolymer non-sintered artificial aggregates and simultaneously significantly reduce costs, but also greatly reduce the time, materials, and cumbersome sample preparation work required in the optimization process, and has the technical advantages of being efficient, fast, time-saving, labor-saving, economical, and reliable. In addition, the present invention also provides an application solution of ultra-high-strength geopolymer non-sintered artificial aggregates developed based on fresh density in ultra-high performance concrete.

Description

Technical Field

[0001] The present invention belongs to the technical field of artificial aggregate preparation, and particularly relates to a physical enhancement method and application of geopolymer non-sintered artificial aggregate based on fresh density. Background Art

[0002] Due to the characteristics of light weight, porous structure and controllable properties, artificial aggregates are widely used in the fields of building materials, horticultural materials, food hygiene materials, industrial filtration materials, radar absorbing and shielding materials, heavy metal solidification materials, oil well production support materials, etc. From the perspective of curing temperature, artificial aggregates are divided into two types: sintered and non-sintered. Among them, non-sintered artificial aggregates can form strength only by curing at room temperature (≤100°C). Although this curing method is obviously more green and low-carbon than sintering, the application of non-sintered artificial aggregates is severely restricted due to limitations such as generally low aggregate strength, generally unstable performance levels, long aggregate production cycles, and generally higher raw material costs. Therefore, how to efficiently and reliably optimize the strength of non-fired artificial aggregates and reduce their raw material costs has become a hot topic in many industries.

[0003] Disk granulation is the most common production method for non-fired artificial aggregates. It is worth mentioning that there are fundamental differences between non-fired artificial aggregates produced by disk granulators and traditional cast-in-place slurry materials (such as concrete, mortar, grouting materials, etc.) in terms of production process, curing method, material structure, material properties, application scenarios, and performance evaluation systems. For example, fresh artificial aggregates are unsaturated and non-plastic agglomerated particles, while fresh concrete is supersaturated and fluid slurry; another example is that compared with the broad application scenarios of the above artificial aggregates, the application scenarios of concrete are usually only used as building materials. Generally speaking, non-fired artificial aggregates and traditional cast-in-place slurry materials are two completely different material systems, so the design and performance optimization methods of traditional cast-in-place slurry materials are basically not applicable to non-fired artificial aggregates.

[0004] In recent years, geopolymer cold-bonded artificial aggregates (GCBA) have become a popular choice in the research and development of new cold-bonded artificial aggregates, which is attributed to the high strength, lower energy consumption, recycling potential of a wide range of solid wastes, and excellent heavy metal fixation ability of GCBA. However, for the performance improvement of geopolymer artificial aggregates, the existing technologies still mainly rely on chemical enhancement methods to achieve, including the use of highly reactive solid precursor materials (such as blast furnace slag powder, metakaolin, etc.), and the use of higher doses or higher concentrations of alkali activator solutions, etc. The purpose is to produce more reaction products to fill and densify the pore structure of artificial aggregates, and finally achieve the improvement of strength. However, this will undoubtedly cause an unignorable huge cost burden, which greatly restricts the application of geopolymer artificial aggregates. For example, the price of alkali activator solution is about 5,000 - 7,000 yuan / ton (accounting for about 80% of the total cost), the price of blast furnace slag powder is about 600 - 800 yuan / ton, the price of metakaolin is about 800 - 1,200 yuan / ton, while the price of traditional cold-bonded artificial aggregates is only about 100 - 400 yuan / ton.

[0005] At the same time, the existing technologies' performance optimization of cold-bonded artificial aggregates is based on the hardened properties of the aggregates, such as the cylinder compressive strength after hardening, water absorption after hardening, apparent density and bulk density after hardening, etc. And evaluating the hardened properties of aggregates often requires a long time period (about 28 days / group) and relatively cumbersome sample preparation work (referring to GB / T17431.2 - 2010, the required hardened sample amount is about 5 - 6 liters (bulk volume) / group). It can be seen that the existing optimization technologies are a time-consuming and laborious arduous project.

[0006] In summary, the existing technologies for optimizing the performance of geopolymer cold-bonded artificial aggregates have limitations such as high cost burden, long time consumption, laborious, cumbersome, and poor reliability, which seriously restrict the development of GCBA. Summary of the Invention

[0007] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, the abstract of the specification and the title of the invention of this application to avoid obscuring the purpose of this part, the abstract of the specification and the title of the invention, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] In view of the above and / or problems existing in the prior art, the present invention is proposed.

[0009] To overcome the limitations of the existing technologies in the field of geopolymer artificial aggregates, the present invention proposes a novel enhancement method based on physical enhancement. This method can not only significantly improve the strength of geopolymer non-fired artificial aggregates and effectively reduce the raw material cost simultaneously, but also greatly shorten the time-consuming and cumbersome sample preparation work required for optimizing the properties of geopolymer artificial aggregates, making the optimization process more efficient, time-saving and labor-saving, and improving the reliability of the optimization results.

[0010] To solve the above technical problems, the present invention provides the following technical solution: A physical enhancement method for geopolymer non-sintered artificial aggregates based on fresh density, comprising,

[0011] Adding the solid precursor powder (hereinafter referred to as the precursor) of the geopolymer non-fired artificial aggregate into a disk granulator, and uniformly spraying the alkali activator solution in the form of mist on the powder until the fine particles are wrapped into fresh particles of the geopolymer non-fired artificial aggregate with the required diameter;

[0012] Testing the fresh density of the fresh particles, and preferably selecting the precursor formulation with the highest fresh density;

[0013] Curing and screening the fresh particles prepared with the preferred formulation to obtain the geopolymer non-sintered artificial aggregate based on physical enhancement;

[0014] Among them, the fresh density is the ratio of the volume V P of the solid precursor in the fresh particles to the apparent volume V F of the fresh particles, and its formula is:

[0015]

[0016] In the formula, m p and m F respectively represent the mass of the solid precursor in the fresh particles and the mass of the fresh particles; LSR represents the liquid-solid ratio; represents the precursor material; ρ x represents the absolute density of the solid precursor component x; VR x represents the volume ratio of the solid precursor component x in the solid precursor mixture, satisfying:

[0017]

[0018] The apparent volume V F of the fresh particles is measured by placing the fresh particles in an oven at 40-80 °C for isothermal heat treatment for 5-15 h, and then measuring by the Archimedes drainage method after cooling;

[0019] Among them, the test of fresh density is divided into two stages: heat treatment and testing. The duration required for the heat treatment stage is 5 to 15 hours, the average duration required for the testing stage is 0.5 hours, and the total time used is 6 to 16 hours; the temperature in the heat treatment stage is 40 to 80 °C.

[0020] As a preferred embodiment of the method of the present invention, wherein: the precursor powder of the fresh particles is fly ash and silica fume rich in silicon and aluminum components, and waste brick powder, a solid waste with certain alkali activation activity.

[0021] As a preferred embodiment of the method of the present invention, wherein: the solid precursor powder of the fresh particles includes a powder rich in silicon and aluminum components and a solid waste powder with alkali activation activity or low alkali activation activity. Among them, the powder rich in silicon and aluminum components includes fly ash and silica fume, and the solid waste powder with alkali activation activity or low alkali activation activity includes one or more of waste brick powder, red mud powder, waste ceramic powder, waste glass powder, biomass fly ash, lithium slag powder, waste stone powder, recycled concrete fine powder, surplus mud powder, engineering muck powder, silt powder, steel slag powder, urban waste incinerator slag powder, and urban waste incineration fly ash

[0022] As a preferred embodiment of the method of the present invention, wherein: the maximum particle size of the solid precursor powder for disk granulation is less than 175 μm, and the particle size dv90 of the cumulative proportion of 90 vol% is less than 75 μm; the solid precursor powder for disk granulation is in a dry state.

[0023] As a preferred embodiment of the method of the present invention, wherein: in the precursor powder of the fresh particles, the Dv90 of the waste brick powder is 65.5 μm, the Dv90 of the fly ash is 39.6 μm, and the Dv90 of the silica fume is 6.3 μm. The maximum particle sizes of all three do not exceed 170 μm.

[0024] As a preferred embodiment of the method of the present invention, wherein: for the solid precursor powder of the fresh particles, the proportion of the powder rich in silicon and aluminum components is 20 to 50 vol%, and the proportion of the solid waste powder is 50 to 80%; the liquid-solid ratio of the fresh particles is 0.12 to 0.35.

[0025] As a preferred embodiment of the method of the present invention, wherein: for the precursor powder of the fresh particles, the proportion of the powder rich in silicon and aluminum components is 25 vol%, of which fly ash and silica fume are each 12.5 vol%; the proportion of the solid waste waste brick powder is 75 vol%.

[0026] As a preferred embodiment of the method of the present invention, wherein: the alkali activator solution includes one of potassium water glass and sodium water glass. Among them, the modulus of potassium water glass is 0.9 to 1.4, and the mass concentration is 25% to 45%. The modulus of sodium water glass is 0.8 to 1.2, and the mass concentration is 25% to 35%.

[0027] As a preferred embodiment of the method of the present invention, wherein: the alkali activator solution is potassium water glass, with a modulus of 1.0, a mass concentration of 40%, and a liquid-solid ratio of 0.17.

[0028] As a preferred embodiment of the method of the present invention, wherein: for the fresh density test, among them, the fresh particles after heat treatment have the ability to maintain their original shape in water and will not disperse in water.

[0029] As a preferred embodiment of the method of the present invention, wherein: the heat treatment temperature of the fresh particles for testing fresh density is 40 to 80 °C, and the heat treatment time is 5 to 15 hours.

[0030] As a preferred embodiment of the method of the present invention, wherein: the curing includes two stages: heat curing at 40 to 80 °C for 10 to 24 hours and subsequent natural static curing at room temperature for more than 1 day; the screening includes screening the cured artificial aggregate particles through a sieve with a size range of 2.36 to 9.5 mm.

[0031] As a preferred embodiment of the method of the present invention, wherein: the heat curing temperature of the fresh particles is 80 °C, the heat treatment time is 24 hours, and the subsequent static curing time at room temperature is 28 days.

[0032] As a preferred embodiment of the method of the present invention, wherein: the highest value of the fresh density is 0.72, the liquid-solid ratio of the corresponding fresh particles is 0.17, the cylinder compressive strength of the cured aggregate is above 40 MPa, and the reaction degree of the cured aggregate is below 8.5%.

[0033] As a preferred embodiment of the method of the present invention, wherein: the 7-day compressive strength of the ultra-high performance concrete produced from the artificial aggregate with a cylinder compressive strength above 40 MPa is above 160 MPa.

[0034] The first object of the present invention is to overcome the limitation of the increase in cost caused by the improvement of strength in the prior art of non-fired artificial aggregates, and to provide a performance optimization method that can simultaneously achieve strength improvement and cost reduction.

[0035] The second objective of the present invention is to overcome the limitation in the prior art of non-fired artificial aggregates that higher-strength artificial aggregates need to be synthesized through a higher degree of reaction, and to provide a physical enhancement method that can synthesize higher-strength artificial aggregates with a lower degree of reaction in the mix ratio.

[0036] The third objective of the present invention is to overcome the limitation in the prior art of optimizing the performance of non-fired artificial aggregates, where the optimization results based on specific experience lead to insufficient reliability of the results, and to provide a performance optimization method with clear physical significance guidance.

[0037] The fourth objective of the present invention is to overcome the limitation in the prior art of non-fired artificial aggregates that the strength optimization cycle takes a long time, and to provide a strength optimization method with an optimization cycle of only within 16 hours.

[0038] The fifth objective of the present invention is to overcome the limitation in the prior art of non-fired artificial aggregates that the sample preparation is large and cumbersome in performance optimization, and to provide a strength optimization method that only requires about 300 ml of samples as optimization consumables.

[0039] The sixth objective of the present invention is to overcome the limitation in the prior art that the strength of non-fired artificial aggregates is generally lower than that of natural aggregates, and to provide a high-strength geopolymer non-sintered artificial aggregate with aggregate strength higher than natural pebbles developed based on the above optimization method. Among them, the liquid-solid ratio of the fresh particles prepared by the selected formula is lower than 0.18, the fresh density is higher than 0.68, the degree of reaction of the cured aggregate is lower than 10%, and the strength of the cured aggregate is higher than that of natural pebbles.

[0040] The seventh objective of the present invention is to overcome the limitation in the prior art that non-fired artificial aggregates are difficult to be applied in ultra-high performance concrete, and to provide an application of the high-strength geopolymer non-sintered artificial aggregate developed based on the above method in ultra-high performance concrete above 150 MPa.

[0041] The eighth objective of the present invention is to overcome the technical problems existing in the prior art, and to provide a geopolymer non-sintered artificial aggregate suitable for application in ordinary concrete, high-strength concrete, and ultra-high performance concrete. Beneficial effects of the present invention:

[0042] By innovatively introducing the fresh density method, the present invention can simultaneously achieve the strength improvement and cost reduction of geopolymer non-fired artificial aggregates, and can also significantly reduce the time required for performance optimization and the cumbersome sample preparation work, providing an efficient, reliable, economical, environmentally friendly, and physically significant-guided high-strength geopolymer artificial aggregate strength optimization method and its application solution in ultra-high performance concrete, which has high technical and economic value. Specifically as follows:

[0043] (1) The effect of strength improvement is significant; the present invention discovers that by improving the fresh density, the strength of geopolymer non-sintered artificial aggregate (GCBA) can be significantly enhanced. For example, as the fresh density increases from 0.55 to 0.72, the cylinder compressive strength of brick powder-based GCBA increases from 11.4 MPa to 42.2 MPa, an increase of 270%, showing a significant exponential growth. The highest cylinder compressive strength of 42.2 MPa (corresponding average single-particle strength of 20.21 MP) even exceeds the strength of natural pebbles (cylinder compressive strength of about 25 - 32 MPa), and is 6 times the highest strength index of high-strength light coarse artificial aggregate (6.5 MPa) specified in GBT 17431.1 - 2010, and exceeds the strength of artificial aggregates reported in most literatures. More notably, the 42.2 MPa GCBA produced with a fresh density of 0.72 can even be used to prepare ultra-high performance concrete (UHPC) with a compressive strength of up to 162.9 MPa, which is 49.9% higher than the UHPC using the same dosage of commercial non-sintered artificial aggregate, and only 9.7% lower than the UHPC using the same dosage of natural coarse aggregate.

[0044] (2) It has strong robustness for strength optimization; the fresh density proposed in the present invention as an evaluation index can accurately reflect the physical packing state of raw materials during the initial granulation stage of artificial aggregates, making the design method applicable to the strength optimization of various solid waste-based GCBA. The present invention provides theoretical guidance with clear physical meaning for the strength optimization design of GCBA for the first time. It improves the robustness and reliability of GCBA performance optimization through physical enhancement methods, avoids the common problem that the optimization results cannot be reproduced due to obtaining optimization parameters from specific raw materials, and helps GCBA achieve more extensive high-value and efficient utilization of solid waste or by-products.

[0045] (3) Effectively reduce the synthesis cost with significant economy; the present invention discovers for the first time that by improving the fresh density of GCBA, the dosage of alkali activator can be effectively reduced, thus significantly reducing the raw material cost of GCBA. Because the alkali activator is the largest synthesis cost of GCBA, accounting for about 80%.

[0046] (4) Shorten the optimization cycle and improve the optimization efficiency; the evaluation time cycle of the performance optimization method based on fresh density in the present invention only needs about 16 hours or less, compared with the evaluation time cycle of 28 days required by the traditional method based on hardened performance optimization, significantly shortening the trial-and-error cycle. The rapid evaluation method significantly improves the production and R & D efficiency, makes the development process of new materials more efficient and fast, and helps to accelerate the market application and promotion of new geopolymer artificial aggregates.

[0047] (5)Effectively reduce the consumables required for performance optimization and the cumbersome sample preparation work, and reduce the trial-and-error cost; compared with the traditional optimization method based on hardening performance, usually more than 5 liters of samples are required. The optimization method based on fresh density of the present invention only requires about 300 ml of samples, significantly reducing the sample consumption, saving the consumables required for trial-and-error optimization, reducing the cumbersome sample preparation work, reducing the trial-and-error cost, making the material performance optimization process more simple and economical, improving the overall R & D efficiency and resource utilization rate. Description of the Drawings

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0049] Figure 1 SEM photograph of the solid precursor and its particle size distribution diagram in the embodiment of the present invention, wherein, (a) waste brick powder, (b) fly ash, (c) silica fume, (d) particle size distribution.

[0050] Figure 2 Composition ratio and distribution diagram of the GCBA solid precursor in the embodiment of the present invention.

[0051] Figure 3 Contour map of the fresh density of the ternary system GCBA fresh particles in the embodiment of the present invention.

[0052] Figure 4 Sample diagram of GCBA with different mixing ratios in the embodiment of the present invention.

[0053] Figure 5 Relationship between the fresh density of 10 groups of GCBA and the cylinder compressive strength and liquid-solid ratio in the embodiment of the present invention.

[0054] Figure 6 Reaction degree contour map of the ternary system GCBA hardened particles in the embodiment of the present invention.

[0055] Figure 7 Cylinder compressive strength contour map of the ternary system GCBA hardened particles in the embodiment of the present invention.

[0056] Figure 8 Exponential relationship diagram between the fresh density and the cylinder compressive strength of 10 groups of GCBA in the embodiment of the present invention.

[0057] Figure 9 Comparison diagram of the single-particle strength of GCBA and the relevant international level in the embodiment of the present invention.

[0058] Figure 10 SEM images of GCBA hardened particles developed with different fresh compactness in the embodiments of the present invention.

[0059] Figure 11 Pore structure diagrams of GCBA hardened particles developed with different fresh compactness in the embodiments of the present invention.

[0060] Figure 12 Compressive strength diagrams of ultra-high performance concrete produced with different coarse aggregates in the embodiments of the present invention. Detailed implementation manners

[0061] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given in conjunction with the embodiments of the specification.

[0062] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0063] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that may be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that excludes other embodiments.

[0064] (1) Methods for measuring the chemical composition, loss on ignition, particle size distribution, micrographs and absolute density (true density) of the precursor materials of the present invention:

[0065] The chemical composition can be measured by an X-ray fluorescence spectrometer;

[0066] The loss on ignition can be measured by a thermogravimetric analyzer or a muffle furnace;

[0067] The particle size distribution can be measured by a laser particle size analyzer; the micrographs are obtained by a SEM scanning electron microscope; the absolute density (true density) can be measured by a full-automatic true density analyzer or the Le Chatelier flask method (such as GB / T 208-2014, etc.).

[0068] (2) The density and water absorption of the hardened GCBA particles in the present invention:

[0069] The loose bulk density, dry apparent density and water absorption of the hardened particles can be carried out in accordance with GB / T17431.2-2010 of the national standard.

[0070] (3) The cylinder compressive strength and single-particle strength of the hardened GCBA particles in the present invention:

[0071] The cylinder compressive strength is a commonly used index for evaluating the strength of artificial aggregates in China, and its test procedure can be carried out with reference to the national standard GB / T17431.2 - 2010;

[0072] The single - particle strength is a commonly used index for evaluating the strength of artificial aggregates internationally, and it can be determined based on the average particle strength of 30 randomly selected GCBA particles.

[0073] (4) The method for terminating the GCBA chemical reaction in the present invention:

[0074] Before more accurately evaluating the microscopic characteristics of GCBA (such as SEM, MIP, BSE - EDS) and the degree of reaction testing, it is advisable to carry out the reaction - termination treatment on the required GCBA samples.

[0075] (5) The degree of reaction of hardened GCBA

[0076] It can be tested by the acid - etching method combined with the loss - on - ignition method, and the average value of three identical tests is taken as the test result.

[0077] (6) The determination methods for the microscopic morphology, pore structure and phase distribution of hardened GCBA:

[0078] The microscopic morphology can be evaluated by scanning electron microscopy;

[0079] The pore - structure parameters can be evaluated by a mercury intrusion porosimeter.

[0080] (7) The compressive strength of ultra - high - performance concrete (UHPC)

[0081] The test procedure for the compressive strength of ultra - high - performance concrete can be carried out with reference to T / CECS864 - 2021.

[0082] Example 1

[0083] The purpose of this example is to demonstrate the whole process of performance optimization of a super - high - strength GCBA based on fresh density and its application in ultra - high - performance concrete.

[0084] In this example, the solid precursors used to manufacture GCBA are waste brick powder (WBP), fly ash (FA) and silica fume (SF);

[0085] (1) The recycling process of WBP:

[0086] First, manually remove the waste mortar attached to the surface of the waste bricks;

[0087] Subsequently, these waste bricks are crushed into waste - brick aggregates with a maximum size of 30 mm by a hammer crusher;

[0088] Finally, the waste brick aggregates were ground into WBP using a ball mill for 30 minutes, and the mass ratio of the grinding medium to the material being ground was 12.5:1.

[0089] (2) FA and SF are commercially available products.

[0090] (3) According to Chinese standard GB / T208 - 2014, the absolute densities (true densities) of WBP, FA, and SF were measured to be 2.738, 2.507, and 2.241 g / cm 3 .

[0091] Table 1 lists the chemical compositions and loss on ignition (LOI) of these solid raw materials, which were determined by X - ray fluorescence spectrometer (XRF) and thermogravimetric analyzer (TG) respectively.

[0092] Table 1

[0093]

[0094] The microscopic morphological characteristics of the solid powders were photographed using a scanning electron microscope (SEM), as shown in Figure 1 (a) - (c), and the particle size distribution was determined by a laser diffraction analyzer, see Figure 1 (d).

[0095] (4) Potassium silicate (K2SiO3) solution with a modulus (SiO2 / K2O molar ratio) of 1.0 and a mass concentration of 40% was prepared one day before its use as the alkali activator solution.

[0096] (5) Mix proportion and production process of fresh GCBA particles

[0097] To obtain GCBA with the highest fresh density produced from the WBP - FA - SF ternary precursor system, 10 groups of GCBA mix proportions were set, see Figure 2 .

[0098] Table 2 lists the detailed information of each combination. Among them, the liquid - solid ratio represents the mass ratio of the alkali activator solution required for the production of fresh particles to the solid precursor, which was determined by comparative preliminary tests on granulation effects and the quality of fresh particles.

[0099] The sample names (GCBA ID.) in Table 2 represent the volume proportions of the solid precursors. For example, "90W - 5F - 5S" represents a GCBA sample produced from a solid precursor composed of "90 vol% WBP, 5 vol% FA, and 5 vol% SF".

[0100] Table 2

[0101]

[0102] Producing fresh particles of GCBA using the disk granulation process:

[0103] First, 800 grams of the precursor mixed powder is added to a disk granulator with a diameter of 500 mm and a disk tilt angle of 36°. Then, the alkali activator solution is evenly sprayed on the powder in a mist form;

[0104] At the beginning, the disk rotation speed of the granulator is set to 35 - 40 revolutions per minute until the powder becomes fine particles;

[0105] Subsequently, the rotation speed is maintained at 15 - 18 revolutions per minute until the fine particles grow into fresh particles with the required diameter;

[0106] During this process, 100 - 200 grams of the precursor powder is added to the granulator every 1 - 2 minutes, and a certain amount of the activator solution is sprayed simultaneously to ensure uniform mixing until fresh particles are obtained.

[0107] (6) Testing and results of fresh density :

[0108] Testing of fresh density :

[0109] The ratio of the volume V P of the precursor in the fresh particles to the apparent volume V F of the fresh particles, and its formula is:

[0110]

[0111] In the formula, m p and m F represent the mass of the solid precursor in the fresh particles and the mass of the fresh particles respectively; LSR represents the liquid - solid ratio; represents the precursor material; ρ x represents the absolute density of the solid precursor component x; VR x represents the volume fraction of the precursor component x in the solid precursor mixture, satisfying:

[0112]

[0113] Among them, the mass of the fresh particles (m F ) is measured using an electronic balance;

[0114] The liquid - solid ratio (LSR) and the volume ratio (VR x ) of the solid precursor x are given in Table 2;

[0115] The apparent volume V FIt was measured by placing fresh particles in an oven at 80°C for isothermal heat treatment for 5 to 12 hours and then cooling, and using the Archimedes drainage method; the fresh density of each group of samples was taken as the average of three identical tests. Each test used approximately 100 grams of fresh particles, with a total of approximately 300 grams of fresh particles.

[0116] The total time required to test the fresh density of each group of samples (heat treatment time and test time) was approximately 6 to 13 hours.

[0117] 10 groups of fresh density The test results are as follows:

[0118] The isotherm of the fresh density of GCBA in the WBP-FA-SF ternary system is shown in Figure 3 , which reflects the physical packing state of the precursor in the fresh particles of GCBA;

[0119] It can be seen that the fresh density of GCBA synthesized by the WBP-FA-SF ternary system is between 0.55 and 0.72;

[0120] Specifically, within the composition range where waste brick powder (WBP) accounts for approximately 45 - 80 vol%, and silica fume (SF) accounts for approximately 10 - 20 vol%, the fresh density of the fresh particle samples is relatively high (0.68 - 0.72);

[0121] When the ratios of WBP, FA, and SF are 75 vol%, 12.5 vol%, and 12.5 vol% respectively, the fresh density is the highest at 0.72, indicating that the solid precursor particles in the fresh particles of GCBA form the densest physical packing state at this time.

[0122] (7) Selection, curing, and screening of GCBA

[0123] The precursor formulation corresponding to the highest fresh density of 0.72 was used as the preferred group, and the other 9 groups were used as its control groups.

[0124] The fresh particles synthesized by the above 10 groups through a disk granulator were first placed in an oven at 80°C for isothermal heat curing for 24 hours, and then sealed at room temperature to continue curing for 28 days.

[0125] After curing, particles with a particle size of 4.75 to 9.5 mm were screened out as the finally produced GCBA;

[0126] Samples of GCBA with 10 different combinations are shown in Figure 4 .

[0127] (8) Hardening strength of the preferred group of GCBA

[0128] After curing (1 day of heat curing + 28 days of room temperature curing), compared with the other 9 control groups of GCBA, the preferred group of GCBA showed the highest cylinder compressive strength (42.2 MPa) and the highest single particle strength (20.21 MPa). This indicates that by selecting the GCBA fresh particles with the highest fresh density and curing them, GCBA particles with the highest strength can be synthesized.

[0129] (9) Synthesis cost of the preferred group of GCBA

[0130] Compared with the other 9 control groups of GCBA, the preferred group of GCBA showed the lowest liquid-solid ratio (0.17). This indicates that after selecting the fresh particles with the highest fresh density, the lowest dosage of the GCBA alkali activator solution can be achieved, thereby realizing the lowest synthesis cost of GCBA.

[0131] (10) Reaction degree of the preferred group of GCBA

[0132] After curing (1 day of heat curing + 28 days of room temperature curing), compared with the other 9 control groups, the preferred group of GCBA showed the lowest reaction degree (8.1%), which indicates that after the GCBA fresh particles are selected with the highest fresh density, only a lower reaction degree (less reaction products) is required to cure and form higher strength GCBA.

[0133] (11) Application of the preferred group of GCBA in ultra-high performance concrete

[0134] Prepare ultra-high performance concrete with the preferred group of GCBA according to the mix ratio in Table 3.

[0135] Table 3

[0136]

[0137] Then, pour the fresh UHPC mixture into a mold with dimensions of 50 mm × 50 mm × 50 mm and vibrate it solid on a vibrating table; then, demold the specimen covered with a plastic film after storing it at room temperature for 15 hours;

[0138] After demolding, the UHPC specimens are cured in a steam curing box at 80 °C for 48 hours, and the heating and cooling rates during the steam curing process are both 12 °C / hour. The cured specimens are transferred to a standard curing box and continue to be cured until the 7th day.

[0139] Refer to T / CECS864-2021 to test the 7-day compressive strength of UHPC containing the preferred group of GCBA, and the result is as high as 162.9 MPa.

[0140] In summary, as can be seen from jointly implementing (5)-(7) in Example 1, the performance optimization method based on fresh density proposed by the present invention has significant advantages of high-efficiency and quick testing, extremely short optimization cycle, extremely few consumables required for optimization, and time-saving and labor-saving optimization process;

[0141] As can be seen from jointly implementing (7)-(10) in Example 1, the GCBA selected based on the highest fresh density can simultaneously have the highest strength and the lowest cost, and only requires the lowest reaction degree to synthesize geopolymer non-sintered artificial aggregates with the highest strength;

[0142] As can be seen from (11) in Example 1, the GCBA selected based on the highest fresh density is suitable for application in ultra-high performance concrete above 150 MPa.

[0143] Example 2

[0144] The purpose of this example is to illustrate that the performance optimization method based on fresh density can simultaneously achieve strength improvement and cost reduction of GCBA.

[0145] Figure 5 Shows the relationships between the fresh densities of 10 groups of GCBA in Example 1 and the cylinder compressive strength and liquid-solid ratio respectively. It can be seen that as the fresh density increases from 0.55 to 0.72, the cylinder compressive strength increases from 11.4 MPa to 42.2 MPa, a 270% increase; while the liquid-solid ratio decreases from 0.33 to 0.17, a 52% decrease.

[0146] As described in the technical background, the cost of the alkali activator solution accounts for about 80% of the total synthesis cost. Therefore, this means that as the fresh density increases from 0.55 to 0.72, the strength of GCBA increases by about 270%, while the synthesis cost decreases by about 40%.

[0147] Example 3

[0148] The purpose of this example is to illustrate that the performance optimization method based on fresh density is a physical enhancement method, which can synthesize artificial aggregates with higher strength through a mix ratio with a lower reaction degree.

[0149] For the reaction degree contour map of the hardened particles of ternary system GCBA in Example 1, see Figure 6 ;

[0150] For the cylinder compressive strength contour map of the hardened particles of ternary system GCBA in Example 1, see Figure 7 ;

[0151] For the fresh density contour map of the hardened particles of ternary system GCBA in Example 1, see Figure 3 ;

[0152] AsFigure 6 As shown, the reaction degree of GCBA is only about 8 - 13%, significantly lower than the typical range of 40 - 60% reported for geopolymer cast-in-place paste materials (such as geopolymer concrete, geopolymer mortar, geopolymer neat paste).

[0153] The main reason for this difference is that the amount of alkali activator solution used in the GCBA of the present invention is less.

[0154] From Figure 6 it can also be seen that within the composition range of about 45 - 80 vol% WBP and about 10 - 20 vol% SF, the reaction degree of GCBA is slightly lower (about 8 - 9%).

[0155] The sample 75W - 12.5F - 12.5S has the lowest reaction degree, only about 8.1%.

[0156] In the combined region of 45 - 70 vol% WBP and 30 - 50 vol% SF, the reaction degree of GCBA is relatively high (about 10 - 12.8%).

[0157] Combining Figure 6 the reaction degree with Figure 3 the fresh density results shown, it seems that a high reaction degree tends to occur in samples with low fresh density, while a low reaction degree occurs in samples with high fresh density. This is because an increase in fresh density leads to a decrease in the amount of alkali activator solution used (as Figure 5 shown), and since the reaction degree of GCBA is affected by the amount of alkali activator used, the lower the amount of alkali activator, the lower the reaction degree.

[0158] Traditionally, the strength of geopolymer concrete, mortar, or neat paste is positively correlated with its reaction degree; however, the opposite phenomenon was observed in GCBA.

[0159] Combining Figure 6 the reaction degree with Figure 7 the cylinder compressive strength results shown, the sample with the highest strength (75W - 12.5F - 12.5S, cylinder compressive strength 42.2 MPa) has the lowest reaction degree (8.1%); while the reaction degree of GCBA with lower strength is relatively high. For example, the sample 45W - 5F - 50S has the highest reaction degree (12.8%) among the 10 groups of GCBA, but the corresponding strength is relatively low (cylinder compressive strength 11.4 MPa).

[0160] Combining the results of the cylinder compressive strength, fresh density, and reaction degree of GCBA ( Figure 7 , Figure 3 , Figure 6) It can be seen that the favorable impact of the increase in fresh density on the strength of GCBA is far greater than the adverse impact of the decrease in reaction degree on the strength.

[0161] Therefore, when the fresh density is relatively high, even if the reaction degree decreases, the strength of GCBA can still be significantly improved.

[0162] Therefore, this can prove that increasing the fresh density is a physical enhancement method for geopolymer non-fired artificial aggregates, and artificial aggregates with higher strength can be synthesized at a lower reaction degree.

[0163] Example 4

[0164] The purpose of this example is to illustrate the effect of the proposed performance optimization method on the strength improvement of GCBA, and to compare the optimized GCBA aggregate strength in Example 1 with the domestic and international levels of artificial aggregate strength and the strength of natural pebbles in turn.

[0165] (1) Improvement effect

[0166] For the 10 groups of artificial aggregates in Example 1, as Figure 8 shown, as the fresh density increases from 0.55 to 0.72, the cylinder compressive strength increases from 11.4 MPa to 42.2 MPa, a 270% increase, showing an exponential growth trend. This indicates the significant improvement effect of the physical enhancement method based on fresh density on the strength of artificial aggregates.

[0167] (2) Comparison with domestic and international artificial aggregate strength levels

[0168] Domestic level: In Example 1, the cylinder compressive strength of the GCBA optimized with the highest fresh density is 42.2 MPa, which is 549% higher than the strength index (strength grade 40, cylinder compressive strength 6.5 MPa) of the high-strength artificial aggregates with the highest strength grade specified in the national standard "GBT 17431.1-2010 Lightweight Aggregates and Their Test Methods Part 1: Lightweight Aggregates".

[0169] International level: In Example 1, the single-particle strength of the GCBA optimized with the highest fresh density is 20.21 MPa, and it is compared with the single-particle strengths of 72 kinds of artificial aggregates collected in the international review literature. It is worth mentioning that the above 72 kinds of artificial aggregates include various types of artificial aggregates including sintered and non-sintered ones, representing the international level of artificial aggregate strength.

[0170] As Figure 9As shown, the strength of most artificial aggregates reported internationally hovers below 12 MPa, especially for non-fired artificial aggregates. The single-particle strength of GCBA (20.21 MPa) developed through the optimization of the highest fresh density in Example 1 exceeds the strength levels of the vast majority of artificial aggregates, including sintered and non-sintered ones, reported internationally and reaches the international leading level.

[0171] Among them, Figure 9 The literature represented by [1] is:

[0172] P.-F. Ren, T.-C. Ling, K.H. Mo, Recent advances in artificial aggregate production, Journal of Cleaner Production. 291(2021), 125215. https: / / doi.org / 10.1016 / j.jclepro.2020.125215

[0173] (3) Comparison with the strength of natural pebbles

[0174] In Example 1, the cylinder compressive strength of GCBA optimized with the highest fresh density is 42.2 MPa, which is about 40% higher than the cylinder compressive strength of natural pebbles in the same particle size range of 28 - 30 MPa.

[0175] In summary, the physical enhancement method based on fresh density has a very significant effect on improving the strength of artificial aggregates. The strength of GCBA developed thereby can even be higher than that of natural pebbles and can reach the international leading level of artificial aggregate strength.

[0176] Example 5

[0177] The purpose of this example is to illustrate the influence of fresh density on the microstructure of GCBA after curing:

[0178] With the increase in fresh density, although the reaction products of GCBA after curing decrease, the microstructure of GCBA after curing is still significantly densified and homogenized.

[0179] Next, GCBA samples (90W - 5F - 5S) with a fresh density of 0.63 and GCBA samples (75W - 12.5F - 12.5S) with a fresh density of 0.72 in Example 1 are selected for microstructure characterization and comparative analysis to prove the above view.

[0180] Figure 10 Shows the micro-morphologies of the two GCBA samples. The microstructure of the GCBA sample (90W - 5F - 5S) with a fresh density of 0.63 is a granular porous structure (Figure 10 (a)), in contrast, the microstructure of the GCBA sample (75W - 12.5F - 12.5S) with a fresh density of 0.72 is more uniform and dense ( Figure 10 (b)).

[0181] Their pore structures are as shown in Figure 11 and Table 4:

[0182] Compared with the GCBA sample (90W - 5F - 5S) with a fresh density of 0.63, the GCBA sample (75W - 12.5F - 12.5S) with a fresh density of 0.72 has a significantly lower porosity ( Figure 11 (b)), and the average pore diameter is reduced by 41.55%, especially the pore diameter above 1 μm (Table 4).

[0183] Table 4

[0184]

[0185] In summary, by regulating and optimizing the physical packing state of the precursors of GCBA fresh particles through fresh density, the pore structure of its solidified particles can be regulated and optimized.

[0186] Example 6

[0187] The purpose of this example is to prove that the ultra - high - strength artificial aggregate physically enhanced based on fresh density is applicable to the production of ultra - high - performance concrete with a compressive strength above 150 MPa

[0188] (1) Mixing ratio, production process and testing of ultra - high - performance concrete (UHPC)

[0189] From Example 1, the GCBA (75W - 12.5F - 12.5S, fresh density 0.72, cylinder compressive strength 42.2 MPa) optimized by the highest fresh density and an ordinary GCBA (90W - 5F - 5S, fresh density 0.62, cylinder compressive strength 17.7 MPa) not optimized by the highest fresh density were selected as coarse aggregates to prepare two types of UHPC, named U - HGCA and U - LGCA respectively.

[0190] For easy reference and comparison, commercial non - fired aggregates (cylinder compressive strength 3.2 MPa) and natural aggregates were also used as coarse aggregates to prepare two other types of UHPC, named U - CCA and U - NA respectively.

[0191] These four types of UHPC adopted the same mix ratio, and the only variable was the type of coarse aggregate. The content of coarse aggregate in all types of UHPC was 20 vol%, and the particle size of the coarse aggregate was between 4.75 - 8 mm.

[0192] The mass of the four types of UHPC fine aggregates (i.e., quartz sand) is 25% of the mass of the cementitious materials.

[0193] The dosages of the four types of UHPC steel fibers and water reducers remain unchanged, and are 2 vol% of the total volume of UHPC and 2 wt% of the mass of the cementitious materials, respectively.

[0194] Table 5 lists the mixing ratios of the four types of ultra-high performance concretes.

[0195] Table 5

[0196]

[0197] The mixing of fresh UHPC is carried out using a vertical planetary mixer, and the mixing process is carried out according to the following steps:

[0198] 1) The cementitious materials and fine aggregates are dry mixed in the mixer at a low speed for 3 minutes;

[0199] 2) Then the mixed solution of water and water reducer is poured into the mixer and stirred at a low speed for 7 minutes.

[0200] During this process, when the mixture has fluidity (starting from about the 3rd minute), the steel fibers are slowly and dispersedly added to the mixer, and then the coarse aggregates without pre-wetting treatment are added;

[0201] 3) Finally, the mixture is continuously stirred at a high speed for 2 minutes.

[0202] Then, the fresh UHPC mixture is poured into a mold with dimensions of 50 mm × 50 mm × 50 mm and vibrated on a vibrating table to remove air bubbles;

[0203] Then, the specimens covered with plastic film are demolded after being stored at room temperature for 15 hours;

[0204] After demolding, the concrete specimens are cured in a steam curing machine at 80 °C for 48 hours. The heating and cooling rates during the steam curing process are both 12 °C / h. After steam curing, the specimens are transferred to a standard curing box at 20 °C and 95% humidity and continue to be cured until the 7th day.

[0205] Before the strength test, these UHPC specimens are dried in an oven at 70 °C for 12 hours to remove the moisture on the surface of the specimens.

[0206] The test procedure for the 7-day compressive strength of ultra-high performance concrete is carried out with reference to T / CECS864-2021.

[0207] (2) Test results of the compressive strength of UHPC

[0208] Figure 12The compressive strength test results of four concrete specimens produced from four types of coarse aggregates are shown. It can be seen that the strength of the concrete specimen U-HGCA containing the optimally selected GCBA (75W-12.5F-12.5S) with the highest fresh density reaches 162.9 MPa, which is only 9.7% lower than the strength of UHPC using natural coarse aggregates (U-NA, 180.3 MPa). In addition, the strength of the concrete specimen U-LGCA containing ordinary GCBA (90W-5F-5S) is 131.1 MPa, which is lower than that of U-HGCA containing optimally selected GCBA with the highest fresh density. It is worth mentioning that among the above three concretes produced from artificial coarse aggregates (U-CCA, U-LGCBA, U-HGCA), only the concrete produced from optimally selected GCBA with the highest fresh density reaches the compressive strength index of ultra-high performance concrete (UHPC) (higher than 150 MPa).

[0209] Compared with U-CCA containing commercial non-fired artificial aggregates and U-LGCA containing ordinary GCBA, the strength of U-HGCA containing optimally selected GCBA with the highest fresh density is significantly increased by 49.9% and 24.3% respectively.

[0210] These results confirm that geopolymers non-fired artificial aggregates based on physical enhancement of fresh density can be applied to produce ultra-high performance concrete with a strength above 150 MPa, which represents an advanced strategy for the high-value recycling of solid waste.

[0211] Example 7

[0212] The purpose of this example is to emphasize the technical advantages of the performance optimization method based on fresh density, which is extremely time-consuming and simple in sample preparation during the optimization process.

[0213] Regarding the test of fresh density, the total amount of fresh particle samples required for each group is 250 - 300 ml (bulk volume), which can meet the total sample amount required for three parallel tests;

[0214] The test of fresh density for each group is divided into two stages: heat treatment and testing. Among them, the required duration of the heat treatment stage is 5 - 15 h, and the average required duration of the testing stage is 0.5 h, that is, the total time is 6 - 16 h / group; the temperature required during the heat treatment stage is 40 - 80 °C.

[0215] Fresh density Is the ratio of the volume V of the precursor in the fresh particles P To the apparent volume V of the fresh particles F The formula is:

[0216]

[0217] In the formula, mp and m F represent the mass of the solid precursor in the fresh particles and the mass of the fresh particles respectively; LSR represents the liquid-solid ratio; represents the precursor material; ρ x represents the absolute density of solid precursor component x; VR x represents the volume proportion of precursor component x in the solid precursor mixture, satisfying:

[0218]

[0219] The apparent volume V of the fresh particles F of the fresh particles that can be heat-treated (pretreatment) can be measured by the Archimedes drainage method;

[0220] Among them, when the heat treatment (pretreatment) time is less than 1-5 h, or the heat treatment temperature is less than 40 °C, the fresh particles may dissolve in water and thus the particle volume cannot be measured by the Archimedes drainage method;

[0221] When the heat treatment time is higher than 15 h, or the heat treatment temperature is higher than 80 °C, the particle volume measured by the drainage method will be different from the apparent volume V of the fresh particles F and there may be a large deviation.

[0222] Therefore, the present invention preferably selects 5-15 h and 40-80 °C as the heat treatment (pretreatment) regime for testing the fresh density, which can not only ensure that the particles after heat treatment maintain their original shape in water and will not dissolve in water, but also the measured particle volume is basically the same as the apparent volume of the actual fresh particles (the theoretical volume deviation is less than 1.0% and can be ignored).

[0223] As is well known, hardened artificial aggregates consist of two major parts: solid and pores, and the reduction of pores (or the increase in density) is the reason for the increase in strength. Among them, the solid part consists of reaction products and unreacted raw material particles. The prior art still mainly relies on chemical enhancement means to improve the performance of geopolymer artificial aggregates, such as using highly reactive raw materials and high-dose and high-concentration alkali activators, etc. Although the proportion of reaction products can be increased to improve the density after hardening, this undoubtedly causes a huge cost burden that cannot be ignored.

[0224] In contrast, the fresh density method proposed by the present invention is a physical enhancement method. First of all, the most significant improvement of this new method compared with the existing chemical enhancement methods is that it can simultaneously achieve strength improvement and cost reduction. Specifically, the motivation of the fresh density method is to improve the packing density of unreacted raw material particles inside the artificial aggregate during the initial granulation stage (fresh stage), so as to improve the density of the hardened artificial aggregate, and ultimately achieve an increase in the hardened strength; in addition, due to the improvement of the density of unreacted particles, the artificial aggregate only needs less reaction products to achieve densification of the hardened particles, which means that a lower dosage or concentration of alkali activator can be used, and ultimately cost reduction is achieved because the alkali activator is the main source of the cost of geopolymer artificial aggregates (accounting for 80% or more). In summary, the primary improvement of the present invention over the existing enhancement technologies is that it can simultaneously achieve strength improvement and cost reduction of geopolymer artificial aggregates.

[0225] Secondly, compared with the existing optimization technologies based on the hardening performance of GCBA, the fresh density-based GCBA optimization technology proposed by the present invention has the significant advantage of being efficient and convenient. Specifically, the existing optimization procedure of GCBA is based on the hardening performance of GCBA, and it usually takes a relatively long time period of more than 28 days and is time-consuming to obtain the hardening performance of GCBA; in contrast, the performance optimization method proposed by the present invention is based on fresh density, and the time period for evaluating the fresh density of artificial aggregates only needs to be within 16 hours, which is significantly shorter than the 28 days generally required for evaluating the hardening performance in the existing technology. In addition, evaluating the hardening performance of a group of artificial aggregates (such as cylinder compressive strength, water absorption rate, apparent density, bulk density) conservatively requires at least more than 5 liters of samples, while evaluating the fresh density of a group of artificial aggregates only requires about 300 milliliters of samples. Therefore, the fresh density-based optimization method proposed by the present invention can greatly shorten the time-consuming for optimizing the performance of artificial aggregates, and can significantly reduce the trial-and-error cost and the cumbersome sample preparation work, being more efficient and rapid.

[0226] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the present invention.

Claims

1. A physical enhancement method for geopolymer non-sintered artificial aggregate based on fresh density, characterized in that: including, adding the solid precursor powder of the geopolymer non-sintered artificial aggregate into a disk granulator, and uniformly spraying the alkali activator solution in a mist form onto the powder until the fine particles are wrapped into fresh particles of the geopolymer non-sintered artificial aggregate with the required diameter; testing the fresh compactness of the fresh particles, and selecting the solid precursor formulation with the highest fresh compactness value; curing and screening the fresh particles prepared with the selected formulation to obtain the geopolymer non-sintered artificial aggregate based on physical enhancement; Among them, the fresh density is the volume V of the solid precursor in the fresh particles P and the apparent volume V of the fresh particles F The ratio is given by the formula: Wherein, m p and m F respectively represent the mass of the solid precursor in the fresh particles and the mass of the fresh particles; LSR represents the liquid-solid ratio, that is, the mass ratio of the alkali activator solution in the fresh particles to the mass of the solid precursor; represents the solid precursor material; ρ x represents the absolute density of the solid precursor component x; VR x represents the volume fraction of the solid precursor component x in the solid precursor mixture, satisfying: Apparent volume V of fresh particles F Measured by the Archimedes drainage method after cooling by subjecting fresh particles to constant temperature heat treatment in an oven at 40 - 80 °C for 5 - 15 h wherein, the test of the fresh compactness includes two stages of heat treatment and testing. The required duration of the heat treatment stage is 5 to 15 hours, and the required average duration of the testing stage is 0.5 hour. The total time used is 6 to 16 hours; the temperature in the heat treatment stage is 40 to 80 °C; wherein, the solid precursor powder of the fresh particles includes a powder rich in silicon-aluminum components and a solid waste powder with alkali activation activity or low alkali activation activity. Among them, the powder rich in silicon-aluminum components includes fly ash and silica fume, and the solid waste powder with alkali activation activity or low alkali activation activity includes one or more of waste brick powder, red mud powder, waste ceramic powder, waste glass powder, biomass fly ash, lithium slag powder, waste stone powder, recycled concrete fine powder, surplus sludge powder, engineering muck powder, silt powder, steel slag powder, municipal solid waste incinerator slag powder, and municipal solid waste incineration fly ash.

2. The method according to claim 1, wherein: The maximum particle size of the solid precursor powder for disk granulation is less than 175 μm, and the particle size dv90 of the cumulative proportion of 90 vol% is less than 75 μm; the solid precursor powder for disk granulation is in a dry state.

3. The method according to claim 1 or 2, characterized in that: For the solid precursor powder of the fresh particles, the proportion of the powder rich in silicon-aluminum components is 20 to 50 vol%, and the proportion of the solid waste powder is 50 to 80%; the liquid-solid ratio of the fresh particles is 0.12 to 0.

35.

4. The method according to claim 1, characterized in that: The alkali activator solution includes one of potassium water glass and sodium water glass. Among them, the modulus of potassium water glass is 0.9 to 1.4, and the mass concentration is 25% to 45%. The modulus of sodium water glass is 0.8 to 1.2, and the mass concentration is 25% to 35%.

5. The method according to claim 1, characterized in that: For the test of the fresh compactness, among them, the fresh particles after heat treatment have the ability to maintain their original shape in water and will not disperse in water.

6. The method according to claim 1, characterized in that: The curing includes two stages of heat curing at 40 to 80 °C for 10 to 24 hours and subsequent natural static curing at room temperature for more than 1 day; the screening includes screening the cured artificial aggregate particles through a sieve with a size range of 2.36 to 9.5 mm.

7. The high-strength geopolymer non-sintered artificial aggregate prepared by the method according to any one of claims 1 to 6, characterized in that: The liquid-solid ratio of the fresh particles prepared with the selected formulation is lower than 0.18, the fresh compactness is higher than 0.68, the reaction degree of the cured aggregate is lower than 10%, and the strength of the cured aggregate is higher than that of natural pebbles.

8. The geopolymer non-sintered artificial aggregate according to claim 7 is applicable to the application in ordinary concrete, high-strength concrete, and ultra-high-performance concrete.

Images