High-strength low-temperature-resistant concrete and preparation method thereof

Abstract

This invention relates to the field of concrete technology, specifically to a high-strength, low-temperature resistant concrete and its preparation method. The raw materials for preparation include the following components in parts by weight: modified SiO₂. 2 10-15 parts, eugenol-ODT 8-12 parts, 52.5 grade ordinary Portland cement 100-150 parts, fine aggregate 50-70 parts, coarse aggregate 30-50 parts, sodium citrate retarder 0.1-0.3 parts, polycarboxylate superplasticizer 0.2-0.3 parts, water 40-50 parts, asphalt base material 30-40 parts, polypropylene fiber 10-16 parts.

Description

Technical Field

[0001] This invention relates to the field of concrete technology, specifically to a high-strength, low-temperature resistant concrete and its preparation method. Background Technology

[0002] As a widely used building material, the durability of concrete directly determines the service life and safety of structures. In cold regions and high-altitude areas, concrete structures are exposed to low temperatures for extended periods or periodically, facing the challenge of freeze-thaw cycle damage. The damage to concrete at low temperatures stems from the phase change of water. Free water in the capillaries and gel pores of concrete freezes at low temperatures, expanding in volume by about 9%. The resulting expansion pressure causes microcracks to form on the pore walls. After multiple freeze-thaw cycles, these microcracks continue to expand and connect, leading to surface spalling, strength loss, and even structural collapse. Traditional methods for achieving excellent compressive strength, crack resistance, and freeze-thaw resistance at low temperatures include adding air-entraining agents, reducing the water-cement ratio, or using antifreeze agents. However, these methods all have drawbacks. For example, adding large amounts of air-entraining agents reduces the compressive strength of the concrete; the introduction of inorganic salt antifreeze agents can corrode steel reinforcement, and excessive use can cause salt precipitation and crystallization, leading to surface powdering. Furthermore, the effectiveness of these antifreeze agents is diluted during hydration, negatively impacting long-term freeze-thaw resistance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention proposes a high-strength, low-temperature resistant concrete and its preparation method.

[0004] This invention is achieved through the following technical solution: A high-strength, low-temperature resistant concrete is prepared from the following raw materials in parts by weight: 10-15 parts modified SiO2, 8-12 parts eugenol-ODT, 100-150 parts 52.5 grade ordinary Portland cement, 50-70 parts fine aggregate, 30-50 parts coarse aggregate, 0.1-0.3 parts sodium citrate retarder, 0.2-0.3 parts polycarboxylate superplasticizer, 40-50 parts water, 30-40 parts asphalt base material, and 10-16 parts polypropylene fiber.

[0005] Furthermore, the fine aggregate is 1 mm-2 mm fine quartz sand, and the coarse aggregate is 4.5 mm-5 mm coarse quartz sand.

[0006] Furthermore, the asphalt base material is 10# flake petroleum asphalt, with a softening point of 105-110℃, a flash point of 240℃, and a needle diameter of 30 mm.

[0007] Furthermore, the polypropylene fiber has a fiber length of 3 mm.

[0008] Furthermore, the raw materials for preparing the modified SiO2 include the following components in parts by weight: 4-6 parts of nano SiO2, 6-9 parts of hexamethylene diisocyanate (HDI), and 4-6 parts of 2-methylimidazole.

[0009] Furthermore, the particle size of the nano-SiO2 is 20-30 nm.

[0010] Furthermore, the method for preparing the modified SiO2 includes the following steps: L1. Nano-SiO2, hexamethylene diisocyanate and toluene were stirred and mixed, dibutyltin dilaurate was added, ultrasonically dispersed, and refluxed at 95℃ for 6 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged at 8000 rpm for 10-15 min, the precipitate was washed with toluene and dried under vacuum to obtain HDI-grafted nano-SiO2. L2. The HDI-grafted nano-SiO2 obtained in step L1 was added to DMF and stirred evenly. 2-methylimidazolium and dibutyltin dilaurate were added, and the mixture was ultrasonically dispersed. The reaction was carried out at 60℃ for 2-3 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged at 8000 rpm for 10-15 min, the precipitate was washed with DMF, and vacuum dried to obtain modified SiO2.

[0011] Furthermore, in step L1, the mass concentration of the nano-SiO2 in toluene is 20 mg / mL.

[0012] Further, in step L1, the amount of dibutyltin dilaurate used is 0.6-0.8 wt% of hexamethylene diisocyanate.

[0013] Further, in step L2, the mass concentration of the 2-methylimidazole in DMF is 50 mg / mL.

[0014] Further, in step L2, the amount of dibutyltin dilaurate is 0.8-1 wt% of 2-methylimidazole.

[0015] Furthermore, the raw materials for preparing eugenol-ODT include the following components in parts by weight: 8-12 parts eugenol, 23-34 parts epichlorohydrin (ECH), and 14-21 parts n-octadecyl mercaptan (ODT).

[0016] Furthermore, the preparation method of the eugenol-ODT includes the following steps: V1. Eugenol, epichlorohydrin and tetramethylammonium bromide were mixed and stirred at 80°C for 6 h. After cooling to room temperature, sodium hydroxide was added and stirred at room temperature for 5-6 h. The mixture was filtered, and the filtrate was washed with deionized water, dried with anhydrous sodium sulfate, and recrystallized from methanol by vacuum distillation to obtain eugenol-ECH. V2. Mix the eugenol-ECH and n-octadecyl mercaptan obtained in step V1, add tetrahydrofuran and photoinitiator 1173, and apply 365 nm ultraviolet light (20 mW / cm²). 2 Under irradiation, the reaction was stirred for 2-3 hours, followed by vacuum distillation to obtain eugenol-ODT.

[0017] Further, in step V1, the mass ratio of eugenol, NaOH, and tetramethylammonium bromide is 8:3.5:0.6.

[0018] Further, in step V2, the amount of photoinitiator 1173 is 1 wt% of the total mass of eugenol-ECH and n-octadecyl mercaptan.

[0019] Furthermore, in step V2, the ratio of n-octadecyl mercaptan to tetrahydrofuran is 1 g: 10 mL.

[0020] Furthermore, the present invention also provides a method for preparing the high-strength, low-temperature resistant concrete, comprising the following steps: S1. Add modified SiO2 to DMF and disperse evenly. Add acetic acid dropwise. After the addition is complete, cool to room temperature. Slowly add eugenol-ODT while stirring. Sonicate at 300W for 4-6 hours at room temperature. Centrifuge at 5000-6000 rpm for 20 minutes. Wash the precipitate with toluene, vacuum dry, and mix evenly with ordinary silicate cement, asphalt base material, fine aggregate, coarse aggregate and retarder sodium citrate to obtain mixed base material. S2. Mix polypropylene fiber, polycarboxylate superplasticizer and water evenly, add to the mixed base material, stir evenly to obtain high-strength low-temperature resistant concrete.

[0021] Further, in step S1, the mass concentration of the modified SiO2 in DMF is 20 mg / mL.

[0022] Further, in step S1, the ratio of eugenol-ODT to acetic acid is 1 g: 0.1 mL.

[0023] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a high-strength, low-temperature resistant concrete. By introducing specific modified SiO2 and eugenol-ODT, and through synergistic effects with asphalt binder, polypropylene fibers, and other components, the prepared concrete exhibits strong mechanical properties. This invention prepares modified SiO2, reacting the isocyanate of hexamethylene diisocyanate with the hydroxyl groups on the surface of nano-SiO2 to graft isocyanate groups onto the nano-SiO2 surface. Subsequently, 2-methylimidazole is introduced for end-capping, introducing imidazole groups onto the SiO2 surface to provide crosslinking sites for subsequent reactions. Nano-SiO2 can fill the capillary and gel pores of cement paste, reducing porosity and refining the pore structure, thereby improving mechanical strength. This invention prepares eugenol-ODT by reacting the phenolic hydroxyl groups of eugenol with the chlorine atoms of epichlorohydrin to obtain eugenol-ECH containing eugenol double bonds and epichlorohydrin epoxy groups. Long-chain n-octadecyl mercaptan is grafted onto the double bonds using click chemistry with the mercaptan groups. The long alkyl chains enhance hydrophobicity, significantly reducing the surface energy of the concrete capillary walls, maintaining excellent flexibility at low temperatures, and improving freeze-thaw resistance. Furthermore, the introduction of a rigid benzene ring structure from eugenol improves mechanical properties, and the epoxy groups provide crosslinking sites for subsequent reactions. This invention also involves reacting modified SiO2 with eugenol-ODT, adding acetic acid to activate the imidazole groups on the surface of the modified SiO2, which then undergo a ring-opening reaction with the epoxy groups in eugenol-ODT. This anchors the long-chain hydrophobic groups to the nano-SiO2 surface through chemical bonds, while simultaneously introducing imidazole-type ionic liquid groups to improve concrete performance. By constructing strong covalent bonds between the organic and inorganic phases, the interfacial strength of the organic-inorganic composite system is improved, the material cohesion is enhanced, and the mechanical properties are improved. Attached Figure Description

[0024] Figure 1 The compressive strength of the concrete described in Examples 1-3 and Comparative Examples 1-3 of this invention; Figure 2 The splitting tensile strength of the concrete described in Examples 1-3 and Comparative Examples 1-3 of this invention; Figure 3 This describes the freeze-thaw resistance of the concrete described in Examples 1-3 and Comparative Examples 1-3 of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. However, this invention is not limited to the following embodiments. It should be noted that, unless otherwise specified, all chemical reagents involved in this invention are purchased through commercial channels.

[0026] Example 1: A high-strength, low-temperature resistant concrete, the raw materials for which are prepared include the following components in parts by weight: 15 parts modified SiO2, 12 parts eugenol-ODT, 150 parts 52.5 grade ordinary Portland cement, 70 parts fine aggregate, 50 parts coarse aggregate, 0.3 parts sodium citrate retarder, 0.3 parts polycarboxylate superplasticizer, 50 parts water, 40 parts asphalt base material, and 16 parts polypropylene fiber.

[0027] The fine aggregate is 2 mm fine quartz sand, and the coarse aggregate is 5 mm coarse quartz sand; the asphalt base is 10# flake petroleum asphalt with a softening point of 110℃, a flash point of 240℃, and a needle size of 30 mm; the polypropylene fiber has a fiber length of 3 mm.

[0028] The raw materials for preparing modified SiO2 include the following components in parts by weight: 6 parts of nano SiO2, 9 parts of hexamethylene diisocyanate (HDI), and 6 parts of 2-methylimidazole.

[0029] The particle size of nano-SiO2 is 30 nm.

[0030] The preparation method of modified SiO2 includes the following steps: L1. 6 g of nano-SiO2, 9 g of hexamethylene diisocyanate and 300 mL of toluene were stirred and mixed. 72 mg of dibutyltin dilaurate was added, and the mixture was ultrasonically dispersed. The mixture was refluxed at 95 °C and stirred for 6 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged at 8000 rpm for 15 min, the precipitate was washed with toluene and dried under vacuum to obtain HDI-grafted nano-SiO2. L2. The HDI-grafted nano-SiO2 obtained in step L1 was added to 120 mL of DMF and stirred evenly. 6 g of 2-methylimidazole and 60 mg of dibutyltin dilaurate were added, and the mixture was ultrasonically dispersed. The reaction was carried out at 60 °C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged at 8000 rpm for 15 min, the precipitate was washed with DMF, and dried under vacuum to obtain modified SiO2.

[0031] The raw materials for preparing eugenol-ODT include the following components in parts by weight: 12 parts eugenol, 34 parts epichlorohydrin (ECH), and 21 parts n-octadecyl mercaptan (ODT).

[0032] The preparation method of eugenol-ODT includes the following steps: V1. Mix 12 g of eugenol, 34 g of epichlorohydrin and 0.9 g of tetramethylammonium bromide, stir at 80 °C for 6 h, cool to room temperature, add 5.25 g of sodium hydroxide, stir at room temperature for 6 h, filter, wash the filtrate with deionized water, dry with anhydrous sodium sulfate, distill under reduced pressure, recrystallize in methanol to obtain eugenol-ECH. V2. Mix 21 g of eugenol-ECH and n-octadecyl mercaptan obtained in step V1, add 210 mL of tetrahydrofuran and photoinitiator 1173, the amount of photoinitiator 1173 being 1 wt% of the total mass of eugenol-ECH and n-octadecyl mercaptan, and apply 365 nm ultraviolet light (20 mW / cm²). 2 Under irradiation, the mixture was stirred for 3 h, and then distilled under reduced pressure to obtain eugenol-ODT.

[0033] This embodiment also provides a method for preparing the high-strength, low-temperature resistant concrete, including the following steps: S1. Modified SiO2 was added to DMF and dispersed evenly. The mass concentration of modified SiO2 in DMF was 20 mg / mL. Acetic acid was added dropwise. After the addition was complete, the mixture was cooled to room temperature. Eugenol-ODT was slowly added under stirring. The ratio of eugenol-ODT to acetic acid was 1 g: 0.1 mL. The mixture was ultrasonically reacted at 300 W for 6 h at room temperature. After centrifugation at 6000 rpm for 20 min, the precipitate was washed with toluene, vacuum dried, and then mixed evenly with ordinary silicate cement, asphalt base material, fine aggregate, coarse aggregate and retarder sodium citrate to obtain a mixed base material. S2. Mix polypropylene fiber, polycarboxylate superplasticizer and water evenly, add to the mixed base material, stir evenly to obtain high-strength low-temperature resistant concrete.

[0034] Example 2: A high-strength, low-temperature resistant concrete, the raw materials for which are prepared include the following components in parts by weight: 10 parts modified SiO2, 8 parts eugenol-ODT, 100 parts 52.5 grade ordinary Portland cement, 50 parts fine aggregate, 30 parts coarse aggregate, 0.1 parts sodium citrate retarder, 0.2 parts polycarboxylate superplasticizer, 40 parts water, 30 parts asphalt base material, and 10 parts polypropylene fiber.

[0035] The fine aggregate is 1 mm fine quartz sand, and the coarse aggregate is 4.5 mm coarse quartz sand; the asphalt base is 10# flake petroleum asphalt with a softening point of 105℃, a flash point of 240℃, and a needle size of 30 mm; the polypropylene fiber has a fiber length of 3 mm.

[0036] The raw materials for preparing modified SiO2 include the following components in parts by weight: 4 parts of nano SiO2, 6 parts of hexamethylene diisocyanate (HDI), and 4 parts of 2-methylimidazole.

[0037] The particle size of nano-SiO2 is 20 nm.

[0038] The preparation method of modified SiO2 includes the following steps: L1. 4 g of nano-SiO2, 6 g of hexamethylene diisocyanate and 200 mL of toluene were stirred and mixed. 36 mg of dibutyltin dilaurate was added, and the mixture was ultrasonically dispersed. The mixture was refluxed at 95 °C and stirred for 6 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged at 8000 rpm for 10 min, and the precipitate was washed with toluene and dried under vacuum to obtain HDI-grafted nano-SiO2. L2. The HDI-grafted nano-SiO2 obtained in step L1 was added to 80 mL of DMF and stirred evenly. 4 g of 2-methylimidazole and 32 mg of dibutyltin dilaurate were added, and the mixture was ultrasonically dispersed. The reaction was carried out at 60 °C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged at 8000 rpm for 10 min, the precipitate was washed with DMF, and dried under vacuum to obtain modified SiO2.

[0039] The raw materials for preparing eugenol-ODT include the following components in parts by weight: 8 parts eugenol, 23 parts epichlorohydrin (ECH), and 14 parts n-octadecyl mercaptan (ODT).

[0040] The preparation method of eugenol-ODT includes the following steps: V1. Mix 8 g of eugenol, 23 g of epichlorohydrin and 0.6 g of tetramethylammonium bromide, stir at 80 °C for 6 h, cool to room temperature, add 3.5 g of sodium hydroxide, stir at room temperature for 5 h, filter, wash the filtrate with deionized water, dry with anhydrous sodium sulfate, distill under reduced pressure, recrystallize in methanol to obtain eugenol-ECH. V2. Mix 14 g of eugenol-ECH and n-octadecyl mercaptan obtained in step V1, add 140 mL of tetrahydrofuran and photoinitiator 1173, the amount of photoinitiator 1173 being 1 wt% of the total mass of eugenol-ECH and n-octadecyl mercaptan, and apply 365 nm ultraviolet light (20 mW / cm²). 2 Under irradiation, the mixture was stirred for 2 h, and then distilled under reduced pressure to obtain eugenol-ODT.

[0041] This embodiment also provides a method for preparing the high-strength, low-temperature resistant concrete, including the following steps: S1. Modified SiO2 was added to DMF and dispersed evenly. The mass concentration of modified SiO2 in DMF was 20 mg / mL. Acetic acid was added dropwise. After the addition was complete, the mixture was cooled to room temperature. Eugenol-ODT was slowly added under stirring. The ratio of eugenol-ODT to acetic acid was 1 g: 0.1 mL. The mixture was ultrasonically reacted at 300 W for 4 h at room temperature. After centrifugation at 5000 rpm for 20 min, the precipitate was washed with toluene, vacuum dried, and then mixed evenly with ordinary silicate cement, asphalt base material, fine aggregate, coarse aggregate and retarder sodium citrate to obtain a mixed base material. S2. Mix polypropylene fiber, polycarboxylate superplasticizer and water evenly, add to the mixed base material, stir evenly to obtain high-strength low-temperature resistant concrete.

[0042] Example 3: A high-strength, low-temperature resistant concrete, the raw materials for which are prepared include the following components in parts by weight: 12 parts modified SiO2, 10 parts eugenol-ODT, 120 parts 52.5 grade ordinary Portland cement, 60 parts fine aggregate, 40 parts coarse aggregate, 0.2 parts sodium citrate retarder, 0.25 parts polycarboxylate superplasticizer, 45 parts water, 35 parts asphalt base material, and 12 parts polypropylene fiber.

[0043] The fine aggregate is 1.5 mm fine quartz sand, and the coarse aggregate is 4.8 mm coarse quartz sand; the asphalt base is 10# flake petroleum asphalt with a softening point of 108℃, a flash point of 240℃, and a needle size of 30 mm; the polypropylene fiber has a fiber length of 3 mm.

[0044] The raw materials for preparing modified SiO2 include the following components in parts by weight: 5 parts nano SiO2, 8 parts hexamethylene diisocyanate (HDI), and 5 parts 2-methylimidazole.

[0045] The particle size of nano-SiO2 is 25 nm.

[0046] The preparation method of modified SiO2 includes the following steps: L1. 5 g of nano-SiO2, 8 g of hexamethylene diisocyanate and 250 mL of toluene were stirred and mixed. 56 mg of dibutyltin dilaurate was added, and the mixture was ultrasonically dispersed. The mixture was refluxed at 95 °C and stirred for 6 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged at 8000 rpm for 12 min, and the precipitate was washed with toluene and dried under vacuum to obtain HDI-grafted nano-SiO2. L2. The HDI-grafted nano-SiO2 obtained in step L1 was added to 100 mL of DMF and stirred evenly. 5 g of 2-methylimidazolium and 45 mg of dibutyltin dilaurate were added, and the mixture was ultrasonically dispersed. The reaction was carried out at 60 °C for 2.5 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged at 8000 rpm for 12 min, the precipitate was washed with DMF, and dried under vacuum to obtain modified SiO2.

[0047] The raw materials for preparing eugenol-ODT include the following components in parts by weight: 10 parts eugenol, 29 parts epichlorohydrin (ECH), and 18 parts n-octadecyl mercaptan (ODT).

[0048] The preparation method of eugenol-ODT includes the following steps: V1. Mix 10 g of eugenol, 29 g of epichlorohydrin and 0.75 g of tetramethylammonium bromide, stir at 80 °C for 6 h, cool to room temperature, add 4.375 g of sodium hydroxide, stir at room temperature for 5.5 h, filter, wash the filtrate with deionized water, dry with anhydrous sodium sulfate, distill under reduced pressure, recrystallize in methanol to obtain eugenol-ECH; V2. Mix 18 g of eugenol-ECH and n-octadecyl mercaptan obtained in step V1, add 180 mL of tetrahydrofuran and photoinitiator 1173, the amount of photoinitiator 1173 being 1 wt% of the total mass of eugenol-ECH and n-octadecyl mercaptan, and apply 365 nm ultraviolet light (20 mW / cm²). 2 Under irradiation, the reaction was stirred for 2.5 h, followed by vacuum distillation to obtain eugenol-ODT.

[0049] This embodiment also provides a method for preparing the high-strength, low-temperature resistant concrete, including the following steps: S1. Modified SiO2 was added to DMF and dispersed evenly. The mass concentration of modified SiO2 in DMF was 20 mg / mL. Acetic acid was added dropwise. After the addition was complete, the mixture was cooled to room temperature. Eugenol-ODT was slowly added under stirring. The ratio of eugenol-ODT to acetic acid was 1 g: 0.1 mL. The mixture was ultrasonically reacted at 300 W for 5 h at room temperature. After centrifugation at 5500 rpm for 20 min, the precipitate was washed with toluene, vacuum dried, and then mixed evenly with ordinary silicate cement, asphalt base material, fine aggregate, coarse aggregate and retarder sodium citrate to obtain a mixed base material. S2. Mix polypropylene fiber, polycarboxylate superplasticizer and water evenly, add to the mixed base material, stir evenly to obtain high-strength low-temperature resistant concrete.

[0050] The only difference between Comparative Example 1 and Example 1 is that no modified SiO2 is added.

[0051] The only difference between Comparative Example 2 and Example 1 is that eugenol-ODT is not added.

[0052] The only difference between Comparative Example 3 and Example 1 is that after physically blending the modified SiO2 with eugenol-ODT, subsequent operations were performed. Specifically, after physically blending the modified SiO2 with eugenol-ODT, the mixture was stirred evenly with ordinary silicate cement, asphalt base material, fine aggregate, coarse aggregate and retarder sodium citrate to obtain a mixed base material.

[0053] Experimental Example 1: The concrete prepared in Examples 1-3 and Comparative Examples 1-3 was made into 100mm×100mm×100mm cubic specimens for performance testing. According to GB / T50081-2002 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete", the compressive strength of each specimen after curing at room temperature for 28 days was tested. The results are as follows: Figure 1 As shown.

[0054] Figure 1 The results showed that the compressive strength of the groups in Examples 1-3 was significantly better than that of the comparative examples 1-3. Comparative example 1 did not add modified SiO2; comparative example 2 did not add eugenol-ODT; and comparative example 3 physically blended modified SiO2 with eugenol-ODT. The compressive strength of the groups in comparative examples 1-3 all decreased, indicating that the concrete prepared by the present invention has high compressive strength and good mechanical properties.

[0055] Experimental Example 2: According to GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", the splitting tensile strength of each group of specimens was tested, and the results are as follows. Figure 2 As shown.

[0056] Figure 1 The results showed that the splitting tensile strength of the groups in Examples 1-3 was significantly better than that of the comparative examples 1-3. Comparative example 1 did not add modified SiO2; comparative example 2 did not add eugenol-ODT; and comparative example 3 physically blended modified SiO2 with eugenol-ODT. The splitting tensile strength of the groups in comparative examples 1-3 all decreased, indicating that the concrete prepared by the present invention has high splitting tensile strength and good mechanical properties.

[0057] Experimental Example 3: Following the slow-freezing method described in GB / T50082-2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete", each specimen underwent 100 freeze-thaw cycles. After the freeze-thaw treatment, the mass loss rate and compressive strength loss rate of each specimen were measured. The results are as follows: Figure 3 As shown.

[0058] Figure 3 The results showed that after 100 freeze-thaw cycles, the concrete in Examples 1-3 had a lower mass loss rate and compressive strength loss rate than that in Comparative Examples 1-3, indicating that the concrete prepared by the present invention can effectively resist freeze-thaw cycles and has good durability.

[0059] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A high-strength, low-temperature resistant concrete, characterized in that, The raw materials for preparation include the following components in parts by weight: 10-15 parts modified SiO2, 8-12 parts eugenol-ODT, 100-150 parts silicate cement, 50-70 parts fine aggregate, 30-50 parts coarse aggregate, 0.1-0.3 parts retarder, 0.2-0.3 parts water-reducing agent, 40-50 parts water, 30-40 parts asphalt base material, and 10-16 parts polypropylene fiber; The raw materials for preparing modified SiO2 include the following components in parts by weight: 4-6 parts of nano SiO2, 6-9 parts of hexamethylene diisocyanate, and 4-6 parts of 2-methylimidazole; The preparation method of modified SiO2 includes the following steps: L1. Nano-SiO2, hexamethylene diisocyanate and toluene were stirred and mixed, dibutyltin dilaurate was added, dispersed, refluxed, cooled, centrifuged, precipitated, washed and dried to obtain HDI-grafted nano-SiO2. L2. The HDI-grafted nano-SiO2 obtained in step L1 was added to DMF and stirred evenly. 2-methylimidazolium and dibutyltin dilaurate were added, dispersed, reacted, cooled, centrifuged, precipitated, washed, and dried to obtain modified SiO2. The raw materials for preparing eugenol-ODT include the following components in parts by weight: 8-12 parts eugenol, 23-34 parts epichlorohydrin, and 14-21 parts n-octadecyl mercaptan. The preparation method of eugenol-ODT includes the following steps: V1. Eugenol, epichlorohydrin and tetramethylammonium bromide were mixed, stirred and cooled, sodium hydroxide was added, stirred and filtered, washed and dried, distilled under reduced pressure and recrystallized to obtain eugenol-ECH; V2. Mix the eugenol-ECH obtained in step V1 with n-octadecyl mercaptan, add tetrahydrofuran and photoinitiator 1173, irradiate with ultraviolet light, and distill under reduced pressure to obtain eugenol-ODT.

2. The high-strength, low-temperature resistant concrete according to claim 1, characterized in that, In step L1, the amount of dibutyltin dilaurate used is 0.6-0.8 wt% of hexamethylene diisocyanate.

3. The high-strength, low-temperature resistant concrete according to claim 2, characterized in that, In step L2, the amount of dibutyltin dilaurate is 0.8-1 wt% of 2-methylimidazole.

4. The high-strength, low-temperature resistant concrete according to claim 3, characterized in that, In step V1, the mass ratio of eugenol, NaOH and tetramethylammonium bromide is 8:3.5:0.

6.

5. The high-strength, low-temperature resistant concrete according to claim 4, characterized in that, In step V2, the amount of photoinitiator 1173 is 1 wt% of the total mass of eugenol-ECH and n-octadecyl mercaptan.

6. A method for preparing high-strength, low-temperature resistant concrete as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Modified SiO2 is added to DMF and dispersed, acetic acid is added dropwise, cooled, eugenol-ODT is added, ultrasonicated, centrifuged, precipitated and washed, dried, and then mixed evenly with ordinary silicate cement, asphalt base material, fine aggregate, coarse aggregate and retarder sodium citrate to obtain mixed base material; S2. Mix polypropylene fiber, polycarboxylate superplasticizer and water evenly, add to the mixed base material, stir evenly to obtain high-strength low-temperature resistant concrete.

Images