Concrete additive with high impact and abrasion resistance as well as preparation method and application of concrete additive

Abstract

The invention discloses a high-abrasion-resistance concrete additive as well as a preparation method and application thereof, and belongs to the technical field of concrete additives. The invention discloses a concrete additive with high abrasion resistance. The concrete additive is prepared from the following raw materials in percentage by mass: 30-40% of silica fume, 15-20% of mineral powder, 8-12% of nano silicon carbide, 2-8% of zirconium oxide microspheres, 10-15% of a polycarboxylic acid water reducer, 3-5% of an organic silicon water repellent, 2-5% of nano titanium dioxide and 5-10% of a modified bamboo-based material. The anti-abrasion additive prepared by the invention can ensure that the permeability coefficient is greater than or equal to 0.5 mm / s while ensuring the high anti-abrasion performance of concrete, is suitable for engineering scenes such as permeable pavements and the like with strict requirements on water permeability, and realizes the synergistic improvement of high water permeability (greater than or equal to 0.5 mm / s) and ultrahigh anti-abrasion performance (the strength ratio is greater than or equal to 140%) of the concrete; the problem that the water permeability and the abrasion resistance of traditional concrete cannot be synchronously improved at the same time is successfully solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of concrete additives, and particularly relates to a high-impact-wear-resistance concrete additive as well as a preparation method and application thereof. BACKGROUND

[0002] In hydraulic structures, high-speed water flow entrains sand and gravel particles, which produces strong scouring and wearing effects on the concrete surface. Such serious wearing greatly shortens the service life of the hydraulic structures, increases the maintenance cost, and even may cause safety hazards. For the pervious pavement, the concrete needs to have good water permeability to realize rapid infiltration of rainwater and relieve urban waterlogging problems. However, when a water reducing agent or silica fume is used alone, although the strength of the concrete can be improved to a certain extent, the problem of coordination between the water permeability and the impact-wear resistance cannot be effectively solved, and it is difficult to meet the comprehensive performance requirements of the pervious pavement concrete in the CJJ / T 135-2009 standard. In the coastal engineering, due to the fact that the concrete is long-term placed in the marine environment with high humidity and rich in chloride ions, the existing anti-wear agent has a high chloride ion migration coefficient, which accelerates the corrosion of the internal steel bars of the concrete, seriously affects the durability and stability of the concrete structure, and does not meet the requirements of the JT / T 537 standard for related engineering materials.

[0003] Although the existing silicate-based anti-wear agent has a certain effect on wear resistance, its water permeability coefficient is less than 0.3 mm / s, which cannot meet the basic requirements of the water permeability of the pervious pavement, and has obvious limitations in application scenarios that require both water permeability and impact-wear resistance. It is difficult to cope with the severe challenges of the impact-wear resistance of the concrete under harsh working conditions such as high-speed sand-laden water flow. In summary, it is of important practical significance and urgency to develop a concrete additive that can effectively solve the above problems and has high impact-wear resistance, good water permeability, and low chloride ion migration coefficient. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a high-impact-wear-resistance concrete additive as well as a preparation method and application thereof, so as to solve the technical problem that the water permeability and the impact-wear resistance of the traditional concrete are difficult to be simultaneously improved.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is to provide a high-impact-wear-resistance concrete additive, and the raw materials used are as follows in terms of mass percentage: silica fume 30-40%, mineral powder 15-20%, nano-silicon carbide 8-12%, zirconia microbeads 2-8%, polycarboxylate superplasticizer 10-15%, organic silicon hydrophobic agent 3-5%, nano-titanium dioxide 2-5%, and modified bamboo-based material 5-10%.

[0006] On the basis of the above technical scheme, the present application can also be improved as follows: Further, the raw materials used include, in mass percentage: silica fume 37%, mineral powder 18%, nano-silicon carbide 10%, zirconia microbeads 6%, polycarboxylate superplasticizer 13%, organic silicon hydrophobic agent 4%, nano-titanium dioxide 4%, and modified bamboo-based material 8%.

[0007] Further, the specific surface area of the silica fume is ≥15000 m 2 / kg, the specific surface area of the mineral powder is ≥440 m 2 / kg; the particle size of the nano-silicon carbide is 50-100 nm, and the particle size of the zirconia microbeads is 0.1-0.3 nm.

[0008] The ultra-fine silica fume has a very high specific surface area, which can fill the tiny pores inside the concrete and significantly improve the density of the concrete. At the same time, its active ingredients can have a secondary reaction with the cement hydration products to generate more gel materials, enhancing the microstructure strength of the concrete and laying the foundation for improving the anti-abrasion performance.

[0009] The mineral powder has good activity and particle size distribution after pretreatment. It not only can replace part of the cement to reduce production cost, but also can improve the workability of the concrete, making it easier to mix, transport and pour during construction. After hardening, the modified mineral powder can form a close bond with the cement stone, improving the overall strength and anti-abrasion ability of the concrete.

[0010] The nano-silicon carbide, with its extremely small particle size, can deeply fill into the micropores inside the concrete, further refining the pore structure and reducing surface defects. At the same time, nano-silicon carbide itself has extremely high hardness and wear resistance. When the concrete is subjected to water flow erosion and sandstone abrasion, nano-silicon carbide can act as a hard support point, effectively resisting abrasion and reducing the length of surface abrasion to ≤28 mm, thereby significantly improving the anti-abrasion performance of the concrete.

[0011] The zirconia microbeads play a rolling buffer role inside the concrete. When the concrete is subjected to water impact or cavitation, the zirconia microbeads can disperse the concentrated impact force and consume impact energy through rolling, effectively reducing the stress on the internal structure of the concrete and avoiding material damage caused by excessive local stress.

[0012] The polycarboxylate superplasticizer has high-efficiency water-reducing performance, which can significantly reduce the water content of the concrete without affecting the workability of the concrete. By reducing the water-cement ratio, the density and strength of the concrete can be improved, and the interfacial adhesion between the cement paste and the aggregate can be improved, optimizing the overall performance of the concrete and providing strong support for the improvement of the anti-abrasion performance.

[0013] The organic silicon hydrophobic agent can form a tight hydrophobic film on the surface of the concrete, so that the surface of the concrete has low surface energy characteristics, and the penetration speed of Cl - is greatly reduced. The hydrophobic film can effectively reduce the adsorption and erosion of water flow on the surface of the concrete, reduce the penetration speed of water in the concrete, reduce the damage of cavitation and water flow scouring to the concrete, thereby improving the water erosion resistance and durability of the concrete. Especially in the environment of long-term contact with water such as hydraulic structures and coastal engineering, the erosion resistance mechanism of the hydrophobic film can significantly improve the durability and abrasion resistance of the concrete.

[0014] The nano-titanium dioxide has unique photocatalytic properties. Under light conditions, it can generate free radicals with strong oxidizing properties. These free radicals can decompose organic pollutants adsorbed on the surface of the concrete, so that they are converted into harmless small molecular substances, thereby realizing the self-cleaning function of the concrete surface. This not only can maintain the beauty of the concrete surface, but also can reduce the erosion of pollutants on the concrete surface, thereby indirectly improving the abrasion resistance of the concrete.

[0015] The nano-silicon carbide fills in the micropores of the concrete, plays a role in strengthening the structure and resisting wear; the zirconia microbeads disperse energy by rolling when subjected to external force impact, thereby reducing the internal stress of the concrete; the hydrophobic film formed by the organic silicon hydrophobic agent on the surface of the concrete effectively prevents the erosion of water flow. Through the synergistic effect of the three abrasion resistance mechanisms of nano-filling, rolling wear reduction and hydrophobic film, the abrasion resistance of the concrete is significantly improved.

[0016] Further, the preparation steps of the modified bamboo-based material include: crushing the bamboo and uniformly mixing with acid solution, reacting at 150-200 DEG C for 1-2h, then adjusting the pH value of the reaction system to 7-7.5, finally adding sodium polyacrylate and reacting at 80-100 DEG C for 40-60 min to obtain the modified bamboo-based material; the ratio of bamboo, acid solution and sodium polyacrylate is 0.8-1.2g: 100-200mL: 0.8-1.2g.

[0017] Further, the particle size of the crushed bamboo is 6-35 mesh, and the water content of the bamboo is 12-20%.

[0018] Further, the acid solution is a phosphoric acid solution or a carbonic acid solution.

[0019] Further, the concentration of the acid solution is 50-55%.

[0020] Further, the reagent used for adjusting the pH value is NaOH solution or KOH solution.

[0021] Further, the concentration of the NaOH solution or KOH solution is 35-45%.

[0022] The application further discloses a preparation method of the high-impact-resistance and high-abrasion-resistance concrete additive. S1, uniformly mixing silica fume, mineral powder, nano silicon carbide and zirconium oxide microbeads to obtain dry mixture; S2, dissolving polycarboxylate superplasticizer, organic silicon hydrophobic agent and nano titanium dioxide in an organic solvent, then mixing the dry mixture by spraying, and finally adding modified bamboo-based material and uniformly mixing; S3, drying the material obtained in S2 at 50-70 DEG C until the water content of the material is 1.5-3%, to obtain the high-impact-resistance and high-abrasion-resistance concrete additive.

[0023] Based on the above technical scheme, the application can be further improved as follows: Further, the silica fume and the mineral powder further include pretreatment of the silica fume and the mineral powder before use, specifically: placing the silica fume and the mineral powder in a muffle furnace at 450-550 DEG C for calcination for 1.5-2.5 h, and then cooling to room temperature, to obtain the silica fume and the mineral powder. This process can effectively remove impurities in the silica fume and the mineral powder, and improve the purity and activity of the silica fume and the mineral powder. The internal microstructure of the calcined silica fume and mineral powder changes, which is more conducive to the synergistic effect of the subsequent components, and lays a foundation for improving the performance of the impact and abrasion resistant agent.

[0024] Further, the rotation speed during the mixing in S1 is 1100-1300 rpm, and the mixing time is 10-20 min. Through high-speed mixing, the components can be uniformly dispersed, the filling effect of the nano silicon carbide and the rolling buffering effect of the zirconium oxide microbeads can be fully played, and the impact and abrasion resistant agent can have good consistency and synergism at the micro level.

[0025] Further, the organic solvent is ethanol.

[0026] The application further discloses application of the high-impact-resistance and high-abrasion-resistance concrete additive in preparation of high-water-permeability and high-impact-resistance and high-abrasion-resistance concrete.

[0027] Based on the above technical scheme, the application can be further improved as follows: Further, the addition amount of the high-impact-resistance and high-abrasion-resistance concrete additive is 3-5 wt% of the concrete gel material.

[0028] The application has the following beneficial effects: Compared with GB 8076 reference concrete, the performance breakthrough of the concrete added with the high-impact-resistance and high-abrasion-resistance concrete additive prepared by the application is embodied in that: 1, 28d flexural strength: the national standard requires that the 28d flexural strength is greater than or equal to 130%, while the 28d flexural strength of the concrete impact and abrasion resistant agent of the application can reach 5.2 MPa in actual application. This shows that the impact and abrasion resistant agent of the application can not only effectively improve the impact and abrasion resistance of the concrete, but also significantly enhance the compressive strength of the concrete, so that the concrete has better performance in structural bearing capacity.

[0029] 2. The underwater steel ball method of anti-abrasion ratio: the national standard is ≥ 140%, the underwater steel ball method of anti-abrasion ratio of the product of the application reaches 148-162%, and the grinding pit length is ≤ 30 mm. This data fully illustrates the significant effect of zirconium oxide microbeads on improving the anti-abrasion performance. Under the working conditions of simulating actual water flow scouring and abrasion, the anti-abrasion agent of the application can endow the concrete with stronger anti-abrasion capacity, effectively prolonging the service life of the concrete structure.

[0030] 3. The water permeability coefficient: the anti-abrasion agent of the application can ensure that the water permeability coefficient is ≥ 0.5 mm / s while ensuring the high anti-abrasion performance of the concrete, and the actual test result is 0.58-0.65 mm / s. This makes the anti-abrasion agent particularly suitable for water-permeable pavement and other engineering scenes with strict requirements for water permeability, realizing the synergistic improvement of high water permeability (≥ 0.5 mm / s) and ultra-high anti-abrasion (strength ratio ≥ 140%) of the concrete, and successfully solving the problem that the traditional concrete is difficult to simultaneously improve the water permeability and the anti-abrasion.

[0031] 4. The chloride ion migration coefficient ratio: the national standard requires ≤ 110%, and the chloride ion migration coefficient ratio of the anti-abrasion agent of the application is only 95-102%. This means that under the harsh conditions rich in chloride ions such as marine environment, the anti-abrasion agent of the application can effectively inhibit the migration of chloride ions to the inside of the concrete, reduce the risk of steel corrosion, and significantly improve the durability and stability of the concrete structure.

[0032] 5. Construction friendly: the concrete anti-abrasion agent of the application has good construction friendliness, and the fluidity is ≥ 175 mm (GB / T 8077), which means that in the actual construction process, the anti-abrasion agent can be fully mixed with dry-mixed mortar and other materials, and is easy to stir, transport and pour, and the construction personnel do not need to make substantial adjustments to the existing construction process and equipment, and the application is simple. DETAILED DESCRIPTION

[0033] The specific embodiments of the application are described below to facilitate the understanding of the application by those skilled in the art. If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the manufacturer of the reagent or instrument is not specified, it is a conventional product that can be purchased on the market. However, it should be clear that the application is not limited to the scope of the specific embodiments. For ordinary skilled persons in the art, it is obvious that all kinds of changes are within the spirit and scope of the application defined and determined by the appended claims, and all kinds of changes using the concept of the application are included in the protection.

[0034] Example 1 A high-impact and abrasion-resistant concrete additive, the raw materials used by weight percentage include: 37% silica fume, 18% mineral powder, 10% nano silicon carbide, 6% zirconium oxide microspheres, 13% polycarboxylate superplasticizer, 4% organosilicon water-repellent agent, 4% nano titanium dioxide, and 8% modified bamboo-based material.

[0035] A method for preparing a high-impact-resistant concrete additive includes the following steps: S1. Crush 1g of bamboo and mix it evenly with 150mL of 53% phosphoric acid solution. React at 170℃ for 1.5h. Then adjust the pH of the reaction system to 7 with NaOH solution. Finally, add 1g of sodium polyacrylate and react at 90℃ for 50min to obtain modified bamboo-based material. S2. Calcinate silica fume and mineral powder at 500℃ for 2 hours, then cool to room temperature. Next, mix silica fume, mineral powder, nano silicon carbide and zirconium oxide microspheres in proportion and stir at 1200 rpm for 15 minutes to obtain dry mixture. S3. Dissolve polycarboxylate superplasticizer, organosilicon water-repellent agent and nano titanium dioxide in ethanol, then mix the mixed solution with the dry mixture through a spraying device, and finally add the modified bamboo-based material and mix evenly. S4. The material obtained in S3 is dried at 60°C until the moisture content of the material is 2.1%, and then sieved through a 45μm sieve to obtain a high-impact and abrasion-resistant concrete additive.

[0036] Example 2 A high-impact and abrasion-resistant concrete additive, the raw materials used by weight percentage include: 30% silica fume, 20% mineral powder, 10% nano silicon carbide, 8% zirconium oxide microspheres, 15% polycarboxylate superplasticizer, 5% organosilicon water-repellent agent, 2% nano titanium dioxide and 10% modified bamboo-based material.

[0037] A method for preparing a high-impact-resistant concrete additive includes the following steps: S1. Crush 0.8g of bamboo and mix it evenly with 100mL of 50% carbonic acid solution. React at 150℃ for 2h. Then adjust the pH of the reaction system to 7.5 with KOH solution. Finally, add 0.8g of sodium polyacrylate and react at 80℃ for 60min to obtain modified bamboo-based material. S2. Calcinate silica fume and mineral powder at 450℃ for 2.5h, then cool to room temperature. Next, mix silica fume, mineral powder, nano silicon carbide and zirconium oxide microspheres in proportion and stir at 1100rpm for 20min to obtain dry mixture. S3. Dissolve polycarboxylate superplasticizer, organosilicon water-repellent agent and nano titanium dioxide in ethanol, then mix the mixed solution with the dry mixture through a spraying device, and finally add the modified bamboo-based material and mix evenly. S4. The material obtained in S3 is dried at 50°C until the moisture content of the material is 3%, and then sieved through a 45μm sieve to obtain a high impact and abrasion resistant concrete additive.

[0038] Example 3 A high-impact and abrasion-resistant concrete additive, the raw materials used by weight percentage include: 40% silica fume, 20% mineral powder, 12% nano silicon carbide, 5% zirconium oxide microspheres, 10% polycarboxylate superplasticizer, 3% organosilicon water-repellent agent, 5% nano titanium dioxide and 5% modified bamboo-based material.

[0039] A method for preparing a high-impact-resistant concrete additive includes the following steps: S1. Crush 1.2g of bamboo and mix it evenly with 200mL of 55% phosphoric acid solution. React at 200℃ for 1h. Then adjust the pH of the reaction system to 7.5 with NaOH solution. Finally, add 1.2g of sodium polyacrylate and react at 100℃ for 40min to obtain modified bamboo-based material. S2. Calcinate silica fume and mineral powder at 550℃ for 1.5h, then cool to room temperature. Next, mix silica fume, mineral powder, nano silicon carbide and zirconium oxide microspheres in proportion and stir at 1300rpm for 10min to obtain dry mixture. S3. Dissolve polycarboxylate superplasticizer, organosilicon water-repellent agent and nano titanium dioxide in ethanol, then mix the mixed solution with the dry mixture through a spraying device, and finally add the modified bamboo-based material and mix evenly. S4. The material obtained in S3 is dried at 70°C until the moisture content of the material is 1.5%, and then sieved through a 45μm sieve to obtain a high impact and abrasion resistant concrete additive.

[0040] Experimental Example 1. Permeable concrete mix proportions Taking the high abrasion-resistant concrete additive prepared in Examples 1-3 as an example, concrete specimens were prepared. 380 kg of P·O 42.5 cement was used as the main cementitious material, and 1200 kg of crushed stone with a particle size of 5-10 mm was selected as aggregate. 130 kg of water was added to meet the requirements for cement hydration and workability. Concrete specimens (Specimens 1-3) were prepared by adding 15 kg of the high abrasion-resistant concrete additive, which is 3.95% of the mass of the gel material. Specimen 4 was prepared using the base concrete without the additive as a control group. Performance tests were conducted on specimens 1-4. By precisely controlling the proportions of each component, it was ensured that the permeable concrete possessed excellent abrasion resistance and permeability while meeting workability requirements.

[0041] 2. Performance Testing (CJJ / T 135-2009) (1) 28d bending tensile strength: The specimens were prepared and cured according to relevant standards. After 28 days of standard curing, the bending tensile strength of the specimens was tested using testing equipment.

[0042] (2) Permeability coefficient: The permeability coefficient of permeable concrete specimens was tested using a permeability coefficient testing device.

[0043] (3) Length of grinding pit: The length of grinding pit was tested on the permeable concrete specimen by simulating the actual working conditions of water flow scouring and sand and gravel abrasion. The maximum value of the depth of the grinding pit on the surface of the specimen after 72 hours of testing was used for evaluation.

[0044] (4) Abrasion resistance ratio: The abrasion resistance performance of permeable concrete specimens was tested by the underwater steel ball method.

[0045] (5) Chloride ion migration coefficient ratio: The parameters of concrete specimens were tested by electromigration method according to the Technical Specification for Testing Chloride Ion Migration in Concrete.

[0046] The test data for specimens 1-3 are shown in Table 1.

[0047] Table 1 Test data for specimens 1-3

[0048] As shown in Table 1, the test results show that the flexural strength of specimen 1 after 28 days can reach 5.2 MPa, which meets the requirements of permeable pavement and other projects for the flexural strength of concrete and can ensure that the concrete structure can resist bending stress during long-term use.

[0049] The permeability coefficients of specimens 1-3 were 0.58-0.65 mm / s, which meet the requirements for permeability of permeable concrete in the CJJ / T 135-2009 standard. This ensures that rainwater and other liquids can quickly infiltrate the concrete, effectively alleviating urban flooding and other problems.

[0050] The abrasion pit length of specimens 1-3 was 22-26 mm, significantly shorter than that of the control group without the abrasion-resistant agent. This indicates that the abrasion-resistant agent of this invention can effectively resist abrasion and significantly improve the abrasion resistance of permeable concrete. The abrasion resistance ratio can reach 162%, fully demonstrating the significant advantage of the abrasion-resistant agent of this invention in improving the abrasion resistance of permeable concrete, and successfully solving the problem that traditional concrete cannot simultaneously improve permeability and abrasion resistance.

[0051] The chloride ion migration coefficient ratio of specimens 1-3 was only 95-102%, which is much smaller than that of the control group without the addition of the anti-impact abrasion agent. This means that under harsh conditions rich in chloride ions, such as marine environments, the anti-impact abrasion agent of this invention can effectively inhibit the migration of chloride ions into the concrete interior, reduce the risk of steel corrosion, and significantly improve the durability and stability of concrete structures.

Claims

1. A high-impact abrasion-resistant concrete additive, characterized in that, The raw materials used, by weight percentage, include: 30-40% silica fume, 15-20% mineral powder, 8-12% nano silicon carbide, 2-8% zirconium oxide microspheres, 10-15% polycarboxylate superplasticizer, 3-5% organosilicon hydrophobic agent, 2-5% nano titanium dioxide, and 5-10% modified bamboo-based materials.

2. The high impact and abrasion resistance concrete additive according to claim 1, characterized in that, The specific surface area of ​​the silica fume is ≥15000 m². 2 / kg, the specific surface area of ​​the mineral powder is ≥440m² 2 / kg; the particle size of the nano-silicon carbide is 50-100nm, and the particle size of the zirconium oxide microspheres is 0.1-0.3nm.

3. The high impact and abrasion resistance concrete additive according to claim 1, characterized in that, The preparation steps of the modified bamboo-based material include: crushing bamboo and mixing it evenly with acid solution, reacting it at 150-200℃ for 1-2 hours, adjusting the pH value of the reaction system to 7-7.5, and finally adding sodium polyacrylate and reacting it at 80-100℃ for 40-60 minutes to obtain the modified bamboo-based material; the ratio of bamboo, acid solution and sodium polyacrylate is 0.8-1.2g: 100-200mL: 0.8-1.2g.

4. The high impact and abrasion resistance concrete additive according to claim 3, characterized in that, The particle size of the crushed bamboo is 6-35 mesh, and the moisture content of the bamboo is 12-20%.

5. The high impact and abrasion resistance concrete additive according to claim 3, characterized in that, The acid solution is a phosphoric acid solution or a carbonic acid solution.

6. The high impact and abrasion resistance concrete additive according to claim 3, characterized in that, The reagents used to adjust the pH value are NaOH solution or KOH solution.

7. The method for preparing the high impact and abrasion resistance concrete additive according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Mix silica fume, mineral powder, nano-silicon carbide and zirconium oxide microspheres evenly to obtain a dry mixture; S2. Dissolve polycarboxylate superplasticizer, organosilicon water-repellent agent and nano titanium dioxide in an organic solvent, then mix with dry mix by spraying, and finally add modified bamboo-based material and mix evenly. S3. The material obtained in S2 is dried at 50-70℃ until the moisture content of the material is 1.5-3% to obtain a high impact and abrasion resistant concrete additive.

8. The method for preparing the high impact and abrasion resistance concrete additive according to claim 7, characterized in that, Before use, the silica fume and mineral powder are pretreated by calcining them at 450-550℃ for 1.5-2.5 hours and then cooling them to room temperature.

9. The use of the high abrasion-resistant concrete additive according to any one of claims 1-6 in the preparation of highly permeable and highly abrasion-resistant concrete.

10. The application according to claim 9, characterized in that, The amount of the high impact and abrasion resistant concrete additive added is 3-5 wt% of the concrete gel material.

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