Modified ultra-high performance concrete, preparation method and application

Abstract

This invention belongs to the field of ultra-high performance concrete technology, specifically relating to a modified ultra-high performance concrete, its preparation method, and its application. The modified ultra-high performance concrete comprises the following raw materials in parts by weight: 60-80 parts cement, 30-40 parts mineral admixtures, 5-10 parts fiber, 120-140 parts sand, 1-1.5 parts water-reducing agent mother liquor, and 0.5-1 parts retarder, with a water-cement ratio of 0.14-0.2; the water-reducing agent mother liquor has a solid content of 35-42 wt% and is copolymerized from acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, and unsaturated polyethers; the retarder is a compound of carboxylated tea polyphenols and salicylic acid, with the carboxylated tea polyphenols obtained by modifying tea polyphenols with chloroacetic acid. The water-reducing agent is first adsorbed onto the surface of cement particles, and the long polyether side chains extend into the water to form a steric hindrance layer, which disperses the cement particles and prevents agglomeration. The carboxylated tea polyphenols and salicylic acid are combined as a retarder to inhibit the dissolution of cement minerals and the crystallization of calcium hydroxide, thus delaying cement hydration. The modified ultra-high performance concrete has low viscosity and controllable retarding.

Description

Technical Field

[0001] This invention belongs to the field of ultra-high performance concrete technology, specifically relating to a modified ultra-high performance concrete, its preparation method, and its application. Background Technology

[0002] Decorative concrete flooring is a green and environmentally friendly flooring material that combines practicality and aesthetic value. Using concrete as a base, it breaks away from the monotonous texture of traditional concrete through color matching, texture creation, and innovative processes, achieving a unity of decoration and structure. It is widely used in public spaces and residential paving. Its core characteristic is that while retaining the original advantages of concrete, such as high strength and controllable cost, it endows the floor with rich visual effects and functional attributes through various processes. Common methods include: mold imprinting to simulate the textures of natural stone, brick, and wood; surface coloring (dry-spraying hardeners, chemical colorants, etc.) to present diverse colors; exposing aggregates to showcase the natural texture of pebbles and stones; and creating figurative patterns, geometric textures, and even three-dimensional effects through photolithography, inlay, and other processes, taking into account both aesthetics and practical needs such as slip resistance and guidance. Decorative concrete flooring not only meets the needs of refined design in modern public spaces, but also adds value through color and pattern combinations, such as traffic guidance, environmental beautification, and cultural expression. It is a new type of paving material that has received much attention and research in recent years. For example, the mud-effect flooring paving method disclosed in patent CN105625687B can produce a mud-like decorative floor by spreading concrete, leveling and smoothing, spreading aggregate, imprinting texture, and curing. The construction method of the color block crack and hole flooring decorative structure disclosed in patent CN114876154B can obtain a floor structure with personalized decorative effect by laying colored concrete containing porous materials, imprinting patterns, spreading colored aggregate, and curing to form holes.

[0003] To further enhance the mechanical properties, durability, and service life of decorative flooring to meet the demands of high-load, long-term use in public spaces, ultra-high performance concrete (UHPC) is gradually being introduced into the decorative flooring industry. UHPC possesses significantly higher strength, toughness, durability, and volume stability than ordinary concrete. It effectively resists pedestrian and vehicle loads in public spaces, as well as environmental erosion, extending the service life of decorative flooring and providing structural support for maintaining its decorative effect over the long term. Under the same load-bearing capacity, UHPC components are much smaller than ordinary concrete, giving it a natural advantage in load-bearing applications such as bridge decks, roofs, floors, and building facades. However, in practical paving applications, especially in decorative flooring projects that pursue high mechanical performance, high flatness, and exquisite appearance quality, ultra-high performance concrete presents significant technological challenges, mainly in the following two aspects: Firstly, ultra-high performance concrete slurry has high viscosity and poor fluidity, and internal air bubbles cannot effectively float to the surface and escape, easily remaining on the concrete surface and forming appearance defects such as pores and pitting. At the same time, it weakens the density of the concrete surface and reduces its mechanical properties and long-term durability. Secondly, in order to obtain a flat and smooth base layer that meets the requirements of subsequent decorative processes such as stamping, coloring, and polishing, finishing (including slurry lifting, smoothing, and troweling) is an indispensable key process in the construction of decorative floor concrete. However, the high viscosity slurry of ultra-high performance concrete has a short initial setting time, and the plasticity of the slurry decays extremely quickly and the strength develops rapidly near the initial setting stage. Whether manual or mechanical finishing is used, it is difficult to control the surface flatness and smoothness within the short plasticity window period, that is, the surface finishing window period is too short.

[0004] Therefore, it is necessary to develop a modified ultra-high performance concrete that, while ensuring high mechanical properties, improves slurry fluidity, extends the surface finishing window, and enhances the slurry's ability to expel air bubbles, in order to meet people's demand for decorative flooring projects with high mechanical properties, high smoothness, and exquisite appearance. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a modified ultra-high performance concrete, its preparation method, and its application. The modified ultra-high performance concrete contains a self-made water-reducing agent, which is copolymerized from acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, and unsaturated polyethers. The sulfonate group is a highly electronegative functional group, while the carboxyl group has weak electronegativity but higher stability for calcium ion adsorption. The water-reducing agent, with its high-density negative charge, rapidly adsorbs onto the surface of cement particles. The long polyether side chains extend into the water, forming a steric hindrance layer that disperses the cement particles and prevents agglomeration. Simultaneously, carboxylated tea polyphenols, obtained by modifying tea polyphenols with chloroacetic acid, are combined with salicylic acid as a retarder. Although the retarder's adsorption rate is slightly slower, it has a stronger complexing ability for calcium ions, inhibiting cement mineral dissolution and calcium hydroxide crystallization, thus delaying cement hydration. Furthermore, the retarder with strongly polar groups can also intersperse between the water-reducing agents, forming a dense adsorption film on the surface of hydrate crystal nuclei, hindering further crystal growth and delaying the crystallization transformation of hydrates. Ultimately, the goal of dispersing viscosity reduction and controlling retardation of modified ultra-high performance concrete is achieved.

[0006] To achieve the above objectives, the following technical solution is adopted:

[0007] A modified ultra-high performance concrete comprises the following raw materials in parts by weight: 60-80 parts cement, 30-40 parts mineral admixtures, 5-10 parts fiber, 120-140 parts sand, 1-1.5 parts water-reducing agent mother liquor, and 0.5-1 parts retarder, with a water-cement ratio of 0.14-0.2; the water-reducing agent mother liquor has a solid content of 35-42 wt% and is copolymerized in water by acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, and unsaturated polyethers; the retarder is compounded from carboxylated tea polyphenols and salicylic acid, wherein the carboxylated tea polyphenols are obtained by modifying tea polyphenols with chloroacetic acid.

[0008] The mass ratio of acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, and unsaturated polyether is 10-20:5-10:15-40:150-200, preferably 10-20:5-10:20-30:150-200.

[0009] The inventors discovered that the proportion of comonomers in water-reducing agents has a significant impact on performance. Unsaturated sulfonate monomers provide strongly electronegative sulfonic acid groups, and their relative proportion needs to be controlled within a reasonable range to ensure that the water-reducing agent can quickly and preferentially adsorb onto the surface of cement particles with high-density negative charges, forming initial electrostatic repulsion. This is the core of achieving early deflocculation, rapid dispersion and viscosity reduction in ultra-high performance concrete, as well as synergistic effects with retarders. Excessive unsaturated sulfonate monomers lead to excessively strong electrostatic repulsion, which damages the stability of the water-reducing agent adsorption layer and prevents the formation of a uniform, dense, and firm adsorption film on the surface of cement particles. Instead, it causes premature desorption of water-reducing agent molecules and a rapid decline in dispersion effect. Insufficient sulfonic acid group content results in a low negative charge density in the system, slow adsorption rate, and weak electrostatic repulsion, making it impossible to quickly disperse the agglomerates of cement and mineral admixtures, leading to high viscosity in ultra-high performance concrete.

[0010] The mass ratio of carboxylated tea polyphenols to salicylic acid is 5-8:1.

[0011] The acrylate monomers are selected from one or a combination of two of sodium methacrylate, sodium acrylate, potassium acrylate, and potassium methacrylate.

[0012] The acrylate monomers are selected from one or more combinations of methyl acrylate, methyl methacrylate, ethyl acrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate.

[0013] The unsaturated sulfonate monomer is selected from one or more of sodium vinyl sulfonate, sodium allyl sulfonate, sodium methpropylene sulfonate, and sodium styrene sulfonate. Sodium styrene sulfonate is preferred.

[0014] The unsaturated polyether has a number-average molecular weight of 1000-3000 and is selected from one or more combinations of allyl polyoxyethylene ether (APEG), isopentenyl polyoxyethylene ether (TPEG), and methyl allyl polyoxyethylene ether (HPEG).

[0015] The water-reducing agent mother liquor is prepared by a method comprising the following steps:

[0016] Under an inert atmosphere, acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, unsaturated polyethers, initiators, and chain transfer agents are dissolved in water, heated to carry out the reaction, and then cooled after the reaction is completed to adjust the solid content, thus obtaining the water-reducing agent mother liquor.

[0017] The initiator is selected from one or more of ammonium persulfate, hydrogen peroxide, and sodium persulfate. The amount of the initiator used is 0.5-2 wt% of the sum of the mass of the four monomers: acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, and unsaturated polyether. The chain transfer agent is selected from one or more of mercaptoethanol, mercaptoacetic acid, and mercaptopropionic acid. The amount of the chain transfer agent used is 0.2-1.5 wt% of the sum of the mass of the four monomers: acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, and unsaturated polyether. The reaction is carried out at 60-80°C for 4-6 hours. The reaction is then cooled to room temperature. The solid content is adjusted by adding water or by distillation.

[0018] The molar ratio of tea polyphenols to chloroacetic acid is 1:3.5-4.

[0019] The carboxylated tea polyphenols are prepared by a method comprising the following steps:

[0020] Dissolve tea polyphenols in water, add chloroacetic acid and alkali, and heat to react to obtain carboxylated tea polyphenols.

[0021] The molar amount of the alkali used is 4-5 times the molar amount of tea polyphenols. The alkali is selected from one or a combination of two of sodium hydroxide and potassium hydroxide. The heating reaction is carried out at 85-100℃ for 1-3 hours. After the reaction, the process includes adjusting the pH to 6.5-7.5, extraction, washing, drying, and distillation. The extractant used for extraction is ethyl acetate. The washing process involves first washing with a 5-10 wt% sodium bicarbonate solution, followed by washing with water until no chloride ions are detected. The drying process involves drying the organic phase with anhydrous sodium sulfate or anhydrous magnesium sulfate.

[0022] The cement is ordinary Portland cement with a strength grade of 42.5 or 52.5.

[0023] The mineral admixture is selected from one or more of fly ash, silica fume, and slag powder.

[0024] The fly ash is selected from one or a combination of two of the following: Grade I fly ash and Grade II fly ash.

[0025] The silica ash contains 85-92% silica, has an average particle size of 0.1-0.2 μm, and a specific surface area of ​​20,000-25,000 m². 2 / kg.

[0026] The slag powder is selected from one or a combination of two of the following: S105 grade slag powder and S95 grade slag powder.

[0027] The fiber is selected from one or a combination of two of polymer fibers and steel fibers.

[0028] The steel fiber is copper-plated steel fiber with a diameter of 0.1-0.2 mm and a length of 6-15 mm.

[0029] The polymer fiber has a diameter of 0.02-0.4 mm and a length of 4-20 mm, and is selected from one or a combination of two of polypropylene fiber, polyvinyl alcohol fiber, polyester fiber, and polyoxymethylene fiber.

[0030] The sand is continuously graded quartz sand with a particle size range of 0.15-0.5 mm.

[0031] A method for preparing modified ultra-high performance concrete includes the following steps:

[0032] Modified ultra-high performance concrete is obtained by mixing cement, mineral admixtures, fibers, sand, water-reducing agent mother liquor, retarder, and water.

[0033] An application of modified ultra-high performance concrete for decorative floor paving.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] This invention relates to ultra-high performance concrete, comprising a water-reducing agent copolymerized from acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, and unsaturated polyethers. The sulfonate group is a highly electronegative functional group, while the carboxyl group, though less electronegative, exhibits higher stability in calcium ion adsorption. The water-reducing agent, with its high-density negative charge, rapidly adsorbs onto the surface of cement particles. The long polyether side chains extend into the water, forming a steric hindrance layer that disperses the cement particles and prevents agglomeration. Simultaneously, carboxylated tea polyphenols, modified with chloroacetic acid, are combined with salicylic acid as a retarder. Although the retarder's adsorption rate is slightly slower, it possesses a stronger complexing ability for calcium ions, inhibiting cement mineral dissolution and calcium hydroxide crystallization, thus delaying cement hydration. Furthermore, the retarder, with its strongly polar groups, can interpenetrate between the water-reducing agents, forming a dense adsorption film on the surface of hydrate crystal nuclei, hindering further crystal growth and delaying the crystallization transformation of hydrates. Ultimately, this achieves the goals of dispersion, viscosity reduction, and controlled retarding in modified ultra-high performance concrete. Detailed Implementation

[0036] The present invention will be further described below with reference to specific embodiments, but is not limited to the contents of the specification. Unless otherwise specified, all "parts" mentioned in the embodiments of the present invention are parts by weight. All reagents used are commercially available in the art.

[0037] Copper-plated steel fibers, with a diameter of 0.1mm, a length of 10mm, and a tensile strength of 2100MPa, are from Shandong Zhongbohui New Material Technology Co., Ltd.

[0038] Allyl polyoxyethylene ethers APEG-2400 and APEG-1000 both come from Haian Petrochemical Plant in Jiangsu Province.

[0039] Example 1

[0040] 1) Under a nitrogen atmosphere, 10 kg of methyl methacrylate and 200 kg of allyl polyoxyethylene ether (APEG-2400) were dissolved in 520 L of water. The mixture was heated to 80 °C and reacted. Simultaneously, a mixed aqueous solution containing 20 kg of sodium methacrylate, 20 kg of sodium styrene sulfonate, the mass of four comonomers plus 2 wt% ammonium persulfate, and the mass of four comonomers plus 0.5 wt% mercaptoethanol (solid content 15 wt%) was added dropwise. The addition was completed in 1.5 h. After the reaction was completed in 6 h, the mixture was cooled to room temperature, and the solid content was adjusted to 40 wt% by distillation to remove water, yielding the water-reducing agent mother liquor. Molecular weight determination: Using an Agilent 1260 gel permeation chromatograph, with 0.1 M NaNO3 aqueous solution as the mobile phase and a flow rate of 1.0 mL / min, the water-reducing agent concentration was diluted to 0.5 wt%, and polyethylene glycol was used as the standard. The weight-average molecular weight of the water-reducing agent was determined to be 94,600.

[0041] 2) Dissolve 1 mol of tea polyphenols in water, add 4 mol of chloroacetic acid and 5 mol of sodium hydroxide, heat to 100℃ and react for 1 h. After the reaction is complete, adjust the pH to 7, extract with ethyl acetate, wash the organic phase with 5 wt% sodium bicarbonate solution, then wash with water until no chloride ions are detected, add anhydrous sodium sulfate for drying, and distill to remove ethyl acetate to obtain carboxylated tea polyphenols.

[0042] 3) Mix 80 kg of ordinary Portland cement with a strength grade of 42.5, 40 kg of S95 grade slag powder, 10 kg of copper-plated steel fiber, 140 kg of 0.15-0.5 mm continuously graded quartz sand, 1.5 kg of water-reducing agent mother liquor, and 1 kg of retarder composed of carboxylated tea polyphenols and salicylic acid in a mass ratio of 8:1. Add water at a water-cement ratio of 0.2 and mix well to obtain modified ultra-high performance concrete.

[0043] 4) Pour modified ultra-high performance concrete on the leveled and compacted ground, spread and vibrate the finished surface, level it with a screed, smooth it with a magnesium trowel, polish it with a steel trowel, make the edge rolling, sprinkle aggregate, pat it, press it with a mud-textured mold, and cure it to get the decorative floor.

[0044] Example 2

[0045] The rest is the same as in Example 1, except that in step 1), the amount of sodium styrene sulfonate used is 30 kg. The weight-average molecular weight of the water-reducing agent is 96,200.

[0046] Example 3

[0047] The rest is the same as in Example 1, except that in step 1), the amount of sodium styrene sulfonate used is 40 kg. The weight-average molecular weight of the water-reducing agent is 92,800.

[0048] Example 4

[0049] The rest is the same as in Example 1, except that in step 1), the amount of sodium styrene sulfonate used is 15 kg. The weight-average molecular weight of the water-reducing agent is 92,800.

[0050] Example 5

[0051] The rest is the same as in Example 1, except that in step 1), sodium methacrylate sulfonate is used instead of sodium styrene sulfonate by an equal mass. The weight-average molecular weight of the water-reducing agent is 93,500.

[0052] Example 6

[0053] The rest is the same as in Example 1, except that in step 3), carboxylated tea polyphenols and salicylic acid are compounded in a mass ratio of 5:1.

[0054] Example 7

[0055] The rest is the same as in Example 1, except that in step 3), the amount of retarder is 0.5 kg.

[0056] Example 8

[0057] The rest is the same as in Example 1, except that in step 3), the amount of water-reducing agent mother liquor used is 1 kg.

[0058] Example 9

[0059] 1) Under a nitrogen atmosphere, 5 kg of methyl methacrylate and 150 kg of allyl polyoxyethylene ether APEG-2400 were dissolved in 520 L of water, and the mixture was heated to 80 °C for reaction. Simultaneously, a mixed aqueous solution containing 10 kg of sodium methacrylate, 20 kg of sodium styrene sulfonate, the mass of four comonomers plus 2 wt% ammonium persulfate, and the mass of four comonomers plus 1 wt% mercaptoethanol (solid content 15 wt%) was added dropwise. The addition was completed in 1.5 h, and after 6 h of reaction, the mixture was cooled to room temperature. Water was removed by distillation, and the solid content was adjusted to 40 wt%, yielding the water-reducing agent mother liquor. The weight-average molecular weight of the water-reducing agent was 81,200.

[0060] 2) Dissolve 1 mol of tea polyphenols in water, add 3.5 mol of chloroacetic acid and 4 mol of sodium hydroxide, heat to 100℃ and react for 1 h. After the reaction is complete, adjust the pH to 7, extract with ethyl acetate, wash the organic phase with 5 wt% sodium bicarbonate solution, then wash with water until no chloride ions are detected, add anhydrous sodium sulfate for drying, and distill to remove ethyl acetate to obtain carboxylated tea polyphenols.

[0061] 3) Mix 60 kg of ordinary Portland cement with a strength grade of 42.5, 30 kg of S95 grade slag powder, 5 kg of copper-plated steel fiber, 120 kg of 0.15-0.5 mm continuously graded quartz sand, 1.5 kg of water-reducing agent mother liquor, and 1 kg of retarder composed of carboxylated tea polyphenols and salicylic acid in a mass ratio of 8:1. Add water at a water-cement ratio of 0.2 and mix well to obtain modified ultra-high performance concrete.

[0062] 4) Pour modified ultra-high performance concrete on the leveled and compacted ground, spread and vibrate the finished surface, level it with a screed, smooth it with a magnesium trowel, polish it with a steel trowel, make the edge rolling, sprinkle aggregate, pat it, press it with a mud-textured mold, and cure it to get the decorative floor.

[0063] Comparative Example 1

[0064] The rest is the same as in Example 1, except that in step 3), the retarder is salicylic acid.

[0065] Comparative Example 2

[0066] The rest is the same as in Example 1, except that in step 3), the retarder is entirely carboxylated tea polyphenols.

[0067] The modified ultra-high performance concrete prepared in the above embodiments and comparative examples was subjected to the following performance tests:

[0068] 1. Compressive strength: Tested according to standard JTG 3420-2020 Test Procedures for Cement and Cement Concrete in Highway Engineering, and naturally cured to strength after 28 days.

[0069] 2. Flexural strength: Tested in accordance with standard GB / T 50081-2019 Test Methods for Physical and Mechanical Properties of Concrete.

[0070] 3. Outflow time: The funnel test is conducted in accordance with the standard GB / T 50080-2016 Test Method for Performance of Ordinary Concrete Mixture. The funnel is filled with concrete, the surface is smoothed, and the bottom cover is opened immediately. The time (s) from opening the cover to the complete outflow of the concrete mixture is recorded as the outflow time. The outflow time is directly related to the plastic viscosity of the concrete. The longer the time, the higher the viscosity.

[0071] 4. Viscosity: The dynamic viscosity of the UHPC slurry was tested using an RST-SST soft solid touchscreen rheometer manufactured by Brookfield Instruments, USA. Cross-shear type-1 blade rotors VT40-20 and VT60-30 were used to measure the slurry, with an agitation speed of 0.01 s. -1 The measurement time was 150 seconds.

[0072] 5. Setting time: Tested in accordance with standard T / CECS 864-2021 Test Method for Ultra-High Performance Concrete.

[0073] Table 1 Performance Test Results

[0074]

[0075] As can be seen from the performance test results in Table 1, the outflow time of the modified ultra-high performance concrete funnel test in the embodiment of the present invention is within 7.2-9.4s, the slurry viscosity is 3207.7-3595.3 Pa·s, the initial setting time is 4-7.5h, the final setting time is 13-17.5h, the compressive strength is 134.4-145.2MPa, and the flexural strength is 21.3-25.0MPa. Compared with the comparative example, except for the compressive strength, the slurry viscosity and fluidity are improved, the setting time is delayed, the plastic window period is increased, and sufficient time is provided for finishing to meet people's requirements for smoothness and gloss.

[0076] Furthermore, the outflow time and viscosity test results in Table 1 show that the water-reducing agent and the retarder significantly synergistically reduce viscosity. This is presumably because the water-reducing agent and the retarder jointly form a "composite adsorption film" on the particle / hydrate surface. This film not only has steric hindrance and inhibition effects but also alters the hydrophilicity and hydrophobicity of the particle surface, enhancing its affinity for free water and reducing the frictional resistance between solid particles. When particles approach each other or undergo relative movement, this lubricating film effectively reduces shear resistance, resulting in a decrease in viscosity.

[0077] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A modified ultra-high performance concrete, characterized in that, The raw materials include the following parts by weight: 60-80 parts cement, 30-40 parts mineral admixtures, 5-10 parts fiber, 120-140 parts sand, 1-1.5 parts water-reducing agent mother liquor, and 0.5-1 parts retarder, with a water-cement ratio of 0.14-0.2; the water-reducing agent mother liquor has a solid content of 35-42 wt% and is copolymerized in water by acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, and unsaturated polyethers; the retarder is compounded from carboxylated tea polyphenols and salicylic acid, and the carboxylated tea polyphenols are obtained by modifying tea polyphenols with chloroacetic acid.

2. The modified ultra-high performance concrete according to claim 1, characterized in that, The mass ratio of acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, and unsaturated polyether is 10-20:5-10:15-40:150-200, preferably 10-20:5-10:20-30:150-200.

3. The modified ultra-high performance concrete according to claim 1, characterized in that, The mass ratio of carboxylated tea polyphenols to salicylic acid is 5-8:

1.

4. The modified ultra-high performance concrete according to claim 1, characterized in that, The acrylate monomers are selected from one or a combination of two of sodium methacrylate, sodium acrylate, potassium acrylate, and potassium methacrylate; the acrylate monomers are selected from one or a combination of more than two of methyl acrylate, methyl methacrylate, ethyl acrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate; the unsaturated sulfonate monomers are selected from one or a combination of more than two of sodium vinyl sulfonate, sodium allyl sulfonate, sodium methpropylene sulfonate, and sodium styrene sulfonate; preferably sodium styrene sulfonate; the unsaturated polyether has a number average molecular weight of 1000-3000 and is selected from one or a combination of more than two of allyl polyoxyethylene ether (APEG), isopentenyl alcohol polyoxyethylene ether (TPEG), and methyl allyl alcohol polyoxyethylene ether (HPEG).

5. The modified ultra-high performance concrete according to claim 1, characterized in that, The water-reducing agent mother liquor is prepared by a method comprising the following steps: Under an inert atmosphere, acrylate monomers, acrylate monomers, unsaturated sulfonate monomers, unsaturated polyethers, initiators, and chain transfer agents are dissolved in water, heated to carry out the reaction, and then cooled after the reaction is completed to adjust the solid content, thus obtaining the water-reducing agent mother liquor.

6. The modified ultra-high performance concrete according to claim 1, characterized in that, The molar ratio of tea polyphenols to chloroacetic acid is 1:3.5-4.

7. The modified ultra-high performance concrete according to claim 1, characterized in that, The carboxylated tea polyphenols are prepared by a method comprising the following steps: dissolving tea polyphenols in water, adding chloroacetic acid and alkali, and heating to react, thereby obtaining carboxylated tea polyphenols.

8. The modified ultra-high performance concrete according to claim 1, characterized in that, The cement is ordinary Portland cement with a strength grade of 42.5 or 52.5; the mineral admixture is selected from one or more combinations of fly ash, silica fume, and slag powder; the fiber is selected from one or more combinations of polymer fiber and steel fiber; and the sand is continuously graded quartz sand with a particle size range of 0.15-0.5 mm.

9. The method for preparing modified ultra-high performance concrete according to any one of claims 1-8, characterized in that, Includes the following steps: Modified ultra-high performance concrete is obtained by mixing cement, mineral admixtures, fibers, sand, water-reducing agent mother liquor, retarder, and water.

10. The application of the modified ultra-high performance concrete according to any one of claims 1-8 or claim 9, characterized in that, The modified ultra-high performance concrete is used for decorative floor paving.

Images