A rheological agent for ultra-high performance concrete and its preparation method and application

Abstract

The present invention discloses a rheological agent for ultra-high performance concrete, a preparation method and an application thereof, and belongs to the technical field of building materials. The preparation method comprises the steps of: adding a water-reducing component B and a reinforcing component C to a viscosity-reducing component A at 50°C, and stirring at 50°C to obtain the rheological agent for ultra-high performance concrete. The present invention obtains a rheological agent that can reduce the viscosity of ultra-high performance concrete, improve the fluidity of ultra-high performance concrete, and does not affect the setting time and strength of ultra-high performance concrete by compounding the three and synergizing.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and specifically relates to a rheological agent for ultra-high performance concrete and a preparation method and application thereof. Background Art

[0002] With the development of the construction industry, the structural form is constantly developing in the direction of thin-walled, lightweight, ultra-large span, and ultra-high-rise. The defects of traditional concrete such as low strength, poor tensile strength, and poor crack resistance have seriously restricted the development of new structures. Ultra-high performance concrete (UHPC) is a new type of cement-based composite material with excellent characteristics such as ultra-high strength, high toughness, high durability, and strong self-healing ability of micro-cracks. It greatly reduces the size of the structure, thereby reducing the weight of the concrete and achieving the requirements of lightweight and high strength of the structure. At the same time, it also has the advantages of long service life and less maintenance in the later stage. Therefore, UHPC is often widely used in new high-rise buildings, large-span bridges, bridge deck pavement, repair and reinforcement of old bridges, explosion-proof engineering and buildings in harsh environments.

[0003] During the preparation of UHPC, a large amount of cement is used, and the water-binder ratio is extremely low, which leads to problems such as high plastic viscosity, difficult construction, and large shrinkage of the mixture, which seriously affects the construction application of UHPC. At present, the main methods to reduce the viscosity of concrete are concrete mix design, optimization of the composition of raw materials, and external addition of viscosity-reducing high-performance water reducers. Among them, the external addition of viscosity-reducing high-performance water reducers has a low dosage and is simple to operate, and has been widely studied at home and abroad. However, viscosity-reducing high-performance water reducers are more suitable for medium and high water-binder ratios. For UHPC with a water-binder ratio of less than 0.2, the viscosity reduction effect is poor. In order to improve the fluidity of concrete and reduce its viscosity, a large amount of high-performance water reducers are often added. Excessive water reducers affect the setting time and early strength of concrete, seriously affecting the on-site concrete pouring and use.

[0004] Therefore, it is of great significance to prepare a rheological agent for reducing viscosity, improving fluidity, and not affecting the setting time and strength of concrete in ultra-high performance concrete. Summary of the invention

[0005] The purpose of the present invention is to provide a rheological agent for ultra-high performance concrete, a preparation method and application thereof. By using a viscosity reducing component A, a water reducing component B and a reinforcing component C in a certain proportion, a rheological agent that can effectively reduce the viscosity of concrete, improve the fluidity of concrete, and does not affect the strength and setting time of concrete is prepared.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a method for preparing a rheological agent for ultra-high performance concrete, comprising the steps of: adding a water-reducing component B and a reinforcing component C to a viscosity-reducing component A at 50° C., and stirring at 50° C. to obtain the rheological agent for ultra-high performance concrete;

[0008] The preparation step of the viscosity reducing component A comprises: dissolving polyethylene glycol with a molecular weight of 6000, polyethylene glycol with a molecular weight of 4000 and polyethylene glycol with a molecular weight of 2000 in water, heating to 130° C., then cooling to 70° C., then dripping 40wt.% of hexamethylene diisocyanate solution and 30wt.% of dibutyltin dilaurate solution, the dripping time is controlled to be 2h, and after the dripping is completed, the solution is kept warm for 0.5h, then dripping 50wt.% of 2,2-dihydroxymethylbutanol solution, the dripping time is controlled to be 2.5h, after the dripping is completed, the solution is kept warm for 0.5h, and finally, hexadecanol is added, and the reaction is carried out at 70° C. for 4h to obtain the viscosity reducing component A;

[0009] The water reducing component B is a polycarboxylic acid high performance water reducing agent;

[0010] The reinforcing component C is a solution prepared from calcium nitrate tetrahydrate, sodium metasilicate, triethanolamine and water.

[0011] The purpose of strictly limiting the preparation conditions of the viscosity reducing component A in the present invention is to make the weight average molecular weight M of the viscosity reducing component A w Maintained at around 15000 g / mol, the synthesis conversion rate was above 90%.

[0012] Preferably, in the rheological agent, the viscosity reducing component A accounts for 1250-1350 parts, the water reducing component B accounts for 200-300 parts, and the reinforcing component C accounts for 50-100 parts by weight.

[0013] Preferably, in the preparation step of the viscosity reducing component A, by weight, the amount of polyethylene glycol with a molecular weight of 6000 is 350 parts, the amount of polyethylene glycol with a molecular weight of 4000 is 120 parts, the amount of polyethylene glycol with a molecular weight of 2000 is 120 parts, the amount of water is 600 parts, the amount of 40wt.% hexamethylene diisocyanate solution is 50 parts, the amount of 30wt.% dibutyltin dilaurate solution is 50 parts, and the amount of 50wt.% 2,2-dihydroxymethylbutanol solution is 20 parts.

[0014] Preferably, the solid content of the polycarboxylic acid high performance water reducer is 40%, the acid-ether ratio is 3:1, the side chain is TPEG2400, and the mass ratio of acrylic acid to maleic anhydride during the preparation process is 6:4.

[0015] Preferably, in the reinforcing component C, the mass ratio of calcium nitrate tetrahydrate, sodium metasilicate, triethanolamine and water is 8:2:1:18, and the preparation temperature is 65°C.

[0016] The second technical solution of the present invention is to provide a rheological agent for ultra-high performance concrete prepared according to the above preparation method.

[0017] The third technical solution of the present invention is to provide an application of the above-mentioned rheological agent for ultra-high performance concrete in the preparation of ultra-high performance concrete.

[0018] The beneficial technical effects of the present invention are as follows:

[0019] The viscosity-reducing component A in the present invention can reduce the charge attraction force between particles in the cement paste, reduce the van der Waals force on the surface of cement particles, and effectively reduce the shear stress and yield strength of the cement paste. Macroscopically, it is manifested as a lower shear-thinning force of the cement paste. The water-reducing component B is adsorbed on the cement particles through anionic groups, forming electrostatic repulsion on the surface of cement particles, improving the dispersibility of the cement paste, and at the same time, the molecular side chains in the water-reducing component form steric hindrance, further improving the dispersibility of the cement paste. The reinforcing component C can effectively solve the problems of long setting time and low early strength caused by excessive water-reducing agent dosage, and can stimulate the hydration of unreacted minerals in cement to increase the amount of cement hydration products and increase the later strength of concrete. Through the combination of the three, a rheological agent that can reduce the viscosity of ultra-high performance concrete, improve the fluidity of ultra-high performance concrete, and does not affect the setting time and strength of ultra-high performance concrete is prepared. DETAILED DESCRIPTION

[0020] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0021] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0022] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the invention.

[0023] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0024] The specific preparation process of the water-reducing component B in the embodiments of the present invention and the comparative example is as follows: in a reactor equipped with a stirrer, a dropping device and a heating device, 96 parts of TPEG2400 and 96 parts of deionized water are added, heated to 35°C, the speed is set to 220r / min, and liquid a and liquid b are added dropwise (liquid a is composed of 6 parts of acrylic acid, 4 parts of maleic anhydride, and 40 parts of deionized water; liquid b is composed of 1 part of ascorbic acid, 2 parts of mercaptopropionic acid, and 30 parts of deionized water), and the initiator is 3 parts of hydrogen peroxide. The dropping time is 2 h, and the reaction is continued for 1 h after the dropwise addition is completed. After the reaction is completed, the temperature of the system is lowered to room temperature, and the solution is neutralized with NaOH solution and deionized water to a pH of 7, and the concentration is adjusted to 40wt.% to obtain a polycarboxylic acid high-performance water reducer having an acid-ether ratio of 3:1 and a side chain of TPEG2400.

[0025] Example 1

[0026] Preparation of rheological agents for ultra-high performance concrete:

[0027] (1) Mixing ratio:

[0028] The viscosity-reducing component A accounts for 1250 parts; the water-reducing component B accounts for 200 parts; the reinforcing component C accounts for 50 parts;

[0029] (2) Preparation steps:

[0030] 350 parts of polyethylene glycol with a molecular weight of 6000, 120 parts of polyethylene glycol with a molecular weight of 4000, and 120 parts of polyethylene glycol with a molecular weight of 2000 were added to a three-necked flask containing 500 parts of deionized water in sequence. After mixing, the stirring speed was 250r / min, the initial temperature was controlled at 20°C, the temperature was raised to 130°C, and stirring was continued for 30 minutes. The heating was stopped, and the temperature was cooled to 70°C. Then, liquid a and liquid b were added dropwise (liquid a was composed of 20 parts of hexamethylene diisocyanate and 30 parts of deionized water; liquid b was composed of 20 parts of hexamethylene diisocyanate and 30 parts of deionized water). Liquid c (liquid c consists of 20 parts of 2,2-dihydroxymethylbutanol and 20 parts of deionized water) was added for 2.5 hours. After the addition was completed, it was kept warm for 0.5 hours. 20 parts of hexadecanol were added at once for end-capping. The reaction was carried out at 70°C for 4 hours to obtain viscosity-reducing component A. The weight-average molecular weight Mw was 15064 g / mol as measured by gel permeation chromatography, and the conversion rate was 94%. Stop heating, cool to a constant temperature of 50°C, add 200 parts of water-reducing component B and 50 parts of reinforcing component C to the viscosity-reducing component A (water-reducing component B is a polycarboxylic acid high-performance water-reducing agent with a solid content of 40%, an acid-ether ratio of 3:1, a side chain TPEG2400, and a mass ratio of acrylic acid to maleic anhydride of 6:4; reinforcing component C is a solution prepared by dispersing 40 parts of calcium nitrate tetrahydrate, 10 parts of sodium metasilicate, 5 parts of triethanolamine and 90 parts of deionized water at a water temperature of 65°C and a high-speed disperser at 3000r / min), keep the temperature at 50°C, and the stirring speed at 300r / min. After the addition is completed, continue to keep warm for 1 hour to obtain a milky white rheological agent for ultra-high performance concrete.

[0031] Example 2

[0032] Preparation of rheological agents for ultra-high performance concrete:

[0033] (1) Mixing ratio:

[0034] The viscosity-reducing component A accounts for 1350 parts; the water-reducing component B accounts for 300 parts; the reinforcing component C accounts for 100 parts;

[0035] (2) Preparation steps:

[0036] 350 parts of polyethylene glycol with a molecular weight of 6000, 120 parts of polyethylene glycol with a molecular weight of 4000, and 120 parts of polyethylene glycol with a molecular weight of 2000 were added to a three-necked flask containing 600 parts of deionized water in sequence. After mixing, the stirring speed was 250r / min, the initial temperature was controlled at 20°C, the temperature was raised to 130°C, and stirring was continued for 30 minutes. The heating was stopped, and the temperature was cooled to 70°C. Then, liquid a and liquid b were added dropwise (liquid a was composed of 20 parts of hexamethylene diisocyanate and 30 parts of deionized water; liquid b ... Liquid c (liquid c consists of 20 parts of 2,2-dihydroxymethylbutanol and 20 parts of deionized water) was added for 2.5 hours. After the addition was completed, it was kept warm for 0.5 hours. 20 parts of hexadecanol were added at once for end-capping. The reaction was carried out at 70°C for 4 hours to obtain viscosity-reducing component A. The weight-average molecular weight Mw was 14987 g / mol as measured by gel permeation chromatography, and the conversion rate was 92%. Stop heating, cool to a constant temperature of 50°C, add 300 parts of water-reducing component B and 100 parts of reinforcing component C to the viscosity-reducing component A (water-reducing component B is a polycarboxylic acid high-performance water-reducing agent with a solid content of 40%, an acid-ether ratio of 3:1, a side chain TPEG2400, and a mass ratio of acrylic acid to maleic anhydride of 6:4; reinforcing component C is a solution prepared by dispersing 40 parts of calcium nitrate tetrahydrate, 10 parts of sodium metasilicate, 5 parts of triethanolamine and 90 parts of deionized water at a water temperature of 65°C and a high-speed disperser at 3000r / min), keep the temperature at 50°C, and the stirring speed at 300r / min. After the addition is completed, continue to keep warm for 1 hour to obtain a milky white rheological agent for ultra-high performance concrete.

[0037] Example 3

[0038] Preparation of rheological agents for ultra-high performance concrete:

[0039] (1) Mixing ratio:

[0040] The viscosity-reducing component A accounts for 1,300 parts; the water-reducing component B accounts for 250 parts; the reinforcing component C accounts for 75 parts;

[0041] (2) Preparation steps:

[0042] 350 parts of polyethylene glycol with a molecular weight of 6000, 120 parts of polyethylene glycol with a molecular weight of 4000, and 120 parts of polyethylene glycol with a molecular weight of 2000 were added to a three-necked flask containing 550 parts of deionized water in sequence. After mixing, the stirring speed was 250r / min, the initial temperature was controlled at 20°C, the temperature was raised to 130°C, and stirring was continued for 30 minutes. The heating was stopped, and the temperature was cooled to 70°C. Then, liquid a and liquid b (liquid a was composed of 20 parts of hexamethylene diisocyanate, 3 0 parts of deionized water; liquid b consists of 15 parts of dibutyltin dilaurate and 35 parts of deionized water;) the addition time is 2h, and the temperature is kept for 0.5h after the addition is completed, and liquid c (liquid c consists of 20 parts of 2,2-dihydroxymethylbutanol and 20 parts of deionized water) is added for 2.5h. After the addition is completed, the temperature is kept for 0.5h, and 20 parts of hexadecanol are added at once for end-capping. The reaction is carried out at 70℃ for 4 hours to obtain a viscosity-reducing component A. The weight average molecular weight M is measured by gel permeation chromatography. w The concentration of the water-reducing component B was 15008 g / mol, and the conversion rate was 95%. The heating was stopped, and the mixture was cooled to a constant temperature of 50°C. 250 parts of water-reducing component B and 75 parts of reinforcing component C were added dropwise to the viscosity-reducing component A (water-reducing component B was a polycarboxylic acid high-performance water-reducing agent with a solid content of 40%, an acid-ether ratio of 3:1, a side chain of TPEG2400, and a mass ratio of acrylic acid to maleic anhydride of 6:4; reinforcing component C was a solution prepared by dispersing 40 parts of calcium nitrate tetrahydrate, 10 parts of sodium metasilicate, 5 parts of triethanolamine and 90 parts of deionized water at a water temperature of 65°C and a high-speed disperser at 3000 r / min), the temperature was kept at 50°C, the stirring speed was 300 r / min, and after the addition was completed, the mixture was kept warm for 1 hour to obtain a milky white rheological agent for ultra-high performance concrete.

[0043] Example 4

[0044] Preparation of rheological agents for ultra-high performance concrete:

[0045] (1) Mixing ratio:

[0046] The viscosity-reducing component A accounts for 1,300 parts; the water-reducing component B accounts for 250 parts; the reinforcing component C accounts for 50 parts;

[0047] (2) Preparation steps:

[0048] 350 parts of polyethylene glycol with a molecular weight of 6000, 120 parts of polyethylene glycol with a molecular weight of 4000, and 120 parts of polyethylene glycol with a molecular weight of 2000 were added to a three-necked flask containing 550 parts of deionized water in sequence. After mixing, the stirring speed was 250r / min, the initial temperature was controlled at 20°C, the temperature was raised to 130°C, and stirring was continued for 30 minutes. The heating was stopped, and the temperature was cooled to 70°C. Then, liquid a and liquid b (liquid a was composed of 20 parts of hexamethylene diisocyanate, 3 0 parts of deionized water; liquid b consists of 15 parts of dibutyltin dilaurate and 35 parts of deionized water;) the addition time is 2h, and the temperature is kept for 0.5h after the addition is completed, and liquid c (liquid c consists of 20 parts of 2,2-dihydroxymethylbutanol and 20 parts of deionized water) is added for 2.5h. After the addition is completed, the temperature is kept for 0.5h, and 20 parts of hexadecanol are added at once for end-capping. The reaction is carried out at 70℃ for 4 hours to obtain a viscosity-reducing component A. The weight average molecular weight M is measured by gel permeation chromatography. w The concentration of the water-reducing component B solution was 15075 g / mol, and the conversion rate was 93%. The heating was stopped, and the mixture was cooled to a constant temperature of 50°C. 250 parts of the water-reducing component B solution and 50 parts of the reinforcing component C were added dropwise to the viscosity-reducing component A (the water-reducing component B was a polycarboxylic acid high-performance water-reducing agent with a solid content of 40%, an acid-ether ratio of 3:1, a side chain of TPEG2400, and a mass ratio of acrylic acid to maleic anhydride of 6:4; the reinforcing component C was a solution prepared by dispersing 40 parts of calcium nitrate tetrahydrate, 10 parts of sodium metasilicate, 5 parts of triethanolamine and 90 parts of deionized water at a water temperature of 65°C and a high-speed disperser at 3000 r / min), the temperature was kept at 50°C, the stirring speed was 300 r / min, and after the addition was completed, the mixture was kept warm for 1 hour to obtain a milky white rheological agent for ultra-high performance concrete.

[0049] Comparative Example 1

[0050] Compared with Example 3, the only difference is that the water-reducing component B is replaced by an equal solid amount of ZK-BF aliphatic hydroxysulfonate condensate high-efficiency water reducer.

[0051] Comparative Example 2

[0052] Compared with Example 3, the only difference is that the reinforcing component C is replaced by an equal amount of calcium formate.

[0053] Comparative Example 3

[0054] Compared with Example 3, the only difference is that the component dosage of the rheological agent for ultra-high performance concrete is adjusted to: viscosity-reducing component A accounts for 1300 parts; water-reducing component B accounts for 150 parts; and reinforcing component C accounts for 20 parts; the preparation method and mixing method of each component remain unchanged.

[0055] Comparative Example 4

[0056] Compared with Example 3, the only difference is that 350 parts of polyethylene glycol with a molecular weight of 6000, 120 parts of polyethylene glycol with a molecular weight of 4000, and 120 parts of polyethylene glycol with a molecular weight of 2000 are added sequentially into a three-necked flask containing 550 parts of deionized water. After mixing, the stirring speed is 250r / min, the initial temperature is controlled at 30°C, the temperature is raised to 150°C, stirring is continued for 30min, heating is stopped, the mixture is cooled to a constant temperature of 40°C, and liquid a and liquid b are added dropwise (liquid a is composed of 20 parts of hexamethylene The addition time of liquid c (liquid c consists of 20 parts of 2,2-dihydroxymethylbutanol and 20 parts of deionized water) is 2.5 hours, and the temperature is kept for 0.5 hours after the addition is completed. 20 parts of hexadecanol are added at once for end-capping, and the reaction is carried out at a constant temperature of 40°C for 4 hours to obtain a viscosity-reducing component A. The weight average molecular weight M is measured by gel permeation chromatography. w It is 22356g / mol, and the conversion rate is 84%.

[0057] The performance of the rheological agent obtained in Examples 1-4 and Comparative Examples 1-4 was tested through concrete tests. The cement was Conch P·O52.5 cement, and the mix ratio was shown in Table 1. The viscosity reduction effect of the rheological agent was measured with reference to the V-type hole passing time specified in T / CECS203-2021 "Technical Specifications for the Application of Self-Compacting Concrete", where the longer the passing time, the greater the viscosity. The fluidity of the concrete refers to the extension test method specified in T / CECS203-2021 "Technical Specifications for the Application of Self-Compacting Concrete". The greater the extension, the better the fluidity. The setting time test of concrete refers to GBT50080-2016 "Standard Test Method for Performance of Ordinary Concrete Mixtures". The molding, production and maintenance of concrete test blocks refer to TCCPA7-2018 "Basic Properties and Test Methods of Ultra-High Performance Concrete", and the concrete strength is in accordance with GBT50081-2019 "Standard Test Method for Physical and Mechanical Properties of Concrete". No rheological agent was added to the blank, and the rheological agents prepared in Examples 1-4 and Comparative Examples 1-4 replaced the admixtures in the formula, with the replacement amount being 0.1% of the mass of the cementitious material (cement+composite admixture+expansion agent). The test results are shown in Table 2.

[0058] Table 1 Ultra-high performance concrete mix ratio (kg / m 3 )

[0059] cement Composite admixture Bulking Agent Quartz sand water Steel Fiber Admixtures 754 280 66 1010 187 157 16.5

[0060] In Table 1, 280kg of composite admixture is compounded by 120kg of silica fume, 80kg of primary fly ash, and 80kg of mineral powder; the expansion agent is mainly aluminum sulfate, aluminum oxide, potassium aluminum sulfate, etc. as multiple expansion sources UEA expansion agent; the amount of admixture added is 1.5% of the mass of the cementitious material (1100×1.5%=16.5), and the admixture is compounded by a water-reducing polycarboxylic acid water-reducing agent and a polyether defoaming agent in a ratio of 99:1. The blank group is 1.5% of the mass of the cementitious material, and the examples and comparative examples are 1.4% of the mass of the cementitious material + 0.1% of the rheological agent. Quartz sand is mixed in a mass ratio of 2:2:1 with 20-40 mesh, 40-70 mesh, and 70-120 mesh. The steel fiber is a copper-plated microfilament steel fiber 0.2±0.02mm non-straight type.

[0061] Table 2 Test results of ultra-high performance concrete

[0062]

[0063] As shown in Table 2, the rheology prepared by the present invention is applied to ultra-high performance concrete. Compared with the blank group, the V funnel emptying time of the concrete in the embodiment is greatly reduced, indicating that its viscosity is greatly reduced; the expansion degree increases significantly, and the fluidity of the concrete is significantly improved and enhanced; in terms of setting time, the embodiment with the addition of rheological agent has little effect on the setting time, and basically has no negative impact; from the perspective of the compressive and flexural strength of 7d and 28d, the strength growth of the ultra-high performance concrete after adding the rheological agent is more obvious. Compared with the comparative group, the V funnel emptying time of the concrete in the embodiment is lower, indicating that its viscosity is large and lower; the expansion degree is larger, and the fluidity of the concrete is better; in terms of setting time, the comparative group delays the initial and final setting of the concrete by about 0.5 to 2 hours, which has a slight impact on the construction; from the perspective of the compressive and flexural strength of 7d and 28d, the strength of the embodiment is higher.

[0064] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a rheological agent for ultra-high performance concrete, characterized in that: The steps include: Adding the water-reducing component B and the reinforcing component C to the viscosity-reducing component A at 50° C., and stirring at 50° C. to obtain the rheological agent for ultra-high performance concrete; The preparation step of the viscosity reducing component A comprises: dissolving polyethylene glycol with a molecular weight of 6000, polyethylene glycol with a molecular weight of 4000 and polyethylene glycol with a molecular weight of 2000 in water, heating to 130° C., then cooling to 70° C., then dripping 40wt.% of hexamethylene diisocyanate solution and 30wt.% of dibutyltin dilaurate solution, the dripping time is controlled to be 2h, and after the dripping is completed, the solution is kept warm for 0.5h, then dripping 50wt.% of 2,2-dihydroxymethylbutanol solution, the dripping time is controlled to be 2.5h, after the dripping is completed, the solution is kept warm for 0.5h, and finally, hexadecanol is added, and the reaction is carried out at 70° C. for 4h to obtain the viscosity reducing component A; The water reducing component B is a polycarboxylic acid high performance water reducing agent; The reinforcing component C is a solution prepared by calcium nitrate tetrahydrate, sodium metasilicate, triethanolamine and water; In terms of weight, the rheological agent comprises 1250-1350 parts of the viscosity reducing component A, 200-300 parts of the water reducing component B and 50-100 parts of the reinforcing component C; In the preparation step of the viscosity reducing component A, the amount of polyethylene glycol with a molecular weight of 6000 is 350 parts, the amount of polyethylene glycol with a molecular weight of 4000 is 120 parts, the amount of polyethylene glycol with a molecular weight of 2000 is 120 parts, the amount of water is 600 parts, the amount of 40wt.% hexamethylene diisocyanate solution is 50 parts, the amount of 30wt.% dibutyltin dilaurate solution is 50 parts, and the amount of 50wt.% 2,2-dihydroxymethylbutanol solution is 20 parts; The solid content of the polycarboxylic acid high-performance water reducer is 40%, the acid-ether ratio is 3:1, the side chain is TPEG2400, and the mass ratio of acrylic acid to maleic anhydride during the preparation process is 6:4; In the reinforcing component C, the mass ratio of calcium nitrate tetrahydrate, sodium metasilicate, triethanolamine and water is 8:2:1:18, and the preparation temperature is 65°C.

2. The rheological agent for ultra-high performance concrete prepared according to the preparation method of claim 1.

3. Use of the rheological agent for ultra-high performance concrete according to claim 2 in the preparation of ultra-high performance concrete.

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