High-strength mortar and preparation method thereof
By optimizing the mortar formula and constructing a three-dimensional reinforcing network using components such as ultrafine quartz sand, metakaolin, and nano-calcium carbonate, the problems of insufficient compressive strength and poor water resistance of mortar in high-rise buildings were solved, achieving high-strength, durable, and stable mortar performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-03-27
AI Technical Summary
Existing mortars have insufficient compressive and bond strength in high-rise buildings, poor water resistance, and are prone to cracking. Furthermore, their unreasonable formulation design leads to performance degradation.
The mortar is made of ultrafine quartz sand, metakaolin, nano-calcium carbonate, composite additives, steel fiber, vanillin-modified carbon nanotubes, and glycine-modified molybdenum disulfide. By constructing a three-dimensional reinforcing network and optimizing the pore structure, the overall load-bearing capacity and bonding strength of the mortar are improved.
It significantly improves the compressive strength and structural stability of mortar, prevents cracking and spalling during long-term use, enhances water resistance, optimizes pore distribution, and improves the bonding strength between components.
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Figure CN121735598A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of building materials technology, specifically to a high-strength mortar and its preparation method. Background Technology
[0002] Mortar is one of the most widely used basic materials in construction engineering, mainly used for bonding, plastering, leveling, filling, and structural reinforcement. Its performance directly affects the quality and service life of construction projects. As the construction industry develops towards high-rise buildings, lightweight structures, and long-lasting structures, higher requirements are being placed on the strength, bonding properties, water resistance, and crack resistance of mortar.
[0003] The following problems are commonly found in existing ordinary mortars: First, their compressive strength and bond strength are insufficient, making it difficult to meet the requirements in scenarios such as the reinforcement of high-rise building structures and the casting of high-grade components. Long-term use can easily lead to cracking and detachment. Second, their water and weather resistance is poor. In humid environments or outdoor exposure conditions, their performance deteriorates rapidly, affecting the stability of building structures. Third, their formula design is unreasonable. Some products excessively increase the amount of cement to improve strength, resulting in increased mortar shrinkage and easy cracking.
[0004] Therefore, developing a high-strength mortar with a scientific formula, excellent strength, stable performance, and simple preparation has become the key to solving industry pain points and meeting the high-quality requirements of construction projects. Summary of the Invention
[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a high-strength mortar and its preparation method, thereby solving the technical problems of insufficient strength, poor adhesion and easy cracking of existing mortars.
[0006] To achieve the above objectives, the present invention provides the following technical solution: a high-strength mortar, composed of the following raw materials in parts by weight: 40-60 parts ordinary silicate cement, 30-45 parts ultrafine quartz sand, 2-4 parts metakaolin, 0.45-1 parts nano-calcium carbonate, 3-5.8 parts composite admixture, 0.5-0.8 parts steel fiber, 1.5-2.5 parts vanillin-modified carbon nanotubes, 1-2 parts glycine-modified molybdenum disulfide, and 15-22 parts water; the composite admixture is composed of 2-4 parts polycarboxylate-based high-efficiency water-reducing agent, 0.5-1 part hydroxypropyl methylcellulose ether, and 0.5-0.8 parts early-strength agent; wherein the ultrafine quartz sand particles are finer and can fill the tiny pores between cement particles, improving the density of the mortar; high The content ensures the wear resistance and chemical stability of the aggregate, avoiding performance degradation caused by aggregate weathering during long-term use; The preparation method of the aminoacetic acid-modified molybdenum disulfide is as follows: Add 28-31g of glycine and 200-210mL of distilled water to a reaction flask, and sonicate for 25-30min. Then add 2-2.06g of molybdenum disulfide powder, and stir at 450-500r / min for 20-24h at room temperature. Then sonicate the molybdenum disulfide blend with preliminary glycine intercalation at 20-23℃ for 10-12h. After that, take out the blend and centrifuge for 85-90min. Add 4.5-5g of glycine to the retained supernatant. The solution is subjected to acid sonication for 5-6 hours, followed by centrifugation for 55-60 minutes, with the supernatant replaced with distilled water every 10 minutes to remove excess glycine. The remaining precipitate is then dried in a drying oven to obtain glycine-modified molybdenum disulfide. The modified layered structure is easier to disperse and can fill the nanoscale pores inside the mortar. The interlayer sliding properties can improve stress distribution, reduce local stress concentration, and enhance the toughness of the mortar. At the same time, its hydrophobic properties can enhance water resistance and reduce the erosion of the interface by water.
[0007] Furthermore, the particle size of the ultrafine quartz sand is 100-200 mesh. The content is ≥98%, and the moisture content is ≤0.5%; the diameter of the steel fiber is 0.1-0.3mm and the length is 6-8mm.
[0008] Furthermore, the metakaolin has a specific surface area of 400-600 m² / kg and a loss on ignition of ≤3%; the nano-calcium carbonate has a particle size of 20-50 nm and a whiteness of ≥93%.
[0009] Furthermore, the early strength agent is one of anhydrous calcium chloride and calcium formate; the viscosity of the hydroxypropyl methylcellulose ether is 10000-20000 mPa. .
[0010] Furthermore, the method for preparing the vanillin-modified carbon nanotubes is as follows: S1. Vanillin and glycerol triglycidyl ether are added to a reaction flask and heated to 105-110℃ under a nitrogen atmosphere. The mixture is stirred and mixed evenly. Then, 4-dimethylaminopyridine is added and the reaction is continued for 2-3 hours to obtain a trialdehyde precursor. A precursor containing multiple aldehyde groups is generated, which provides active sites for subsequent grafting. S2. Add trialdehyde precursor and octadecylamine to N,N-dimethylformamide solvent, stir and react at 75-80℃ for 4-6h, and after the reaction is completed, distill under reduced pressure and wash to obtain Schiff base vanillin. S3. Add 50-60 mL After being uniformly dispersed by ultrasonication in dimethylformamide solvent, 1.5-2g of carboxylated carbon nanotubes and 20-21g of thionyl chloride, the mixture was heated to reflux and reacted at 110-120℃ for 14-16h. After the reaction was completed, the mixture was rotary evaporated, washed with tetrahydrofuran, and dried to obtain acyl chloride carbon nanotubes. S4. Add 60-70mL 1.5-1.8 mmol of Schiff base vanillin was added to dimethylformamide solvent and stirred to dissolve. Then, 0.3-0.4 mmol of acyl chloride carbon nanotubes and 0.01-0.02 g of triethylamine catalyst were added. The reaction was carried out at 90-95 °C for 5-6 h. After the reaction was completed, the mixture was distilled under reduced pressure, filtered, and washed to obtain vanillin-modified carbon nanotubes.
[0011] Furthermore, in S1, the ratio of vanillin, glycerol triglycidyl ether, and 4-dimethylaminopyridine is 25-30 mmol: 8-10 mmol: 0.5-0.6 mmol.
[0012] Furthermore, in S2, the ratio of N,N-dimethylformamide, trialdehyde precursor, and octadecylamine is 50-60 mL: 4-5 mmol: 12-16 mmol.
[0013] Further, ordinary silicate cement, ultrafine quartz sand, metakaolin, nano-calcium carbonate, composite admixture, steel fiber, vanillin-modified carbon nanotubes, and glycine-modified molybdenum disulfide are added to a mixer and stirred for 5-8 minutes. Then water is added and stirring is continued for 4-8 minutes to obtain a slurry. The stirred slurry is allowed to stand and age for 10-15 minutes. The aged slurry is poured into a mold, vibrated and compacted, and the surface is smoothed. After curing for 24 hours, it is demolded and cured for another 7 days to obtain a high-strength mortar product.
[0014] Compared with the prior art, the present invention has the following beneficial technical effects: In the technical solution of this invention, vanillin-modified carbon nanotubes construct a three-dimensional reinforcing network inside the mortar, which can effectively transfer external loads, bridge the interfacial gaps between cement hydration products and aggregates, inhibit the initiation and propagation of microcracks, and improve the overall load-bearing capacity of the mortar from a structural perspective. The active groups after surface modification form a strong chemical bond with cement hydration products, further enhancing the bonding strength between the components. After intercalation modification, the interlayer force of glycine-modified molybdenum disulfide is weakened and the dispersion is significantly improved. It can uniformly fill the nanoscale pores inside the mortar, optimize the pore structure distribution, and reduce stress concentration points. At the same time, its interlayer sliding characteristics can buffer the stress transmission under load, form a synergistic reinforcement effect with steel fibers, construct a support system, and greatly improve the compressive strength and structural stability of the mortar. The active functional groups on the surfaces of vanillin-modified carbon nanotubes and glycine-modified molybdenum disulfide form strong chemical bonds with cement substrates and aggregate surfaces, replacing the weak physical adsorption interfaces in traditional mortars. This significantly improves the bonding force between components and effectively avoids cracking and detachment caused by interface peeling during long-term use.
[0015] The fine particle characteristics of ultrafine quartz sand can fill the micron-sized pores formed by the accumulation of cement particles. It works synergistically with metakaolin to promote the full hydration reaction, generate more dense hydration products, further compact the mortar structure, and enhance the strength foundation. Attached Figure Description
[0016] Figure 1 This is the synthesis reaction formula of Schiff base vanillin in Example 1. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0018] Ordinary silicate cement: grade 42.5, specific surface area 360 m² / kg; the water reduction rate of the polycarboxylate-based high-efficiency water-reducing agent is ≥30%. Glyceryl ether triglycidol (GTE, 0.68 mol / 100 g) Shanghai Maclean Biochemical Technology Co., Ltd. Preparation of carboxylated carbon nanotubes: Reference "Carboxyl Functionalization of Carbon Nanotubes and Its Influence on Cement Stone". A small amount of carbon nanotubes was placed in a beaker, moistened with 10 mL of ethanol, and 10 mL of dilute sulfuric acid solution was thoroughly mixed with the carbon nanotubes. The solution was slowly stirred at 80℃ for 6 hours. After the mixture was allowed to cool to room temperature, 1 mL of nitric acid was added dropwise under slow stirring. After stirring for 24 hours, the mixture was washed with water until the pH value reached 7. The particle size of the ultrafine quartz sand is 100-200 mesh. The content is ≥98%, and the moisture content is ≤0.5%; the diameter of the steel fiber is 0.1-0.3mm, and the length is 6-8mm. The specific surface area of the metakaolin is 400-600m² / kg, and the loss on ignition is ≤3%; the particle size of the nano-calcium carbonate is 20-50nm, and the whiteness is ≥93%. Example 1
[0019] A high-strength mortar is composed of the following raw materials in parts by weight: 40 parts ordinary silicate cement, 30 parts ultrafine quartz sand, 2 parts metakaolin, 0.45 parts nano-calcium carbonate, 3 parts composite admixture, 0.5 parts steel fiber, 1.5 parts vanillin-modified carbon nanotubes, 1 part glycine-modified molybdenum disulfide, and 15 parts water; wherein the composite admixture is composed of 2 parts polycarboxylate-based high-efficiency water-reducing agent, 0.5 parts hydroxypropyl methylcellulose ether, and 0.5 parts early-strength agent; The preparation method of the aminoacetic acid-modified molybdenum disulfide is as follows: 28g of glycine and 200mL of distilled water were added to a reaction flask and ultrasonically dispersed for 25min. Then, 2g of molybdenum disulfide powder was added and stirred at 450r / min for 20h at room temperature. The molybdenum disulfide blend with preliminary glycine intercalation was then ultrasonicated for 10h at 20℃. After that, the blend was centrifuged for 85min. 4.5g of glycine was added to the retained supernatant and ultrasonicated for 5h. Then, it was centrifuged for 55min. During this period, the supernatant was replaced with distilled water every 10min to remove excess glycine. Finally, the retained precipitate was dried in a drying oven to obtain glycine-modified molybdenum disulfide.
[0020] The ultrafine quartz sand has a particle size of 100 mesh; the steel fiber has a diameter of 0.1 mm and a length of 6 mm.
[0021] The specific surface area of the metakaolin is 400 m² / kg; the particle size of the nano-calcium carbonate is 20 nm.
[0022] The early strength agent is one of calcium formate; the viscosity of the hydroxypropyl methylcellulose ether is 10000 mPa. .
[0023] The method for preparing the vanillin-modified carbon nanotubes is as follows: S1. Add 25 mmol vanillin and 8 mmol glycerol triglycidyl ether to a reaction flask, heat to 105 °C under a nitrogen atmosphere, stir and mix evenly, then add 0.5 mmol of 4-dimethylaminopyridine and continue the reaction for 2 h to obtain the trialdehyde precursor. S2. Add 4 mmol of trialdehyde precursor and 12 mmol of octadecylamine to 50 mL of N,N-dimethylformamide solvent, stir at 75 °C for 4 h, and after the reaction is completed, distill under reduced pressure and wash to obtain Schiff base vanillin. S3. Add 50mL of Dimethylformamide solvent, 1.5 g of carboxylated carbon nanotubes and 20 g of thionyl chloride were ultrasonically dispersed and heated under reflux at 110 °C for 14 h. After the reaction was completed, the mixture was rotary evaporated, washed with tetrahydrofuran and dried to obtain acyl chloride carbon nanotubes. S4. To 60mL 1.5 mmol of Schiff base vanillin was added to dimethylformamide solvent and stirred to dissolve. Then, 0.3 mmol of acyl chloride carbon nanotubes and 0.01 g of triethylamine catalyst were added. The reaction was carried out at 90 °C for 5 h. After the reaction was completed, the mixture was distilled under reduced pressure, filtered, and washed to obtain vanillin-modified carbon nanotubes.
[0024] The preparation method of high-strength mortar is as follows: ordinary silicate cement, ultrafine quartz sand, metakaolin, nano calcium carbonate, composite admixture, steel fiber, vanillin-modified carbon nanotubes, and glycine-modified molybdenum disulfide are added to a mixer and stirred for 5 minutes. Then water is added and stirred for another 4 minutes to obtain a slurry. The stirred slurry is allowed to stand and age for 10 minutes. The aged slurry is poured into a mold, vibrated and compacted, and the surface is smoothed. After curing for 24 hours, the mortar is demolded and cured for another 7 days to obtain the finished high-strength mortar. Example 2
[0025] A high-strength mortar is composed of the following raw materials in parts by weight: 60 parts ordinary silicate cement, 45 parts ultrafine quartz sand, 4 parts metakaolin, 1 part nano-calcium carbonate, 5.8 parts composite admixture, 0.8 parts steel fiber, 2.5 parts vanillin-modified carbon nanotubes, 2 parts glycine-modified molybdenum disulfide, and 22 parts water; wherein the composite admixture is composed of 4 parts polycarboxylate-based high-efficiency water-reducing agent, 1 part hydroxypropyl methylcellulose ether, and 0.8 parts early-strength agent; The preparation method of the aminoacetic acid-modified molybdenum disulfide is as follows: 31 g of glycine and 210 mL of distilled water were added to a reaction flask and ultrasonically dispersed for 30 min. Then, 2.06 g of molybdenum disulfide powder was added, and the mixture was stirred at 500 r / min for 24 h at room temperature. The molybdenum disulfide blend with preliminary glycine intercalation was then ultrasonicated for 12 h at 23 °C. The blend was then centrifuged for 90 min, and 5 g of glycine was added to the supernatant and ultrasonicated for 6 h. The mixture was then centrifuged for 60 min, with the supernatant replaced with distilled water every 10 min to remove excess glycine. Finally, the precipitate was dried in a drying oven to obtain glycine-modified molybdenum disulfide.
[0026] The ultrafine quartz sand has a particle size of 200 mesh; the steel fiber has a diameter of 0.3 mm and a length of 8 mm.
[0027] The specific surface area of the metakaolin is 600 m² / kg; the particle size of the nano-calcium carbonate is 50 nm.
[0028] The early strength agent is anhydrous calcium chloride; the viscosity of the hydroxypropyl methylcellulose ether is 20000 mPa. .
[0029] The method for preparing the vanillin-modified carbon nanotubes is as follows: S1. Add 30 mmol vanillin and 10 mmol glycerol triglycidyl ether to a reaction flask, heat to 110 °C under a nitrogen atmosphere, stir and mix evenly, then add 0.6 mmol of 4-dimethylaminopyridine and continue the reaction for 3 h to obtain the trialdehyde precursor. S2. Add 5 mmol of trialdehyde precursor and 16 mmol of octadecylamine to 60 mL of N,N-dimethylformamide solvent, stir at 80 °C for 6 h, and after the reaction is completed, distill under reduced pressure and wash to obtain Schiff base vanillin. S3. Add 60mL of Dimethylformamide solvent, 2g of carboxylated carbon nanotubes and 21g of thionyl chloride were ultrasonically dispersed and heated to reflux at 120℃ for 16h. After the reaction was completed, the mixture was rotary evaporated, washed with tetrahydrofuran and dried to obtain acyl chloride carbon nanotubes. S4. To 70mL 1.8 mmol of Schiff base vanillin was added to dimethylformamide solvent and stirred to dissolve. Then, 0.4 mmol of acyl chloride carbon nanotubes and 0.02 g of triethylamine catalyst were added. The reaction was carried out at 95 °C for 6 h. After the reaction was completed, the mixture was distilled under reduced pressure, filtered, and washed to obtain vanillin-modified carbon nanotubes.
[0030] The preparation method of high-strength mortar is as follows: ordinary silicate cement, ultrafine quartz sand, metakaolin, nano calcium carbonate, composite admixture, steel fiber, vanillin-modified carbon nanotubes, and glycine-modified molybdenum disulfide are added to a mixer and stirred for 8 minutes. Then water is added and stirred for another 8 minutes to obtain slurry. The stirred slurry is allowed to stand and age for 15 minutes. The aged slurry is poured into a mold, vibrated and compacted, and the surface is smoothed. After curing for 24 hours, it is demolded and cured for another 7 days to obtain the finished high-strength mortar. Example 3
[0031] A high-strength mortar is composed of the following raw materials in parts by weight: 50 parts ordinary silicate cement, 40 parts ultrafine quartz sand, 3 parts metakaolin, 0.72 parts nano-calcium carbonate, 4.4 parts composite admixture, 0.6 parts steel fiber, 2 parts vanillin-modified carbon nanotubes, 1.5 parts glycine-modified molybdenum disulfide, and 18 parts water; wherein the composite admixture is composed of 3 parts polycarboxylate-based high-efficiency water-reducing agent, 0.7 parts hydroxypropyl methylcellulose ether, and 0.6 parts early-strength agent; The preparation method of the aminoacetic acid-modified molybdenum disulfide is as follows: 29.5 g of glycine and 205 mL of distilled water were added to a reaction flask and ultrasonically dispersed for 28 min. Then, 2.03 g of molybdenum disulfide powder was added, and the mixture was stirred at 480 r / min for 22 h at room temperature. The molybdenum disulfide blend with preliminary glycine intercalation was then ultrasonicated for 11 h at 21 °C. The blend was then centrifuged for 88 min, and 4.8 g of glycine was added to the supernatant and ultrasonicated for 5.5 h. The mixture was then centrifuged for 58 min, with the supernatant replaced with distilled water every 10 min to remove excess glycine. Finally, the precipitate was dried in a drying oven to obtain glycine-modified molybdenum disulfide.
[0032] The ultrafine quartz sand has a particle size of 150 mesh; the steel fiber has a diameter of 0.2 mm and a length of 7 mm.
[0033] The specific surface area of the metakaolin is 500 m² / kg; the particle size of the nano-calcium carbonate is 30 nm.
[0034] The early strength agent is anhydrous calcium chloride; the viscosity of the hydroxypropyl methylcellulose ether is 15000 mPa. .
[0035] The method for preparing the vanillin-modified carbon nanotubes is as follows: S1. Add 27.5 mmol vanillin and 9 mmol glycerol triglycidyl ether to a reaction flask, heat to 108 °C under a nitrogen atmosphere, stir and mix thoroughly, then add 0.55 mmol 4-dimethylaminopyridine and continue the reaction for 2.5 h to obtain the trialdehyde precursor. S2. Add 4.5 mmol of trialdehyde precursor and 14 mmol of octadecylamine to 55 mL of N,N-dimethylformamide solvent, stir at 78 °C for 5 h, and after the reaction is completed, distill under reduced pressure and wash to obtain Schiff base vanillin. S3. Add 55mL of Dimethylformamide solvent, 1.8 g of carboxylated carbon nanotubes and 20.5 g of thionyl chloride were ultrasonically dispersed and then heated under reflux at 115 °C for 15 h. After the reaction was completed, the mixture was rotary evaporated, washed with tetrahydrofuran, and dried to obtain acyl chloride carbon nanotubes. S4. To 65mL 1.65 mmol of Schiff base vanillin was added to dimethylformamide solvent and stirred to dissolve. Then, 0.35 mmol of acyl chloride carbon nanotubes and 0.015 g of triethylamine catalyst were added. The reaction was carried out at 93 °C for 5.5 h. After the reaction was completed, the mixture was distilled under reduced pressure, filtered, and washed to obtain vanillin-modified carbon nanotubes.
[0036] The preparation method of high-strength mortar is as follows: ordinary silicate cement, ultrafine quartz sand, metakaolin, nano calcium carbonate, composite admixture, steel fiber, vanillin-modified carbon nanotubes, and glycine-modified molybdenum disulfide are added to a mixer and stirred for 6 minutes. Then water is added and stirred for another 7 minutes to obtain a slurry. The stirred slurry is allowed to stand and age for 12 minutes. The aged slurry is poured into a mold, vibrated and compacted, and the surface is smoothed. After curing for 24 hours, the mortar is demolded and cured for another 7 days to obtain the finished high-strength mortar. Comparative Example 1
[0037] The difference between this comparative example and Example 3 is that molybdenum disulfide was used instead of aminoacetic acid-modified molybdenum disulfide. Comparative Example 2
[0038] The difference between this comparative example and Example 3 is that a trialdehyde precursor was used instead of vanillin-modified carbon nanotubes.
[0039] The following tests were conducted in accordance with national standards: compressive strength (GB / T17671-2021), bond strength (GB / T25181-2019), water resistance (compressive strength retention rate after 28 days of immersion in water, GB / T17671-2021), and crack resistance (crack observation after 28 days of curing, self-made grading: no cracks = excellent, micro-cracks ≤0.1mm = good, obvious cracks ≥0.1mm = poor); the test results are shown in Table 1.
[0040] Table 1: Performance Tests
[0041] Table 1 shows that the 28-day compressive strength of Examples 1-3 all reached above 79.5 MPa (with Example 2 reaching a maximum of 82.6 MPa), while Comparative Example 1 (molybdenum disulfide replacing modified molybdenum disulfide) reached 65.8 MPa and Comparative Example 2 (trialdehyde-based precursor replacing modified carbon nanotubes) reached 62.9 MPa, representing decreases of 19.0% and 23.6% respectively compared to Example 3. The 7-day compressive strength of Examples 1-3 was above 56.8 MPa, while Comparative Examples 1-2 only reached 43.6-45.1 MPa. The reason for this is that in the examples, vanillin-modified carbon nanotubes formed a three-dimensional reinforcing network, transferring stress and suppressing microcracks; glycine-modified molybdenum disulfide filled the nanopores, optimizing stress distribution. Together with steel fibers and ultrafine quartz sand, these components constructed a high-strength support system. In Comparative Example 1, the unmodified molybdenum disulfide exhibited strong interlayer forces and poor dispersion, failing to effectively fill pores and exhibiting poor compatibility with the substrate, leading to easy formation of cracks at the interface. In Comparative Example 2, the trialdehyde-based precursor lacked the high aspect ratio reinforcement effect of carbon nanotubes, providing only limited interfacial bonding and failing to form a continuous reinforcing network. Water resistance analysis: The compressive strength retention rate of Examples 1-3 after 28 days of immersion in water reached 94.3%-96.5%, while that of Comparative Examples 1-2 was only 83.2%-85.4%, a decrease of 9.6%-12.1% compared to Example 3. Reason analysis: In the examples, the hydrophobic properties of glycine-modified molybdenum disulfide formed a nano-protective film, reducing water penetration; the modified filler and the base raw materials were synergistically optimized, reducing the capillary porosity of the mortar to below 12%, blocking the intrusion of water and harmful ions, and preventing interfacial erosion. In Comparative Example 1, the unmodified molybdenum disulfide was unevenly dispersed, forming local pores that became channels for water penetration. In Comparative Example 2, the trialdehyde-based precursor could not effectively fill the pores, resulting in insufficient density of the mortar structure. After long-term immersion in water, the interface was easily peeled off, and the strength decreased significantly.
[0042] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
[0044] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments.
Claims
1. A high-strength mortar, characterized in that, It is composed of the following raw materials in parts by weight: 40-60 parts ordinary silicate cement, 30-45 parts ultrafine quartz sand, 2-4 parts metakaolin, 0.45-1 parts nano calcium carbonate, 3-5.8 parts composite admixture, 0.5-0.8 parts steel fiber, 1.5-2.5 parts vanillin-modified carbon nanotubes, 1-2 parts glycine-modified molybdenum disulfide, and 15-22 parts water; the composite admixture is composed of 2-4 parts polycarboxylate-based high-efficiency water-reducing agent, 0.5-1 part hydroxypropyl methylcellulose ether, and 0.5-0.8 parts early-strength agent; The preparation method of the aminoacetic acid-modified molybdenum disulfide is as follows: Add 28-31g of glycine and 200-210mL of distilled water to a reaction flask and sonicate for 25-30min. Then add 2-2.06g of molybdenum disulfide powder and stir at 450-500r / min at room temperature for 20-24h. Then sonicate the molybdenum disulfide blend with preliminary glycine intercalation at 20-23℃ for 10-12h. After that, take out the blend and centrifuge for 85-90min. Add 4.5-5g of glycine to the retained supernatant and sonicate for 5-6h. Then centrifuge for 55-60min, replacing the supernatant with distilled water every 10min to remove excess glycine in the solution. Finally, place the retained precipitate in a drying oven and dry to obtain glycine-modified molybdenum disulfide.
2. The high-strength mortar according to claim 1, characterized in that, The ultrafine quartz sand has a particle size of 100-200 mesh. The content is ≥98%, and the moisture content is ≤0.5%; the diameter of the steel fiber is 0.1-0.3mm and the length is 6-8mm.
3. The high-strength mortar according to claim 1, characterized in that, The metakaolin has a specific surface area of 400-600 m² / kg and a loss on ignition of ≤3%; the nano-calcium carbonate has a particle size of 20-50 nm and a whiteness of ≥93%.
4. The high-strength mortar according to claim 1, characterized in that, The early strength agent is one of anhydrous calcium chloride and calcium formate; the viscosity of the hydroxypropyl methylcellulose ether is 10000-20000 mPa. .
5. The high-strength mortar according to claim 1, characterized in that, The method for preparing the vanillin-modified carbon nanotubes is as follows: S1. Add vanillin and glycerol triglycidyl ether to a reaction flask, heat to 105-110℃ under a nitrogen atmosphere, stir and mix evenly, then add 4-dimethylaminopyridine and continue the reaction for 2-3 hours to obtain the trialdehyde precursor. S2. Add trialdehyde precursor and octadecylamine to N,N-dimethylformamide solvent, stir and react at 75-80℃ for 4-6h, and after the reaction is completed, distill under reduced pressure and wash to obtain Schiff base vanillin. S3. Add 50-60 mL After being uniformly dispersed by ultrasonication in dimethylformamide solvent, 1.5-2g of carboxylated carbon nanotubes and 20-21g of thionyl chloride, the mixture was heated to reflux and reacted at 110-120℃ for 14-16h. After the reaction was completed, the mixture was rotary evaporated, washed with tetrahydrofuran, and dried to obtain acyl chloride carbon nanotubes. S4. Add 60-70mL 1.5-1.8 mmol of Schiff base vanillin was added to dimethylformamide solvent and stirred to dissolve. Then, 0.3-0.4 mmol of acyl chloride carbon nanotubes and 0.01-0.02 g of triethylamine catalyst were added. The reaction was carried out at 90-95 °C for 5-6 h. After the reaction was completed, the mixture was distilled under reduced pressure, filtered, and washed to obtain vanillin-modified carbon nanotubes.
6. The high-strength mortar according to claim 5, characterized in that, In S1, the ratio of vanillin, glycerol triglycidyl ether, and 4-dimethylaminopyridine is 25-30 mmol: 8-10 mmol: 0.5-0.6 mmol.
7. The high-strength mortar according to claim 5, characterized in that, In S2, the ratio of N,N-dimethylformamide, trialdehyde precursor, and octadecylamine is 50-60 mL: 4-5 mmol: 12-16 mmol.
8. A method for preparing high-strength mortar as described in any one of claims 1-7, characterized in that, Ordinary silicate cement, ultrafine quartz sand, metakaolin, nano calcium carbonate, composite admixture, steel fiber, vanillin-modified carbon nanotubes, and glycine-modified molybdenum disulfide are added to a mixer and stirred for 5-8 minutes. Then water is added and stirring is continued for 4-8 minutes to obtain a slurry. The stirred slurry is allowed to stand and age for 10-15 minutes. The aged slurry is poured into a mold, vibrated and compacted, and the surface is smoothed. After curing for 24 hours, it is demolded and cured for another 7 days to obtain a high-strength mortar product.