Polycarboxylate water reducing agent, concrete containing the same and method of preparation

Abstract

This invention relates to the technical field of concrete and its additives, and provides a polycarboxylate superplasticizer, concrete containing the superplasticizer, and a preparation method thereof. The polycarboxylate superplasticizer of this invention uses acrylic acid and sodium methacrylate as small monomers, and is linked by C=C double bonds and -COO bonds. ‑ The triazine derivatives of the two-arm polyoxyethylene ether chains are macromonomers. Compared with conventional polycarboxylate superplasticizers, the polycarboxylate superplasticizer of this invention can both improve the anchoring effect of anions on the surface of cement particles and increase the steric hindrance effect that hinders the flocculation of cement particles. Therefore, it can significantly improve the dispersion ability of cement particles, improve the fluidity of cement paste, and hinder the flocculation of cement particles, thereby reducing the slump loss of concrete.

Description

Technical Field

[0001] This invention relates to the technical field of concrete and its additives, and provides a polycarboxylate superplasticizer, concrete containing the superplasticizer, and a preparation method thereof. Background Technology

[0002] Concrete, as one of the most important building materials, is not only abundant and inexpensive in raw materials and simple in production process, but also possesses characteristics such as high compressive strength, good durability, and a wide range of strength grades. These advantages make concrete widely used, not only in various civil engineering projects, but also in shipbuilding, machinery industry, marine development, geothermal engineering, and other fields.

[0003] During the mixing process, admixtures are typically added to concrete to improve its performance and meet different application requirements. These admixtures include water-reducing agents, air-entraining agents, accelerators, and pumping agents. Among these, water-reducing agents are the most widely used, and their main functions are: first, to increase hydration efficiency, reduce unit water consumption, lower the water-cement ratio, increase concrete strength, improve concrete workability, and save cement usage; second, to improve the workability of concrete, reduce setting shrinkage, and prevent cracking in concrete components; third, to improve impermeability, prevent water leakage in building structures, increase durability, and increase resistance to chemical corrosion; and fourth, to improve frost resistance, which is beneficial for winter construction.

[0004] There are many types of concrete water-reducing agents: according to their water-reducing effect, they can be divided into ordinary water-reducing agents and high-efficiency water-reducing agents; according to their air entrainment capacity, they can be divided into air-entraining water-reducing agents and non-air-entraining water-reducing agents; according to their chemical composition, they can be divided into lignin sulfonate water-reducing agents, naphthalene-based water-reducing agents, melamine-formaldehyde resin sulfonate water-reducing agents, polycarboxylate water-reducing agents, aminosulfonic acid water-reducing agents, etc.

[0005] Polycarboxylate superplasticizers are commonly used high-efficiency superplasticizers, achieving high water-reducing effects at relatively low dosages. Furthermore, the structure of polycarboxylate superplasticizers is designable, allowing for modifications such as changing the functional group composition, main chain length, side chain length, or density. Obtaining higher-performance polycarboxylate superplasticizers through structural design has become an important development direction for polycarboxylate superplasticizers. Summary of the Invention

[0006] In view of this, the present invention proposes a polycarboxylate superplasticizer, concrete containing the superplasticizer, and a preparation method thereof. By improving the macromonomer, the polycarboxylate superplasticizer improves the dispersion ability of cement particles, increases the fluidity of cement paste, and inhibits the flocculation of cement particles, thereby reducing the slump loss of concrete.

[0007] The present invention achieves the above objectives through the following technical solutions:

[0008] First, this invention provides a method for preparing a polycarboxylate superplasticizer, comprising the following steps:

[0009] (1) Dissolve methoxy polyethylene glycol in dichloromethane with stirring, add anhydrous potassium carbonate, preheat to 43°C, then slowly add thionyl chloride dropwise, and heat to 45°C while stirring and refluxing for 22-24 hours. Cool to room temperature, filter, and evaporate the filtrate under reduced pressure to obtain chloromethoxy polyethylene glycol, the structural formula of which is shown in the attached figure. Figure 1 As shown;

[0010] The molar ratio of methoxy polyethylene glycol, thionyl chloride, potassium carbonate, and dichloromethane is 1:4-5:2:20-25.

[0011] Preferably, the degree of polymerization of methoxy polyethylene glycol is 10-20.

[0012] (2) Chloromethoxy polyethylene glycol was dissolved in acetonitrile under stirring. Anhydrous potassium carbonate and potassium iodide were added. Ethanolamine was added dropwise under nitrogen protection and in the dark. The mixture was stirred and refluxed at 85°C for 24-26 hours. After cooling to room temperature, the mixture was filtered. The filtrate was then evaporated under reduced pressure to obtain two-arm polyethylene glycol-substituted ethanolamine, the structural formula of which is shown in the attached figure. Figure 2 As shown;

[0013] The molar ratio of chloromethoxy polyethylene glycol, ethanolamine, potassium carbonate, potassium iodide, and acetonitrile is 1:0.4:2:0.05:20-25.

[0014] (3) Add cyanuric chloride to the ice-water mixture, slurry for 20-30 minutes, place in a constant temperature bath at 0-5℃, and dropwise add two-arm polyethylene glycol-substituted ethanolamine and sodium hydroxide solution. React for 1-1.5 hours to generate triazine derivative 1, the structural formula of which is attached. Figure 3 As shown;

[0015] Among them, the number of moles of polyethylene glycol replacing ethanolamine and sodium hydroxide in the two arms is the same as the number of moles of cyanuric chloride;

[0016] Preferably, the mass ratio of cyanuric chloride to ice water is 1:50.

[0017] (4) Transfer the system from step (3) to a constant temperature bath at 30-35℃. After the temperature stabilizes, add 3-aminopropylene and sodium hydroxide solution dropwise. React for 3-3.5 hours to generate triazine derivative 2, the structural formula of which is shown in the attached figure. Figure 4 As shown;

[0018] The number of moles of 3-aminopropylene and sodium hydroxide is the same as the number of moles of cyanuric chloride in step (3).

[0019] (5) Dissolve the amino acid in water, add sodium carbonate to obtain an amino acid sodium solution; transfer the system from step (4) to an 80-85℃ constant temperature bath, and after the temperature is constant, add the amino acid sodium solution and sodium hydroxide solution dropwise, react for 5-5.5 h, pass through an Al2O3 chromatography column, and evaporate under reduced pressure to obtain triazine derivative 3, the structural formula of which is attached. Figure 5 As shown (using glycine as an example); the amino acid is at least one of glycine, alanine, and leucine;

[0020] The molar ratio of amino acids to sodium carbonate is 2:1.

[0021] The number of moles of sodium amino acid and sodium hydroxide is the same as the number of moles of cyanuric chloride in step (3);

[0022] Preferably, the concentration of the sodium amino acid solution is 1 mol / L.

[0023] (6) Dissolve triazine derivative 3 in water and place it in a constant temperature bath at 75-80℃. Then, add ammonium persulfate aqueous solution and acrylic acid / sodium methacrylate mixed aqueous solution dropwise over 2-2.5h. Continue the reaction for 2.5-3.5h, adjust the pH to 7, pass through an Al2O3 chromatography column, and evaporate under reduced pressure to obtain polycarboxylate superplasticizer.

[0024] The molar ratio of triazine derivative 3, acrylic acid, sodium methacrylate sulfonate, and ammonium persulfate is 1:2.5-3:0.6-0.8:0.2-0.4.

[0025] Preferably, the mass ratio of triazine derivative 3 to water is 1:10;

[0026] Preferably, the concentration of the ammonium persulfate aqueous solution is 1-2 mol / L;

[0027] Preferably, in the mixed aqueous solution of acrylic acid / sodium methacrylate, the concentration of acrylic acid is 1-2 mol / L.

[0028] In the above preparation process, preferably, the concentration of the sodium hydroxide solution is 0.5-1 mol / L.

[0029] The present invention also provides a polycarboxylate superplasticizer prepared by the above preparation method.

[0030] Polycarboxylate superplasticizers are produced by free radical polymerization of macromonomers and small monomers containing C=C double bonds. The small monomers provide the polycarboxylate superplasticizer with anions (such as -COO-). - -SO3 - The short side chains of the anion can react with Ca on the surface of cement particles. 2+Complexation acts as an anchoring agent, causing water-reducing agent molecules to adsorb onto the surface of cement particles. Electrostatic repulsion disperses the cement particles, releasing free water from the system and improving the fluidity of the cement paste. The macromonomer provides hydrophilic long side chains (such as polyoxyethylene ether chains) for the polycarboxylate water-reducing agent. These long side chains extend in aqueous solutions. When cement particles approach each other, the long side chains adsorbed on the surface of the water-reducing agent molecules create a steric hindrance effect, hindering flocculation between cement particles, further improving the dispersion effect, and reducing slump loss in concrete.

[0031] The polycarboxylate superplasticizer of the present invention uses acrylic acid and sodium methacrylate as monomers, with acrylic acid providing -COO-containing monomers. - The short side chain of sodium methacrylate provides -SO3 - The short side chains. Further, the polycarboxylate superplasticizer of the present invention uses the triazine derivative 3 prepared above as the macromonomer. Triazine derivative 3 is obtained by the sequential reaction of three chlorine groups on a six-membered ring of cyanuric chloride. First, one chlorine group on the six-membered ring reacts with the hydroxyl group of the two-arm polyethylene glycol-substituted ethanolamine, connecting two polyoxyethylene ether chains to the triazine ring structure; then, another chlorine group on the six-membered ring reacts with the amino group of 3-aminopropylene, connecting a C=C double bond that can participate in free radical polymerization to the triazine ring structure; finally, the third chlorine group on the six-membered ring reacts with the amino group of sodium amino acid, connecting a -COO group to the triazine ring structure. - .

[0032] Then, the present invention provides a method for preparing concrete, specifically comprising: mixing the above-mentioned polycarboxylate superplasticizer with cement, fly ash, sand, aggregate, fine aggregate, and water, and stirring evenly. The amount of polycarboxylate superplasticizer used is 0.2-0.4% of the cement mass.

[0033] Preferably, the cement is ordinary Portland cement;

[0034] Preferably, the fineness modulus of the sand is 2.4-2.8;

[0035] Preferably, the particle size of the large stones is 10-25mm;

[0036] Preferably, the particle size of the fine stones is 5-10 mm;

[0037] Preferably, the density of fly ash is 2100-2300 kg / m³. 3 .

[0038] A further preferred mass ratio of cement, fly ash, sand, large stones, fine stones, and water is 450-480:150-160:1100-1200:1000-1100:460-500:230-260.

[0039] The present invention also provides concrete prepared by the above preparation method.

[0040] This invention provides a polycarboxylate superplasticizer, concrete containing the superplasticizer, and a preparation method thereof. Its outstanding features and superior effects lie in the following: This invention uses cyanuric chloride to prepare a triazine macromonomer through the reaction of three chlorine atoms on its six-membered ring. Through the reaction of the three chlorine atoms, a C=C double bond and a -COO bond are attached to the triazine ring structure. - And a two-armed polyoxyethylene ether chain. This triazine macromonomer is polymerized with small monomers acrylic acid and sodium methacrylate via C=C polymerization to obtain a polycarboxylate superplasticizer. On the one hand, compared with conventional polycarboxylate superplasticizers, the polycarboxylate superplasticizer of the present invention not only utilizes the small monomers to provide anions, but also contains anions on its macromonomers, thus playing a better anchoring role on the surface of cement particles and improving dispersion ability; on the other hand, compared with conventional polycarboxylate superplasticizers, the polycarboxylate superplasticizer of the present invention has a two-armed polyoxyethylene ether chain on the macromonomer, which is equivalent to each macromonomer containing two hydrophilic side chains, increasing the density of hydrophilic side chains, thus increasing the steric hindrance effect that hinders the flocculation of cement particles, and further improving dispersion ability. It can be seen that the present invention, by using a C=C double bond and a -COO bond, achieves a significant improvement in dispersion ability. - The triazine derivative 3 of the two-arm polyoxyethylene ether chain is a macromonomer, which can not only improve the anchoring effect of anions on the surface of cement particles, but also increase the steric hindrance effect that hinders the flocculation of cement particles. Therefore, it can significantly improve the dispersion ability of cement particles, improve the fluidity of cement paste, and hinder the flocculation of cement particles, thereby reducing the slump loss of concrete. Attached Figure Description

[0041] Figure 1 The structural formula of the chloromethoxy polyethylene glycol obtained in step (1) is shown below;

[0042] Figure 2 The structural formula of the two-arm polyethylene glycol-substituted ethanolamine obtained in step (2);

[0043] Figure 3 The structural formula of the triazine derivative 1 obtained in step (3) is shown below;

[0044] Figure 4 The structural formula of the triazine derivative 2 obtained in step (4) is shown below;

[0045] Figure 5 The structure of the triazine derivative 3 obtained from glycine in step (5) is shown below. Detailed Implementation

[0046] The present invention will be further described in detail below through specific embodiments, but it should not be construed as limiting the scope of the invention to the following examples. Various substitutions or modifications made based on ordinary technical knowledge and conventional methods in the art without departing from the above-described methodological spirit of the invention should be included within the scope of the invention.

[0047] Raw material preparation: Methoxylated polyethylene glycol with a degree of polymerization of 15 is used; glycine is used as the amino acid; a 2 mol / L ammonium persulfate aqueous solution is prepared; a 1 mol / L sodium hydroxide solution is prepared; a mixed aqueous solution of acrylic acid / sodium methacrylate is prepared, wherein the concentration of acrylic acid is 1.5 mol / L and the concentration of sodium methacrylate is 0.35 mol / L; 42.5 grade ordinary Portland cement is used; sand with a fineness modulus of 2.4-2.8 is selected; large stones with a particle size of 15-25 mm are selected; fine stones with a particle size of 5-10 mm are selected; the density of fly ash is 2200 kg / m³. 3 .

[0048] Example

[0049] Preparation of polycarboxylate superplasticizer:

[0050] (1) Dissolve methoxy polyethylene glycol in dichloromethane by stirring, add anhydrous potassium carbonate, preheat to 43°C, then slowly add thionyl chloride dropwise, and heat to 45°C and stir under reflux for 22 hours. Cool to room temperature, filter, and evaporate the filtrate under reduced pressure to obtain chloromethoxy polyethylene glycol; the molar ratio of methoxy polyethylene glycol, thionyl chloride, potassium carbonate, and dichloromethane is 1:5:2:20.

[0051] (2) Chloromethoxy polyethylene glycol was dissolved in acetonitrile by stirring, anhydrous potassium carbonate and potassium iodide were added, and ethanolamine was added dropwise under nitrogen protection and in the dark. The mixture was stirred and refluxed at 85°C for 24 h, cooled to room temperature, filtered, and the filtrate was evaporated under reduced pressure to obtain two-arm polyethylene glycol-substituted ethanolamine; the molar ratio of chloromethoxy polyethylene glycol, ethanolamine, potassium carbonate, potassium iodide and acetonitrile was 1:0.4:2:0.05:20.

[0052] (3) Add cyanuric chloride to a mixture of 50 times its weight of ice and water, beat for 25 min, place in a constant temperature bath at 2℃, add two-arm polyethylene glycol-substituted ethanolamine and sodium hydroxide solution dropwise, react for 1.2 h, and generate triazine derivative 1; the number of moles of two-arm polyethylene glycol-substituted ethanolamine and sodium hydroxide is the same as the number of moles of cyanuric chloride;

[0053] (4) Transfer the system from step (3) to a constant temperature bath at 33°C. After the temperature is constant, add 3-aminopropylene and sodium hydroxide solution dropwise. React for 3.2 h to generate triazine derivative 2. The molar amounts of 3-aminopropylene and sodium hydroxide are the same as the molar amounts of cyanuric chloride.

[0054] (5) Dissolve the amino acid in water and add sodium carbonate to obtain a 1 mol / L sodium amino acid solution; transfer the system from step (4) to an 82℃ constant temperature bath, and after the temperature is constant, add sodium amino acid solution and sodium hydroxide solution dropwise, react for 5 h, pass through an Al2O3 chromatography column, and evaporate under reduced pressure to obtain triazine derivative 3; the number of moles of sodium amino acid and sodium hydroxide is the same as the number of moles of cyanuric chloride;

[0055] (6) Dissolve triazine derivative 3 in 10 times its weight of water, place it in a constant temperature bath at 75°C, and then simultaneously add ammonium persulfate aqueous solution and a mixed aqueous solution of acrylic acid / sodium methacrylate. The addition is completed within 2 hours, and the reaction continues for 3 hours. The pH value is adjusted to 7, and the mixture is passed through an Al2O3 chromatography column and evaporated under reduced pressure to obtain polycarboxylate superplasticizer. The molar ratio of triazine derivative 3, acrylic acid, sodium methacrylate, and ammonium persulfate is 1:3:0.7:0.3.

[0056] Concrete was prepared using the polycarboxylate superplasticizer obtained above.

[0057] Example 1: Polycarboxylate superplasticizer, cement, fly ash, sand, large stones, fine stones, and water are mixed and stirred evenly; wherein, the mass ratio of cement, fly ash, sand, large stones, fine stones, and water is 460:155:1150:1100:480:240; the amount of polycarboxylate superplasticizer is 0.2% of the cement mass.

[0058] Example 2: Polycarboxylate superplasticizer, cement, fly ash, sand, large stones, fine stones, and water are mixed and stirred evenly; wherein, the mass ratio of cement, fly ash, sand, large stones, fine stones, and water is 460:155:1150:1100:480:240; the amount of polycarboxylate superplasticizer is 0.3% of the cement mass.

[0059] Example 3: Polycarboxylate superplasticizer, cement, fly ash, sand, large stones, fine stones, and water are mixed and stirred evenly; wherein, the mass ratio of cement, fly ash, sand, large stones, fine stones, and water is 460:155:1150:1100:480:240; the amount of polycarboxylate superplasticizer is 0.4% of the cement mass.

[0060] Cement paste fluidity test: The test was conducted at a temperature of 25±2℃ and a relative humidity of 60±5%. Fresh cement paste was prepared with a water-cement ratio of 0.35, and the amount of polycarboxylate superplasticizer added was 0.3% of the cement mass. The polycarboxylate superplasticizer was first added to the water, and then mixed with the cement. The mixture was mixed at low speed for 2 minutes, paused for 15 seconds, and then mixed at high speed for 2 minutes. A metal truncated cone (60 mm high, 36 mm top diameter, and 60 mm bottom diameter) was placed on a horizontal glass plate. Fresh cement paste was poured into the cone, and the paste was leveled with the top of the cone with a scraper. The cone was pulled vertically upward to allow the cement paste to flow freely on the glass plate. After 30 seconds, the average diffusion diameter of the cement paste was measured, which is the cement paste fluidity.

[0061] The fluidity of the cement paste containing the polycarboxylate superplasticizer from the example was measured to be 252.5 mm.

[0062] Concrete slump loss rate test: For the concrete mixed in Examples 1-3, the slump test was carried out in accordance with the provisions of "Test Method for Performance of Ordinary Concrete Mixtures" (GB / T50080-2002). First, the initial slump was obtained, and then the concrete was sealed and stored at normal temperature and pressure. The corresponding slump was tested at 60 min, and the slump loss rate was calculated. The calculation method is (initial slump - 60 min slump) × 100% / initial slump.

[0063] The slump loss rate of the concrete in Example 1 was measured to be 7.3%; the slump loss rate of the concrete in Example 2 was 5.2%; and the slump loss rate of the concrete in Example 3 was 3.5%.

[0064] Comparative Example

[0065] Preparation of polycarboxylate superplasticizer: The preparation process of steps (1)-(5) is omitted. Instead, methyl allyl polyoxyethylene ether (polymerization degree of 15) is used as the macromonomer. Other preparation conditions are the same as in step (6) of the example.

[0066] Concrete preparation:

[0067] Comparative Example 1: The raw material ratio is the same as in Example 1, except that the polycarboxylate superplasticizer prepared in the comparative example is used.

[0068] Comparative Example 2: The raw material ratio is the same as in Example 2, except that the polycarboxylate superplasticizer prepared in the comparative example is used.

[0069] Comparative Example 3: The raw material ratio is the same as in Example 3, except that the polycarboxylate superplasticizer prepared in the comparative example is used.

[0070] The fluidity of cement paste containing comparative polycarboxylate superplasticizer was measured to be 215.8 mm according to the above test method.

[0071] The slump loss rate of the concrete in Comparative Example 1 was 11.2% according to the above test method; the slump loss rate of the concrete in Comparative Example 2 was 9.6%; and the slump loss rate of the concrete in Comparative Example 3 was 8.3%.

Claims

1. A method for producing a polycarboxylate water reducer, characterized by, Comprising the following steps: (1) stirring methoxy polyethylene glycol is dissolved in dichloromethane, adding anhydrous potassium carbonate, preheating to 43 DEG C, then slowly droping sulfoxide chloride, and heating to 45 DEG C stirring reflux reaction 22-24h, cooling to room temperature, filtration, rotary evaporation of the filtrate under reduced pressure, to obtain chloromethoxy polyethylene glycol; the molar ratio of methoxy polyethylene glycol, sulfoxide chloride, potassium carbonate, dichloromethane is 1:4-5:2:20-25; the polymerization degree of methoxy polyethylene glycol is 10-20; (2) stirring chloromethoxy polyethylene glycol is dissolved in acetonitrile, adding anhydrous potassium carbonate, potassium iodide, droping ethanolamine under nitrogen protection and light protection environment, stirring reflux reaction at 85 DEG C for 24-26h, cooling to room temperature, filtration, rotary evaporation of the filtrate under reduced pressure, to obtain two-arm polyethylene glycol substituted ethanolamine; the molar ratio of chloromethoxy polyethylene glycol, ethanolamine, potassium carbonate, potassium iodide, acetonitrile is 1:0.4:2:0.05:20-25; (3) adding cyanuric chloride into ice water mixture, beating for 20-30min, placing in 0-5 DEG C constant temperature tank, droping two-arm polyethylene glycol substituted ethanolamine and sodium hydroxide solution, reacting for 1-1.5h, to generate triazine derivative 1; the molar number of two-arm polyethylene glycol substituted ethanolamine and sodium hydroxide is same as that of cyanuric chloride; (4) transferring the system of step (3) to 30-35 DEG C constant temperature tank, after temperature constant, droping 3-amino acryl and sodium hydroxide solution, reacting for 3-3.5h, to generate triazine derivative 2; the molar number of 3-amino acryl and sodium hydroxide is same as that of cyanuric chloride in step (3); (5) dissolving amino acid in water, adding sodium carbonate, to obtain amino acid sodium solution; transferring the system of step (4) to 80-85 DEG C constant temperature tank, after temperature constant, droping amino acid sodium solution and sodium hydroxide solution, reacting for 5-5.5h, passing Al2O3 chromatographic column, rotary evaporation under reduced pressure, to obtain triazine derivative 3; the amino acid is at least one of glycine, alanine, leucine; the molar ratio of amino acid and sodium carbonate is 2:1; the molar number of amino acid sodium and sodium hydroxide is same as that of cyanuric chloride in step (3); (6) dissolving triazine derivative 3 in water, placing in 75-80 DEG C constant temperature tank, then simultaneously droping ammonium persulfate aqueous solution, acrylic acid / sodium methacryl sulfonate mixed aqueous solution, droping for 2-2.5h, continuing to react for 2.5-3.5h, adjusting pH value to 7, passing Al2O3 chromatographic column, rotary evaporation under reduced pressure, to obtain polycarboxylic acid water reducer; the molar ratio of triazine derivative 3, acrylic acid, sodium methacryl sulfonate, ammonium persulfate is 1:2.5-3:0.6-0.8:0.2-0.

4.

2. The method of claim 1, wherein: In step (3), the mass ratio of cyanuric chloride and ice water mixture is 1:

50.

3. The method of claim 1, wherein: In step (5), the concentration of amino acid sodium solution is 1 mol / L.

4. The method of claim 1, wherein: In step (6), the mass ratio of triazine derivative 3 and water is 1:10; the concentration of ammonium persulfate aqueous solution is 1-2 mol / L; in acrylic acid / sodium methacryl sulfonate mixed aqueous solution, the concentration of acrylic acid is 1-2 mol / L.

5. The method of claim 1, wherein: The concentration of the sodium hydroxide solution is 0.5-1 mol / L.

6. The polycarboxylate water reducer prepared by the preparation method in any one of claims 1-5.

7. A method of making concrete, characterized by The specific preparation method is: mixing the polycarboxylate water reducer in claim 6 with cement, fly ash, sand, large stone, fine stone and water, and stirring uniformly; the amount of the polycarboxylate water reducer is 0.2-0.4% of the mass of the cement.

8. The method of claim 7, wherein: The cement is ordinary Portland cement; the fineness modulus of sand is 2.4-2.8; the particle size of large stone is 10-25 mm; the particle size of fine stone is 5-10 mm; the density of fly ash is 2100-2300 kg / m 3 .

9. The method of claim 7, wherein: The mass ratio of the cement, fly ash, sand, large stone, fine stone and water is 450-480:150-160:1100-1200:1000-1100:460-500:230-260.

10. The concrete prepared by the preparation method in any one of claims 7-9.

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