An in-situ generated aerogel-modified ultra-high performance geopolymer material and its preparation method

Abstract

This invention belongs to the field of cement technology, specifically relating to an in-situ generated aerogel-modified ultra-high performance geopolymer material and its preparation method. The material, by mass parts, comprises the following components: 977-1203 parts aggregate, 969.3-1283.5 parts cementitious material, 1.00-1.22 parts defoamer, 20.1-24.4 parts water-reducing agent, and 201.8-244.2 parts water. The aggregate is modified ceramsite sand after aerogel modification, including shale ceramsite sand, compounded alkali solution, and aerogel. The aerogel is generated in-situ in the shale ceramsite sand by adding compounded alkali solution during the aerogel modification process. This invention overcomes the technical problem in the prior art where the aerogel is dispersed in a slurry and bonded to the aggregate, resulting in a weak bonding effect due to the silane coupling agent, leading to strength performance defects in the resulting UHPG product.

Description

Technical Field

[0001] This invention belongs to the field of cement technology, specifically relating to an in-situ generated aerogel-modified ultra-high performance geopolymer material and its preparation method. Background Technology

[0002] The deep integration of industrialized building and green, low-carbon development has driven the iterative upgrading of high-performance cementitious materials. Ultra-high performance geopolymers (UHPCs), due to their excellent mechanical and durability properties, are increasingly widely used in major engineering projects. The strength of geopolymers (alkali-activated cementitious materials) comes from the process in which their amorphous silica-alumina phase undergoes bond breaking via hydroxyl attack in an alkaline environment, recombining to form a three-dimensional aluminosilicate gel. However, the inherent high brittleness of traditional geopolymers and the high density of high-performance geopolymers limit their feasibility in lightweight design, resulting in limited engineering applicability. Increasing the porosity of geopolymers significantly affects their strength, especially since their inherent high brittleness leads to easy fracture and poor crack resistance in lightweight geopolymers. Summary of the Invention

[0003] The purpose of this invention is to provide an in-situ generated aerogel-modified ultra-high performance geopolymer material to solve the technical problem that high performance geopolymers in the prior art are inherently brittle and have high density, making it difficult to meet the requirements of lightweighting and high strength performance.

[0004] The in-situ generated aerogel-modified ultra-high performance geopolymer material comprises, by mass parts: 977-1203 parts aggregate, 969.3-1283.5 parts cementitious material, 1.00-1.22 parts defoamer, 20.1-24.4 parts water-reducing agent, and 201.8-244.2 parts water; the aggregate is modified ceramic sand after aerogel modification, including shale ceramic sand, compound alkali solution, and aerogel; the aerogel is generated in-situ in shale ceramic sand by adding compound alkali solution during the aerogel modification process.

[0005] Preferably, the compound alkaline solution comprises the following components by mass: 100 parts water glass and 5.39-8.98 parts sodium hydroxide, and the modulus of the compound alkaline solution is 1.8-2.2.

[0006] Preferably, the water glass has a modulus of 3.3 and a solid content of not less than 35%.

[0007] Preferably, the cementitious material comprises the following components by mass: 728.6-891.2 parts fly ash, 140.4-168.1 parts slag powder, and 100.3-224.2 parts limestone powder.

[0008] Preferably, the in-situ generated aerogel modified ultra-high performance geopolymer material further includes copper-plated steel fibers as a reinforcing phase.

[0009] This invention also provides a method for preparing in-situ aerogel-modified ultra-high performance geopolymer materials, comprising the following steps: I. Preparation of compound alkaline solution: Take 100 parts of water glass and mix it with 5.39-8.98 parts of sodium hydroxide, stirring until the mixture is uniform to obtain a compound alkaline solution with a modulus of 1.8-2.2, where the modulus of water glass is 3.3 and the solid content is not less than 35%. II. In-situ generation of aerogel-modified shale ceramic sand; modified ceramic sand is obtained through hydrolysis, soaking, gelation and aging, and the compound alkaline solution obtained in step one is added during the gelation process. III. Preparation of ultra-high performance geopolymer materials: Modified ceramic sand is pretreated and then used as aggregate, mixed with cementitious materials, defoamers, water-reducing agents and water, stirred to form a slurry and then solidified.

[0010] Preferably, step two specifically includes: Hydrolysis: yields an acidic silica sol precursor; Soaking: Take 1000 parts of shale ceramic sand and completely immerse it in 150 parts of prepared acidic silica sol precursor, and let it stand for 24 hours. Gelation: Slowly add 560.5-765.2 parts of the compound alkaline solution obtained in step one to the system obtained from soaking to initiate the transformation of sol into gel; Aging: Add anhydrous ethanol to the system obtained in the previous step, let it stand for 1-3 hours to age, and keep the modified ceramic sand for later use. The volume of anhydrous ethanol is 1 / 20 of the volume of the compound alkali solution used in the previous step.

[0011] Preferably, the hydrolysis step specifically includes: adding 20.8 parts by mass of tetraethyl orthosilicate to a mixed solution of 27.6-34.5 parts of anhydrous ethanol and 5.4-9 parts of deionized water at a constant temperature of 40°C; then adding dilute hydrochloric acid dropwise to adjust the pH of the mixed solution to 3-5, and continuously stirring at 40°C, adding 0.2-0.6 parts of silane coupling agent during stirring, and continuing to stir for a total of 2 hours to obtain an acidic silica sol precursor.

[0012] Preferably, step three specifically includes: Aggregate pretreatment: The modified ceramic sand obtained in step two is transferred into a mixed solvent and ultrasonically treated for 20-40 minutes. The mixed solvent is a mixture of ethanol and n-hexane in a volume ratio of 1:1. Preparation of slurry from ultra-high performance geopolymer: Weigh 969.3-1283.5 parts of cementitious material and 1.00-1.22 parts of defoamer according to the formula, place them in a planetary mortar mixer and dry mix for 120 seconds until uniform to obtain a mixture of cementitious material and defoamer; then take 977-1203 parts of pretreated modified ceramic sand and mix it with the mixture, and while stirring, add 201.8-244.2 parts of water and 20.1-24.4 parts of water-reducing agent, and then continue stirring until the mixture is fluid to obtain slurry; Curing and molding: The slurry obtained in the previous step is poured into a mold, compacted, and then cured to the specified age to complete the curing process and obtain the desired product.

[0013] Preferably, step three further includes: after stirring the mixture to a fluid state, slowly sprinkling in copper-plated steel fibers as the reinforcing phase, and allowing the copper-plated steel fibers to be evenly dispersed.

[0014] The technical advantages of this invention are as follows: This invention modifies shale ceramic sand, a lightweight aggregate, with aerogel. As a porous lightweight aggregate, shale ceramic sand provides sites for in-situ aerogel formation. By adding a compound alkaline solution to catalyze the condensation reaction between silicates, a stable nanoscale porous aerogel material is formed, thereby achieving low thermal conductivity and lightweight concrete materials. Furthermore, the modified aerogel is formed in-situ on the shale ceramic sand, resulting in a strong bonding ability between the shale ceramic sand and the aerogel. This overcomes the technical problem in existing technologies where the aerogel is dispersed in a slurry and bonded to the aggregate, leading to a weaker bonding effect due to the silane coupling agent, resulting in strength performance defects in the resulting UHPG product.

[0015] Meanwhile, this invention also controls the component ratio and modulus of the compound alkaline solution, thereby utilizing the regulatory mechanism of the compound alkaline solution on the properties of geopolymers. This allows the compound alkaline solution to simultaneously meet the specific chemical conditions required for the catalytic formation of aerogels and provide the strong alkaline activation environment needed for the geopolymer reaction. This achieves a "dual-effect" technical effect. Furthermore, the use of the compound alkaline solution in the aerogel reaction significantly simplifies the process, providing an innovative and feasible technical path for the multifunctional design and large-scale application of geopolymer materials. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the principle behind multi-slit cracking in existing technologies.

[0017] Figure 2 This is a microstructure diagram of the in-situ generated aerogel-modified ultra-high performance geopolymer material obtained in Example 1 of the present invention.

[0018] Figure 3This is a microstructure diagram showing the distribution of aerogel in the matrix for the ultra-high performance geopolymer material of Example 1 of the present invention.

[0019] Figure 4 The microstructure diagram shows the morphology of aerogel in the matrix for the ultra-high performance geopolymer material of Example 1 of the present invention. Detailed Implementation

[0020] The following detailed description of the embodiments, with reference to the accompanying drawings, will further illustrate the specific implementation of the present invention, in order to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of the present invention.

[0021] The strength of geopolymers (alkali-activated cementitious materials) derives from the process by which their amorphous aluminosilicate phase undergoes bond breaking via hydroxyl attack under alkaline conditions, recombining to form a three-dimensional aluminosilicate gel. Lightweighting methods include using porous lightweight aggregates and aerogels, but current technologies typically involve directly adding aerogel particles during the preparation process to form a slurry. For example, a process using a planetary mixer combined with a vibratory compaction table allows some aerogel particles from the surface and pores of the modified ceramic sand to be incorporated into the slurry.

[0022] like Figure 1 As shown, the bonding between the aerogel and aggregate is weak due to the addition of silane coupling agents. These nanoscale aerogels, after dispersing and solidifying in the slurry, become artificially introduced defect points. Under bending loads, these defect points provide controllable initiation sites for crack propagation. Because these defect points are numerous and uniformly distributed, load energy is absorbed simultaneously at multiple locations, macroscopically manifesting as multi-crack propagation. Combined with the inherent brittleness and high defects of geopolymers, existing technologies for lightweighting ultra-high-performance geopolymers significantly impact strength properties, making it difficult to effectively meet engineering requirements.

[0023] To address the aforementioned technical problems, this invention provides an in-situ generated aerogel-modified ultra-high performance geopolymer material and its preparation method. Specific embodiments of this invention are as follows: Example 1 Example 1 provides an in-situ generated aerogel modified ultra-high performance geopolymer material, which, by mass parts, comprises the following components: 1121 parts modified ceramic sand, 728.6 parts fly ash, 168.1 parts slag powder, 224.2 parts limestone powder, 1.22 parts defoamer, 22.4 parts water-reducing agent, and 201.8 parts water; and 202.8 parts copper-plated steel fiber as a reinforcing phase.

[0024] Example 1 also provides a method for preparing in-situ aerogel-modified ultra-high performance geopolymer materials, specifically including the following steps: I. Preparation of compound alkali solution.

[0025] Step one specifically includes: taking 100 parts of water glass and mixing them with 5.39 parts of solid sodium hydroxide (NaOH); stirring with a magnetic stirrer at 500 rpm for 10 minutes until the mixture is uniform, thus obtaining a compound alkaline solution with a modulus of 2.2, and sealing it for later use.

[0026] II. In-situ generation of aerogel-modified shale ceramic sand (i.e. aggregate).

[0027] Step two specifically includes the following steps: Hydrolysis: Under constant temperature of 40℃, 20.8 parts by mass of tetraethyl orthosilicate (TEOS) were added to a mixed solution of 32.2 parts anhydrous ethanol and 5.4 parts deionized water; then dilute hydrochloric acid was added dropwise to adjust the pH of the mixed solution to 3, and the mixture was stirred continuously at 40℃. During stirring, 0.4 parts of silane coupling agent KH550 were added, and stirring was continued for 2 hours to obtain a homogeneous acidic silica sol precursor.

[0028] Soaking: Take 1000 parts of shale ceramic sand and completely immerse it in 150 parts of prepared acidic silica sol precursor, and let it stand for 24 hours.

[0029] Gelation: 560.5 parts of the compound alkaline solution obtained in step one were slowly added to the system obtained from soaking to initiate the transformation of the sol into a gel.

[0030] Aging: Add anhydrous ethanol to the system obtained in the previous step, let it stand for 2 hours to age, and obtain the modified ceramic sand for later use; the volume of anhydrous ethanol is 1 / 20 of the volume of the compound alkali solution used in the previous step.

[0031] III. Preparation of ultra-high performance geopolymer materials.

[0032] Step three specifically includes the following steps: Aggregate pretreatment: The modified ceramic sand obtained in step two is transferred into a mixed solvent and ultrasonically treated for 30 minutes. The mixed solvent is composed of ethanol and n-hexane in a volume ratio of 1:1.

[0033] Preparation of ultra-high performance geopolymer slurry: 728.6 parts fly ash, 168.1 parts slag powder, 224.2 parts limestone powder, and 1.12 parts defoamer were weighed according to the specified ratio and placed in a planetary mortar mixer for dry mixing for 120 seconds until homogeneous, resulting in a mixture of cementitious material and defoamer. Then, 1121 parts of pretreated modified ceramic sand (i.e., aggregate) were mixed with the cementitious material, and while stirring, 201.8 parts water and 22.4 parts water-reducing agent were added. Stirring was continued for 120 seconds until the mixture reached a fluid state. Then, 202.8 parts of copper-plated steel fibers were slowly sprinkled in as a reinforcing phase, and the copper-plated steel fibers were uniformly dispersed to obtain the slurry.

[0034] Curing and molding: The slurry obtained in the previous step is poured into a mold, compacted, and cured to the specified age to complete the curing process, thus obtaining the desired product, namely the in-situ generated aerogel modified ultra-high performance geopolymer (UHPG).

[0035] The water glass has a modulus of 3.3 and a solid content ≥35%. Analytical grade solid sodium hydroxide is used. The shale ceramsite sand is a continuously graded ceramsite sand with a particle size of 0.15-1.18 mm and a compressive strength ≥5.5 MPa. The cementitious material consists of Grade I fly ash, 325-mesh S95 granulated blast furnace slag powder, and 400-mesh high-calcium limestone powder. A polycarboxylate high-performance water-reducing agent with a water reduction rate ≥25% is used. The reinforcing phase is copper-plated steel fiber with a length of 13 mm and a diameter of 0.2 mm.

[0036] The silica source for the aerogel was analytical grade tetraethyl orthosilicate with a solid content ≥95%, the dilute hydrochloric acid solution was a 0.1 mol / L standard titration solution, and the anhydrous ethanol solution was an ethanol solution with a concentration ≥95%. The silane coupling agent was analytical grade KH550, and the n-hexane was an analytical grade reagent with a purity ≥99%.

[0037] The microstructure diagram of the product obtained in Example 1—an in-situ generated aerogel-modified ultra-high performance geopolymer material—is shown below. Figures 2-4 As shown.

[0038] Example 2 Compared with Example 1, Example 2 has the following technical differences: Example 2 provides an in-situ generated aerogel modified ultra-high performance geopolymer material, which, by mass parts, includes the following components: 977 parts modified ceramic sand, 891.2 parts fly ash, 146.5 parts slag powder, 183.1 parts limestone powder, 1.09 parts defoamer, 21.6 parts water-reducing agent, and 225.6 parts water; and 202.8 parts copper-plated steel fiber as a reinforcing phase.

[0039] Example 1 also provides a method for preparing in-situ aerogel-modified ultra-high performance geopolymer materials, specifically including the following steps: I. Preparation of compound alkali solution.

[0040] Step one specifically includes: taking 100 parts of water glass and mixing them with 7.01 parts of solid sodium hydroxide (NaOH); stirring with a magnetic stirrer at 500 rpm for 10 minutes until the mixture is uniform, thus obtaining a compound alkaline solution with a modulus of 2.0, and sealing it for later use.

[0041] II. In-situ generation of aerogel-modified shale ceramic sand (i.e. aggregate).

[0042] Step two specifically includes the following steps: Hydrolysis: Under constant temperature of 40℃, 20.8 parts by mass of tetraethyl orthosilicate (TEOS) were added to a mixed solution of 27.6 parts anhydrous ethanol and 9 parts deionized water; then dilute hydrochloric acid was added dropwise to adjust the pH of the mixed solution to 5, and the mixture was stirred continuously at 40℃. During stirring, 0.2 parts of silane coupling agent KH550 were added, and stirring was continued for 2 hours to obtain a homogeneous acidic silica sol precursor.

[0043] Soaking: Take 1000 parts of shale ceramic sand and completely immerse it in 150 parts of prepared acidic silica sol precursor, and let it stand for 24 hours.

[0044] Gelation: 651.7 parts of the compound alkaline solution obtained in step one were slowly added to the system obtained from soaking to initiate the transformation of the sol into a gel.

[0045] Aging: Add anhydrous ethanol to the system obtained in the previous step, let it stand for 2 hours to age, and obtain the modified ceramic sand for later use; the volume of anhydrous ethanol is 1 / 20 of the volume of the compound alkali solution used in the previous step.

[0046] III. Preparation of ultra-high performance geopolymer materials.

[0047] Step three specifically includes the following steps: Aggregate pretreatment: The modified ceramic sand obtained in step two is transferred into a mixed solvent and ultrasonically treated for 20 minutes. The mixed solvent is composed of ethanol and n-hexane in a volume ratio of 1:1.

[0048] Preparation of ultra-high performance geopolymer slurry: 891.2 parts fly ash, 146.5 parts slag powder, 183.1 parts limestone powder, and 1.09 parts defoamer were weighed according to the formula and placed in a planetary mortar mixer for dry mixing for 120 seconds until homogeneous, resulting in a mixture of cementitious material and defoamer. Then, 977 parts of pretreated modified ceramic sand (i.e., aggregate) were mixed with the cementitious material, and while stirring, 225.6 parts water and 21.6 parts water-reducing agent were added. Stirring was continued for 120 seconds until the mixture reached a fluid state. Then, 202.8 parts of copper-plated steel fibers were slowly sprinkled in as a reinforcing phase, and the copper-plated steel fibers were uniformly dispersed to obtain the slurry.

[0049] Curing and molding: The slurry obtained in the previous step is poured into a mold, compacted, and cured to the specified age to complete the curing process, thus obtaining the desired product, namely the in-situ generated aerogel modified ultra-high performance geopolymer (UHPG).

[0050] Example 3 Compared with Example 1, Example 3 has the following technical differences: Example 3 provides an in-situ generated aerogel modified ultra-high performance geopolymer material, which, by mass parts, includes the following components: 1203 parts modified ceramic sand, 782 parts fly ash, 140.4 parts slag powder, 100.3 parts limestone powder, 1 part defoamer, 20.1 parts water-reducing agent, and 244.2 parts water.

[0051] Example 3 also provides a method for preparing in-situ aerogel-modified ultra-high performance geopolymer materials, specifically including the following steps: I. Preparation of compound alkali solution.

[0052] Step one specifically includes: taking 100 parts of water glass and mixing them with 8.98 parts of solid sodium hydroxide (NaOH); stirring with a magnetic stirrer at 500 rpm for 10 minutes until the mixture is uniform, thus obtaining a compound alkaline solution with a modulus of 1.8, and sealing it for later use.

[0053] II. In-situ generation of aerogel-modified shale ceramic sand (i.e. aggregate).

[0054] Step two specifically includes the following steps: Hydrolysis: Under constant temperature of 40℃, 20.8 parts by mass of tetraethyl orthosilicate (TEOS) were added to a mixed solution of 34.5 parts anhydrous ethanol and 6.3 parts deionized water; then dilute hydrochloric acid was added dropwise to adjust the pH of the mixed solution to 4, and the mixture was stirred continuously at 40℃. During stirring, 0.6 parts of silane coupling agent KH550 were added, and stirring was continued for a total of 2 hours to obtain a homogeneous acidic silica sol precursor.

[0055] Soaking: Take 1000 parts of shale ceramic sand and completely immerse it in 150 parts of prepared acidic silica sol precursor, and let it stand for 24 hours.

[0056] Gelation: 765.2 parts of the compound alkaline solution obtained in step one were slowly added to the system obtained from soaking to initiate the transformation of the sol into a gel.

[0057] Aging: Add anhydrous ethanol to the system obtained in the previous step, let it stand for 1 hour to obtain the modified ceramic sand for later use; the volume of anhydrous ethanol is 1 / 20 of the volume of the compound alkali solution used in the previous step.

[0058] III. Preparation of ultra-high performance geopolymer materials.

[0059] Step three specifically includes the following steps: Aggregate pretreatment: The modified ceramic sand obtained in step two is transferred into a mixed solvent and ultrasonically treated for 40 minutes. The mixed solvent is composed of ethanol and n-hexane in a volume ratio of 1:1.

[0060] Preparation of ultra-high performance geopolymer slurry: 782 parts fly ash, 140.4 parts slag powder, 100.3 parts limestone powder, and 1 part defoamer were weighed according to the formula and placed in a planetary mortar mixer for dry mixing for 120 seconds until homogeneous, resulting in a mixture of cementitious material and defoamer. Then, 1203 parts of pretreated modified ceramic sand (i.e., aggregate) were mixed with the cementitious material, and while stirring, 244.2 parts of water and 20.1 parts of water-reducing agent were added. The mixture was then stirred for another 120 seconds until it reached a fluid state. Finally, 202.8 parts of copper-plated steel fiber as a reinforcing phase were slowly sprinkled in and uniformly dispersed to obtain the slurry.

[0061] Curing and molding: The slurry obtained in the previous step is poured into a mold, compacted, and cured to the specified age to complete the curing process, thus obtaining the desired product, namely the in-situ generated aerogel modified ultra-high performance geopolymer (UHPG).

[0062] The comparison is provided below, and the details are as follows.

[0063] A comparative example provides an ultra-high performance geopolymer material (UHPG) comprising the following components by mass: 1212 parts of ceramic sand, 707.5 parts of fly ash, 151.6 parts of slag powder, 151.6 parts of limestone powder, 1 part of defoamer, 20.2 parts of water-reducing agent, and 222.4 parts of water.

[0064] The preparation method of the comparative example specifically includes the following steps: Preparation of ultra-high performance geopolymer slurry: 707.5 parts fly ash, 151.6 parts slag powder, 151.6 parts limestone powder, and 1.01 parts defoamer were weighed according to the specified ratio and placed in a planetary mortar mixer for dry mixing for 120 seconds until homogeneous, resulting in a mixture of cementitious material and defoamer. Then, 1212 parts of ceramic sand (without in-situ aerogel modification) were mixed with the cementitious material, and while stirring, 222.4 parts of water and 20.2 parts of water-reducing agent were added. Stirring was continued for 120 seconds until the mixture reached a fluid state. Then, 202.8 parts of copper-plated steel fibers were slowly sprinkled in as a reinforcing phase, and the copper-plated steel fibers were uniformly dispersed to obtain the slurry.

[0065] Curing and molding: The slurry obtained in the previous step is poured into a mold, compacted, and cured to the specified age to complete the curing process, thus obtaining the desired product, namely the in-situ generated aerogel modified ultra-high performance geopolymer (UHPG).

[0066] Next, the products obtained in Examples 1-3 and the comparative product were subjected to performance testing. The performance testing experiments included the Split Hopkinson Bar (SHPB) test. This test is used to measure the mechanical properties of materials under high-speed impact and mainly consists of an incident bar and a transmission bar, with the sample sandwiched between the two bars. The experiment involves a high-pressure gas-fired projectile impacting the incident bar, generating a stress wave. The wave propagates to the sample; part is reflected, and the other part passes through the sample and is transmitted to the transmission bar. Strain gauges attached to the bars record the signals of the incident, reflected, and transmitted waves. By analyzing these signals, the dynamic properties of the material under high strain rates can be obtained. The formulas for calculating stress, strain rate, and strain are as follows.

[0067]

[0068]

[0069]

[0070] in, , These represent the strains in the column during the propagation of the reflected and transmitted waves, respectively. A / A s The ratio of the sample area to the cross-sectional area of ​​the compression bar is given. C0 represents the wave propagation velocity in the compression bar, which is related to the elastic modulus and density of the compression bar itself. L represents the thickness of the sample.

[0071] Table 1 shows a comparison of the performance data of the various products obtained from the experiment: Table 1. Performance Comparison of Products Obtained in Examples 1-3 and Comparative Examples

[0072] By comparing the performance data in Table 1, it can be clearly seen that: The porosity of the comparative example was only 9.6%, while the porosity of Examples 1-3 reached 13.7%-16.8%. At the same time, the 28-day compressive strength (115.4-120.9 MPa) and flexural strength (15.5-17.3 MPa) of Examples 1-3 were higher than those of the comparative example (113.7 MPa and 13.4 MPa). This indicates that the material of the comparative example is dense but heavy, while the material of the examples has significantly improved lightweighting. At the same time, the examples have higher strength, achieving the technical effect of balancing lightweight requirements and high strength performance.

[0073] The fracture energy of the example (42.7~46.2kJ / m²) was significantly higher than that of the comparative example (38.5kJ / m²), indicating that the solution overcomes the defect of insufficient aerogel bonding effect in the prior art by improving the aerogel modification technology; and the incorporation of steel fibers achieves a synergistic effect of reinforcement and toughening, effectively improving the fracture toughness of the material and solving the problems of easy brittle fracture and poor crack resistance of traditional geopolymers.

[0074] The peak impact strain (0.021~0.024) of the SHPB in the example was higher than that of the comparative example (0.018), and the peak stress was better than that of the comparative example overall. This indicates that the material's impact deformation resistance is improved, which solves the problem that existing geopolymers have weak impact resistance and are difficult to adapt to complex engineering scenarios.

[0075] In summary, this solution effectively addresses the technical problems of imbalance between lightweight and high performance, as well as insufficient toughness and impact resistance in existing geopolymers, thereby improving the overall performance of the material.

[0076] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. An aerogel-modified ultra-high performance geopolymer material generated in situ, characterized in that, The following components are included in mass fraction: aggregate 977-1203 parts, cementitious material 969.3-1283.5 parts, defoaming agent 1.00-1.22 parts, water reducing agent 20.1-24.4 parts and water 201.8-244.2 parts; the aggregate is modified ceramic sand modified by aerogel, including shale ceramic sand, compound lye and aerogel; the aerogel is generated in situ in the shale ceramic sand by adding the compound lye in the aerogel modification process.

2. An in-situ aerogel modified ultra-high performance geopolymer material according to claim 1, characterized in that, The compound lye includes the following components in mass fraction: water glass 100 parts and sodium hydroxide 5.39-8.98 parts, and the modulus of the compound lye is 1.8-2.

2.

3. An in-situ aerogel modified ultra-high performance geopolymer material according to claim 2, wherein, The modulus of the water glass is 3.3 and the solid content is not less than 35%.

4. The in-situ aerogel modified ultra-high-performance geopolymer material of claim 1, wherein, The cementitious material includes the following components in mass fraction: fly ash 728.6-891.2 parts, slag powder 140.4-168.1 parts and limestone powder 100.3-224.2 parts.

5. The in-situ aerogel modified ultra-high-performance geopolymer material of claim 1, wherein, It also includes copper-plated steel fiber as a reinforcing phase, and the mass fraction of the copper-plated steel fiber is 202.8 parts.

6. A method for the preparation of an aerogel-modified ultra-high performance geopolymer material generated in situ, characterized in that, It includes the following steps: I. Compound lye preparation; 100 parts of water glass are mixed with 5.39-8.98 parts of sodium hydroxide, and stirred until uniform, to obtain a compound lye with a modulus of 1.8-2.2, and the modulus of the water glass is 3.3 and the solid content is not less than 35%; II. In-situ generation of aerogel modified shale ceramic sand; the modified ceramic sand is prepared by hydrolysis, soaking, gelation and aging, and the compound lye obtained in step I is added during the gelation process; III. Preparation of ultra-high performance geopolymer material; the pretreated modified ceramic sand is mixed with cementitious material, defoaming agent, water reducing agent and water as aggregate, and the slurry is formed after stirring and then solidified and molded.

7. A method of manufacture according to claim 6, wherein, The step II specifically includes: Hydrolysis: to obtain an acidic silica sol precursor; Soaking: 1000 parts of shale ceramic sand are completely immersed in 150 parts of prepared acidic silica sol precursor, and soaked for 24 hours; Gelation: slowly add 560.5-765.2 parts of the compound lye obtained in step I to the system obtained by soaking to induce the transformation of sol to gel; Aging: add anhydrous ethanol to the system obtained in the previous step, and let it stand for 1-3 hours to obtain the modified modified ceramic sand for standby, and the volume of anhydrous ethanol is 1 / 20 of the volume of the compound lye used in the previous step.

8. The preparation method according to claim 7, characterized in that, The hydrolysis step specifically includes: under constant temperature conditions of 40℃, 20.8 parts of tetraethyl orthosilicate is added to a mixed solution of 27.6-34.5 parts of anhydrous ethanol and 5.4-9 parts of deionized water; then add dilute hydrochloric acid dropwise to adjust the pH value of the mixed solution to 3-5, and continuously stir at 40℃, add 0.2-0.6 parts of silane coupling agent during stirring, and continue to stir for a total of 2 hours to obtain an acidic silica sol precursor.

9. The preparation method according to claim 6, characterized in that, The step III specifically includes: Aggregate pretreatment: the modified ceramic sand obtained in step II is transferred into a mixed solvent for ultrasonic treatment for 20-40 minutes, and the mixed solvent is a mixture of ethanol and n-hexane in a volume ratio of 1:1; Preparation of slurry of ultra-high performance geopolymer: the cementitious material 969.3-1283.5 parts and 1.00-1.22 parts of defoaming agent are weighed according to the proportion, placed in a planetary mortar mixer and dry mixed for 120 seconds to be uniform, to obtain a mixture of cementitious material and defoaming agent; then 977-1203 parts of modified ceramic sand after pretreatment are mixed with the mixture, and in the state of stirring, 201.8-244.2 parts of water and 20.1-24.4 parts of water reducing agent are added, and then the mixture is continuously stirred until the mixture is in a flowable state, to obtain the slurry; Curing and forming: the slurry obtained in the previous step is loaded into a mold, and after being vibrated and compacted, it is cured to the specified age to complete the curing, to obtain the desired product.

10. The preparation method according to claim 9, characterized in that, The step three specifically further comprises: after the mixture is in a flowable state, the copper-plated steel fiber as the reinforcing phase is slowly scattered and evenly dispersed.

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