A kind of corrosion-resistant concrete with good anti-penetration performance and preparation method thereof

Abstract

The invention relates to the technical field of building materials, and discloses corrosion-resistant concrete with good anti-permeability performance and a preparation method thereof. The surface of the organosilicon-modified epoxy resin contains abundant hydroxyl and oxygen functional groups, which can effectively fill the pores and cracks in the concrete material, thereby improving the compressive strength and flexural strength of the concrete; the organosilicon-modified epoxy resin can accelerate the hydration reaction, produce physical adsorption on chloride ions, reduce the electromigration effect of chloride ions in concrete, and improve the resistance of the concrete material to chloride ion corrosion; the mineral admixture, the organosilicon-modified epoxy resin and the modified basalt fiber have a synergistic effect, form a spatial network structure, can make the structure of the concrete more compact, increase the water-blocking effect of the concrete, thereby improving the anti-permeability and corrosion resistance of the concrete, and further broadening the application range of the concrete.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, in particular to corrosion-resistant concrete with good anti-penetration performance and a preparation method thereof. Background Art

[0002] Concrete refers to the material obtained by uniformly mixing, molding and hardening cement as the main gel material with water, sand, gravel, chemical additives and admixtures; with the continuous improvement of engineering requirements, people's performance requirements for concrete materials are becoming more and more stringent. At present, concrete materials mainly have disadvantages such as poor toughness, insufficient impermeability and low corrosion resistance. In some oceans, groundwater or surfaces sprayed with deicing salt, concrete structures are often corroded and damaged by harmful ions around them. At the same time, due to the existence of pores inside the concrete, it is possible for water to penetrate, which in turn causes stress failure inside the concrete, resulting in a decrease in the strength of the concrete structure, thereby affecting the life and use of the concrete. Therefore, the development of a concrete with good impermeability and corrosion resistance has become a hot topic in current research.

[0003] At present, the simplest and most effective technical measure to improve the corrosion resistance of concrete is to add corrosion inhibitors. Some corrosion inhibitor products have appeared on the domestic market, mainly composites of expansion agents, mineral admixtures and water reducers. Through the interaction of the above substances, the density of concrete is improved, thereby improving the corrosion resistance of concrete; but this type of corrosion inhibitor often does not have special targeted ingredients to resist steel corrosion caused by chloride ion penetration, but only reduces the penetration of chloride ions by increasing the density of concrete; at the same time, the effective components of some corrosion inhibitors that have the effect of inhibiting chloride ion penetration are mostly nitrites. Due to some negative effects of nitrites, their scope of application is limited.

[0004] Chinese patent CN109761561B discloses a method for preparing impermeable concrete and impermeable concrete. While maintaining the original strength of concrete, asphalt particles are added, heated to soften the concrete and attached to the pore surface to increase its impermeability. However, after the asphalt particles are ground into powder, they have poor dispersion performance in the concrete matrix and are easy to agglomerate, which will reduce the slump and fluidity of the concrete, and the demand for water is large, which is not conducive to engineering application. There is also a technology that often applies a layer of waterproof coating on the concrete surface to increase the impermeability of concrete. However, in actual environments, the waterproof coating often has reduced anti-aging performance after being used for a short time. The present invention utilizes polar groups such as epoxy groups, hydroxyl groups and ether bonds of organosilicon-modified epoxy resin, which can be well combined with modified basalt fibers and cement-based materials, and uses stearic acid to modify microsilica fume powder to improve the problem of poor dispersion and improve the impermeability and corrosion resistance of concrete. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art, provide a corrosion-resistant concrete with good anti-permeability and a preparation method thereof, and solve the problem that the existing concrete has poor anti-permeability and corrosion resistance.

[0006] The technical solution adopted by the present invention is:

[0007] A corrosion-resistant concrete with good anti-penetration performance comprises the following components in parts by weight: 400-550 parts of cement, 170-200 parts of deionized water, 800-1250 parts of coarse aggregate, 650-900 parts of fine aggregate, 30-150 parts of mineral admixture, 3-8 parts of polycarboxylate high-efficiency water reducing agent, 1-3 parts of early strength agent, 0.5-2.5 parts of modified basalt fiber and 2-10 parts of silicone modified epoxy resin.

[0008] The preparation method of the mineral admixture is as follows: add 1g of microsilica fume and 15-25mL of ethanol into a reaction flask, stir evenly, then add 2.2-3g of stearic acid, react at 65-80°C for 1-3h, cool and filter, wash with ethanol, and dry to obtain the mineral admixture.

[0009] Preferably, the coarse aggregate is crushed stone with a particle size of 15-30 mm, and the fine aggregate is quartz sand with a fineness modulus of 1.5-3.

[0010] Preferably, the early strength agent is any one of triethanolamine, water glass or sodium aluminate.

[0011] Preferably, the preparation method of the organosilicon-modified epoxy resin is:

[0012] (1) Under a nitrogen atmosphere, 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and tetrahydrofuran were added to a reaction flask, and after stirring, allyl glycidyl ether and chloroplatinic acid isopropanol solution were added, and the mixture was stirred for reaction. After the reaction was completed, the mixture was distilled under reduced pressure to obtain diepoxy-terminated siloxane.

[0013] (2) Under nitrogen atmosphere, add bisphenol A epoxy resin and diepoxy-terminated siloxane into a reaction flask, stir evenly, heat to 120-130°C, add methyltetrahydrophthalic anhydride and 2,4,6-tris(dimethylaminomethyl)phenol, stir at 20-35°C until mixed evenly, then vacuum degas at 55-70°C for 20-40 min, and cool naturally to room temperature to obtain a silicone-modified epoxy resin.

[0014] Preferably, the mass concentration of the chloroplatinic acid isopropanol solution in step (1) is 0.02-0.04 g / mL.

[0015] Preferably, in step (1), the ratio of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, tetrahydrofuran, allyl glycidyl ether, and chloroplatinic acid isopropanol solution is 1 g: (10-20) mL: (0.7-0.85) g: (0.3-0.5) mL.

[0016] Preferably, in step (1), the reaction temperature is 60-75° C. and the reaction time is 5-10 h.

[0017] Preferably, in step (1), the ratio of bisphenol A epoxy resin, diepoxy-terminated siloxane, methyltetrahydrophthalic anhydride, and 2,4,6-tris(dimethylaminomethyl)phenol is 1 g: (0.2-0.35) g: (0.5-0.65) g: (0.01-0.02) g.

[0018] Preferably, the preparation method is: weigh the cement, coarse aggregate, fine aggregate, mineral admixture and polycarboxylate high-efficiency water reducing agent of the above-mentioned weight components, pour them into a concrete mixer and dry mix for 30-50s. After mixing evenly, add deionized water and early strength agent, mix and stir for 5-10min, then add modified basalt fiber and silicone modified epoxy resin, continue to stir for 20-40min, mix evenly, pour into a standard mold, oscillate to compact, and naturally cure after molding to obtain corrosion-resistant concrete with good anti-penetration performance.

[0019] Preferably, the temperature of natural curing is 20-30°C and the humidity is 90-95%.

[0020] The beneficial effects of the present invention are:

[0021] The present invention firstly allows 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and allyl glycidyl ether to undergo a silylation reaction under the action of a platinum catalyst to obtain a diepoxy-terminated siloxane, which is then reacted with a bisphenol A epoxy resin and related additives to obtain an organosilicon-modified epoxy resin, and then the surface of microsilica fume is modified by stearic acid to obtain a mineral admixture, and finally the organosilicon-modified epoxy resin, the mineral admixture, cement, a water reducer and the like are uniformly mixed to obtain corrosion-resistant concrete with good anti-penetration performance.

[0022] The surface of silicone-modified epoxy resin contains abundant hydroxyl and oxygen functional groups and has good workability. After combining with cement-based materials, it will tightly cross-link the hydration products together to form a dense grid structure, thereby improving the bonding strength between the hydration products and effectively filling the pores and cracks in the concrete material, thereby improving the compressive strength and flexural strength of the concrete. The addition of silicone-modified epoxy resin accelerates the hydration reaction, and the generated hydration products will physically adsorb chloride ions, reducing the electromigration of chloride ions in concrete and increasing the difficulty of chloride ion diffusion, thereby improving the concrete material's resistance to chloride ion corrosion.

[0023] The modified basalt fiber is modified by KH550, which increases its specific surface area, reduces interfacial tension, improves dispersibility and dispersion stability in the matrix, improves the compatibility and bonding between basalt fiber, epoxy resin and concrete, reduces concrete cracking, and can also fill and improve the void structure inside the concrete, thereby increasing the density of the concrete. After being modified by stearic acid, the microsilica fume has good compatibility with concrete and good dispersibility in the concrete matrix. It can be filled between concrete particles, thereby increasing the density of cement slurry from a microscopic scale, reducing and reducing the pore size, and blocking many connected pores, thereby greatly improving the concrete's anti-permeability and corrosion resistance.

[0024] Mineral admixtures, silicone-modified epoxy resins and modified basalt fibers have a synergistic effect, forming a spatial network structure that can make the structure of concrete more compact, increase the water-blocking effect of concrete, thereby improving the concrete's impermeability and corrosion resistance, and further broadening the application range of concrete. DETAILED DESCRIPTION

[0025] The embodiments given below are for further explanation of the present invention, but should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above contents of the present invention still fall within the scope of protection of the present invention.

[0026] Preparation of modified basalt fiber: Add 2 g of KH550 and 30 mL of ethanol into a reaction flask, stir evenly, add 40 g of basalt fiber, disperse evenly by ultrasonication, react at 60°C for 3 h, and centrifuge to obtain modified basalt fiber. Example

[0027] (1) Under nitrogen atmosphere, add 28g of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and 420mL of tetrahydrofuran to a reaction flask, stir evenly, then add 21g of allyl glycidyl ether and 9.8mL of 0.03g / mL chloroplatinic acid isopropanol solution, react at 65°C for 8h, and distill under reduced pressure to obtain diepoxy-terminated siloxane. The preparation reaction formula is as follows:

[0028]

[0029] (2) Under a nitrogen atmosphere, add 22 g of bisphenol A epoxy resin and 5.5 g of diepoxy-terminated siloxane into a reaction flask, stir evenly, heat to 125°C, add 12.1 g of methyltetrahydrophthalic anhydride and 0.33 g of 2,4,6-tris(dimethylaminomethyl)phenol, stir at 25°C until mixed evenly, then vacuum degas at 65°C for 30 min, and cool naturally to room temperature to obtain a silicone-modified epoxy resin.

[0030] (3) Add 18 g of microsilica fume and 360 mL of ethanol into a reaction flask, stir evenly, then add 45 g of stearic acid, react at 75 °C for 2 h, cool and filter, wash with ethanol, and dry to obtain a mineral admixture.

[0031] (4) Weigh 450 g of cement, 1050 g of crushed stone with a particle size of 25 mm, 850 g of quartz sand with a fineness modulus of 2, 30 g of mineral admixture and 5 g of polycarboxylate high-efficiency water reducer, pour them into a concrete mixer and dry mix for 40 s. After mixing evenly, add 180 g of deionized water and 2 g of triethanolamine and mix for 9 min. Then add 0.5 g of modified basalt fiber and 2 g of silicone-modified epoxy resin and continue to stir for 30 min. After mixing evenly, pour them into a standard mold, shake and compact them. After molding, naturally cure them at a curing temperature of 25 °C and a curing humidity of 92% to obtain corrosion-resistant concrete with good anti-penetration performance. Example

[0032] (1) Under nitrogen atmosphere, add 35 g of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and 350 mL of tetrahydrofuran into a reaction flask, stir evenly, then add 24.5 g of allyl glycidyl ether and 10.5 mL of 0.04 g / mL chloroplatinic acid isopropanol solution, react at 75 °C for 5 h, and distill under reduced pressure to obtain diepoxy-terminated siloxane.

[0033] (2) Under nitrogen atmosphere, add 30 g of bisphenol A epoxy resin and 6 g of diepoxy-terminated siloxane into a reaction flask, stir evenly, heat to 130°C, add 15 g of methyltetrahydrophthalic anhydride and 0.3 g of 2,4,6-tris(dimethylaminomethyl)phenol, stir at 35°C until mixed evenly, then vacuum degas at 70°C for 20 min, and cool naturally to room temperature to obtain a silicone-modified epoxy resin.

[0034] (3) Add 25 g of microsilica fume and 375 mL of ethanol into a reaction flask, stir evenly, then add 55 g of stearic acid, react at 80 °C for 1 h, cool and filter, wash with ethanol, and dry to obtain a mineral admixture.

[0035] (4) Weigh 400 g of cement, 1250 g of crushed stone with a particle size of 30 mm, 650 g of quartz sand with a fineness modulus of 3, 30 g of mineral admixture and 3 g of polycarboxylate high-efficiency water reducing agent, pour them into a concrete mixer and dry mix for 50 s. After mixing evenly, add 200 g of deionized water and 1 g of water glass and mix and stir for 10 min. Then add 1 g of modified basalt fiber and 4 g of silicone-modified epoxy resin and continue stirring for 40 min. After mixing evenly, pour them into a standard mold, oscillate to compact them, and naturally cure them after molding. The curing temperature is 30 °C and the curing humidity is 90% to obtain corrosion-resistant concrete with good anti-penetration performance. Example

[0036] (1) Under nitrogen atmosphere, add 12 g of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and 240 mL of tetrahydrofuran into a reaction flask. After stirring evenly, add 10.2 g of allyl glycidyl ether and 6 mL of 0.02 g / mL chloroplatinic acid isopropanol solution. React at 60 °C for 10 h, and distill under reduced pressure to obtain diepoxy-terminated siloxane.

[0037] (2) Under nitrogen atmosphere, add 20 g of bisphenol A epoxy resin and 7 g of diepoxy-terminated siloxane into a reaction flask, stir evenly, heat to 120°C, add 13 g of methyltetrahydrophthalic anhydride and 0.4 g of 2,4,6-tris(dimethylaminomethyl)phenol, stir at 20°C until mixed evenly, then vacuum degas at 55°C for 40 min, and cool naturally to room temperature to obtain a silicone-modified epoxy resin.

[0038] (3) Add 15 g of microsilica fume and 375 mL of ethanol into a reaction flask, stir evenly, then add 45 g of stearic acid, react at 65 °C for 3 h, cool and filter, wash with ethanol, and dry to obtain a mineral admixture.

[0039] (4) Weigh 550 g of cement, 800 g of crushed stone with a particle size of 15 mm, 900 g of quartz sand with a fineness modulus of 1.5, 30 g of mineral admixture and 8 g of polycarboxylate high-efficiency water reducer, pour them into a concrete mixer and dry mix them for 50 s. After mixing evenly, add 170 g of deionized water and 3 g of sodium aluminate and mix and stir for 10 min. Then add 1.5 g of modified basalt fiber and 6 g of silicone-modified epoxy resin and continue stirring for 20 min. After mixing evenly, pour them into a standard mold, shake and compact them, and naturally cure them after molding. The curing temperature is 20 °C and the curing humidity is 90% to obtain corrosion-resistant concrete with good anti-penetration performance. Example

[0040] (1) Under nitrogen atmosphere, 20 g of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and 280 mL of tetrahydrofuran were added to a reaction flask. After stirring evenly, 15.6 g of allyl glycidyl ether and 9 mL of 0.025 g / mL chloroplatinic acid isopropanol solution were added. The mixture was reacted at 70 °C for 9 h and distilled under reduced pressure to obtain diepoxy-terminated siloxane.

[0041] (2) Under a nitrogen atmosphere, 14 g of bisphenol A epoxy resin and 3.5 g of diepoxy-terminated siloxane were added to a reaction flask. After stirring evenly, the temperature was raised to 130°C, and 7.9 g of methyltetrahydrophthalic anhydride and 0.28 g of 2,4,6-tris(dimethylaminomethyl)phenol were added. The mixture was stirred at 30°C until uniformly mixed. The mixture was then vacuum-degassed at 65°C for 35 min and naturally cooled to room temperature to obtain a silicone-modified epoxy resin.

[0042] (3) Add 5 g of microsilica fume and 90 mL of ethanol into a reaction flask, stir evenly, then add 13 g of stearic acid, react at 70 °C for 3 h, cool and filter, wash with ethanol, and dry to obtain a mineral admixture.

[0043] (4) Weigh 500 g of cement, 1100 g of crushed stone with a particle size of 20 mm, 850 g of quartz sand with a fineness modulus of 2.5, 30 g of mineral admixture and 5 g of polycarboxylate high-efficiency water reducer, pour them into a concrete mixer and dry mix for 40 s. After mixing evenly, add 190 g of deionized water and 3 g of triethanolamine and mix for 8 min. Then add 2 g of modified basalt fiber and 8 g of silicone-modified epoxy resin and continue to stir for 35 min. After mixing evenly, pour them into a standard mold, shake and compact them, and naturally cure them after molding. The curing temperature is 25 °C and the curing humidity is 91% to obtain corrosion-resistant concrete with good anti-penetration performance. Example

[0044] (1) Under nitrogen atmosphere, add 25 g of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and 400 mL of tetrahydrofuran into a reaction flask. After stirring evenly, add 19 g of allyl glycidyl ether and 12 mL of 0.04 g / mL chloroplatinic acid isopropanol solution. The mixture is reacted at 75 °C for 6 h and distilled under reduced pressure to obtain diepoxy-terminated siloxane.

[0045] (2) Under nitrogen atmosphere, add 5 g of bisphenol A epoxy resin and 1.4 g of diepoxy-terminated siloxane into a reaction flask, stir evenly, heat to 130°C, add 2.9 g of methyltetrahydrophthalic anhydride and 0.06 g of 2,4,6-tris(dimethylaminomethyl)phenol, stir at 30°C until mixed evenly, then vacuum degas at 60°C for 40 min, and cool naturally to room temperature to obtain a silicone-modified epoxy resin.

[0046] (3) Add 10 g of microsilica fume and 220 mL of ethanol into a reaction flask, stir evenly, then add 26 g of stearic acid, react at 75 °C for 3 h, cool and filter, wash with ethanol, and dry to obtain a mineral admixture.

[0047] (4) Weigh 520 g of cement, 930 g of crushed stone with a particle size of 25 mm, 850 g of quartz sand with a fineness modulus of 1.5, 30 g of mineral admixture and 6 g of polycarboxylate high-efficiency water reducing agent, pour them into a concrete mixer and dry mix for 40 s. After mixing evenly, add 200 g of deionized water and 3 g of water glass and mix and stir for 9 min. Then add 2.5 g of modified basalt fiber and 10 g of silicone-modified epoxy resin and continue stirring for 35 min. After mixing evenly, pour them into a standard mold, shake and compact them. After molding, naturally cure them at a curing temperature of 20 °C and a curing humidity of 95% to obtain corrosion-resistant concrete with good anti-penetration performance.

[0048] Comparative Example 1

[0049] Weigh 450g of cement, 1050g of crushed stone with a particle size of 25mm, 850g of quartz sand with a fineness modulus of 2, 30g of mineral admixture and 5g of polycarboxylate high-efficiency water reducing agent, pour them into a concrete mixer and dry mix for 40s. After mixing evenly, add 180g of deionized water and 2g of triethanolamine, mix and stir for 9min, then add 0.5g of basalt fiber and 2g of silicone-modified epoxy resin, continue stirring for 30min, mix evenly, pour into a standard mold, oscillate to compact, and naturally cure after molding. The curing temperature is 25°C and the curing humidity is 92% to obtain concrete.

[0050] Comparative Example 2

[0051] 450 g of cement, 1050 g of crushed stone with a particle size of 25 mm, 850 g of quartz sand with a fineness modulus of 2, 30 g of mineral admixture (prepared in Example 1) and 5 g of polycarboxylate high-efficiency water reducing agent were weighed and poured into a concrete mixer and dry mixed for 40 seconds. After mixing evenly, 180 g of deionized water and 2 g of triethanolamine were added, and the mixture was mixed and stirred for 9 minutes. Then, 0.5 g of modified basalt fiber and 2 g of bisphenol A epoxy resin were added, and stirring was continued for 30 minutes. After mixing evenly, the mixture was poured into a standard mold, oscillated for compaction, and naturally cured after molding at a curing temperature of 25° C. and a curing humidity of 92% to obtain concrete.

[0052] Comparative Example 3

[0053] 450 g of cement, 1050 g of crushed stone with a particle size of 25 mm, 850 g of quartz sand with a fineness modulus of 2, 30 g of mineral admixture (prepared in Example 1) and 5 g of polycarboxylate high-efficiency water reducing agent were weighed and poured into a concrete mixer and dry mixed for 40 seconds. After mixing evenly, 180 g of deionized water and 2 g of triethanolamine were added, mixed and stirred for 9 minutes, and then 0.5 g of modified basalt fiber was added, and stirring was continued for 30 minutes. After mixing evenly, the mixture was poured into a standard mold, oscillated for compaction, and naturally cured after molding at a curing temperature of 25° C. and a curing humidity of 92% to obtain concrete.

[0054] Mechanical properties test: According to GB / T 50081-2002 "Standard for Test Methods for Mechanical Properties of Ordinary Concrete", the compressive strength and flexural strength of the prepared concrete were tested. The curing age was 7 days, the sample size was 100mm×100mm×100mm, and the universal testing machine had a given loading rate of 2.4kN / s.

[0055] Table 1 Compressive strength and flexural strength test

[0056] Compressive strength (MPa) Flexural strength (MPa) Example 1 27.2 4.3 Example 2 28.6 4.8 Example 3 30.1 5.3 Example 4 32.6 5.7 Example 5 31.7 5.4 Comparative Example 1 26.8 4.0 Comparative Example 2 25.6 3.5 Comparative Example 3 22.3 3.1

[0057] It can be seen from the test results in the above table that with the increase of the content of organosilicon-modified epoxy resin, the mechanical properties of concrete are enhanced. In Example 4, the compressive strength of concrete reaches 32.6 MPa and the flexural strength reaches 5.7 MPa. This is because, on the one hand, the organosilicon-modified epoxy resin has relatively abundant hydroxyl and oxygen functional groups on its surface, contains relatively flexible Si-O bonds in its structure, has good workability, and after combining with cement-based materials, it will closely cross-link the hydration products together to form a dense grid structure, improve the bonding strength between the hydration products, and effectively fill the pores and cracks in the concrete material, thereby improving the compressive strength and flexural strength of the concrete; on the other hand, the modified basalt fiber is modified by KH550 to increase its specific surface area, which not only reduces the interfacial tension, but also improves its dispersibility and dispersion stability in the matrix, improves the compatibility and bonding between the basalt fiber, epoxy resin and concrete, thereby further improving the mechanical properties of the concrete.

[0058] The surface of the basalt fiber in Comparative Example 1 is not modified, and it is inert, highly polar and has a high surface energy. It has low interfacial bonding ability with the epoxy resin matrix, and its mechanical properties are inferior to those of the embodiments; the epoxy resin in Comparative Example 2 is not modified with silicone, does not contain relatively flexible Si-O bonds, and cannot effectively improve the compatibility and network crosslinking degree of the blend; Comparative Example 3 does not contain epoxy resin, does not form a dense grid structure, and has the worst mechanical properties.

[0059] Determination of chloride ion diffusion coefficient: concrete with a curing age of 7 days was prepared into a sample with a size of 100mm×100mm×50mm, and placed in a sodium chloride solution with a concentration of 4mol / L. The sample was then subjected to vacuum water retention treatment, and the chloride ion diffusion coefficient was determined using a concrete chloride ion diffusion coefficient tester.

[0060] Table 2 Corrosion resistance test

[0061] Chloride ion diffusion coefficient (cm / s) Example 1 <![CDATA[6.3×10 -8 ]]> Example 2 <![CDATA[4.2×10 -8 ]]> Example 3 <![CDATA[1.6×10 -8 ]]> Example 4 <![CDATA[9.3×10 -9 ]]> Example 5 <![CDATA[8.2×10 -9 ]]> Comparative Example 1 <![CDATA[7.5×10 -8 ]]> Comparative Example 2 <![CDATA[8.7×10 -8 ]]> Comparative Example 3 <![CDATA[9.6×10 -8 ]]>

[0062] In evaluating the durability of concrete, the chloride ion diffusion coefficient is one of the main parameters that characterize the safety and life of concrete. The lower the chloride ion diffusion coefficient, the better the concrete's resistance to chloride ion corrosion. From the test results in the above table, it can be seen that with the increase of the content of organosilicon-modified epoxy resin, the chloride ion diffusion coefficient of concrete gradually decreases. The chloride ion diffusion coefficient in Example 5 is only 8.2×10 -9cm / s. This is because the addition of silicone-modified epoxy resin accelerates the hydration reaction. The generated hydration products will physically adsorb chloride ions, reducing the electromigration of chloride ions in concrete. In addition, silicone-modified epoxy resin combined with modified basalt fiber, mineral admixtures, etc. can form a spatial network structure with cement, reduce concrete cracking, and fill and improve the void structure inside the concrete. The density of the concrete is increased, and the diffusion difficulty of chloride ions increases, thereby improving the concrete material's resistance to chloride ion corrosion.

[0063] Water penetration resistance test: Referring to GB / T 50082-2009 "Standard for test methods for long-term performance and durability of ordinary concrete", the water penetration height method is used to test the water penetration resistance of concrete. The concrete with a curing age of 7 days is made into a truncated cone with an upper inner diameter of 175mm, a lower inner diameter of 185mm, and a height of 150mm, and placed in a concrete permeameter for water penetration resistance test.

[0064] Table 3 Anti-seepage performance test

[0065] Water seepage height (mm) Example 1 14.5 Example 2 12.8 Example 3 9.7 Example 4 8.0 Example 5 8.4 Comparative Example 1 15.1 Comparative Example 2 16.6 Comparative Example 3 19.3

[0066] It can be seen from the test results in the above table that with the increase of the content of organosilicon-modified epoxy resin, the impermeability of concrete gradually increases. This is because on the one hand, the film-forming effect of organosilicon epoxy resin can improve the pore structure inside the concrete, fill the internal voids, and thus reduce water infiltration; on the other hand, organosilicon epoxy resin has a certain water-reducing effect, which can reduce the water-cement ratio, improve the workability of concrete, and make the concrete more compact. Example

[0067] The difference between this embodiment and embodiment 4 is that the amount of mineral admixture added is 60 g, and other conditions remain the same.

[0068] Weigh 500g of cement, 1100g of crushed stone with a particle size of 20mm, 850g of quartz sand with a fineness modulus of 2.5, 60g of mineral admixture and 5g of polycarboxylate high-efficiency water reducer, pour them into a concrete mixer and dry mix for 40s. After mixing evenly, add 190g of deionized water and 3g of triethanolamine, mix and stir for 8min, then add 2g of modified basalt fiber and 8g of silicone-modified epoxy resin, continue stirring for 35min, mix evenly, pour into a standard mold, oscillate to compact, and naturally cure after molding. The curing temperature is 25℃ and the curing humidity is 91% to obtain corrosion-resistant concrete with good anti-penetration performance. Example

[0069] The difference between this embodiment and embodiment 4 is that the amount of mineral admixture added is 90 g, and other conditions remain the same.

[0070] Weigh 500g of cement, 1100g of crushed stone with a particle size of 20mm, 850g of quartz sand with a fineness modulus of 2.5, 90g of mineral admixture and 5g of polycarboxylate high-efficiency water reducer, pour them into a concrete mixer and dry mix for 40s. After mixing evenly, add 190g of deionized water and 3g of triethanolamine, mix and stir for 8min, then add 2g of modified basalt fiber and 8g of silicone-modified epoxy resin, continue stirring for 35min, mix evenly, pour into a standard mold, oscillate to compact, and naturally cure after molding. The curing temperature is 25℃ and the curing humidity is 91% to obtain corrosion-resistant concrete with good anti-penetration performance. Example

[0071] The difference between this embodiment and embodiment 4 is that the amount of mineral admixture added is 120 g, and other conditions remain the same.

[0072] Weigh 500g of cement, 1100g of crushed stone with a particle size of 20mm, 850g of quartz sand with a fineness modulus of 2.5, 120g of mineral admixture and 5g of polycarboxylate high-efficiency water reducer, pour them into a concrete mixer and dry mix for 40s. After mixing evenly, add 190g of deionized water and 3g of triethanolamine, mix and stir for 8min, then add 2g of modified basalt fiber and 8g of silicone-modified epoxy resin, continue stirring for 35min, mix evenly, pour into a standard mold, oscillate to compact, and naturally cure after molding. The curing temperature is 25℃ and the curing humidity is 91% to obtain corrosion-resistant concrete with good anti-penetration performance. Example

[0073] The difference between this embodiment and embodiment 4 is that the amount of mineral admixture added is 150 g, and other conditions remain the same.

[0074] Weigh 500g of cement, 1100g of crushed stone with a particle size of 20mm, 850g of quartz sand with a fineness modulus of 2.5, 150g of mineral admixture and 5g of polycarboxylate high-efficiency water reducer, pour them into a concrete mixer and dry mix for 40s. After mixing evenly, add 190g of deionized water and 3g of triethanolamine, mix and stir for 8min, then add 2g of modified basalt fiber and 8g of silicone-modified epoxy resin, continue stirring for 35min, mix evenly, pour into a standard mold, oscillate to compact, and naturally cure after molding. The curing temperature is 25℃ and the curing humidity is 91% to obtain corrosion-resistant concrete with good anti-penetration performance.

[0075] Comparative Example 4

[0076] The difference between this comparative example and Example 4 is that no mineral admixture is added, and other conditions remain the same.

[0077] Weigh 500g of cement, 1100g of crushed stone with a particle size of 20mm, 850g of quartz sand with a fineness modulus of 2.5 and 5g of polycarboxylate high-efficiency water reducing agent, pour them into a concrete mixer and dry mix for 40s. After mixing evenly, add 190g of deionized water and 3g of triethanolamine, mix and stir for 8min, then add 2g of modified basalt fiber and 8g of silicone-modified epoxy resin, continue stirring for 35min, mix evenly, pour into a standard mold, oscillate to compact, and naturally cure after molding. The curing temperature is 25°C and the curing humidity is 91% to obtain concrete.

[0078] Table 4 Corrosion resistance and impermeability test

[0079] Chloride ion diffusion coefficient (cm / s) Water seepage height (mm) Example 4 <![CDATA[9.3×10 -9 ]]> 8.0 Example 6 <![CDATA[8.8×10 -9 ]]> 7.6 Example 7 <![CDATA[8.1×10 -9 ]]> 7.5 Example 8 <![CDATA[7.5×10 -9 ]]> 6.8 Example 9 <![CDATA[8.3×10 -9 ]]> 7.2 Comparative Example 4 <![CDATA[2.2×10 -8 ]]> 10.5

[0080] It can be seen from the test results in the above table that with the increase of the content of mineral admixtures, the corrosion resistance and permeability resistance of concrete gradually increase. This is because the microsilica fume powder has good compatibility with concrete after being modified with stearic acid, and has good dispersibility in the concrete matrix. It can be filled between the concrete particles, thereby improving the density of the cement slurry from a microscopic scale, reducing and reducing the pore size, and at the same time being able to block many connected pores, greatly improving the permeability resistance and corrosion resistance of the concrete; Comparative Example 4 adds microsilica fume powder, which has not been modified with stearic acid, resulting in poor dispersibility in the concrete matrix, easy agglomeration, and cannot play a good reinforcing role of the mineral admixture.

[0081] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A corrosion-resistant concrete with good anti-penetration performance, characterized in that: The corrosion-resistant concrete comprises the following components in parts by weight: 400-550 parts of cement, 170-200 parts of deionized water, 800-1250 parts of coarse aggregate, 650-900 parts of fine aggregate, 30-150 parts of mineral admixture, 3-8 parts of polycarboxylate high-efficiency water reducing agent, 1-3 parts of early strength agent, 0.5-2.5 parts of modified basalt fiber and 2-10 parts of organosilicon-modified epoxy resin; The preparation method of the mineral admixture is as follows: add 1g of microsilica fume and 15-25mL of ethanol into a reaction flask, stir evenly, add 2.2-3g of stearic acid, react at 65-80°C for 1-3h, cool and filter, wash with ethanol, and dry to obtain the mineral admixture; The preparation method of the organosilicon-modified epoxy resin is: (1) Under a nitrogen atmosphere, 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and tetrahydrofuran were added to a reaction flask, and after stirring, allyl glycidyl ether and chloroplatinic acid isopropanol solution were added, and the mixture was stirred for reaction. After the reaction was completed, the mixture was distilled under reduced pressure to obtain a diepoxy-terminated siloxane; (2) Under nitrogen atmosphere, add bisphenol A epoxy resin and diepoxy-terminated siloxane into a reaction flask, stir evenly, heat to 120-130°C, add methyltetrahydrophthalic anhydride and 2,4,6-tris(dimethylaminomethyl)phenol, stir at 20-35°C until mixed evenly, then vacuum degas at 55-70°C for 20-40 min, and cool naturally to room temperature to obtain a silicone-modified epoxy resin.

2. The corrosion-resistant concrete with good anti-penetration performance according to claim 1 is characterized in that: The coarse aggregate is crushed stone with a particle size of 15-30 mm, and the fine aggregate is quartz sand with a fineness modulus of 1.5-3.

3. The corrosion-resistant concrete with good anti-penetration performance according to claim 1, characterized in that: The early strength agent is any one of triethanolamine, water glass or sodium aluminate.

4. The corrosion-resistant concrete with good anti-penetration performance according to claim 1, characterized in that: The mass concentration of the chloroplatinic acid isopropanol solution in step (1) is 0.02-0.04 g / mL.

5. The corrosion-resistant concrete with good anti-penetration performance according to claim 1, characterized in that: In the step (1), the ratio of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, tetrahydrofuran, allyl glycidyl ether, and chloroplatinic acid isopropanol solution is 1 g: (10-20) mL: (0.7-0.85) g: (0.3-0.5) mL.

6. The corrosion-resistant concrete with good anti-penetration performance according to claim 1, characterized in that: In the step (1), the reaction temperature is 60-75° C. and the reaction time is 5-10 h.

7. The corrosion-resistant concrete with good anti-penetration performance according to claim 1, characterized in that: In the step (2), the ratio of bisphenol A epoxy resin, diepoxy-terminated siloxane, methyltetrahydrophthalic anhydride and 2,4,6-tris(dimethylaminomethyl)phenol is 1 g: (0.2-0.35) g: (0.5-0.65) g: (0.01-0.02) g.

8. A method for preparing corrosion-resistant concrete with good anti-penetration performance according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: weighing the cement, coarse aggregate, fine aggregate, mineral admixture and polycarboxylate high-efficiency water reducing agent of the above weight components, pouring them into a concrete mixer and dry mixing them for 30-50 seconds, adding deionized water and an early strength agent after mixing them evenly, mixing and stirring for 5-10 minutes, then adding modified basalt fiber and silicone-modified epoxy resin, continuing to stir for 20-40 minutes, pouring them into a standard mold after mixing them evenly, oscillating and compacting them, and naturally curing them after forming to obtain corrosion-resistant concrete with good anti-penetration performance.

9. The method for preparing corrosion-resistant concrete with good anti-penetration performance according to claim 8, characterized in that: The temperature of the natural curing is 20-30° C., and the humidity is 90-95%.

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